"use client";

import { useCallback, useEffect, useState } from "react";
import { useTranslations } from "next-intl";
import { X, Calendar, Trash2, Plus } from "lucide-react";
import { Button } from "@/shared/components/ui/button";
import { FocusTrap } from "@/shared/components/a11y/focus-trap";
import { toast } from "sonner";
import {
  getLessonPlanSchedulesAction,
  createLessonPlanScheduleAction,
  deleteLessonPlanScheduleAction,
} from "../actions-schedules";
import type { LessonPlanScheduleRecord } from "../data-access-schedules";

interface ScheduleOption {
  id: string;
  name: string;
}

interface Props {
  planId: string;
  classes: ScheduleOption[];
  onClose: () => void;
  onScheduled?: () => void;
}

/**
 * V5-7：课时绑定对话框
 *
 * 功能：
 * 1. 列出课案已绑定的课时
 * 2. 添加新课时绑定（选班级 + 日期 + 节次 + 时长）
 * 3. 删除课时绑定
 *
 * 不通过 service 注入，直接调用 actions（因为是新增功能，且仅教师使用）。
 */
export function ScheduleDialog({ planId, classes, onClose, onScheduled }: Props) {
  const t = useTranslations("lessonPreparation");
  const [schedules, setSchedules] = useState<LessonPlanScheduleRecord[]>([]);
  const [loading, setLoading] = useState(true);
  const [submitting, setSubmitting] = useState(false);

  // 表单状态
  const [classId, setClassId] = useState("");
  const [scheduledDate, setScheduledDate] = useState("");
  const [period, setPeriod] = useState(1);
  const [durationMin, setDurationMin] = useState(40);
  const [error, setError] = useState<string | null>(null);

  const loadSchedules = useCallback(async () => {
    setLoading(true);
    try {
      const res = await getLessonPlanSchedulesAction(planId);
      if (res.success && res.data) {
        setSchedules(res.data.items);
      }
    } catch (e) {
      console.error("[ScheduleDialog] load failed", e);
      toast.error(t("error.getOne"));
    } finally {
      setLoading(false);
    }
  }, [planId, t]);

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

  useEffect(() => {
    function handleEsc(e: KeyboardEvent) {
      if (e.key === "Escape") onClose();
    }
    document.addEventListener("keydown", handleEsc);
    return () => document.removeEventListener("keydown", handleEsc);
  }, [onClose]);

  async function handleAdd() {
    if (!classId) {
      setError(t("schedule.selectClass"));
      return;
    }
    if (!scheduledDate) {
      setError(t("schedule.selectDate"));
      return;
    }
    setSubmitting(true);
    setError(null);
    try {
      const res = await createLessonPlanScheduleAction({
        planId,
        classId,
        scheduledDate,
        period,
        durationMin,
      });
      if (res.success) {
        toast.success(t("schedule.addSuccess"));
        void loadSchedules();
        onScheduled?.();
      } else {
        setError(res.message ?? t("error.save"));
      }
    } catch (e) {
      console.error("[ScheduleDialog] add failed", e);
      setError(t("error.save"));
    } finally {
      setSubmitting(false);
    }
  }

  async function handleDelete(id: string) {
    try {
      const res = await deleteLessonPlanScheduleAction(id);
      if (res.success) {
        toast.success(t("schedule.deleteSuccess"));
        void loadSchedules();
        onScheduled?.();
      } else {
        toast.error(res.message ?? t("error.save"));
      }
    } catch (e) {
      console.error("[ScheduleDialog] delete failed", e);
      toast.error(t("error.save"));
    }
  }

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/30">
      {/* arbitrary-value: dialog fixed width */}
      <div
        role="dialog"
        aria-modal="true"
        aria-label={t("schedule.title")}
        className="bg-surface rounded-lg shadow-xl w-[560px] max-h-[80vh] flex flex-col"
      >
        <FocusTrap className="contents">
          <div className="flex justify-between items-center p-4 border-b">
            <h3 className="font-title-md flex items-center gap-2">
              <Calendar className="w-4 h-4" aria-hidden="true" />
              {t("schedule.title")}
            </h3>
            <button onClick={onClose} aria-label={t("action.close")}>
              <X className="w-4 h-4" aria-hidden="true" />
            </button>
          </div>

