feat(invoices): full invoice + line items module

The most complex module. Two-table model: invoices (header) +
invoice_items (lines). Auto-numbering via tenant_settings.invoiceCounter,
auto-totals on item changes.

Schema/validation:
- lib/validation/invoices.ts: invoiceSchema (header) + invoiceItemSchema
  (line). Both coerce comma decimals.
- lib/appwrite/invoice-actions.ts:
  * createInvoiceAction — fetches tenant_settings, increments
    invoiceCounter, formats number as '{prefix}-{year}-{0000}',
    persists totals as 0/0/0 (recomputed when items added).
  * updateInvoiceAction / deleteInvoiceAction — header CRUD; delete
    cascades to remove all items first then header.
  * addInvoiceItemAction / updateInvoiceItemAction /
    deleteInvoiceItemAction — line CRUD. Each computes lineTotal
    (qty*unit + vat) and triggers recomputeTotals(invoiceId) which
    re-sums all items and updates the header subtotal/vatTotal/total.
  All audit-logged.

Queries:
- listInvoices, getInvoice (with tenant cross-check), listInvoiceItems.

UI:
- /invoices index: 4 stat cards (Toplam / Tahsil edildi / Bekleyen /
  Gecikmiş), table with overdue-aware due date coloring, status badges,
  number is a Link to detail.
- InvoiceFormSheet: customer + dates (default issue=today, due=+30d) +
  status + notes. After create, redirects to /invoices/[id] for adding
  items.
- /invoices/[id] detail: header strip with status, dates, customer name;
  print/edit/delete actions; items editor card; subtotal/VAT/total card;
  notes card.
- InvoiceItemsEditor: rows are clickable to edit, X button to delete.
  ItemFormSheet for add/edit (description + qty + unitPrice + VAT %).

Print is just window.print() for now — relies on browser dialog. Detail
page deliberately uses tabular-nums for amounts.

src/app/(dashboard)/invoices/[id]/components/header-actions.tsx

@@ -0,0 +1,95 @@
+"use client";
+
+import { useState, useTransition } from "react";
+import { useRouter } from "next/navigation";
+import { Loader2, Pencil, Printer, Trash2 } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { deleteInvoiceAction } from "@/lib/appwrite/invoice-actions";
+
+import { InvoiceFormSheet } from "../../components/invoice-form-sheet";
+import type { Customer, InvoiceRow } from "../../components/types";
+
+type Props = { invoice: InvoiceRow; customers: Customer[] };
+
+export function InvoiceHeaderActions({ invoice, customers }: Props) {
+  const router = useRouter();
+  const [editOpen, setEditOpen] = useState(false);
+  const [deleting, setDeleting] = useState(false);
+  const [busy, startTransition] = useTransition();
+
+  const handleDelete = () => {
+    startTransition(async () => {
+      const fd = new FormData();
+      fd.set("id", invoice.id);
+      const result = await deleteInvoiceAction(fd);
+      if (result.ok) {
+        toast.success("Fatura silindi.");
+        router.push("/invoices");
+      } else {
+        toast.error(result.error ?? "Silme başarısız.");
+        setDeleting(false);
+      }
+    });
+  };
+
+  return (
+    <>
+      <div className="flex flex-wrap gap-2">
+        <Button variant="outline" size="sm" onClick={() => window.print()}>
+          <Printer className="size-3.5" />
+          Yazdır
+        </Button>
+        <Button variant="outline" size="sm" onClick={() => setEditOpen(true)}>
+          <Pencil className="size-3.5" />
+          Düzenle
+        </Button>
+        <Button
+          variant="ghost"
+          size="sm"
+          className="text-destructive hover:text-destructive"
+          onClick={() => setDeleting(true)}
+        >
+          <Trash2 className="size-3.5" />
+          Sil
+        </Button>
+      </div>
+
+      <InvoiceFormSheet
+        open={editOpen}
+        onOpenChange={setEditOpen}
+        invoice={invoice}
+        customers={customers}
+      />
+
+      <Dialog open={deleting} onOpenChange={setDeleting}>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Faturayı sil</DialogTitle>
+            <DialogDescription>
+              <strong>{invoice.number}</strong> ve tüm kalemleri silinecek. Bu işlem geri alınamaz.
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setDeleting(false)} disabled={busy}>
+              Vazgeç
+            </Button>
+            <Button variant="destructive" onClick={handleDelete} disabled={busy}>
+              {busy ? <Loader2 className="size-4 animate-spin" /> : <Trash2 className="size-4" />}
+              Sil
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+    </>
+  );
+}

