// Minimal Gitea API client (fetch-based, no deps).

// URL path segment from webhook/API-supplied values (owner, repo, refs,
// shas): never trust them as URL-safe — branch names can carry '/', '#', '?'.
const seg = (s) => encodeURIComponent(String(s));

export class GiteaClient {
  constructor({ baseUrl, token, timeoutMs = 30000 }) {
    this.baseUrl = baseUrl.replace(/\/$/, '');
    this.token = token;
    this.timeoutMs = timeoutMs;
  }

  async req(method, path, { body, raw = false, ok = [200, 201] } = {}) {
    const res = await fetch(`${this.baseUrl}${path}`, {
      method,
      headers: {
        Authorization: `token ${this.token}`,
        ...(body ? { 'Content-Type': 'application/json' } : {})
      },
      body: body ? JSON.stringify(body) : undefined,
      signal: AbortSignal.timeout(this.timeoutMs)
    });
    if (!ok.includes(res.status)) {
      const text = await res.text().catch(() => '');
      const err = new Error(`gitea ${method} ${path} -> ${res.status}: ${text.slice(0, 300)}`);
      err.status = res.status;
      throw err;
    }
    return raw ? res.text() : res.json().catch(() => ({}));
  }

  // PR diff
  getPrDiff(owner, repo, index) {
    return this.req('GET', `/api/v1/repos/${seg(owner)}/${seg(repo)}/pulls/${seg(index)}.diff`, { raw: true });
  }

  // Single-commit diff
  getCommitDiff(owner, repo, sha) {
    return this.req('GET', `/api/v1/repos/${seg(owner)}/${seg(repo)}/git/commits/${seg(sha)}.diff`, { raw: true });
  }

  // Compare (commit list between two shas)
  compare(owner, repo, before, after) {
    return this.req('GET', `/api/v1/repos/${seg(owner)}/${seg(repo)}/compare/${seg(before)}...${seg(after)}`);
  }

  // Full-range diff for a push (base...head) in ONE request. Gitea 1.27's API
  // has no compare .diff variant, but the web compare route serves .diff.
  // CAVEAT (probed live on 1.27.1): the web route does NOT honor
  // `Authorization: token` for private repos — it resolves as anonymous and
  // answers 404 even for valid refs. Callers must be ready to fall back to
  // the API-based sources below (fetchDiff in review.js does).
  getCompareDiff(owner, repo, before, after) {
    return this.req('GET', `/${seg(owner)}/${seg(repo)}/compare/${seg(before)}...${seg(after)}.diff`, { raw: true });
  }

  // Repo metadata (used for default_branch when the job doesn't carry it)
  getRepo(owner, repo) {
    return this.req('GET', `/api/v1/repos/${seg(owner)}/${seg(repo)}`);
  }

  // Add a collaborator (requires owner/admin token). 204 on success.
  addCollaborator(owner, repo, username, permission = 'write') {
    return this.req('PUT', `/api/v1/repos/${owner}/${repo}/collaborators/${username}`, {
      body: { permission }, ok: [204]
    });
  }

  // File content at HEAD (returns null when absent)
  async getFileHead(owner, repo, path, maxBytes = 8192) {
    try {
      const txt = await this.req('GET',
        `/api/v1/repos/${owner}/${repo}/raw/${encodeURIComponent(path)}`, { raw: true });
      return txt.slice(0, maxBytes);
    } catch (e) {
      if (e.status === 404) return null;
      throw e;
    }
  }

  postStatus(owner, repo, sha, { state, context, description, target_url }) {
    return this.req('POST', `/api/v1/repos/${owner}/${repo}/statuses/${sha}`, {
      body: { state, context, description: (description || '').slice(0, 255), target_url }
    });
  }

  postIssueComment(owner, repo, index, body) {
    return this.req('POST', `/api/v1/repos/${owner}/${repo}/issues/${index}/comments`, {
      body: { body }
    });
  }

  getPrCommits(owner, repo, index) {
    return this.req('GET', `/api/v1/repos/${owner}/${repo}/pulls/${index}/commits?limit=50`);
  }

  getCommit(owner, repo, sha) {
    return this.req('GET', `/api/v1/repos/${owner}/${repo}/git/commits/${sha}?stat=false&verification=false&files=false`);
  }
}