"use client";

import { useState } from "react";
import { useQuery, useMutation } from "@tanstack/react-query";
import { toast } from "sonner";
import { ArrowRight } from "lucide-react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/Card";
import { Button } from "@/components/ui/Button";
import { Input } from "@/components/ui/Input";
import { Table, TableHead, TableBody, TableRow, Th, Td, EmptyState } from "@/components/ui/Table";
import { Badge } from "@/components/ui/Badge";
import { Modal } from "@/components/ui/Modal";
import { AccountingNav } from "@/components/accounting/AccountingNav";
import { formatCurrency } from "@/lib/utils";
import api from "@/lib/api";
import type { CompanyAccount, CompanyAccountType, Transfer } from "@/types/index";

function formatDate(iso: string) {
  return new Date(iso).toLocaleDateString("en-PH", { year: "numeric", month: "short", day: "numeric" });
}

const TYPE_COLORS: Record<CompanyAccountType, "default" | "success" | "warning"> = {
  CASH: "success",
  BANK: "default",
  EWALLET: "warning",
};

const ACCOUNT_TYPES: CompanyAccountType[] = ["CASH", "BANK", "EWALLET"];

export default function CompanyAccountsPage() {
  const today = new Date().toISOString().split("T")[0];

  const [showAdd, setShowAdd] = useState(false);
  const [addForm, setAddForm] = useState({
    name: "", type: "BANK" as CompanyAccountType,
    bankName: "", accountNumber: "", initialBalance: "0",
  });

  const [transferAccount, setTransferAccount] = useState<CompanyAccount | null>(null);
  const [transferForm, setTransferForm] = useState({ toAccountId: "", amount: "", date: today, note: "" });

  const { data: accounts = [], isLoading, refetch: refetchAccounts } = useQuery<CompanyAccount[]>({
    queryKey: ["company-accounts"],
    queryFn: async () => {
      const res = await api.get<CompanyAccount[] | { data: CompanyAccount[] }>("/api/v1/company-accounts");
      const d = res.data;
      return Array.isArray(d) ? d : (d as { data: CompanyAccount[] }).data ?? [];
    },
  });

  const { data: transfers = [], refetch: refetchTransfers } = useQuery<Transfer[]>({
    queryKey: ["transfers"],
    queryFn: async () => {
      const res = await api.get<Transfer[] | { data: Transfer[] }>("/api/v1/transfers");
      const d = res.data;
      return Array.isArray(d) ? d : (d as { data: Transfer[] }).data ?? [];
    },
  });

  const addMutation = useMutation({
    mutationFn: async () => {
      await api.post("/api/v1/company-accounts", {
        name: addForm.name,
        type: addForm.type,
        bankName: addForm.bankName || undefined,
        accountNumber: addForm.accountNumber || undefined,
        initialBalance: parseFloat(addForm.initialBalance) || 0,
      });
    },
    onSuccess: () => {
      toast.success("Account added");
      setShowAdd(false);
      setAddForm({ name: "", type: "BANK", bankName: "", accountNumber: "", initialBalance: "0" });
      refetchAccounts();
    },
    onError: () => toast.error("Failed to add account"),
  });

  const transferMutation = useMutation({
    mutationFn: async () => {
      if (!transferAccount) return;
      await api.post("/api/v1/transfers", {
        fromAccountId: transferAccount.id,
        toAccountId: transferForm.toAccountId,
        amount: parseFloat(transferForm.amount),
        date: transferForm.date,
        note: transferForm.note || undefined,
      });
    },
    onSuccess: () => {
      toast.success("Transfer completed");
      setTransferAccount(null);
      setTransferForm({ toAccountId: "", amount: "", date: today, note: "" });
      refetchAccounts();
      refetchTransfers();
    },
    onError: () => toast.error("Failed to process transfer"),
  });

  const toAccounts = accounts.filter((a) => a.id !== transferAccount?.id);

  return (
    <div className="space-y-4">
      <div className="flex items-start justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900">Accounting</h1>
          <p className="text-sm text-gray-500">Company cash, bank, and e-wallet accounts</p>
        </div>
        <Button size="sm" onClick={() => setShowAdd(true)}>+ Add Account</Button>
      </div>

