'use strict';

const { downloadBodyToFile, fetchOrThrow } = require('./http-download');

function normalizeGiteaBaseUrl(raw) {
  let b = String(raw || '').trim().replace(/\/+$/, '');
  if (!b) return '';
  if (!/^https?:\/\//i.test(b)) b = `https://${b}`;
  return b;
}

function giteaApiBase(cfg) {
  const base = normalizeGiteaBaseUrl(cfg.gitea.base_url);
  return `${base}/api/v1`;
}

function giteaToken(cfg) {
  const name = cfg.gitea && cfg.gitea.token_env;
  if (name && process.env[name]) return String(process.env[name]).trim();
  return String(process.env.GITEA_TOKEN || '').trim();
}

function giteaHeaders(token, json = false) {
  const h = { 'User-Agent': 'Fractured-Launcher-Electron' };
  if (json) h.Accept = 'application/json';
  if (token) h.Authorization = `token ${token}`;
  return h;
}

function useGiteaReleases(cfg) {
  const g = cfg.gitea;
  if (!g) return false;
  return !!(String(g.base_url || '').trim() && String(g.owner || '').trim() && String(g.repo || '').trim());
}

async function fetchGiteaReleaseRecord(cfg) {
  const api = giteaApiBase(cfg);
  const { owner, repo } = cfg.gitea;
  const tag = (cfg.gitea.release_tag || 'latest').trim() || 'latest';
  const token = giteaToken(cfg);

  let listUrl;
  if (tag.toLowerCase() === 'latest') {
    listUrl = `${api}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases/latest`;
  } else {
    listUrl = `${api}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases/tags/${encodeURIComponent(tag)}`;
  }

  const res = await fetchOrThrow(listUrl, { headers: giteaHeaders(token, true) });
  const text = await res.text();
  if (!res.ok) {
    let hint = '';
    if (res.status === 404) hint = ' (wrong tag / no release / check base_url owner repo)';
    if (res.status === 401 || res.status === 403) hint = ' (set GITEA_TOKEN or gitea.token_env)';
    throw new Error(`Gitea release ${res.status}${hint}: ${text.slice(0, 600)}`);
  }
  return JSON.parse(text);
}

async function listGiteaReleaseAttachmentNames(cfg) {
  const rel = await fetchGiteaReleaseRecord(cfg);
  const list = rel.attachments || rel.assets || [];
  return list.map((x) => x.name).filter(Boolean);
}

async function downloadGiteaReleaseAsset(cfg, assetName, destPath) {
  const token = giteaToken(cfg);
  const rel = await fetchGiteaReleaseRecord(cfg);
  const list = rel.attachments || rel.assets || [];
  let downloadUrl = '';
  for (const a of list) {
    if (a.name !== assetName) continue;
    downloadUrl = a.browser_download_url || a.download_url || '';
    break;
  }
  if (!downloadUrl) {
    const names = list.map((x) => x.name).filter(Boolean);
    throw new Error(`Gitea release asset "${assetName}" not found; attachments: ${names.join(', ') || '(none)'}`);
  }

  const h = { Accept: 'application/octet-stream' };
  if (token) h.Authorization = `token ${token}`;
  const dl = await fetchOrThrow(downloadUrl, { headers: h, redirect: 'follow' });
  await downloadBodyToFile(dl, destPath);
}

/**
 * Base URL for electron-updater generic provider (expects latest.yml under this path).
 * Matches Gitea’s pattern: …/owner/repo/releases/download/{tag}/latest.yml
 */
async function getGiteaUpdaterFeedBase(cfg) {
  if (!useGiteaReleases(cfg)) return null;
  const api = giteaApiBase(cfg);
  const { owner, repo } = cfg.gitea;
  const tag = (cfg.gitea.release_tag || 'latest').trim() || 'latest';
  const token = giteaToken(cfg);
  let listUrl;
  if (tag.toLowerCase() === 'latest') {
    listUrl = `${api}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases/latest`;
  } else {
    listUrl = `${api}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases/tags/${encodeURIComponent(tag)}`;
  }
  const res = await fetchOrThrow(listUrl, { headers: giteaHeaders(token, true) });
  if (!res.ok) return null;
  const rel = await res.json();
  const tagName = rel.tag_name;
  if (!tagName || typeof tagName !== 'string') return null;
  const root = normalizeGiteaBaseUrl(cfg.gitea.base_url);
  const url = `${root}/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/releases/download/${encodeURIComponent(tagName)}/`;
  return { url, token };
}

module.exports = {
  downloadGiteaReleaseAsset,
  fetchGiteaReleaseRecord,
  listGiteaReleaseAttachmentNames,
  giteaToken,
  useGiteaReleases,
  getGiteaUpdaterFeedBase,
};