/**
 * Forgejo API client.
 *
 * A thin wrapper around the Forgejo REST API (`/api/v1`). It supports two
 * authentication modes:
 *   - Basic auth (username/password) — required by Forgejo for the personal
 *     access token endpoints (create/delete).
 *   - Token auth — used for every other call.
 *
 * Each public method maps to a single endpoint; see the README for the
 * command-to-endpoint mapping.
 */

const pkg = require('../package.json');

const REQUEST_TIMEOUT_MS = 30000;
// Repository migrations clone the full source repository and can legitimately
// take minutes, so they get a much longer budget.
const MIGRATE_TIMEOUT_MS = 10 * 60 * 1000;

class ForgejoClient {
  constructor(baseUrl, token = null) {
    this.baseUrl = baseUrl.replace(/\/$/, '');
    this.token = token;
  }

  static fromConfig(config) {
    if (!config || !config.url || !config.token) {
      throw new Error('Not authenticated. Run: stoke auth login');
    }
    return new ForgejoClient(config.url, config.token);
  }

  withBasicAuth(username, password) {
    const clone = new ForgejoClient(this.baseUrl);
    clone.basicAuth = Buffer.from(`${username}:${password}`).toString('base64');
    return clone;
  }

  headers(extra = {}) {
    const h = {
      Accept: 'application/json',
      'Content-Type': 'application/json',
      'User-Agent': `stoke/${pkg.version}`,
      ...extra,
    };
    if (this.token) {
      h.Authorization = `token ${this.token}`;
    } else if (this.basicAuth) {
      h.Authorization = `Basic ${this.basicAuth}`;
    }
    return h;
  }

  async request(method, endpoint, body = null, { timeout = REQUEST_TIMEOUT_MS } = {}) {
    const url = `${this.baseUrl}/api/v1${endpoint}`;
    const opts = {
      method,
      headers: this.headers(),
      signal: AbortSignal.timeout(timeout),
    };
    if (body !== null) {
      opts.body = JSON.stringify(body);
    }

    let res;
    try {
      res = await fetch(url, opts);
    } catch (err) {
      if (err.name === 'TimeoutError') {
        throw new Error(`Request to ${this.baseUrl} timed out after ${timeout / 1000}s`);
      }
      throw new Error(`Network error reaching ${this.baseUrl}: ${err.message}`);
    }

    const text = await res.text();
    let data = null;
    if (text) {
      try {
        data = JSON.parse(text);
      } catch {
        data = { raw: text };
      }
    }

    if (!res.ok) {
      const msg = data?.message || data?.raw || `HTTP ${res.status}`;
      const err = new Error(msg);
      err.status = res.status;
      err.body = data;
      throw err;
    }

    return data;
  }

  get(endpoint) {
    return this.request('GET', endpoint);
  }

  post(endpoint, body, opts) {
    return this.request('POST', endpoint, body, opts);
  }

  del(endpoint) {
    return this.request('DELETE', endpoint);
  }

  async verifyBasicAuth(username, password) {
    const client = this.withBasicAuth(username, password);
    return client.get('/user');
  }

  async createToken(username, password, name, scopes) {
    const client = this.withBasicAuth(username, password);
    return client.post(`/users/${encodeURIComponent(username)}/tokens`, { name, scopes });
  }

  // Forgejo requires Basic auth for token management endpoints; a token
  // cannot be used to revoke itself (the API answers 401).
  async deleteToken(username, password, login, id) {
    const client = this.withBasicAuth(username, password);
    return client.del(`/users/${encodeURIComponent(login)}/tokens/${id}`);
  }

  async createRepo(payload) {
    return this.post('/user/repos', payload);
  }

  async migrateRepo(payload) {
    return this.post('/repos/migrate', payload, { timeout: MIGRATE_TIMEOUT_MS });
  }

  async getAll(endpoint, params = {}) {
    const pageSize = 50;
    const all = [];
    for (let page = 1; page <= 1000; page += 1) {
      const query = new URLSearchParams({ ...params, limit: String(pageSize), page: String(page) }).toString();
      const items = await this.get(`${endpoint}?${query}`);
      if (!Array.isArray(items) || items.length === 0) break;
      all.push(...items);
      if (items.length < pageSize) break;
    }
    return all;
  }

  async listRepos(opts = {}) {
    return this.getAll('/user/repos', opts);
  }

  async listIssues(owner, repo, opts = {}) {
    const params = {};
    if (opts.state) params.state = opts.state;
    if (opts.type) params.type = opts.type;
    return this.getAll(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/issues`, params);
  }

  async createIssue(owner, repo, payload) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/issues`, payload);
  }

  async listPullRequests(owner, repo, opts = {}) {
    return this.getAll(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/pulls`, opts);
  }

  async createPullRequest(owner, repo, payload) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/pulls`, payload);
  }

  async getPullRequest(owner, repo, index) {
    return this.get(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/pulls/${index}`);
  }

  async createPullRequestComment(owner, repo, index, body) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/issues/${index}/comments`, { body });
  }

  async createPullRequestReview(owner, repo, index, event, body) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/pulls/${index}/reviews`, {
      event,
      body: body || '',
    });
  }

  async mergePullRequest(owner, repo, index, payload) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/pulls/${index}/merge`, payload);
  }

  async listBranches(owner, repo, opts = {}) {
    return this.getAll(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/branches`, opts);
  }

  async addCollaborator(owner, repo, username, permission) {
    return this.request('PUT', `/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/collaborators/${encodeURIComponent(username)}`, {
      permission,
    });
  }

  async renameRepo(owner, repo, newName) {
    return this.request('PATCH', `/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}`, {
      name: newName,
    });
  }

  async transferRepo(owner, repo, newOwner) {
    return this.post(`/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/transfer`, {
      new_owner: newOwner,
    });
  }

  async createOrg(payload) {
    return this.post('/orgs', payload);
  }

  async listOrgRepos(org, opts = {}) {
    return this.getAll(`/orgs/${encodeURIComponent(org)}/repos`, opts);
  }

  async updateOrgAvatar(org, base64Image) {
    return this.post(`/orgs/${encodeURIComponent(org)}/avatar`, {
      image: base64Image,
    });
  }

  async searchUsers(query = '', opts = {}) {
    const pageSize = 50;
    const all = [];
    for (let page = 1; page <= 1000; page += 1) {
      const queryString = new URLSearchParams({
        q: query,
        ...opts,
        limit: String(pageSize),
        page: String(page),
      }).toString();
      const res = await this.get(`/users/search?${queryString}`);
      const items = Array.isArray(res?.data) ? res.data : [];
      if (items.length === 0) break;
      all.push(...items);
      if (items.length < pageSize) break;
    }
    return all;
  }

  async listOrgTeams(org, opts = {}) {
    return this.getAll(`/orgs/${encodeURIComponent(org)}/teams`, opts);
  }

  async createTeam(org, payload) {
    return this.post(`/orgs/${encodeURIComponent(org)}/teams`, payload);
  }

  async addTeamMember(teamId, username) {
    return this.request('PUT', `/teams/${teamId}/members/${encodeURIComponent(username)}`);
  }

  async listTeamMembers(teamId, opts = {}) {
    return this.getAll(`/teams/${teamId}/members`, opts);
  }

  async removeTeamMember(teamId, username) {
    return this.del(`/teams/${teamId}/members/${encodeURIComponent(username)}`);
  }

  async getUser(username) {
    return this.get(`/users/${encodeURIComponent(username)}`);
  }
}

module.exports = { ForgejoClient };