src/app/(dashboard)/invoices/[id]/components/items-editor.tsx

@@ -0,0 +1,303 @@
+"use client";
+
+import { useActionState, useEffect, useState, useTransition } from "react";
+import { Loader2, Plus, Save, Trash2 } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import { Card, CardContent } from "@/components/ui/card";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import {
+  Sheet,
+  SheetContent,
+  SheetFooter,
+  SheetHeader,
+  SheetTitle,
+} from "@/components/ui/sheet";
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from "@/components/ui/table";
+import {
+  addInvoiceItemAction,
+  deleteInvoiceItemAction,
+  updateInvoiceItemAction,
+} from "@/lib/appwrite/invoice-actions";
+import { initialInvoiceState } from "@/lib/appwrite/invoice-types";
+import { formatTRY } from "@/lib/format";
+
+export type InvoiceItemRow = {
+  id: string;
+  description: string;
+  quantity: number;
+  unitPrice: number;
+  vatRate: number;
+  lineTotal: number;
+};
+
+type Props = { invoiceId: string; items: InvoiceItemRow[] };
+
+export function InvoiceItemsEditor({ invoiceId, items }: Props) {
+  const [formOpen, setFormOpen] = useState(false);
+  const [editing, setEditing] = useState<InvoiceItemRow | null>(null);
+  const [deleting, setDeleting] = useState<InvoiceItemRow | null>(null);
+  const [busy, startTransition] = useTransition();
+
+  const handleDelete = () => {
+    if (!deleting) return;
+    startTransition(async () => {
+      const fd = new FormData();
+      fd.set("id", deleting.id);
+      const result = await deleteInvoiceItemAction(fd);
+      if (result.ok) {
+        toast.success("Kalem silindi.");
+        setDeleting(null);
+      } else {
+        toast.error(result.error ?? "Silme başarısız.");
+      }
+    });
+  };
+
+  return (
+    <>
+      <Card>
+        <CardContent className="p-0">
+          <div className="flex items-center justify-between border-b p-4">
+            <h2 className="text-sm font-semibold">Kalemler ({items.length})</h2>
+            <Button
+              size="sm"
+              onClick={() => {
+                setEditing(null);
+                setFormOpen(true);
+              }}
+            >
+              <Plus className="size-3.5" />
+              Kalem ekle
+            </Button>
+          </div>
+
+          <Table>
+            <TableHeader>
+              <TableRow>
+                <TableHead>Açıklama</TableHead>
+                <TableHead className="w-[100px] text-right">Miktar</TableHead>
+                <TableHead className="w-[140px] text-right">Birim fiyat</TableHead>
+                <TableHead className="w-[80px] text-right">KDV %</TableHead>
+                <TableHead className="w-[140px] text-right">Toplam</TableHead>
+                <TableHead className="w-[60px]"></TableHead>
+              </TableRow>
+            </TableHeader>
+            <TableBody>
+              {items.length ? (
+                items.map((it) => (
+                  <TableRow
+                    key={it.id}
+                    className="cursor-pointer"
+                    onClick={() => {
+                      setEditing(it);
+                      setFormOpen(true);
+                    }}
+                  >
+                    <TableCell className="font-medium">{it.description}</TableCell>
+                    <TableCell className="text-right tabular-nums">{it.quantity}</TableCell>
+                    <TableCell className="text-right tabular-nums">
+                      {formatTRY(it.unitPrice)}
+                    </TableCell>
+                    <TableCell className="text-right tabular-nums">{it.vatRate}%</TableCell>
+                    <TableCell className="text-right font-medium tabular-nums">
+                      {formatTRY(it.lineTotal)}
+                    </TableCell>
+                    <TableCell className="text-right">
+                      <Button
+                        variant="ghost"
+                        size="icon"
+                        className="size-7"
+                        onClick={(e) => {
+                          e.stopPropagation();
+                          setDeleting(it);
+                        }}
+                      >
+                        <Trash2 className="size-3.5" />
+                      </Button>
+                    </TableCell>
+                  </TableRow>
+                ))
+              ) : (
+                <TableRow>
+                  <TableCell colSpan={6} className="h-20 text-center">
+                    <p className="text-muted-foreground text-sm">
+                      Henüz kalem eklenmemiş. Yukarıdan ekleyin.
+                    </p>
+                  </TableCell>
+                </TableRow>
+              )}
+            </TableBody>
+          </Table>
+        </CardContent>
+      </Card>
+
+      <ItemFormSheet
+        open={formOpen}
+        onOpenChange={(v) => {
+          setFormOpen(v);
+          if (!v) setEditing(null);
+        }}
+        invoiceId={invoiceId}
+        item={editing}
+      />
+
+      <Dialog open={Boolean(deleting)} onOpenChange={(v) => !v && setDeleting(null)}>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Kalemi sil</DialogTitle>
+            <DialogDescription>
+              <strong>{deleting?.description}</strong> kalemini silmek istediğinize emin misiniz?
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setDeleting(null)} disabled={busy}>
+              Vazgeç
+            </Button>
+            <Button variant="destructive" onClick={handleDelete} disabled={busy}>
+              {busy ? <Loader2 className="size-4 animate-spin" /> : <Trash2 className="size-4" />}
+              Sil
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+    </>
+  );
+}
+
+function ItemFormSheet({
+  open,
+  onOpenChange,
+  invoiceId,
+  item,
+}: {
+  open: boolean;
+  onOpenChange: (v: boolean) => void;
+  invoiceId: string;
+  item?: InvoiceItemRow | null;
+}) {
+  const isEdit = Boolean(item);
+  const action = isEdit ? updateInvoiceItemAction : addInvoiceItemAction;
+  const [state, formAction, isPending] = useActionState(action, initialInvoiceState);
+
+  useEffect(() => {
+    if (state.ok) {
+      toast.success(isEdit ? "Kalem güncellendi." : "Kalem eklendi.");
+      onOpenChange(false);
+    } else if (state.error) {
+      toast.error(state.error);
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [state]);
+
+  return (
+    <Sheet open={open} onOpenChange={onOpenChange}>
+      <SheetContent className="flex w-full flex-col gap-0 p-0 sm:max-w-md">
+        <SheetHeader className="border-b px-6 py-4">
+          <SheetTitle>{isEdit ? "Kalemi düzenle" : "Yeni kalem"}</SheetTitle>
+        </SheetHeader>
+
+        <form action={formAction} className="flex flex-1 flex-col">
+          {isEdit && item && <input type="hidden" name="id" value={item.id} />}
+          {!isEdit && <input type="hidden" name="invoiceId" value={invoiceId} />}
+
+          <div className="flex-1 space-y-4 overflow-y-auto px-6 py-5">
+            <div className="grid gap-2">
+              <Label htmlFor="description">Açıklama *</Label>
+              <Input
+                id="description"
+                name="description"
+                defaultValue={item?.description ?? ""}
+                placeholder="Hizmet / ürün açıklaması"
+                required
+              />
+            </div>
+
+            <div className="grid gap-4 md:grid-cols-3">
+              <div className="grid gap-2">
+                <Label htmlFor="quantity">Miktar *</Label>
+                <Input
+                  id="quantity"
+                  name="quantity"
+                  type="number"
+                  step="0.01"
+                  min="0.01"
+                  defaultValue={item?.quantity ?? "1"}
+                  required
+                />
+              </div>
+              <div className="grid gap-2">
+                <Label htmlFor="unitPrice">Birim (₺) *</Label>
+                <Input
+                  id="unitPrice"
+                  name="unitPrice"
+                  type="number"
+                  step="0.01"
+                  min="0"
+                  defaultValue={item?.unitPrice ?? ""}
+                  placeholder="0.00"
+                  required
+                />
+              </div>
+              <div className="grid gap-2">
+                <Label htmlFor="vatRate">KDV %</Label>
+                <Input
+                  id="vatRate"
+                  name="vatRate"
+                  type="number"
+                  step="0.1"
+                  min="0"
+                  max="100"
+                  defaultValue={item?.vatRate ?? "20"}
+                />
+              </div>
+            </div>
+          </div>
+
+          <SheetFooter className="border-t bg-muted/30 px-6 py-4">
+            <div className="flex w-full justify-end gap-2">
+              <Button
+                type="button"
+                variant="outline"
+                onClick={() => onOpenChange(false)}
+                disabled={isPending}
+              >
+                Vazgeç
+              </Button>
+              <Button type="submit" disabled={isPending}>
+                {isPending ? (
+                  <>
+                    <Loader2 className="size-4 animate-spin" />
+                    Kaydediliyor...
+                  </>
+                ) : (
+                  <>
+                    <Save className="size-4" />
+                    {isEdit ? "Güncelle" : "Ekle"}
+                  </>
+                )}
+              </Button>
+            </div>
+          </SheetFooter>
+        </form>
+      </SheetContent>
+    </Sheet>
+  );
+}

