import { readFileSync } from 'node:fs';
import { join } from 'node:path';
// 项目墙数据（极客层 P0）：构建时双源拉取 + 仓内缓存兜底
// 双源 = 自家 gitea（数据自控叙事）+ GitHub（社区 star 真值）；置顶清单人工维护
export interface RepoCard {
  source: 'gitea' | 'github';
  name: string;
  description: string;
  language: string | null;
  stars: number;
  url: string;
  updatedAt: string;
}

interface RawRepo {
  full_name?: string;
  name?: string;
  description?: string | null;
  language?: string | null;
  stars_count?: number;
  stargazers_count?: number;
  html_url?: string;
  updated_at?: string;
}

export const GITEA_API = 'https://git.wait4x.online/api/v1/users/wait4x/repos?limit=50';
export const GITHUB_API = 'https://api.github.com/users/wait4xx/repos?per_page=100&sort=updated';

/** 默认置顶（仅在调用方未传 pinned 时生效）：现由 content/site/opensource.yaml 的 pinned 供数 */
export const PINNED_DEFAULT: string[] = ['blog'];

async function fetchJson(url: string): Promise<RawRepo[]> {
  const headers: Record<string, string> = { 'User-Agent': 'wait4x-blog-build' };
  // GitHub 无鉴权仅 60 次/小时（多次构建就耗尽）→ 有 token 就带上（5000/小时）
  if (url.includes('api.github.com')) {
    try {
      const token = readFileSync(join(process.env.HOME ?? '', 'docker_apps/blog/github-token.txt'), 'utf8').trim();
      if (token) headers.Authorization = `Bearer ${token}`;
    } catch {
      /* token 缺位则匿名（可能被限流，走兜底） */
    }
  }
  const res = await fetch(url, {
    headers: { ...headers, Accept: 'application/json' },
    signal: AbortSignal.timeout(10_000),
  });
  if (!res.ok) throw new Error(`${url} -> ${res.status}`);
  return (await res.json()) as RawRepo[];
}

function toCard(r: RawRepo, source: RepoCard['source']): RepoCard | null {
  const name = r.name ?? r.full_name?.split('/')[1];
  if (!name || !r.html_url) return null;
  return {
    source,
    name,
    description: r.description ?? '',
    language: r.language ?? null,
    stars: r.stars_count ?? r.stargazers_count ?? 0,
    url: r.html_url,
    updatedAt: r.updated_at ?? '',
  };
}

/**
 * 拉双源合并去重（同名优先 gitea 自托管叙事，star 取 GitHub 真值）。
 * 任一源失败不抛：置顶项回落仓内缓存 JSON（构建产物绝不被网络单点卡死）。
 */
export interface LoadProjectsOptions {
  /** 置顶仓短名（顺序即顺序），缺省 PINNED_DEFAULT */
  pinned?: string[];
  /** 可见性：all=全部 / only=仅 include / exclude=排除 exclude */
  mode?: 'all' | 'only' | 'exclude';
  include?: string[];
  exclude?: string[];
  /** 排序：pinned-first（默认）/ stars / updated */
  sort?: 'pinned-first' | 'stars' | 'updated';
  /** 来源过滤：both（默认）/ github / gitea */
  perSource?: 'both' | 'github' | 'gitea';
}

/**
 * 拉取双源并按选项过滤/排序（选项来自 content/site/opensource.yaml，缺省 = 现状行为）
 * @returns 未截断的完整列表：展示上限由调用方 slice（首页 6 / 开源页 99）
 */
export async function loadProjects(options: LoadProjectsOptions = {}): Promise<RepoCard[]> {
  const { pinned = PINNED_DEFAULT, mode = 'all', include = [], exclude = [], sort = 'pinned-first', perSource = 'both' } = options;
  const [gitea, github] = await Promise.allSettled([fetchJson(GITEA_API), fetchJson(GITHUB_API)]);
  // 单源失败不拦构建，但必须在日志里点名——否则“怪了，这个仓怎么没显示”要排查很久
  if (gitea.status === 'rejected') {
    console.warn(`[opensource] projects：gitea 源不可用（${(gitea.reason as Error).message}），仅用 GitHub 源`);
  }
  if (github.status === 'rejected') {
    console.warn(`[opensource] projects：GitHub 源不可用（${(github.reason as Error).message}），仅用 gitea 源`);
  }
  const byName = new Map<string, RepoCard>();

  for (const r of gitea.status === 'fulfilled' ? gitea.value : []) {
    const c = toCard(r, 'gitea');
    if (c) byName.set(c.name, c);
  }
  for (const r of github.status === 'fulfilled' ? github.value : []) {
    const c = toCard(r, 'github');
    if (!c) continue;
    const existing = byName.get(c.name);
    if (!existing) byName.set(c.name, c);
    else if (c.stars > existing.stars) existing.stars = c.stars; // 社区真值覆盖镜像计数
  }