          <div className="p-4 overflow-y-auto flex-1 space-y-4">
            {/* 已绑定课时列表 */}
            <div>
              <label className="text-sm font-medium block mb-2">
                {t("schedule.boundList")}
              </label>
              {loading ? (
                <p className="text-sm text-on-surface-variant text-center py-4">
                  {t("version.loading")}
                </p>
              ) : schedules.length === 0 ? (
                <p className="text-sm text-on-surface-variant text-center py-4">
                  {t("schedule.empty")}
                </p>
              ) : (
                <ul className="space-y-1">
                  {schedules.map((s) => (
                    <li
                      key={s.id}
                      className="flex items-center gap-2 border rounded p-2 text-sm"
                    >
                      <span className="flex-1">
                        <strong>{s.className}</strong>
                        <span className="text-on-surface-variant ml-2">
                          {s.scheduledDate} · {t("schedule.period", { n: s.period })} · {t("schedule.duration", { n: s.durationMin })}
                        </span>
                      </span>
                      <button
                        className="text-error hover:bg-error/10 p-1 rounded"
                        onClick={() => void handleDelete(s.id)}
                        aria-label={t("schedule.delete")}
                      >
                        <Trash2 className="w-3 h-3" aria-hidden="true" />
                      </button>
                    </li>
                  ))}
                </ul>
              )}
            </div>

            {/* 添加新绑定 */}
            <div className="border-t pt-3 space-y-2">
              <label className="text-sm font-medium block">
                {t("schedule.addNew")}
              </label>
              <div className="grid grid-cols-2 gap-2">
                <div>
                  <label className="text-xs text-on-surface-variant">
                    {t("schedule.classLabel")}
                  </label>
                  <select
                    value={classId}
                    onChange={(e) => setClassId(e.target.value)}
                    className="w-full border rounded px-2 py-1 mt-0.5 text-sm"
                  >
                    <option value="">{t("schedule.selectClass")}</option>
                    {classes.map((c) => (
                      <option key={c.id} value={c.id}>
                        {c.name}
                      </option>
                    ))}
                  </select>
                </div>
                <div>
                  <label className="text-xs text-on-surface-variant">
                    {t("schedule.dateLabel")}
                  </label>
                  <input
                    type="date"
                    value={scheduledDate}
                    onChange={(e) => setScheduledDate(e.target.value)}
                    className="w-full border rounded px-2 py-1 mt-0.5 text-sm"
                  />
                </div>
                <div>
                  <label className="text-xs text-on-surface-variant">
                    {t("schedule.periodLabel")}
                  </label>
                  <select
                    value={period}
                    onChange={(e) => setPeriod(Number(e.target.value))}
                    className="w-full border rounded px-2 py-1 mt-0.5 text-sm"
                  >
                    {Array.from({ length: 12 }, (_, i) => i + 1).map((n) => (
                      <option key={n} value={n}>
                        {t("schedule.period", { n })}
                      </option>
                    ))}
                  </select>
                </div>
                <div>
                  <label className="text-xs text-on-surface-variant">
                    {t("schedule.durationLabel")}
                  </label>
                  <input
                    type="number"
                    min={5}
                    max={180}
                    value={durationMin}
                    onChange={(e) => setDurationMin(Number(e.target.value))}
                    className="w-full border rounded px-2 py-1 mt-0.5 text-sm"
                  />
                </div>
              </div>
              {error && <p className="text-error text-sm">{error}</p>}
              <Button
                size="sm"
                onClick={handleAdd}
                disabled={submitting}
                className="w-full"
              >
                <Plus className="w-4 h-4 mr-1" />
                {t("schedule.add")}
              </Button>
            </div>
          </div>

          <div className="p-4 border-t flex justify-end">
            <Button variant="outline" onClick={onClose}>
              {t("action.close")}
            </Button>
          </div>
        </FocusTrap>
      </div>
    </div>
  );
}