src/app/(dashboard)/invoices/[id]/page.tsx

@@ -0,0 +1,134 @@
+import type { Metadata } from "next";
+import Link from "next/link";
+import { notFound, redirect } from "next/navigation";
+import { ArrowLeft } from "lucide-react";
+
+import { Button } from "@/components/ui/button";
+import { Card, CardContent } from "@/components/ui/card";
+import { listCustomers } from "@/lib/appwrite/customer-queries";
+import { getInvoice, listInvoiceItems } from "@/lib/appwrite/invoice-queries";
+import { requireTenant } from "@/lib/appwrite/tenant-guard";
+import { formatDate, formatTRY } from "@/lib/format";
+import { cn } from "@/lib/utils";
+
+import { STATUS_COLOR, STATUS_LABEL } from "../components/types";
+import { InvoiceItemsEditor } from "./components/items-editor";
+import { InvoiceHeaderActions } from "./components/header-actions";
+
+export const metadata: Metadata = {
+  title: "İşletmem — Fatura",
+};
+
+export default async function InvoiceDetailPage({
+  params,
+}: {
+  params: Promise<{ id: string }>;
+}) {
+  const { id } = await params;
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    redirect("/onboarding");
+  }
+
+  const invoice = await getInvoice(ctx.tenantId, id);
+  if (!invoice) notFound();
+
+  const [items, customers] = await Promise.all([
+    listInvoiceItems(ctx.tenantId, id),
+    listCustomers(ctx.tenantId),
+  ]);
+
+  const customerName = customers.find((c) => c.$id === invoice.customerId)?.name ?? "—";
+
+  return (
+    <div className="flex-1 space-y-6 px-6 pt-0">
+      <div className="flex items-center gap-2">
+        <Button asChild variant="ghost" size="sm">
+          <Link href="/invoices">
+            <ArrowLeft className="size-3.5" />
+            Faturalar
+          </Link>
+        </Button>
+      </div>
+
+      <div className="flex flex-col items-start justify-between gap-4 md:flex-row md:items-center">
+        <div>
+          <p className="text-muted-foreground text-sm">{customerName}</p>
+          <h1 className="font-mono text-2xl font-bold tracking-tight">{invoice.number}</h1>
+          <div className="mt-2 flex flex-wrap items-center gap-3 text-sm">
+            <span
+              className={cn(
+                "inline-flex items-center gap-1 rounded-full border px-2 py-0.5 text-xs",
+                STATUS_COLOR[invoice.status ?? "draft"],
+              )}
+            >
+              {STATUS_LABEL[invoice.status ?? "draft"]}
+            </span>
+            <span className="text-muted-foreground">
+              Düzenleme: {formatDate(invoice.issueDate)}
+            </span>
+            <span className="text-muted-foreground">Vade: {formatDate(invoice.dueDate)}</span>
+          </div>
+        </div>
+        <InvoiceHeaderActions
+          invoice={{
+            id: invoice.$id,
+            number: invoice.number,
+            customerId: invoice.customerId,
+            customerName,
+            issueDate: invoice.issueDate,
+            dueDate: invoice.dueDate,
+            status: invoice.status ?? "draft",
+            subtotal: invoice.subtotal ?? 0,
+            vatTotal: invoice.vatTotal ?? 0,
+            total: invoice.total ?? 0,
+            notes: invoice.notes ?? "",
+          }}
+          customers={customers.map((c) => ({ id: c.$id, name: c.name }))}
+        />
+      </div>
+
+      <InvoiceItemsEditor
+        invoiceId={id}
+        items={items.map((it) => ({
+          id: it.$id,
+          description: it.description,
+          quantity: it.quantity,
+          unitPrice: it.unitPrice,
+          vatRate: it.vatRate ?? 0,
+          lineTotal: it.lineTotal,
+        }))}
+      />
+
+      <Card>
+        <CardContent className="space-y-2 p-4">
+          <div className="flex justify-between text-sm">
+            <span className="text-muted-foreground">Ara toplam</span>
+            <span className="tabular-nums">{formatTRY(invoice.subtotal ?? 0)}</span>
+          </div>
+          <div className="flex justify-between text-sm">
+            <span className="text-muted-foreground">KDV</span>
+            <span className="tabular-nums">{formatTRY(invoice.vatTotal ?? 0)}</span>
+          </div>
+          <div className="border-t pt-2"></div>
+          <div className="flex justify-between text-base font-semibold">
+            <span>Genel toplam</span>
+            <span className="tabular-nums">{formatTRY(invoice.total ?? 0)}</span>
+          </div>
+        </CardContent>
+      </Card>
+
+      {invoice.notes && (
+        <Card>
+          <CardContent className="p-4">
+            <p className="text-muted-foreground text-xs font-medium uppercase">Notlar</p>
+            <p className="mt-1 whitespace-pre-line text-sm">{invoice.notes}</p>
+          </CardContent>
+        </Card>
+      )}
+    </div>
+  );
+}

