"use client";

import { useMemo, useState, Suspense } from "react";
import { useSearchParams } from "next/navigation";
import { useMutation, useQuery } from "@tanstack/react-query";
import { toast } from "sonner";
import { accountingApi } from "@/lib/accounting-api";
import { useTenantId } from "@/hooks/useTenantId";
import { formatMoney } from "@/lib/utils";
import { BusinessDocsPage } from "@/components/accounting/BusinessDocsPage";
import {
  PageHeader,
  Button,
  LoadingState,
  ErrorState,
  Card,
  CardContent,
  CardHeader,
  CardTitle,
  Badge,
  Select,
  FormField,
  DataTable,
  EmptyState,
} from "@/components/ds";

type ReportKind = "trial-balance" | "balance-sheet" | "income-statement";

const LABELS: Record<ReportKind, string> = {
  "trial-balance": "تراز آزمایشی",
  "balance-sheet": "ترازنامه",
  "income-statement": "سود و زیان",
};

const OPS_REPORTS: Record<string, { title: string; module: string; docType: string }> = {
  "cash-flow": { title: "جریان وجوه نقد", module: "reports", docType: "cash_flow" },
  equity: { title: "تغییرات حقوق صاحبان سهام", module: "reports", docType: "equity" },
  subsidiary: { title: "گزارش معین", module: "reports", docType: "subsidiary" },
  detail: { title: "گزارش تفصیلی", module: "reports", docType: "detail" },
  analytical: { title: "گزارش تحلیلی", module: "reports", docType: "analytical" },
};

const FIELD_LABELS: Record<string, string> = {
  total_debit: "جمع بدهکار",
  total_credit: "جمع بستانکار",
  difference: "اختلاف",
  is_balanced: "متوازن",
  total_assets: "جمع دارایی‌ها",
  account_count: "تعداد حساب",
  total_revenue: "جمع درآمد",
  total_expense: "جمع هزینه",
  net: "خالص",
};

function parseReportData(data: unknown): Record<string, unknown> | null {
  if (!data) return null;
  if (typeof data === "string") {
    try {
      return JSON.parse(data) as Record<string, unknown>;
    } catch {
      return { raw: data };
    }
  }
  if (typeof data === "object" && !Array.isArray(data)) {
    return data as Record<string, unknown>;
  }
  return { value: data };
}

function formatCellValue(key: string, value: unknown): React.ReactNode {
  if (value === null || value === undefined) return "—";
  if (typeof value === "boolean") return value ? "بله" : "خیر";
  if (key.includes("total") || key.includes("difference") || key === "net" || key.includes("amount")) {
    return formatMoney(String(value));
  }
  return String(value);
}

function EngineReports({ initialKind }: { initialKind?: string }) {
  const { tenantId } = useTenantId();
  const [periodId, setPeriodId] = useState("");
  const [result, setResult] = useState<{ kind: ReportKind; payload: { id: string; data: unknown } } | null>(
    null
  );

  const periodsQ = useQuery({
    queryKey: ["accounting", tenantId, "fiscal-periods"],
    queryFn: () => accountingApi.fiscal.listPeriods(tenantId!),
    enabled: !!tenantId,
  });

  const runM = useMutation({
    mutationFn: async (kind: ReportKind) => {
      if (!periodId) throw new Error("دوره مالی را انتخاب کنید");
      if (kind === "trial-balance") {
        const payload = await accountingApi.reporting.trialBalance(tenantId!, periodId);
        return { kind, payload };
      }
      if (kind === "balance-sheet") {
        const payload = await accountingApi.reporting.balanceSheet(tenantId!, periodId);
        return { kind, payload };
      }
      const payload = await accountingApi.reporting.incomeStatement(tenantId!, periodId);
      return { kind, payload };
    },
    onSuccess: (data) => {
      setResult(data);
      toast.success("گزارش تولید شد");
    },
    onError: (e: Error) => toast.error(e.message),
  });

  const exportM = useMutation({
    mutationFn: (format: "json" | "csv") =>
      accountingApi.reporting.export(tenantId!, result!.payload.id, format),
    onSuccess: (data) => {
      toast.success(`خروجی ${data.format} ثبت شد`);
      if (data.file_path) toast.message(data.file_path);
      if (result) {
        const blob = new Blob([JSON.stringify(result.payload, null, 2)], {
          type: "application/json",
        });
        const url = URL.createObjectURL(blob);
        const a = document.createElement("a");
        a.href = url;
        a.download = `report-${result.payload.id}.json`;
        a.click();
        URL.revokeObjectURL(url);
      }
    },
    onError: (e: Error) => toast.error(e.message),
  });

