"use client";

import { useRef, useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { ArrowLeft, Loader2, Save } from "lucide-react";
import {
  apiAdminCreateAnnouncement,
  apiAdminUpdateAnnouncement,
  type Announcement,
  type AnnouncementColor,
  type AnnouncementInput,
} from "@/lib/api";
import { toast } from "@/lib/toast";
import MarkdownEditor from "@/components/MarkdownEditor";
import { AdminSegmented, AdminSwitch } from "@/components/admin";
import { ANNOUNCEMENT_COLORS } from "./announcementColors";

type PublishKey = "published" | "draft";

type FormState = {
  title: string;
  content: string;
  tag: string;
  tag_color: AnnouncementColor;
  published: boolean;
  pinned: boolean;
};

function toForm(a?: Announcement | null): FormState {
  return {
    title: a?.title ?? "",
    content: a?.content ?? "",
    tag: a?.tag ?? "公告",
    tag_color: a?.tag_color ?? "blue",
    published: a?.published ?? true,
    pinned: a?.pinned ?? false,
  };
}

export default function AnnouncementComposeClient({
  mode,
  initial,
}: {
  mode: "create" | "edit";
  initial?: Announcement | null;
}) {
  const router = useRouter();
  const [form, setForm] = useState<FormState>(() => toForm(initial));
  const formRef = useRef(form);
  const [saving, setSaving] = useState(false);
  const isEdit = mode === "edit" && initial != null;

  const patchForm = (patch: Partial<FormState> | ((prev: FormState) => FormState)) => {
    setForm((prev) => {
      const next = typeof patch === "function" ? patch(prev) : { ...prev, ...patch };
      formRef.current = next;
      return next;
    });
  };

  async function save() {
    if (saving) return;
    const current = formRef.current;
    const payload: AnnouncementInput = {
      title: current.title.trim(),
      content: current.content.trim(),
      tag: current.tag.trim() || "公告",
      tag_color: current.tag_color,
      published: current.published,
      pinned: current.pinned,
    };
    if (!payload.title || !payload.content) {
      toast("标题和内容不能为空");
      return;
    }
    setSaving(true);
    try {
      if (isEdit) {
        await apiAdminUpdateAnnouncement(initial.id, payload);
        toast("公告已更新", "ok");
      } else {
        await apiAdminCreateAnnouncement(payload);
        toast(payload.published ? "公告已发布" : "草稿已保存", "ok");
      }
      router.push("/admin/announcements");
      router.refresh();
    } catch (e) {
      toast(e instanceof Error ? e.message : "保存失败");
    } finally {
      setSaving(false);
    }
  }

  return (
    <div className="j13-compose-page w-full">
      <div className="j13-compose-stage">
        <header className="j13-compose-toolbar">
          <h1 className="j13-compose-toolbar-title">
            {isEdit ? "编辑公告" : "新建公告"}
          </h1>
          <div className="j13-compose-toolbar-actions">
            <Link href="/admin/announcements" className="btn btn-line btn-sm">
              <ArrowLeft size={14} /> 返回列表
            </Link>
            <button
              type="button"
              className="btn btn-primary btn-sm min-w-[4.5rem]"
              disabled={saving}
              onClick={() => void save()}
            >
              {saving ? <Loader2 size={14} className="animate-spin" /> : <Save size={14} />}
              保存
            </button>
          </div>
        </header>

        <div className="j13-compose-body">
          <section className="j13-compose-section" aria-label="发布设置">
            <h2 className="j13-compose-section-title">发布设置</h2>
            <div className="j13-compose-typepanel space-y-4">
              <div>
                <label className="field-label" htmlFor="anno-tag">
                  标签
                </label>
                <input
                  id="anno-tag"
                  className="j13-compose-field w-full max-w-[12rem]"
                  maxLength={32}
                  value={form.tag}
                  onChange={(e) => patchForm({ tag: e.target.value })}
                  placeholder="公告"
                />
              </div>

              <div>
                <p className="field-label">标签颜色</p>
                <div className="flex items-center gap-2 flex-wrap">
                  {ANNOUNCEMENT_COLORS.map((c) => (
                    <button
                      key={c.value}
                      type="button"
                      data-tip={c.label}
                      aria-label={c.label}
                      aria-pressed={form.tag_color === c.value}
                      className={`j13-anno-dot is-${c.value}`}
                      onClick={() => patchForm({ tag_color: c.value })}
                    />
                  ))}
                </div>
              </div>

              <div>
                <p className="field-label">发布状态</p>
                <AdminSegmented<PublishKey>
                  role="group"
                  ariaLabel="发布状态"
                  value={form.published ? "published" : "draft"}
                  onChange={(key) => patchForm({ published: key === "published" })}
                  options={[
                    { key: "published", label: "立即发布" },
                    { key: "draft", label: "存为草稿" },
                  ]}
                />
              </div>

              <div className="flex items-center justify-between gap-3 flex-wrap">
                <div>
                  <p className="text-[14px] font-medium" style={{ color: "var(--ink)" }}>
                    置顶公告
                  </p>
                  <p className="meta text-[12px] mt-0.5">置顶后优先显示在首页右栏</p>
                </div>
                <AdminSwitch
                  checked={form.pinned}
                  onChange={() => patchForm((f) => ({ ...f, pinned: !f.pinned }))}
                  label="置顶公告"
                />
              </div>
            </div>
          </section>

          <section className="j13-compose-section j13-compose-section-writing" aria-label="标题与正文">
            <div className="flex items-center justify-between gap-2 mb-3">
              <h2 className="j13-compose-section-title !mb-0">标题与正文</h2>
            </div>
            <input
              className="j13-compose-title"
              maxLength={200}
              value={form.title}
              onChange={(e) => patchForm({ title: e.target.value })}
              placeholder="请输入公告标题"
              aria-label="公告标题"
            />
            <div className="j13-compose-canvas">
              <MarkdownEditor
                value={form.content}
                onChange={(content) => patchForm({ content })}
                allowHide
                allowReplyHide={false}
                placeholder="请输入公告正文，支持 Markdown…"
                rows={18}
                onSubmitShortcut={() => void save()}
              />
            </div>
          </section>
        </div>

        <div className="j13-compose-actions">
          <div className="j13-compose-actions-end">
            <Link href="/admin/announcements" className="btn btn-line">
              取消
            </Link>
            <button
              type="button"
              className="btn btn-primary"
              disabled={saving}
              onClick={() => void save()}
            >
              {saving ? (
                <>
                  <Loader2 size={15} className="animate-spin" /> 保存中…
                </>
              ) : (
                <>
                  <Save size={15} /> {isEdit ? "保存修改" : form.published ? "发布公告" : "保存草稿"}
                </>
              )}
            </button>
          </div>
        </div>
      </div>
    </div>
  );
}