src/app/(dashboard)/invoices/components/invoice-form-sheet.tsx

@@ -0,0 +1,190 @@
+"use client";
+
+import { useActionState, useEffect } from "react";
+import { useRouter } from "next/navigation";
+import { Loader2, Save } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import {
+  Sheet,
+  SheetContent,
+  SheetDescription,
+  SheetFooter,
+  SheetHeader,
+  SheetTitle,
+} from "@/components/ui/sheet";
+import { Textarea } from "@/components/ui/textarea";
+import {
+  createInvoiceAction,
+  updateInvoiceAction,
+} from "@/lib/appwrite/invoice-actions";
+import { initialInvoiceState } from "@/lib/appwrite/invoice-types";
+
+import type { Customer, InvoiceRow } from "./types";
+
+type Props = {
+  open: boolean;
+  onOpenChange: (v: boolean) => void;
+  invoice?: InvoiceRow | null;
+  customers: Customer[];
+};
+
+function isoToDate(iso: string): string {
+  if (!iso) return "";
+  return iso.slice(0, 10);
+}
+
+export function InvoiceFormSheet({ open, onOpenChange, invoice, customers }: Props) {
+  const isEdit = Boolean(invoice);
+  const action = isEdit ? updateInvoiceAction : createInvoiceAction;
+  const [state, formAction, isPending] = useActionState(action, initialInvoiceState);
+  const router = useRouter();
+
+  useEffect(() => {
+    if (state.ok) {
+      toast.success(isEdit ? "Fatura güncellendi." : "Fatura oluşturuldu.");
+      onOpenChange(false);
+      if (!isEdit && state.invoiceId) {
+        router.push(`/invoices/${state.invoiceId}`);
+      }
+    } else if (state.error) {
+      toast.error(state.error);
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [state]);
+
+  const today = new Date().toISOString().slice(0, 10);
+  const inThirty = new Date(Date.now() + 30 * 24 * 60 * 60 * 1000)
+    .toISOString()
+    .slice(0, 10);
+
+  return (
+    <Sheet open={open} onOpenChange={onOpenChange}>
+      <SheetContent className="flex w-full flex-col gap-0 p-0 sm:max-w-xl">
+        <SheetHeader className="border-b px-6 py-4">
+          <SheetTitle>{isEdit ? "Faturayı düzenle" : "Yeni fatura"}</SheetTitle>
+          <SheetDescription>
+            {isEdit
+              ? "Fatura bilgilerini güncelleyin. Kalem eklemek için fatura detayına gidin."
+              : "Faturayı oluşturun, ardından detay sayfasında kalemleri ekleyin. Numara otomatik üretilir."}
+          </SheetDescription>
+        </SheetHeader>
+
+        <form action={formAction} className="flex flex-1 flex-col">
+          {isEdit && invoice && <input type="hidden" name="id" value={invoice.id} />}
+
+          <div className="flex-1 space-y-4 overflow-y-auto px-6 py-5">
+            <div className="grid gap-2">
+              <Label htmlFor="customerId">Müşteri *</Label>
+              <Select
+                name="customerId"
+                defaultValue={invoice?.customerId ?? ""}
+                disabled={customers.length === 0}
+              >
+                <SelectTrigger id="customerId">
+                  <SelectValue placeholder="Müşteri seçin" />
+                </SelectTrigger>
+                <SelectContent>
+                  {customers.map((c) => (
+                    <SelectItem key={c.id} value={c.id}>
+                      {c.name}
+                    </SelectItem>
+                  ))}
+                </SelectContent>
+              </Select>
+              {state.fieldErrors?.customerId && (
+                <p className="text-destructive text-xs">{state.fieldErrors.customerId}</p>
+              )}
+            </div>
+
+            <div className="grid gap-4 md:grid-cols-2">
+              <div className="grid gap-2">
+                <Label htmlFor="issueDate">Düzenleme tarihi *</Label>
+                <Input
+                  id="issueDate"
+                  name="issueDate"
+                  type="date"
+                  defaultValue={isoToDate(invoice?.issueDate ?? today)}
+                  required
+                />
+              </div>
+              <div className="grid gap-2">
+                <Label htmlFor="dueDate">Vade tarihi *</Label>
+                <Input
+                  id="dueDate"
+                  name="dueDate"
+                  type="date"
+                  defaultValue={isoToDate(invoice?.dueDate ?? inThirty)}
+                  required
+                />
+              </div>
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="status">Durum</Label>
+              <Select name="status" defaultValue={invoice?.status ?? "draft"}>
+                <SelectTrigger id="status">
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="draft">Taslak</SelectItem>
+                  <SelectItem value="sent">Gönderildi</SelectItem>
+                  <SelectItem value="paid">Ödendi</SelectItem>
+                  <SelectItem value="overdue">Gecikmiş</SelectItem>
+                  <SelectItem value="cancelled">İptal</SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="notes">Notlar</Label>
+              <Textarea
+                id="notes"
+                name="notes"
+                rows={4}
+                defaultValue={invoice?.notes ?? ""}
+                placeholder="Faturada görünecek not, ödeme talimatları, vb."
+              />
+            </div>
+          </div>
+
+          <SheetFooter className="border-t bg-muted/30 px-6 py-4">
+            <div className="flex w-full justify-end gap-2">
+              <Button
+                type="button"
+                variant="outline"
+                onClick={() => onOpenChange(false)}
+                disabled={isPending}
+              >
+                Vazgeç
+              </Button>
+              <Button type="submit" disabled={isPending || customers.length === 0}>
+                {isPending ? (
+                  <>
+                    <Loader2 className="size-4 animate-spin" />
+                    Kaydediliyor...
+                  </>
+                ) : (
+                  <>
+                    <Save className="size-4" />
+                    {isEdit ? "Güncelle" : "Oluştur"}
+                  </>
+                )}
+              </Button>
+            </div>
+          </SheetFooter>
+        </form>
+      </SheetContent>
+    </Sheet>
+  );
+}

