"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>
  );
}