// 站点文案单例访问层（cms 车道 A）：后台改 content/site/*.yaml → 页面读此处
// 兜底纪律：文件缺 → 用默认文案；字段缺/空串 → 用默认文案（构建绝不因文案炸）
// 注意：整文件被删会先在 file() loader 层报错（误删级），此处守的是字段级缺失/空值
import { getEntry } from 'astro:content';
import type { ImageMetadata } from 'astro';
import type { Locale } from './locale';

export interface Bi {
  zh: string;
  en: string;
}

/** 与仓库现状逐字一致的默认文案：yaml 全空时产物不变（零回归可视验证锚点） */
export const SITE_DEFAULTS = {
  homeTagline: {
    zh: '写作者 · 读者 · 快门按压者，拥抱开源。',
    en: 'Writer · Reader · Shutter-presser — embracing open source.',
  },
  aboutIntro: {
    zh: '写作者 · 读者 · 快门按压者，拥抱开源。这里是我三条轨道的公开工作台：读过的书留下评注，写过的代码进项目墙，按下的快门收入图库。',
    en: 'Writer · Reader · Shutter-presser, embracing open source. This is the public workbench of my three tracks — books that left notes, code that reaches the project wall, and shutters I pressed.',
  },
  opensource: {
    blurb: { zh: '本站本身即开源：', en: 'This site is itself open source: ' },
    blurbAfter: {
      zh: '—— Astro SSG、双写作流、构建发布全链皆在仓中。以下是我在自托管 gitea 与 GitHub 上的全部公开仓库，以及最近一年的贡献活动。',
      en: '— the Astro SSG, dual-writing workflow, and the full build & deploy pipeline live in the repo. Below are all my public repositories on self-hosted gitea and GitHub, plus contributions from the past year.',
    },
    repoUrl: 'https://git.wait4x.online/wait4x/blog',
    repoLabel: 'git.wait4x.online/wait4x/blog',
    pinned: ['blog'] as string[],
  },
} as const;

/** 字段级回落：yaml 值非空才采信（空白串视为空） */
const pick = (value: string | undefined, fallback: string): string =>
  value && value.trim() ? value : fallback;

const pickBi = (value: { zh?: string; en?: string } | undefined, fallback: Bi, locale: Locale): string =>
  pick(value?.[locale], fallback[locale]);

/** 主页 tagline（zh/en） */
export async function homeTagline(locale: Locale): Promise<string> {
  const entry = await getEntry('siteHome', 'home');
  return pickBi(entry?.data.tagline, SITE_DEFAULTS.homeTagline, locale);
}

/** 关于页身份陈述段（zh/en） */
export async function aboutIntro(locale: Locale): Promise<string> {
  const entry = await getEntry('siteAbout', 'about');
  return pickBi(entry?.data.intro, SITE_DEFAULTS.aboutIntro, locale);
}

export interface OpenSourceCopy {
  blurb: string;
  blurbAfter: string;
  repoUrl: string;
  repoLabel: string;
  /** 置顶仓短名（顺序即顺序）；yaml 空数组/缺省 → 默认 ['blog'] */
  pinned: string[];
}

/** 开源页叙述 + 置顶名单 */
export async function openSourceCopy(locale: Locale): Promise<OpenSourceCopy> {
  const entry = await getEntry('siteOpenSource', 'opensource');
  const d = SITE_DEFAULTS.opensource;
  const pinned = entry?.data.pinned?.filter((n) => n.trim()) ?? [];
  return {
    blurb: pickBi(entry?.data.blurb, d.blurb, locale),
    blurbAfter: pickBi(entry?.data.blurb_after, d.blurbAfter, locale),
    repoUrl: pick(entry?.data.repo_url, d.repoUrl),
    repoLabel: pick(entry?.data.repo_label, d.repoLabel),
    pinned: pinned.length ? pinned : [...d.pinned],
  };
}