src/app/(dashboard)/invoices/components/invoices-client.tsx

@@ -0,0 +1,372 @@
+"use client";
+
+import { useMemo, useState, useTransition } from "react";
+import Link from "next/link";
+import {
+  type ColumnDef,
+  flexRender,
+  getCoreRowModel,
+  getFilteredRowModel,
+  getPaginationRowModel,
+  getSortedRowModel,
+  type SortingState,
+  useReactTable,
+} from "@tanstack/react-table";
+import {
+  ArrowUpRight,
+  ChevronLeft,
+  ChevronRight,
+  ExternalLink,
+  Loader2,
+  MoreHorizontal,
+  Plus,
+  Receipt,
+  Search,
+  Trash2,
+} from "lucide-react";
+import { toast } from "sonner";
+
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import { Card, CardContent } from "@/components/ui/card";
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from "@/components/ui/dialog";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+import { Input } from "@/components/ui/input";
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from "@/components/ui/table";
+import { deleteInvoiceAction } from "@/lib/appwrite/invoice-actions";
+import { formatDate, formatTRY } from "@/lib/format";
+import { cn } from "@/lib/utils";
+
+import { InvoiceFormSheet } from "./invoice-form-sheet";
+import { type Customer, type InvoiceRow, STATUS_COLOR, STATUS_LABEL } from "./types";
+
+type Props = { invoices: InvoiceRow[]; customers: Customer[] };
+
+export function InvoicesClient({ invoices, customers }: Props) {
+  const [search, setSearch] = useState("");
+  const [sorting, setSorting] = useState<SortingState>([]);
+  const [formOpen, setFormOpen] = useState(false);
+  const [deleting, setDeleting] = useState<InvoiceRow | null>(null);
+  const [busy, startTransition] = useTransition();
+
+  const stats = useMemo(() => {
+    let total = 0;
+    let outstanding = 0;
+    let paid = 0;
+    let overdue = 0;
+    for (const i of invoices) {
+      total += i.total;
+      if (i.status === "paid") paid += i.total;
+      else if (i.status === "overdue") {
+        outstanding += i.total;
+        overdue += i.total;
+      } else if (i.status === "sent" || i.status === "draft") outstanding += i.total;
+    }
+    return { total, outstanding, paid, overdue };
+  }, [invoices]);
+
+  const columns = useMemo<ColumnDef<InvoiceRow>[]>(
+    () => [
+      {
+        accessorKey: "number",
+        header: "Numara",
+        cell: ({ row }) => (
+          <Link
+            href={`/invoices/${row.original.id}`}
+            className="hover:text-primary inline-flex items-center gap-1 font-mono text-sm font-medium"
+          >
+            {row.original.number}
+            <ExternalLink className="size-3 opacity-0 transition-opacity group-hover:opacity-100" />
+          </Link>
+        ),
+      },
+      {
+        accessorKey: "customerName",
+        header: "Müşteri",
+        cell: ({ row }) => row.original.customerName,
+      },
+      {
+        accessorKey: "issueDate",
+        header: "Tarih",
+        cell: ({ row }) => (
+          <span className="text-muted-foreground">{formatDate(row.original.issueDate)}</span>
+        ),
+      },
+      {
+        accessorKey: "dueDate",
+        header: "Vade",
+        cell: ({ row }) => {
+          const overdue =
+            row.original.status !== "paid" &&
+            row.original.status !== "cancelled" &&
+            new Date(row.original.dueDate) < new Date();
+          return (
+            <span
+              className={cn(
+                "text-muted-foreground",
+                overdue && "text-destructive font-medium",
+              )}
+            >
+              {formatDate(row.original.dueDate)}
+            </span>
+          );
+        },
+      },
+      {
+        accessorKey: "status",
+        header: "Durum",
+        cell: ({ row }) => (
+          <Badge variant="outline" className={cn("border-0", STATUS_COLOR[row.original.status])}>
+            {STATUS_LABEL[row.original.status]}
+          </Badge>
+        ),
+      },
+      {
+        accessorKey: "total",
+        header: "Toplam",
+        cell: ({ row }) => (
+          <span className="font-medium tabular-nums">{formatTRY(row.original.total)}</span>
+        ),
+      },
+      {
+        id: "actions",
+        cell: ({ row }) => (
+          <div className="flex justify-end">
+            <DropdownMenu>
+              <DropdownMenuTrigger asChild>
+                <Button variant="ghost" size="icon" className="size-8">
+                  <MoreHorizontal className="size-4" />
+                </Button>
+              </DropdownMenuTrigger>
+              <DropdownMenuContent align="end">
+                <DropdownMenuItem asChild>
+                  <Link href={`/invoices/${row.original.id}`}>
+                    <ArrowUpRight className="size-3.5" />
+                    Aç
+                  </Link>
+                </DropdownMenuItem>
+                <DropdownMenuItem
+                  variant="destructive"
+                  onClick={() => setDeleting(row.original)}
+                >
+                  <Trash2 className="size-3.5" />
+                  Sil
+                </DropdownMenuItem>
+              </DropdownMenuContent>
+            </DropdownMenu>
+          </div>
+        ),
+      },
+    ],
+    [],
+  );
+
+  const table = useReactTable({
+    data: invoices,
+    columns,
+    state: { globalFilter: search, sorting },
+    onGlobalFilterChange: setSearch,
+    onSortingChange: setSorting,
+    getCoreRowModel: getCoreRowModel(),
+    getFilteredRowModel: getFilteredRowModel(),
+    getSortedRowModel: getSortedRowModel(),
+    getPaginationRowModel: getPaginationRowModel(),
+    initialState: { pagination: { pageSize: 25 } },
+    globalFilterFn: (row, _id, fv) => {
+      const v = String(fv).toLowerCase();
+      return [row.original.number, row.original.customerName, row.original.notes]
+        .join(" ")
+        .toLowerCase()
+        .includes(v);
+    },
+  });
+
+  const handleDelete = () => {
+    if (!deleting) return;
+    startTransition(async () => {
+      const fd = new FormData();
+      fd.set("id", deleting.id);
+      const result = await deleteInvoiceAction(fd);
+      if (result.ok) {
+        toast.success("Fatura silindi.");
+        setDeleting(null);
+      } else {
+        toast.error(result.error ?? "Silme başarısız.");
+      }
+    });
+  };
+
+  return (
+    <>
+      <div className="grid grid-cols-2 gap-3 md:grid-cols-4">
+        <Card>
+          <CardContent className="p-4">
+            <p className="text-muted-foreground text-xs">Toplam</p>
+            <p className="mt-1 text-xl font-semibold">{formatTRY(stats.total)}</p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-4">
+            <p className="text-muted-foreground text-xs">Tahsil edildi</p>
+            <p className="mt-1 text-xl font-semibold text-emerald-600 dark:text-emerald-400">
+              {formatTRY(stats.paid)}
+            </p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-4">
+            <p className="text-muted-foreground text-xs">Bekleyen</p>
+            <p className="mt-1 text-xl font-semibold text-blue-600 dark:text-blue-400">
+              {formatTRY(stats.outstanding)}
+            </p>
+          </CardContent>
+        </Card>
+        <Card>
+          <CardContent className="p-4">
+            <p className="text-muted-foreground text-xs">Gecikmiş</p>
+            <p className="mt-1 text-xl font-semibold text-red-600 dark:text-red-400">
+              {formatTRY(stats.overdue)}
+            </p>
+          </CardContent>
+        </Card>
+      </div>
+
+      <Card>
+        <CardContent className="p-0">
+          <div className="flex flex-col gap-3 p-4 md:flex-row md:items-center md:justify-between">
+            <div className="relative md:max-w-xs md:flex-1">
+              <Search className="text-muted-foreground absolute top-1/2 left-3 size-4 -translate-y-1/2" />
+              <Input
+                value={search}
+                onChange={(e) => setSearch(e.target.value)}
+                placeholder="Numara, müşteri, not..."
+                className="pl-9"
+              />
+            </div>
+            <Button onClick={() => setFormOpen(true)} disabled={customers.length === 0}>
+              <Plus className="size-4" />
+              Yeni fatura
+            </Button>
+          </div>
+
+          <Table>
+            <TableHeader>
+              {table.getHeaderGroups().map((hg) => (
+                <TableRow key={hg.id}>
+                  {hg.headers.map((h) => (
+                    <TableHead key={h.id}>
+                      {h.isPlaceholder
+                        ? null
+                        : flexRender(h.column.columnDef.header, h.getContext())}
+                    </TableHead>
+                  ))}
+                </TableRow>
+              ))}
+            </TableHeader>
+            <TableBody>
+              {table.getRowModel().rows.length ? (
+                table.getRowModel().rows.map((r) => (
+                  <TableRow key={r.id} className="group">
+                    {r.getVisibleCells().map((c) => (
+                      <TableCell key={c.id}>
+                        {flexRender(c.column.columnDef.cell, c.getContext())}
+                      </TableCell>
+                    ))}
+                  </TableRow>
+                ))
+              ) : (
+                <TableRow>
+                  <TableCell colSpan={columns.length} className="h-32 text-center">
+                    <div className="text-muted-foreground flex flex-col items-center gap-2">
+                      <Receipt className="size-6" />
+                      <p className="text-sm">
+                        {customers.length === 0
+                          ? "Önce müşteri ekleyin, sonra fatura kesebilirsiniz."
+                          : "Henüz fatura yok."}
+                      </p>
+                    </div>
+                  </TableCell>
+                </TableRow>
+              )}
+            </TableBody>
+          </Table>
+
+          <div className="flex items-center justify-between border-t px-4 py-3">
+            <p className="text-muted-foreground text-sm">
+              Toplam {table.getFilteredRowModel().rows.length} fatura
+            </p>
+            <div className="flex items-center gap-2">
+              <Button
+                variant="outline"
+                size="icon"
+                className="size-8"
+                onClick={() => table.previousPage()}
+                disabled={!table.getCanPreviousPage()}
+              >
+                <ChevronLeft className="size-4" />
+              </Button>
+              <span className="text-muted-foreground text-sm">
+                Sayfa {table.getState().pagination.pageIndex + 1} /{" "}
+                {Math.max(table.getPageCount(), 1)}
+              </span>
+              <Button
+                variant="outline"
+                size="icon"
+                className="size-8"
+                onClick={() => table.nextPage()}
+                disabled={!table.getCanNextPage()}
+              >
+                <ChevronRight className="size-4" />
+              </Button>
+            </div>
+          </div>
+        </CardContent>
+      </Card>
+
+      <InvoiceFormSheet
+        open={formOpen}
+        onOpenChange={setFormOpen}
+        customers={customers}
+      />
+
+      <Dialog open={Boolean(deleting)} onOpenChange={(v) => !v && setDeleting(null)}>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Faturayı sil</DialogTitle>
+            <DialogDescription>
+              <strong>{deleting?.number}</strong> ve tüm kalemleri silinecek. Bu işlem geri alınamaz.
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setDeleting(null)} disabled={busy}>
+              Vazgeç
+            </Button>
+            <Button variant="destructive" onClick={handleDelete} disabled={busy}>
+              {busy ? <Loader2 className="size-4 animate-spin" /> : <Trash2 className="size-4" />}
+              Sil
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
+    </>
+  );
+}