  const parsed = useMemo(
    () => (result ? parseReportData(result.payload.data) : null),
    [result]
  );

  const tableRows = useMemo(() => {
    if (!parsed) return [];
    return Object.entries(parsed).map(([key, value]) => ({
      id: key,
      field: FIELD_LABELS[key] ?? key,
      value,
      rawKey: key,
    }));
  }, [parsed]);

  if (!tenantId || periodsQ.isLoading) return <LoadingState />;
  if (periodsQ.error) {
    return <ErrorState message={periodsQ.error.message} onRetry={() => periodsQ.refetch()} />;
  }

  const highlight =
    initialKind === "trial-balance" ||
    initialKind === "balance-sheet" ||
    initialKind === "income-statement"
      ? (initialKind as ReportKind)
      : null;

  return (
    <div>
      <PageHeader
        title="گزارش‌های مالی"
        description="تراز آزمایشی، ترازنامه و سود و زیان — از Report Engine."
      />

      <Card className="mb-6">
        <CardContent className="grid gap-4 pt-6 sm:grid-cols-[1fr_auto] sm:items-end">
          <FormField label="دوره مالی">
            <Select value={periodId} onChange={(e) => setPeriodId(e.target.value)}>
              <option value="">انتخاب دوره</option>
              {(periodsQ.data ?? []).map((p) => (
                <option key={p.id} value={p.id}>
                  {p.name}
                </option>
              ))}
            </Select>
          </FormField>
          <div className="flex flex-wrap gap-2">
            {(Object.keys(LABELS) as ReportKind[]).map((kind) => (
              <Button
                key={kind}
                type="button"
                variant={highlight === kind ? "default" : "outline"}
                disabled={runM.isPending || !periodId}
                onClick={() => runM.mutate(kind)}
              >
                {LABELS[kind]}
              </Button>
            ))}
          </div>
        </CardContent>
      </Card>

      {result ? (
        <Card>
          <CardHeader>
            <CardTitle className="flex flex-wrap items-center gap-2">
              {LABELS[result.kind]}
              <Badge tone="primary">زنده</Badge>
              <span className="text-xs font-normal text-[var(--muted)]" dir="ltr">
                ID: {result.payload.id}
              </span>
              <Button
                type="button"
                size="sm"
                variant="outline"
                className="ms-auto"
                disabled={exportM.isPending}
                onClick={() => exportM.mutate("json")}
              >
                خروجی / Export
              </Button>
            </CardTitle>
          </CardHeader>
          <CardContent className="space-y-4">
            {parsed && tableRows.length > 0 ? (
              <DataTable
                columns={[
                  { key: "field", header: "عنوان" },
                  {
                    key: "value",
                    header: "مقدار",
                    render: (r) => formatCellValue(String(r.rawKey), r.value),
                  },
                ]}
                rows={tableRows as unknown as Record<string, unknown>[]}
              />
            ) : (
              <EmptyState title="داده‌ای برای نمایش نیست" />
            )}
            <details className="rounded-xl border border-[var(--border)] bg-[var(--surface-muted)] p-3">
              <summary className="cursor-pointer text-sm font-medium text-secondary">JSON خام</summary>
              <pre
                className="mt-3 max-h-[320px] overflow-auto text-xs leading-relaxed text-secondary"
                dir="ltr"
              >
                {JSON.stringify(result.payload, null, 2)}
              </pre>
            </details>
          </CardContent>
        </Card>
      ) : (
        <p className="text-sm text-[var(--muted)]">یک دوره انتخاب کنید و گزارش را اجرا کنید.</p>
      )}
    </div>
  );
}

function ReportsRouter() {
  const sp = useSearchParams();
  const type = sp.get("type") || "";
  const ops = OPS_REPORTS[type];
  if (ops) {
    return <BusinessDocsPage title={ops.title} module={ops.module} docType={ops.docType} />;
  }
  return <EngineReports initialKind={type || undefined} />;
}

export default function ReportsPage() {
  return (
    <Suspense fallback={<LoadingState />}>
      <ReportsRouter />
    </Suspense>
  );
}