/**
 * 设置页的表单化：schema 驱动。
 *
 * 后端是唯一事实源 —— schema、取值、合并、序列化都在这里做，
 * 前端只负责把 schema 画成表单、把用户改的值原样传回来，完全不碰 YAML。
 *
 * 数据流：
 *   GET /settings/form  → parseSimpleYaml(config_yaml 或模板) → { schema, values, extra }
 *   PUT /settings/form  → mergeForm(values, extra) → toSimpleYaml → 走 settingApply 的
 *                         全部回填逻辑（frontend_conf / captcha / human_check /
 *                         moderator / ip_region / site_default），保证行为和手改 YAML 一致。
 *
 * ★ `extra` 是 schema 之外的键（admin_users、admin_notify、auth……），
 *   前端不渲染但会原样传回 —— 这样表单化永远不会静默丢配置。
 */

export interface FieldDef {
  /** 配置路径，如 'frontend.pagination.pageSize' */
  path: string;
  label: string;
  type?: 'text' | 'bool' | 'number' | 'select';
  options?: { v: string; t: string }[];
  /** 解析结果里没有这个键时的表单默认值 */
  def?: unknown;
  /** 生成 YAML 时写在该键上方的注释 */
  desc?: string;
  /** 表单里的辅助说明 */
  hint?: string;
}

export interface GroupDef {
  title: string;
  desc?: string;
  fields: FieldDef[];
}

export const SETTINGS_FORM: GroupDef[] = [
  {
    title: '站点身份',
    desc: '评论归属与站点身份',
    fields: [
      { path: 'site_default', label: '默认站点名', type: 'text', desc: '默认站点名', hint: '没有匹配到 page 的 site 时用它' },
    ],
  },
  {
    title: '审核与风控',
    desc: '什么评论需要人来看一眼',
    fields: [
      { path: 'moderator.pending_default', label: '新评论默认待审', type: 'bool', def: false, desc: '默认待审', hint: '开了之后所有新评论都要后台审核才显示' },
      { path: 'human_check.enabled', label: '人机验证（一键验证）', type: 'bool', def: false, desc: 'human_check 开关（存 KV，评论提交时读）', hint: '读者无感，可疑请求才出验证' },
      { path: 'captcha.enabled', label: '验证码', type: 'bool', def: false, desc: '启用验证码' },
      { path: 'ip_region.enabled', label: '显示 IP 归属地', type: 'bool', def: false, desc: '启用 IP 属地展示', hint: '如 CN / US' },
    ],
  },
  {
    title: '评论列表',
    desc: '前台评论区的排列与分页',
    fields: [
      { path: 'frontend.pagination.pageSize', label: '每页评论数', type: 'number', def: 20, desc: '每页评论数' },
      { path: 'frontend.countOfCommentsOnPageInit', label: '初始加载条数', type: 'number', def: 20 },
      { path: 'frontend.nestMax', label: '最大嵌套层数', type: 'number', def: 2, desc: '最大嵌套层数' },
      {
        path: 'frontend.nestSort', label: '嵌套排序', type: 'select', def: 'DATE_ASC', desc: '嵌套评论排序规则',
        options: [
          { v: 'DATE_ASC', t: '最早优先' },
          { v: 'DATE_DESC', t: '最新优先' },
          { v: 'VOTE_UP_DESC', t: '点赞优先' },
        ],
      },
      {
        path: 'frontend.darkMode', label: '夜间模式', type: 'select', def: 'inherit', desc: '夜间模式',
        options: [
          { v: 'inherit', t: '跟随页面' },
          { v: 'auto', t: '自动' },
        ],
      },
      { path: 'frontend.heightLimit.content', label: '评论内容限高 (px)', type: 'number', def: 300 },
      { path: 'frontend.heightLimit.children', label: '子评论区限高 (px)', type: 'number', def: 400 },
    ],
  },
  {
    title: '评论框',
    desc: '输入区与按钮的文字、开关',
    fields: [
      { path: 'frontend.placeholder', label: '占位文字', type: 'text', desc: '评论框占位文字' },
      { path: 'frontend.noComment', label: '无评论提示文字', type: 'text', desc: '无评论显示文字' },
      { path: 'frontend.sendBtn', label: '发送按钮文字', type: 'text', desc: '发送按钮文字' },
      { path: 'frontend.emoticons', label: '表情包地址', type: 'text', desc: '表情包', hint: 'JSON 配置地址，留空关闭' },
      { path: 'frontend.editorTravel', label: '评论框穿梭', type: 'bool', def: true, desc: '评论框穿梭', hint: '点「回复」时输入框跟过去' },
      { path: 'frontend.preview', label: '实时预览', type: 'bool', def: true, desc: '编辑器实时预览功能' },
      { path: 'frontend.vote', label: '投票按钮（赞）', type: 'bool', def: true, desc: '投票按钮' },
      { path: 'frontend.voteDown', label: '反对按钮（踩）', type: 'bool', def: false, desc: '反对按钮' },
      { path: 'frontend.listSort', label: '评论排序切换', type: 'bool', def: true, desc: '评论排序功能' },
      { path: 'frontend.uaBadge', label: 'UA 徽标', type: 'bool', def: false, desc: '用户 UA 徽标', hint: '显示读者的操作系统 / 浏览器' },
    ],
  },
  {
    title: '头像与其他',
    fields: [
      { path: 'frontend.gravatar.mirror', label: '头像源地址', type: 'text', desc: '头像 Gravatar API 地址' },
      { path: 'frontend.gravatar.params', label: '头像参数', type: 'text', desc: '头像 API 参数', hint: '如 sha256=1&d=mp&s=240' },
      { path: 'frontend.imgLazyLoad', label: '图片懒加载', type: 'select', def: 'false', desc: '图片懒加载',
        options: [
          { v: 'false', t: '关闭' },
          { v: 'native', t: 'native' },
          { v: 'data-src', t: 'data-src' },
        ] },
      { path: 'frontend.reqTimeout', label: '请求超时 (ms)', type: 'number', def: 15000, desc: '请求超时（毫秒）' },
      { path: 'frontend.versionCheck', label: '版本检测', type: 'bool', def: true, desc: '版本检测' },
    ],
  },
];