src/app/(dashboard)/invoices/components/types.ts

@@ -0,0 +1,33 @@
+export type InvoiceStatus = "draft" | "sent" | "paid" | "overdue" | "cancelled";
+
+export type InvoiceRow = {
+  id: string;
+  number: string;
+  customerId: string;
+  customerName: string;
+  issueDate: string;
+  dueDate: string;
+  status: InvoiceStatus;
+  subtotal: number;
+  vatTotal: number;
+  total: number;
+  notes: string;
+};
+
+export type Customer = { id: string; name: string };
+
+export const STATUS_LABEL: Record<InvoiceStatus, string> = {
+  draft: "Taslak",
+  sent: "Gönderildi",
+  paid: "Ödendi",
+  overdue: "Gecikmiş",
+  cancelled: "İptal",
+};
+
+export const STATUS_COLOR: Record<InvoiceStatus, string> = {
+  draft: "bg-slate-500/15 text-slate-700 dark:text-slate-300 border-slate-500/30",
+  sent: "bg-blue-500/15 text-blue-700 dark:text-blue-300 border-blue-500/30",
+  paid: "bg-emerald-500/15 text-emerald-700 dark:text-emerald-300 border-emerald-500/30",
+  overdue: "bg-red-500/15 text-red-700 dark:text-red-300 border-red-500/30",
+  cancelled: "bg-muted text-muted-foreground border-muted-foreground/30",
+};

src/app/(dashboard)/invoices/page.tsx

@@ -0,0 +1,56 @@
+import type { Metadata } from "next";
+import { redirect } from "next/navigation";
+
+import { listCustomers } from "@/lib/appwrite/customer-queries";
+import { listInvoices } from "@/lib/appwrite/invoice-queries";
+import { requireTenant } from "@/lib/appwrite/tenant-guard";
+import { InvoicesClient } from "./components/invoices-client";
+
+export const metadata: Metadata = {
+  title: "İşletmem — Faturalar",
+};
+
+export default async function InvoicesPage() {
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    redirect("/onboarding");
+  }
+
+  const [invoices, customers] = await Promise.all([
+    listInvoices(ctx.tenantId),
+    listCustomers(ctx.tenantId),
+  ]);
+
+  const customerMap = new Map(customers.map((c) => [c.$id, c.name]));
+
+  return (
+    <div className="flex-1 space-y-6 px-6 pt-0">
+      <div className="flex flex-col gap-1">
+        <p className="text-muted-foreground text-sm">{ctx.settings?.companyName ?? "Çalışma alanı"}</p>
+        <h1 className="text-2xl font-bold tracking-tight">Faturalar</h1>
+        <p className="text-muted-foreground text-sm">
+          Müşterilerinize fatura kesin, kalemleri yönetin, durumu takip edin.
+        </p>
+      </div>
+
+      <InvoicesClient
+        invoices={invoices.map((i) => ({
+          id: i.$id,
+          number: i.number,
+          customerId: i.customerId,
+          customerName: customerMap.get(i.customerId) ?? "—",
+          issueDate: i.issueDate,
+          dueDate: i.dueDate,
+          status: i.status ?? "draft",
+          subtotal: i.subtotal ?? 0,
+          vatTotal: i.vatTotal ?? 0,
+          total: i.total ?? 0,
+          notes: i.notes ?? "",
+        }))}
+        customers={customers.map((c) => ({ id: c.$id, name: c.name }))}
+      />
+    </div>
+  );
+}