// ---- 车道「后台能力扩展」：社交链接 / 头像 / 站点图标 / markdown 正文 ----

export interface SocialLink {
  label: string;
  url: string;
  /** 内置图标键：github / rss / email / bilibili / x；未知或空 → 纯文字按钮 */
  icon?: string;
}

export const DEFAULT_SOCIALS: SocialLink[] = [
  { label: 'GitHub', url: 'https://github.com/wait4xx', icon: 'github' },
  { label: 'RSS', url: '/rss.xml', icon: 'rss' },
  { label: '邮件', url: 'mailto:admin@wait4x.online', icon: 'email' },
];

/** 社交链接（顺序即展示顺序）；yaml 空/缺省 → 默认三条（与历史硬编码一致） */
export async function homeSocials(): Promise<SocialLink[]> {
  const entry = await getEntry('siteHome', 'home');
  const list = entry?.data.socials?.filter((s) => s.label?.trim() && s.url?.trim()) ?? [];
  return list.length ? list : DEFAULT_SOCIALS;
}

/** 头像（Astro 图片管线的 ImageMetadata）；未配置 → null，调用方回退渐变占位 */
export async function homeAvatar(): Promise<ImageMetadata | null> {
  const entry = await getEntry('siteHome', 'home');
  return entry?.data.avatar ?? null;
}

/** 站点图标路径：yaml 值非空即采信，否则 /favicon.svg；值不带前导 / 时自动补 */
export async function siteFavicon(): Promise<{ href: string; type: string }> {
  const entry = await getEntry('siteHome', 'home');
  const raw = pick(entry?.data.favicon, '/favicon.svg');
  const href = raw.startsWith('/') || raw.startsWith('http') ? raw : `/${raw}`;
  const type = href.endsWith('.svg')
    ? 'image/svg+xml'
    : href.endsWith('.ico')
      ? 'image/x-icon'
      : href.endsWith('.png')
        ? 'image/png'
        : '';
  return { href, type };
}

/** markdown 字符串 → HTML（进程内单例处理器，构建期复用） */
let mdProcessor: Promise<import('@astrojs/markdown-remark').MarkdownProcessor> | null = null;
export async function renderMarkdown(md: string): Promise<string> {
  const { createMarkdownProcessor } = await import('@astrojs/markdown-remark');
  // 与 astro.config.mjs 的文章管线同序：raw → 内容净化（标签/属性/协议）→
  // class 白名单 → 链接卡片。此前这里 createMarkdownProcessor() 无参，页面
  // 文案的 raw HTML 直通 set:html（方案 10 §7.1 实锤漏洞：script/style/on* 不剥）。
  mdProcessor ??= (async () => {
    const [{ default: rehypeRaw }, { default: rehypeContentSanitize }, { default: rehypeClassWhitelist }, { default: rehypeLinkCards }] =
      await Promise.all([
        import('rehype-raw'),
        import('./rehype-content-sanitize'),
        import('./rehype-class-whitelist'),
        import('./rehype-link-cards'),
      ]);
    return createMarkdownProcessor({
      rehypePlugins: [rehypeRaw, rehypeContentSanitize, rehypeClassWhitelist, rehypeLinkCards],
    });
  })();
  const { code } = await (await mdProcessor).render(md);
  return code;
}

/** 关于页正文（markdown，未渲染）；空 → 默认文案 */
export async function aboutIntroMarkdown(locale: Locale): Promise<string> {
  const entry = await getEntry('siteAbout', 'about');
  return pickBi(entry?.data.intro, SITE_DEFAULTS.aboutIntro, locale);
}

// ---- 车道「首页+开源页后台扩展」：首页四项可配 + 项目墙可见性 + README 开篇 ----

export interface HomeSections {
  tracks: boolean;
  photos: boolean;
  heatmap: boolean;
  projects: boolean;
}

export interface HomeConfig {
  /** 副标题 markdown 原文；空串 = 不渲染 */
  subtitle: string;
  /** 最新影像张数：0 = 隐藏区块 */
  latestPhotos: number;
  /** 每轨文章条数 */
  perTrackLimit: number;
  sections: HomeSections;
}

const clampInt = (value: number | undefined, min: number, max: number, fallback: number): number => {
  if (typeof value !== 'number' || Number.isNaN(value)) return fallback;
  return Math.min(max, Math.max(min, Math.trunc(value)));
};