      <AccountingNav />

      {/* Account Cards */}
      {isLoading ? (
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
          {Array.from({ length: 3 }).map((_, i) => (
            <div key={i} className="h-36 animate-pulse bg-gray-100 rounded-xl" />
          ))}
        </div>
      ) : accounts.length === 0 ? (
        <Card>
          <CardContent className="py-12 text-center text-sm text-gray-400">
            No company accounts yet. Add your first account to get started.
          </CardContent>
        </Card>
      ) : (
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
          {accounts.map((acct) => (
            <Card key={acct.id}>
              <CardContent className="pt-5">
                <div className="flex items-start justify-between mb-3">
                  <div>
                    <p className="font-semibold text-gray-900">{acct.name}</p>
                    {acct.bankName && (
                      <p className="text-xs text-gray-400 mt-0.5">{acct.bankName}</p>
                    )}
                    {acct.accountNumber && (
                      <p className="text-xs text-gray-400 font-mono">{acct.accountNumber}</p>
                    )}
                  </div>
                  <Badge variant={TYPE_COLORS[acct.type]}>{acct.type}</Badge>
                </div>
                <p className="text-2xl font-bold text-gray-900">{formatCurrency(Number(acct.balance))}</p>
                <div className="mt-3">
                  <Button
                    size="sm"
                    variant="outline"
                    onClick={() => {
                      setTransferAccount(acct);
                      setTransferForm({ toAccountId: "", amount: "", date: today, note: "" });
                    }}
                  >
                    <ArrowRight className="h-3 w-3 mr-1" /> Transfer
                  </Button>
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
      )}

      {/* Recent Transfers */}
      <Card>
        <CardHeader>
          <CardTitle>Recent Transfers</CardTitle>
        </CardHeader>
        <CardContent className="p-0">
          <Table>
            <TableHead>
              <TableRow>
                <Th>Date</Th>
                <Th>From</Th>
                <Th></Th>
                <Th>To</Th>
                <Th>Amount</Th>
                <Th>Note</Th>
              </TableRow>
            </TableHead>
            <TableBody>
              {transfers.length === 0 ? (
                <EmptyState message="No transfers yet" />
              ) : (
                transfers.slice(0, 20).map((t) => (
                  <TableRow key={t.id}>
                    <Td className="text-sm">{formatDate(t.date)}</Td>
                    <Td className="font-medium text-sm">{t.fromAccount?.name ?? "—"}</Td>
                    <Td className="text-gray-400"><ArrowRight className="h-4 w-4" /></Td>
                    <Td className="font-medium text-sm">{t.toAccount?.name ?? "—"}</Td>
                    <Td className="font-semibold text-sm">{formatCurrency(Number(t.amount))}</Td>
                    <Td className="text-sm text-gray-500">{t.note ?? "—"}</Td>
                  </TableRow>
                ))
              )}
            </TableBody>
          </Table>
        </CardContent>
      </Card>