src/lib/appwrite/invoice-actions.ts

@@ -0,0 +1,486 @@
+"use server";
+
+import { revalidatePath } from "next/cache";
+import { AppwriteException, ID, Permission, Query, Role } from "node-appwrite";
+import { z } from "zod";
+
+import { logAudit } from "./audit";
+import {
+  DATABASE_ID,
+  TABLES,
+  type Invoice,
+  type InvoiceItem,
+  type TenantSettings,
+} from "./schema";
+import { createAdminClient } from "./server";
+import { requireTenant } from "./tenant-guard";
+import type { InvoiceActionState } from "./invoice-types";
+import { invoiceItemSchema, invoiceSchema } from "@/lib/validation/invoices";
+
+function appwriteError(e: unknown): string {
+  if (e instanceof AppwriteException) return e.message || "Beklenmeyen hata.";
+  return "Bağlantı hatası. Tekrar deneyin.";
+}
+
+function flattenErrors(err: z.ZodError): Record<string, string> {
+  const out: Record<string, string> = {};
+  for (const issue of err.issues) {
+    const key = issue.path.join(".");
+    if (key && !out[key]) out[key] = issue.message;
+  }
+  return out;
+}
+
+function teamRowPermissions(tenantId: string) {
+  return [
+    Permission.read(Role.team(tenantId)),
+    Permission.update(Role.team(tenantId)),
+    Permission.delete(Role.team(tenantId, "owner")),
+    Permission.delete(Role.team(tenantId, "admin")),
+  ];
+}
+
+function toIso(v: string): string {
+  if (!v) return v;
+  if (/^\d{4}-\d{2}-\d{2}$/.test(v)) return `${v}T00:00:00.000+00:00`;
+  return v;
+}
+
+async function nextInvoiceNumber(
+  tenantId: string,
+): Promise<{ number: string; settingsId: string | null }> {
+  const { tablesDB } = createAdminClient();
+  const result = await tablesDB.listRows({
+    databaseId: DATABASE_ID,
+    tableId: TABLES.tenantSettings,
+    queries: [Query.equal("tenantId", tenantId), Query.limit(1)],
+  });
+  const settings = result.rows[0] as unknown as TenantSettings | undefined;
+  const prefix = settings?.invoicePrefix || "INV";
+  const counter = (settings?.invoiceCounter ?? 0) + 1;
+  const year = new Date().getFullYear();
+  const number = `${prefix}-${year}-${String(counter).padStart(4, "0")}`;
+
+  if (settings) {
+    await tablesDB.updateRow(DATABASE_ID, TABLES.tenantSettings, settings.$id, {
+      invoiceCounter: counter,
+    });
+    return { number, settingsId: settings.$id };
+  }
+  return { number, settingsId: null };
+}
+
+async function recomputeTotals(
+  tenantId: string,
+  invoiceId: string,
+): Promise<{ subtotal: number; vatTotal: number; total: number }> {
+  const { tablesDB } = createAdminClient();
+  const result = await tablesDB.listRows({
+    databaseId: DATABASE_ID,
+    tableId: TABLES.invoiceItems,
+    queries: [
+      Query.equal("tenantId", tenantId),
+      Query.equal("invoiceId", invoiceId),
+      Query.limit(500),
+    ],
+  });
+  let subtotal = 0;
+  let vatTotal = 0;
+  for (const r of result.rows as unknown as InvoiceItem[]) {
+    const lineNet = (r.quantity ?? 0) * (r.unitPrice ?? 0);
+    const lineVat = lineNet * ((r.vatRate ?? 0) / 100);
+    subtotal += lineNet;
+    vatTotal += lineVat;
+  }
+  const total = subtotal + vatTotal;
+  await tablesDB.updateRow(DATABASE_ID, TABLES.invoices, invoiceId, {
+    subtotal: Number(subtotal.toFixed(2)),
+    vatTotal: Number(vatTotal.toFixed(2)),
+    total: Number(total.toFixed(2)),
+  });
+  return { subtotal, vatTotal, total };
+}
+
+// -------------------- Invoice header --------------------
+
+function pickInvoiceFields(formData: FormData) {
+  return {
+    customerId: String(formData.get("customerId") ?? ""),
+    issueDate: String(formData.get("issueDate") ?? ""),
+    dueDate: String(formData.get("dueDate") ?? ""),
+    status:
+      (formData.get("status") as "draft" | "sent" | "paid" | "overdue" | "cancelled" | null) ??
+      "draft",
+    notes: String(formData.get("notes") ?? "").trim(),
+  };
+}
+
+export async function createInvoiceAction(
+  _prev: InvoiceActionState,
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  const parsed = invoiceSchema.safeParse(pickInvoiceFields(formData));
+  if (!parsed.success) {
+    return { ok: false, error: "Form geçersiz.", fieldErrors: flattenErrors(parsed.error) };
+  }
+
+  let invoiceId = "";
+  try {
+    const { tablesDB } = createAdminClient();
+    const { number } = await nextInvoiceNumber(ctx.tenantId);
+
+    const data = {
+      ...parsed.data,
+      issueDate: toIso(parsed.data.issueDate),
+      dueDate: toIso(parsed.data.dueDate),
+      number,
+      subtotal: 0,
+      vatTotal: 0,
+      total: 0,
+    };
+
+    const row = await tablesDB.createRow(
+      DATABASE_ID,
+      TABLES.invoices,
+      ID.unique(),
+      {
+        tenantId: ctx.tenantId,
+        createdBy: ctx.user.id,
+        ...data,
+      },
+      teamRowPermissions(ctx.tenantId),
+    );
+    invoiceId = row.$id;
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "create",
+      entityType: "invoice",
+      entityId: row.$id,
+      changes: { number, customerId: parsed.data.customerId },
+    });
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  revalidatePath("/invoices");
+  return { ok: true, invoiceId };
+}
+
+export async function updateInvoiceAction(
+  _prev: InvoiceActionState,
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  const id = String(formData.get("id") ?? "");
+  if (!id) return { ok: false, error: "ID eksik." };
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  const parsed = invoiceSchema.safeParse(pickInvoiceFields(formData));
+  if (!parsed.success) {
+    return { ok: false, error: "Form geçersiz.", fieldErrors: flattenErrors(parsed.error) };
+  }
+
+  try {
+    const { tablesDB } = createAdminClient();
+    const existing = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoices,
+      id,
+    )) as unknown as Invoice;
+    if (existing.tenantId !== ctx.tenantId) {
+      return { ok: false, error: "Erişim engellendi." };
+    }
+
+    const data = {
+      ...parsed.data,
+      issueDate: toIso(parsed.data.issueDate),
+      dueDate: toIso(parsed.data.dueDate),
+    };
+    await tablesDB.updateRow(DATABASE_ID, TABLES.invoices, id, data);
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "update",
+      entityType: "invoice",
+      entityId: id,
+      changes: data,
+    });
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  revalidatePath("/invoices");
+  revalidatePath(`/invoices/${id}`);
+  return { ok: true, invoiceId: id };
+}
+
+export async function deleteInvoiceAction(
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  const id = String(formData.get("id") ?? "");
+  if (!id) return { ok: false, error: "ID eksik." };
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  try {
+    const { tablesDB } = createAdminClient();
+    const existing = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoices,
+      id,
+    )) as unknown as Invoice;
+    if (existing.tenantId !== ctx.tenantId) {
+      return { ok: false, error: "Erişim engellendi." };
+    }
+
+    // Delete items first
+    const items = await tablesDB.listRows({
+      databaseId: DATABASE_ID,
+      tableId: TABLES.invoiceItems,
+      queries: [
+        Query.equal("tenantId", ctx.tenantId),
+        Query.equal("invoiceId", id),
+        Query.limit(500),
+      ],
+    });
+    for (const it of items.rows) {
+      await tablesDB.deleteRow(DATABASE_ID, TABLES.invoiceItems, it.$id);
+    }
+
+    await tablesDB.deleteRow(DATABASE_ID, TABLES.invoices, id);
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "delete",
+      entityType: "invoice",
+      entityId: id,
+      changes: { number: existing.number, items: items.rows.length },
+    });
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  revalidatePath("/invoices");
+  return { ok: true };
+}
+
+// -------------------- Invoice items --------------------
+
+function pickItemFields(formData: FormData) {
+  return {
+    description: String(formData.get("description") ?? "").trim(),
+    quantity: String(formData.get("quantity") ?? "1"),
+    unitPrice: String(formData.get("unitPrice") ?? "0"),
+    vatRate: String(formData.get("vatRate") ?? "20"),
+  };
+}
+
+function lineTotal(qty: number, unitPrice: number, vatRate: number): number {
+  const net = qty * unitPrice;
+  const vat = net * (vatRate / 100);
+  return Number((net + vat).toFixed(2));
+}
+
+export async function addInvoiceItemAction(
+  _prev: InvoiceActionState,
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  const invoiceId = String(formData.get("invoiceId") ?? "");
+  if (!invoiceId) return { ok: false, error: "Fatura ID eksik." };
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  const parsed = invoiceItemSchema.safeParse(pickItemFields(formData));
+  if (!parsed.success) {
+    return { ok: false, error: "Kalem geçersiz.", fieldErrors: flattenErrors(parsed.error) };
+  }
+
+  try {
+    const { tablesDB } = createAdminClient();
+    const invoice = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoices,
+      invoiceId,
+    )) as unknown as Invoice;
+    if (invoice.tenantId !== ctx.tenantId) {
+      return { ok: false, error: "Erişim engellendi." };
+    }
+
+    const total = lineTotal(parsed.data.quantity, parsed.data.unitPrice, parsed.data.vatRate ?? 0);
+
+    const row = await tablesDB.createRow(
+      DATABASE_ID,
+      TABLES.invoiceItems,
+      ID.unique(),
+      {
+        tenantId: ctx.tenantId,
+        createdBy: ctx.user.id,
+        invoiceId,
+        description: parsed.data.description,
+        quantity: parsed.data.quantity,
+        unitPrice: parsed.data.unitPrice,
+        vatRate: parsed.data.vatRate ?? 0,
+        lineTotal: total,
+      },
+      teamRowPermissions(ctx.tenantId),
+    );
+
+    await recomputeTotals(ctx.tenantId, invoiceId);
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "create",
+      entityType: "invoice_item",
+      entityId: row.$id,
+      changes: { invoiceId, ...parsed.data, lineTotal: total },
+    });
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  revalidatePath(`/invoices/${invoiceId}`);
+  return { ok: true, invoiceId };
+}
+
+export async function updateInvoiceItemAction(
+  _prev: InvoiceActionState,
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  const id = String(formData.get("id") ?? "");
+  if (!id) return { ok: false, error: "ID eksik." };
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  const parsed = invoiceItemSchema.safeParse(pickItemFields(formData));
+  if (!parsed.success) {
+    return { ok: false, error: "Kalem geçersiz.", fieldErrors: flattenErrors(parsed.error) };
+  }
+
+  try {
+    const { tablesDB } = createAdminClient();
+    const existing = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoiceItems,
+      id,
+    )) as unknown as InvoiceItem;
+    if (existing.tenantId !== ctx.tenantId) {
+      return { ok: false, error: "Erişim engellendi." };
+    }
+
+    const total = lineTotal(parsed.data.quantity, parsed.data.unitPrice, parsed.data.vatRate ?? 0);
+
+    await tablesDB.updateRow(DATABASE_ID, TABLES.invoiceItems, id, {
+      description: parsed.data.description,
+      quantity: parsed.data.quantity,
+      unitPrice: parsed.data.unitPrice,
+      vatRate: parsed.data.vatRate ?? 0,
+      lineTotal: total,
+    });
+
+    await recomputeTotals(ctx.tenantId, existing.invoiceId);
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "update",
+      entityType: "invoice_item",
+      entityId: id,
+      changes: { ...parsed.data, lineTotal: total },
+    });
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  revalidatePath(`/invoices/${(await getItemInvoiceId(id)) ?? ""}`);
+  return { ok: true };
+}
+
+async function getItemInvoiceId(itemId: string): Promise<string | null> {
+  try {
+    const { tablesDB } = createAdminClient();
+    const row = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoiceItems,
+      itemId,
+    )) as unknown as InvoiceItem;
+    return row.invoiceId;
+  } catch {
+    return null;
+  }
+}
+
+export async function deleteInvoiceItemAction(
+  formData: FormData,
+): Promise<InvoiceActionState> {
+  const id = String(formData.get("id") ?? "");
+  if (!id) return { ok: false, error: "ID eksik." };
+
+  let ctx;
+  try {
+    ctx = await requireTenant();
+  } catch {
+    return { ok: false, error: "Yetkiniz yok." };
+  }
+
+  try {
+    const { tablesDB } = createAdminClient();
+    const existing = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoiceItems,
+      id,
+    )) as unknown as InvoiceItem;
+    if (existing.tenantId !== ctx.tenantId) {
+      return { ok: false, error: "Erişim engellendi." };
+    }
+
+    await tablesDB.deleteRow(DATABASE_ID, TABLES.invoiceItems, id);
+    await recomputeTotals(ctx.tenantId, existing.invoiceId);
+
+    await logAudit({
+      tenantId: ctx.tenantId,
+      userId: ctx.user.id,
+      action: "delete",
+      entityType: "invoice_item",
+      entityId: id,
+      changes: { invoiceId: existing.invoiceId },
+    });
+
+    revalidatePath(`/invoices/${existing.invoiceId}`);
+  } catch (e) {
+    return { ok: false, error: appwriteError(e) };
+  }
+
+  return { ok: true };
+}