// ------------------------------------------------------------------ 工具

function getByPath(obj: unknown, path: string): unknown {
  let cur: unknown = obj;
  for (const k of path.split('.')) {
    if (cur === null || typeof cur !== 'object' || Array.isArray(cur)) return undefined;
    cur = (cur as Record<string, unknown>)[k];
  }
  return cur;
}

function setByPath(obj: Record<string, unknown>, path: string, value: unknown): void {
  const parts = path.split('.');
  let cur: Record<string, unknown> = obj;
  for (let i = 0; i < parts.length - 1; i++) {
    const k = parts[i];
    if (cur[k] === null || typeof cur[k] !== 'object' || Array.isArray(cur[k])) cur[k] = {};
    cur = cur[k] as Record<string, unknown>;
  }
  cur[parts[parts.length - 1]] = value;
}

function deleteByPath(obj: Record<string, unknown>, path: string): void {
  const parts = path.split('.');
  let cur: unknown = obj;
  for (let i = 0; i < parts.length - 1; i++) {
    if (cur === null || typeof cur !== 'object' || Array.isArray(cur)) return;
    cur = (cur as Record<string, unknown>)[parts[i]];
  }
  if (cur !== null && typeof cur === 'object' && !Array.isArray(cur)) {
    delete (cur as Record<string, unknown>)[parts[parts.length - 1]];
  }
}

function defaultFor(f: FieldDef): unknown {
  if (f.def !== undefined) return f.def;
  if (f.type === 'bool') return false;
  if (f.type === 'number') return '';
  return '';
}

/** 把解析好的配置拆成「表单值」+「schema 外的剩余键」 */
export function extractForm(parsed: Record<string, unknown>): {
  values: Record<string, unknown>;
  extra: Record<string, unknown>;
} {
  const extra: Record<string, unknown> = JSON.parse(JSON.stringify(parsed ?? {}));
  const values: Record<string, unknown> = {};
  for (const g of SETTINGS_FORM) {
    for (const f of g.fields) {
      const v = getByPath(extra, f.path);
      values[f.path] = v === undefined ? defaultFor(f) : v;
      deleteByPath(extra, f.path);
    }
  }
  return { values, extra };
}

/** 表单值 + 剩余键 → 完整配置对象（types 走一层宽松校正，避免写出非法 YAML） */
export function mergeForm(
  values: Record<string, unknown>,
  extra: Record<string, unknown>,
): Record<string, unknown> {
  const out: Record<string, unknown> = JSON.parse(JSON.stringify(extra ?? {}));
  for (const g of SETTINGS_FORM) {
    for (const f of g.fields) {
      const raw = values ? values[f.path] : undefined;
      if (raw === undefined) continue;
      if (f.type === 'bool') {
        setByPath(out, f.path, raw === true || raw === 'true');
      } else if (f.type === 'number') {
        const n = typeof raw === 'number' ? raw : Number(String(raw).trim());
        setByPath(out, f.path, String(raw).trim() === '' ? (typeof f.def === 'number' ? f.def : 0) : Number.isFinite(n) ? n : f.def ?? 0);
      } else {
        setByPath(out, f.path, String(raw));
      }
    }
  }
  return out;
}

/** schema 里声明的注释（生成 YAML 时带回去，配置文件不至于变成天书） */
export function formComments(): Map<string, string> {
  const m = new Map<string, string>();
  for (const g of SETTINGS_FORM) {
    for (const f of g.fields) {
      if (f.desc) m.set(f.path, f.desc);
    }
  }
  return m;
}