import { Link, useSearchParams } from "react-router-dom";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { toast } from "sonner";
import { isApiError } from "../api/types";
import { mapApiErrorMessage } from "../api/errorMessages";
import { approveWorkflowTask, fetchWorkflowTasks } from "../api/workflow";
import { PageHeader } from "../components/common/PageHeader";
import { Pagination } from "../components/common/Pagination";
import { StatusBadge } from "../components/common/StatusBadge";
import { TableSkeleton } from "../components/common/TableSkeleton";
import { Button } from "../components/ui/button";
import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "../components/ui/table";
import { Tabs, TabsList, TabsTrigger } from "../components/ui/tabs";
import { TEST_IDS } from "../lib/testIds";

const PAGE_SIZE = 20;

function entityLabel(entityType: string | undefined) {
  if (entityType === "leave") {
    return "请假";
  }
  if (entityType === "reimbursement") {
    return "报销";
  }
  if (entityType === "purchase_request") {
    return "采购";
  }
  if (entityType === "travel_request") {
    return "差旅";
  }
  return entityType || "-";
}

export function WorkflowTasksPage() {
  const [searchParams, setSearchParams] = useSearchParams();
  const queryClient = useQueryClient();

  const status =
    (searchParams.get("status") as
      | "pending"
      | "completed"
      | "rejected"
      | "cancelled"
      | "skipped"
      | null) ?? "pending";
  const page = Number(searchParams.get("page") ?? "1") || 1;

  const query = useQuery({
    queryKey: ["workflow", "tasks", status, page],
    queryFn: () => fetchWorkflowTasks({ status, page, pageSize: PAGE_SIZE }),
  });

  const approveMutation = useMutation({
    mutationFn: (taskId: string) => approveWorkflowTask(taskId),
    onSuccess: async () => {
      await Promise.all([
        queryClient.invalidateQueries({ queryKey: ["workflow", "tasks"] }),
        queryClient.invalidateQueries({ queryKey: ["portal-home"] }),
        queryClient.invalidateQueries({ queryKey: ["notifications"] }),
      ]);
      toast.success("审批已通过");
    },
    onError: (error) => {
      const message = isApiError(error)
        ? `${error.code}: ${mapApiErrorMessage(error.code, error.details, error.message)}`
        : error instanceof Error
          ? error.message
          : "审批失败，请稍后重试";
      toast.error(message);
    },
  });

  const totalPages = Math.max(1, Math.ceil((query.data?.total ?? 0) / PAGE_SIZE));
  const taskItems = query.data?.items ?? [];

  return (
    <div className="space-y-4 md:space-y-6">
      <PageHeader title="待我处理" subtitle="待处理审批。" />

      <div className="card-std space-y-4 p-4 md:p-5">
        <Tabs
          data-testid="workflow-tasks-status-tabs"
          value={status}
          onValueChange={(value) => setSearchParams({ status: value, page: "1" })}
        >
          <TabsList className="flex w-full flex-wrap justify-start gap-1">
            {[
              { value: "pending", label: "待处理" },
              { value: "completed", label: "已通过" },
              { value: "rejected", label: "已驳回" },
              { value: "cancelled", label: "已取消" },
              { value: "skipped", label: "已跳过" },
            ].map((item) => (
              <TabsTrigger
                data-testid={`workflow-tasks-tab-${item.value}`}
                key={item.value}
                value={item.value}
              >
                {item.label}
              </TabsTrigger>
            ))}
          </TabsList>
        </Tabs>

        {query.isLoading ? <TableSkeleton columns={5} rows={5} /> : null}

        {query.isError ? (
          <p className="rounded-lg border border-red-200 bg-red-50 px-3 py-2 text-sm text-red-600">
            {isApiError(query.error)
              ? `${query.error.code}: ${mapApiErrorMessage(
                  query.error.code,
                  query.error.details,
                  query.error.message,
                )}`
              : "加载待办失败，请稍后重试"}
          </p>
        ) : null}