      {/* Add Account Modal */}
      <Modal isOpen={showAdd} onClose={() => setShowAdd(false)} title="Add Company Account">
        <form onSubmit={(e) => { e.preventDefault(); addMutation.mutate(); }} className="space-y-4">
          <Input
            label="Account Name *"
            value={addForm.name}
            onChange={(e) => setAddForm((f) => ({ ...f, name: e.target.value }))}
            placeholder="e.g. BDO Savings"
          />
          <div className="flex flex-col gap-1.5">
            <label className="text-sm font-medium text-gray-700">Type *</label>
            <select
              className="block w-full rounded-lg border border-gray-300 bg-white px-3 py-2 text-sm focus:border-blue-500 focus:outline-none focus:ring-1 focus:ring-blue-500"
              value={addForm.type}
              onChange={(e) => setAddForm((f) => ({ ...f, type: e.target.value as CompanyAccountType }))}
            >
              {ACCOUNT_TYPES.map((t) => (
                <option key={t} value={t}>{t}</option>
              ))}
            </select>
          </div>
          <div className="grid grid-cols-2 gap-3">
            <Input
              label="Bank Name"
              value={addForm.bankName}
              onChange={(e) => setAddForm((f) => ({ ...f, bankName: e.target.value }))}
              placeholder="e.g. BDO"
            />
            <Input
              label="Account Number"
              value={addForm.accountNumber}
              onChange={(e) => setAddForm((f) => ({ ...f, accountNumber: e.target.value }))}
              placeholder="e.g. 0012-3456-7890"
            />
          </div>
          <Input
            label="Initial Balance (₱)"
            type="number"
            min="0"
            step="0.01"
            value={addForm.initialBalance}
            onChange={(e) => setAddForm((f) => ({ ...f, initialBalance: e.target.value }))}
          />
          <div className="flex justify-end gap-2">
            <Button type="button" variant="outline" size="sm" onClick={() => setShowAdd(false)}>Cancel</Button>
            <Button type="submit" size="sm" isLoading={addMutation.isPending} disabled={!addForm.name.trim()}>
              Add Account
            </Button>
          </div>
        </form>
      </Modal>

      {/* Transfer Modal */}
      <Modal
        isOpen={!!transferAccount}
        onClose={() => setTransferAccount(null)}
        title={`Transfer from ${transferAccount?.name ?? ""}`}
      >
        <form onSubmit={(e) => { e.preventDefault(); transferMutation.mutate(); }} className="space-y-4">
          <div className="p-3 rounded-lg bg-blue-50 text-sm">
            <span className="text-blue-700 font-medium">Available balance: </span>
            <span className="text-blue-900 font-bold">{formatCurrency(Number(transferAccount?.balance ?? 0))}</span>
          </div>
          <div className="flex flex-col gap-1.5">
            <label className="text-sm font-medium text-gray-700">To Account *</label>
            <select
              className="block w-full rounded-lg border border-gray-300 bg-white px-3 py-2 text-sm focus:border-blue-500 focus:outline-none focus:ring-1 focus:ring-blue-500"
              value={transferForm.toAccountId}
              onChange={(e) => setTransferForm((f) => ({ ...f, toAccountId: e.target.value }))}
            >
              <option value="">Select destination account</option>
              {toAccounts.map((a) => (
                <option key={a.id} value={a.id}>{a.name} ({a.type})</option>
              ))}
            </select>
          </div>
          <div className="grid grid-cols-2 gap-3">
            <Input
              label="Amount (₱) *"
              type="number"
              min="0.01"
              step="0.01"
              value={transferForm.amount}
              onChange={(e) => setTransferForm((f) => ({ ...f, amount: e.target.value }))}
              placeholder="0.00"
            />
            <Input
              label="Date *"
              type="date"
              value={transferForm.date}
              onChange={(e) => setTransferForm((f) => ({ ...f, date: e.target.value }))}
            />
          </div>
          <Input
            label="Note"
            value={transferForm.note}
            onChange={(e) => setTransferForm((f) => ({ ...f, note: e.target.value }))}
            placeholder="Optional note"
          />
          <div className="flex justify-end gap-2">
            <Button type="button" variant="outline" size="sm" onClick={() => setTransferAccount(null)}>Cancel</Button>
            <Button
              type="submit"
              size="sm"
              isLoading={transferMutation.isPending}
              disabled={!transferForm.toAccountId || !transferForm.amount || !transferForm.date}
            >
              Transfer Funds
            </Button>
          </div>
        </form>
      </Modal>
    </div>
  );
}