"use client";

import { ListChecks } from "lucide-react";
import { useCallback, useEffect, useState } from "react";
import { adminApi, errMessage, type TodoItem } from "@/lib/admin-api";
import {
  Badge,
  Button,
  Card,
  EmptyState,
  ErrorState,
  LoadingBlock,
  Pagination,
  SearchInput,
  Select,
  TableWrap,
  Td,
  Th,
  formatTime,
  isOverdue,
  statusTone,
  useToast,
} from "@/components/admin/ui";

const STATUS_OPTIONS = [
  { value: "", label: "全部状态" },
  { value: "待处理", label: "待处理" },
  { value: "处理中", label: "处理中" },
  { value: "已完成", label: "已完成" },
];

const PRIORITY_TONE = { 高: "danger", 中: "warning", 低: "neutral" } as const;

export function TodosSection({ onOpenCustomer }: { onOpenCustomer?: (customerId: number) => void }) {
  const toast = useToast();
  const [items, setItems] = useState<TodoItem[]>([]);
  const [total, setTotal] = useState(0);
  const [totalPages, setTotalPages] = useState(0);
  const [page, setPage] = useState(1);
  const [status, setStatus] = useState("待处理");
  const [type, setType] = useState("");
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");
  const [busyId, setBusyId] = useState<number | null>(null);

  const load = useCallback(async () => {
    setLoading(true);
    setError("");
    try {
      const result = await adminApi.todos({ status: status || undefined, todo_type: type || undefined, page, page_size: 10 });
      setItems(result.items ?? []);
      setTotal(result.total ?? 0);
      setTotalPages(result.total_pages ?? 0);
    } catch (e) {
      setError(errMessage(e, "待办加载失败"));
    } finally {
      setLoading(false);
    }
  }, [status, type, page]);

  useEffect(() => {
    void load();
  }, [load]);

  async function handle(todo: TodoItem, action: "process" | "done") {
    setBusyId(todo.id);
    try {
      await adminApi.handleTodo(todo.id, action);
      toast(action === "done" ? "待办已标记完成" : "待办已开始处理");
      await load();
    } catch (e) {
      toast(errMessage(e, "操作失败"), "error");
    } finally {
      setBusyId(null);
    }
  }

  return (
    <Card
      title="我的待办"
      description="投顾待办事项，支持按状态筛选和直接处理"
      bodyClassName="p-0"
    >
      <div className="flex flex-wrap items-center gap-3 border-b border-slate-100 p-4">
        <Select value={status} onChange={(event) => { setStatus(event.target.value); setPage(1); }}>
          {STATUS_OPTIONS.map((option) => (
            <option key={option.value} value={option.value}>
              {option.label}
            </option>
          ))}
        </Select>
        <SearchInput
          className="w-56"
          placeholder="按待办类型筛选"
          value={type}
          onChange={(event) => { setType(event.target.value); setPage(1); }}
        />
        <Button size="sm" className="ml-auto" onClick={() => void load()} loading={loading}>
          刷新
        </Button>
      </div>

      {loading ? (
        <LoadingBlock />
      ) : error ? (
        <ErrorState message={error} onRetry={() => void load()} />
      ) : items.length === 0 ? (
        <EmptyState text="没有符合条件的待办" />
      ) : (
        <>
          <TableWrap>
            <thead>
              <tr>
                <Th>待办类型</Th>
                <Th>关联客户</Th>
                <Th>优先级</Th>
                <Th>状态</Th>
                <Th>截止时间</Th>
                <Th className="text-right">操作</Th>
              </tr>
            </thead>
            <tbody className="divide-y divide-slate-50">
              {items.map((todo) => (
                <tr key={todo.id} className="transition-colors hover:bg-slate-50">
                  <Td className="font-medium text-slate-900">{todo.todo_type}</Td>
                  <Td>
                    {todo.customer_id ? (
                      <button
                        onClick={() => onOpenCustomer?.(todo.customer_id as number)}
                        className="text-indigo-600 hover:underline"
                      >
                        客户 #{todo.customer_id}
                      </button>
                    ) : (
                      <span className="text-slate-400">--</span>
                    )}
                  </Td>
                  <Td>
                    <Badge tone={PRIORITY_TONE[todo.priority as keyof typeof PRIORITY_TONE] ?? "neutral"}>
                      {todo.priority ?? "普通"}
                    </Badge>
                  </Td>
                  <Td>
                    <Badge tone={statusTone(todo.status)}>{todo.status}</Badge>
                  </Td>
                  <Td className={isOverdue(todo.due_at) && todo.status !== "已完成" ? "text-red-500" : "text-slate-500"}>
                    {formatTime(todo.due_at)}
                    {isOverdue(todo.due_at) && todo.status !== "已完成" && " · 已逾期"}
                  </Td>
                  <Td>
                    <div className="flex justify-end gap-2">
                      {todo.status === "待处理" && (
                        <Button size="sm" loading={busyId === todo.id} onClick={() => void handle(todo, "process")}>
                          开始处理
                        </Button>
                      )}
                      {todo.status !== "已完成" && (
                        <Button
                          size="sm"
                          variant="primary"
                          loading={busyId === todo.id}
                          onClick={() => void handle(todo, "done")}
                        >
                          完成
                        </Button>
                      )}
                      {todo.status === "已完成" && <ListChecks className="h-4 w-4 text-emerald-500" />}
                    </div>
                  </Td>
                </tr>
              ))}
            </tbody>
          </TableWrap>
          <Pagination page={page} totalPages={totalPages} total={total} onChange={setPage} />
        </>
      )}
    </Card>
  );
}