        {!query.isLoading && !query.isError ? (
          <>
            <div className="space-y-3 md:hidden" data-testid="workflow-tasks-mobile-list">
              {taskItems.length ? (
                taskItems.map((task) => (
                  <article className="rounded-xl border border-zinc-200 bg-white p-4 shadow-sm" key={task.id}>
                    <div className="flex items-start justify-between gap-3">
                      <div className="min-w-0">
                        <div className="truncate text-sm font-semibold text-zinc-900">{task.stepName}</div>
                        <div className="mt-1 text-xs text-zinc-500">
                          {entityLabel(task.workflowInstance?.entityType)} · {new Date(task.createdAt).toLocaleString()}
                        </div>
                      </div>
                      <StatusBadge className="shrink-0" status={task.status} />
                    </div>
                    <div className="mt-3 truncate rounded-lg bg-zinc-50 px-3 py-2 font-mono text-xs text-zinc-500">
                      {task.workflowInstance?.entityId ?? task.id}
                    </div>
                    <div className="mt-3 grid grid-cols-2 gap-2">
                      {status === "pending" && (task.allowedActions ?? []).includes("approve") ? (
                        <Button
                          className="min-h-11"
                          size="sm"
                          type="button"
                          data-testid={TEST_IDS.workflow.quickApprove}
                          disabled={approveMutation.isPending && approveMutation.variables === task.id}
                          onClick={() => approveMutation.mutate(task.id)}
                        >
                          {approveMutation.isPending && approveMutation.variables === task.id ? "通过中..." : "通过"}
                        </Button>
                      ) : null}
                      <Button
                        asChild
                        className={`min-h-11 ${
                          status === "pending" && (task.allowedActions ?? []).includes("approve") ? "" : "col-span-2"
                        }`}
                        size="sm"
                        variant="secondary"
                        data-testid={TEST_IDS.workflow.detailLink}
                      >
                        <Link to={`/workflow/tasks/${task.id}`}>详情</Link>
                      </Button>
                    </div>
                  </article>
                ))
              ) : (
                <div className="rounded-xl border border-dashed border-zinc-300 px-4 py-8 text-center text-sm text-zinc-500">
                  暂无数据
                </div>
              )}
            </div>

            <div className="hidden rounded-lg border border-zinc-200 md:block">
              <Table data-testid="workflow-tasks-table">
                <TableHeader>
                  <tr>
                    <TableHead>任务</TableHead>
                    <TableHead>业务对象</TableHead>
                    <TableHead>状态</TableHead>
                    <TableHead>创建时间</TableHead>
                    <TableHead className="w-24">操作</TableHead>
                  </tr>
                </TableHeader>
                <TableBody>
                  {taskItems.length ? (
                    taskItems.map((task) => (
                      <TableRow data-testid="workflow-task-row" key={task.id}>
                        <TableCell>
                          <div className="font-medium text-zinc-900">{task.stepName}</div>
                          <div className="text-xs text-zinc-500">{task.id}</div>
                        </TableCell>
                        <TableCell>
                          <div className="font-medium text-zinc-900">
                            {entityLabel(task.workflowInstance?.entityType)}
                          </div>
                          <div className="font-mono text-xs text-zinc-500">
                            {task.workflowInstance?.entityId ?? "-"}
                          </div>
                        </TableCell>
                        <TableCell><StatusBadge status={task.status} /></TableCell>
                        <TableCell>{new Date(task.createdAt).toLocaleString()}</TableCell>
                        <TableCell>
                          <div className="flex flex-wrap gap-2">
                            {status === "pending" && (task.allowedActions ?? []).includes("approve") ? (
                              <Button
                                size="sm"
                                type="button"
                                data-testid={TEST_IDS.workflow.quickApprove}
                                disabled={approveMutation.isPending && approveMutation.variables === task.id}
                                onClick={() => approveMutation.mutate(task.id)}
                              >
                                {approveMutation.isPending && approveMutation.variables === task.id ? "通过中..." : "通过"}
                              </Button>
                            ) : null}
                            <Button
                              asChild
                              size="sm"
                              variant="secondary"
                              data-testid={TEST_IDS.workflow.detailLink}
                            >
                              <Link to={`/workflow/tasks/${task.id}`}>详情</Link>
                            </Button>
                          </div>
                        </TableCell>
                      </TableRow>
                    ))
                  ) : (
                    <TableRow>
                      <TableCell className="py-3 text-zinc-500" colSpan={5}>
                        暂无数据
                      </TableCell>
                    </TableRow>
                  )}
                </TableBody>
              </Table>
            </div>
          </>
        ) : null}

        <Pagination
          page={page}
          totalPages={totalPages}
          onPageChange={(p) => setSearchParams({ status, page: String(p) })}
          testIdPrefix="workflow-tasks"
        />
      </div>
    </div>
  );
}