/** 首页可配项（字段级回落：零配置 = 现有形态；越界值夹取而非报错） */
export async function homeConfig(locale: Locale): Promise<HomeConfig> {
  const entry = await getEntry('siteHome', 'home');
  const d = entry?.data;
  return {
    subtitle: pickBi(d?.subtitle, { zh: '', en: '' }, locale),
    latestPhotos: clampInt(d?.latestPhotos, 0, 6, 4),
    perTrackLimit: clampInt(d?.perTrackLimit, 4, 8, 6),
    sections: {
      tracks: d?.sections?.tracks ?? true,
      photos: d?.sections?.photos ?? true,
      heatmap: d?.sections?.heatmap ?? true,
      projects: d?.sections?.projects ?? true,
    },
  };
}

export type ProjectMode = 'all' | 'only' | 'exclude';
export type ProjectSort = 'pinned-first' | 'stars' | 'updated';
export type ProjectSource = 'both' | 'github' | 'gitea';

export interface OpenSourceOptions {
  mode: ProjectMode;
  include: string[];
  exclude: string[];
  sort: ProjectSort;
  perSource: ProjectSource;
  introFrom: 'off' | 'github-readme';
}

/** 开源页项目墙选项（缺省 = 现状：all / pinned-first / 双源） */
export async function openSourceOptions(): Promise<OpenSourceOptions> {
  const entry = await getEntry('siteOpenSource', 'opensource');
  const d = entry?.data;
  return {
    mode: d?.mode ?? 'all',
    include: (d?.include ?? []).filter((n) => n.trim()),
    exclude: (d?.exclude ?? []).filter((n) => n.trim()),
    sort: d?.sort ?? 'pinned-first',
    perSource: d?.perSource ?? 'both',
    introFrom: d?.intro_from ?? 'off',
  };
}

/** GitHub profile README 缓存：取不到网就吃缓存，都无则调用方回落 yaml blurb */
const README_CACHE = 'content/.github-readme.md';
const PROFILE_REPO = 'wait4xx/wait4xx';

/**
 * 构建期取 profile 仓 README（Accept: raw），成功后回写 content/.github-readme.md（入仓缓存）
 * @returns README markdown；网络/权限/仓无 README 时回落缓存，仍无 → null
 */
export async function githubReadmeMarkdown(): Promise<string | null> {
  const { readFileSync, writeFileSync, existsSync } = await import('node:fs');
  const { join } = await import('node:path');
  const cachePath = join(process.cwd(), README_CACHE);
  const readCache = (): string | null => {
    try {
      return existsSync(cachePath) ? readFileSync(cachePath, 'utf8') : null;
    } catch {
      return null;
    }
  };

  let token: string | null = null;
  try {
    token = readFileSync(join(process.env.HOME ?? '', 'docker_apps/blog/github-token.txt'), 'utf8').trim() || null;
  } catch {
    token = null;
  }
  if (!token) {
    console.warn('[opensource] github-readme：token 缺位，用缓存/回落 yaml blurb');
    return readCache();
  }

  try {
    const res = await fetch(`https://api.github.com/repos/${PROFILE_REPO}/readme`, {
      headers: { Authorization: `Bearer ${token}`, Accept: 'application/vnd.github.raw', 'User-Agent': 'wait4x-blog-build' },
    });
    if (!res.ok) {
      console.warn(`[opensource] github-readme：${PROFILE_REPO} 取 README 失败 HTTP ${res.status}，用缓存/回落`);
      return readCache();
    }
    const md = (await res.text()).trim();
    if (!md) {
      console.warn('[opensource] github-readme：README 为空，用缓存/回落');
      return readCache();
    }
    const cached = readCache();
    if (cached !== md) {
      writeFileSync(cachePath, `${md}\n`, 'utf8');
      console.log(`[opensource] github-readme：已刷新缓存 ${README_CACHE}（${md.length} 字符）`);
    }
    return md;
  } catch (err) {
    console.warn(`[opensource] github-readme：请求异常（${(err as Error).message}），用缓存/回落`);
    return readCache();
  }
}