  if (byName.size === 0) {
    console.warn('[opensource] projects：双源均无可用数据，改用仓内兜底 src/data/projects-fallback.json');
    const fb = (await import('../data/projects-fallback.json')).default as RepoCard[];
    const out = arrange(fb, pinned, mode, include, exclude, sort, perSource);
    warnMissedIncludes(out, fb, include, mode, perSource);
    return out;
  }
  const merged = [...byName.values()];
  const out = arrange(merged, pinned, mode, include, exclude, sort, perSource);
  warnMissedIncludes(out, merged, include, mode, perSource);
  return out;
}

/**
 * mode=only 时点名 include 里“写了却没显示”的仓名——避开设了一个看不见的黑洞。
 * 未命中分两类，日志措词区分：①双源结果里根本没有（拼写错 / 私有仓 / 该源刚失败）；
 * ②有，但被 perSource 过滤掉了（配置与仓来源不匹配）。
 */
function warnMissedIncludes(
  showing: RepoCard[],
  pool: RepoCard[],
  include: string[],
  mode: 'all' | 'only' | 'exclude',
  perSource: 'both' | 'github' | 'gitea',
): void {
  if (mode !== 'only' || include.length === 0) return;
  const shown = new Set(showing.map((r) => r.name));
  const available = new Map(pool.map((r) => [r.name, r.source]));
  for (const name of include) {
    if (shown.has(name)) continue;
    const src = available.get(name);
    console.warn(
      src
        ? `[opensource] projects：include 里的 「${name}」命中 ${src} 源，但被 perSource=${perSource} 过滤掉——改 perSource=both 或把它移出 include`
        : `[opensource] projects：include 里的 「${name}」在双源结果中没有命中（仓名拼写？私有仓？源刚失败？）——它不会出现在项目墙上`,
    );
  }
}

/** 来源过滤 + 可见性过滤 + 排序（不截断：上限交给调用方） */
function arrange(
  list: RepoCard[],
  pinned: string[],
  mode: 'all' | 'only' | 'exclude',
  include: string[],
  exclude: string[],
  sort: 'pinned-first' | 'stars' | 'updated',
  perSource: 'both' | 'github' | 'gitea',
): RepoCard[] {
  let out = perSource === 'both' ? list : list.filter((r) => r.source === perSource);
  if (mode === 'only') out = out.filter((r) => include.includes(r.name));
  else if (mode === 'exclude') out = out.filter((r) => !exclude.includes(r.name));

  if (sort === 'stars') return [...out].sort((a, b) => b.stars - a.stars);
  if (sort === 'updated') {
    return [...out].sort((a, b) => new Date(b.updatedAt).getTime() - new Date(a.updatedAt).getTime());
  }
  return [...out].sort((a, b) => {
    const pa = pinned.indexOf(a.name), pb = pinned.indexOf(b.name);
    if (pa !== -1 || pb !== -1) return (pa === -1 ? 99 : pa) - (pb === -1 ? 99 : pb);
    return b.stars - a.stars;
  });
}

/** GitHub 账号统计（followers / public repos）：token 缺位或请求失败一律返回 null（调用方隐藏数字） */
export interface GithubUserStats {
  followers: number;
  publicRepos: number;
}

export async function githubUserStats(
  login = 'wait4xx',
): Promise<GithubUserStats | null> {
  const { readFileSync } = await import('node:fs');
  const { join } = await import('node:path');
  let token: string | null = null;
  try {
    token = readFileSync(join(process.env.HOME ?? '', 'docker_apps/blog/github-token.txt'), 'utf8').trim() || null;
  } catch {
    token = null;
  }
  try {
    const res = await fetch(`https://api.github.com/users/${login}`, {
      headers: {
        ...(token ? { Authorization: `Bearer ${token}` } : {}),
        Accept: 'application/vnd.github+json',
        'User-Agent': 'wait4x-blog-build',
      },
    });
    if (!res.ok) {
      console.warn(`[profile] GitHub 用户统计获取失败 HTTP ${res.status}，相关数字已隐藏`);
      return null;
    }
    const data = (await res.json()) as { followers?: number; public_repos?: number };
    return {
      followers: Number(data.followers ?? 0),
      publicRepos: Number(data.public_repos ?? 0),
    };
  } catch (err) {
    console.warn(`[profile] GitHub 用户统计请求异常（${(err as Error).message}），相关数字已隐藏`);
    return null;
  }
}