src/lib/appwrite/invoice-queries.ts

@@ -0,0 +1,64 @@
+import "server-only";
+
+import { Query } from "node-appwrite";
+
+import { createAdminClient } from "./server";
+import { DATABASE_ID, TABLES, type Invoice, type InvoiceItem } from "./schema";
+
+export async function listInvoices(tenantId: string): Promise<Invoice[]> {
+  try {
+    const { tablesDB } = createAdminClient();
+    const result = await tablesDB.listRows({
+      databaseId: DATABASE_ID,
+      tableId: TABLES.invoices,
+      queries: [
+        Query.equal("tenantId", tenantId),
+        Query.orderDesc("issueDate"),
+        Query.limit(500),
+      ],
+    });
+    return result.rows as unknown as Invoice[];
+  } catch {
+    return [];
+  }
+}
+
+export async function getInvoice(
+  tenantId: string,
+  id: string,
+): Promise<Invoice | null> {
+  try {
+    const { tablesDB } = createAdminClient();
+    const row = (await tablesDB.getRow(
+      DATABASE_ID,
+      TABLES.invoices,
+      id,
+    )) as unknown as Invoice;
+    if (row.tenantId !== tenantId) return null;
+    return row;
+  } catch {
+    return null;
+  }
+}
+
+export async function listInvoiceItems(
+  tenantId: string,
+  invoiceId: string,
+): Promise<InvoiceItem[]> {
+  try {
+    const { tablesDB } = createAdminClient();
+    const result = await tablesDB.listRows({
+      databaseId: DATABASE_ID,
+      tableId: TABLES.invoiceItems,
+      queries: [
+        Query.equal("tenantId", tenantId),
+        Query.equal("invoiceId", invoiceId),
+        Query.orderAsc("$createdAt"),
+        Query.limit(500),
+      ],
+    });
+    return result.rows as unknown as InvoiceItem[];
+  } catch {
+    return [];
+  }
+}

src/lib/appwrite/invoice-types.ts

@@ -0,0 +1,8 @@
+export type InvoiceActionState = {
+  ok: boolean;
+  error?: string;
+  fieldErrors?: Record<string, string>;
+  invoiceId?: string;
+};
+
+export const initialInvoiceState: InvoiceActionState = { ok: false };

src/lib/validation/invoices.ts

@@ -0,0 +1,36 @@
+import { z } from "zod";
+
+export const invoiceSchema = z.object({
+  customerId: z.string().min(1, "Müşteri seçin."),
+  issueDate: z.string().min(1, "Düzenleme tarihi zorunlu."),
+  dueDate: z.string().min(1, "Vade tarihi zorunlu."),
+  status: z
+    .enum(["draft", "sent", "paid", "overdue", "cancelled"])
+    .optional()
+    .default("draft"),
+  notes: z.string().trim().max(2000).optional().transform((v) => (v ? v : undefined)),
+});
+
+export type InvoiceInput = z.infer<typeof invoiceSchema>;
+
+export const invoiceItemSchema = z.object({
+  description: z.string().trim().min(1, "Açıklama zorunlu.").max(1000),
+  quantity: z
+    .union([z.number(), z.string()])
+    .transform((v) => (typeof v === "string" ? Number(v.replace(",", ".")) : v))
+    .pipe(z.number().positive("Miktar 0'dan büyük olmalı.")),
+  unitPrice: z
+    .union([z.number(), z.string()])
+    .transform((v) => (typeof v === "string" ? Number(v.replace(",", ".")) : v))
+    .pipe(z.number().nonnegative("Negatif olamaz.")),
+  vatRate: z
+    .union([z.number(), z.string()])
+    .optional()
+    .transform((v) => {
+      if (v === undefined || v === "") return 0;
+      const n = typeof v === "string" ? Number(v.replace(",", ".")) : v;
+      return Number.isFinite(n) ? n : 0;
+    }),
+});
+
+export type InvoiceItemInput = z.infer<typeof invoiceItemSchema>;