/**
 * setup/git.ts — Provision a local Bastille git jail.
 *
 * Creates a thin jail with git + rsync, mirrors from REMOTE_GIT_URL
 * plus any GIT_MIRROR_URLS, or creates an empty bare repo as fallback.
 * Fully idempotent — safe to rerun.
 */
import { execSync, spawnSync } from 'child_process';
import path from 'path';

import {
  AGENT_INTERNAL_DOMAIN,
  AGENT_NAME,
  CODE_HOSTING_MODE,
  FEATURE_GIT,
  GIT_DEFAULT_REPO_NAME,
  GIT_JAIL_NAME,
  GIT_MIRROR_URLS,
  GIT_JAIL_IP,
  GIT_STORAGE_ROOT,
  REMOTE_GIT_URL,
  SUBNET_BASE,
} from '../src/config.js';
import { logger } from '../src/logger.js';
import { loadPackageList, mountPkgCacheInJail } from './packages.js';
import { getPlatform } from './platform.js';
import { emitStatus } from './status.js';
import { maybeEnableTailscaleInJail } from './tailscale.js';

const LOG = 'logs/setup.log';

function bastille(...args: string[]): { ok: boolean; output: string } {
  const result = spawnSync('bastille', args, {
    encoding: 'utf-8',
    env: process.env,
  });
  const output = [result.stdout || '', result.stderr || '']
    .filter(Boolean)
    .join('\n')
    .trim();
  return { ok: (result.status ?? 1) === 0, output };
}

function jailExists(name: string): boolean {
  const { output } = bastille('list');
  return output.split('\n').some((line) => {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('JID')) {
      return false;
    }
    const cols = trimmed.split(/\s+/u);
    return cols.length > 1 && cols[1] === name;
  });
}

function detectFreeBSDRelease(): string {
  const output = execSync('freebsd-version -u', { encoding: 'utf-8' }).trim();
  const match = output.match(/^(\d+\.\d+-\w+)/);
  return match?.[1] ?? output;
}

function repoNameFromRemote(remote: string): string | null {
  const trimmed = remote.trim();
  if (!trimmed) return null;
  const hashIndex = trimmed.indexOf('#');
  const clean = hashIndex >= 0 ? trimmed.slice(0, hashIndex) : trimmed;

  try {
    const url = new URL(clean);
    const base = path.posix.basename(url.pathname);
    return base || null;
  } catch {
    // Fall through to SCP-style parsing.
  }

  const colonIndex = clean.lastIndexOf(':');
  if (colonIndex !== -1 && clean.slice(colonIndex + 1).includes('/')) {
    const base = path.posix.basename(clean.slice(colonIndex + 1));
    return base || null;
  }

  const base = path.posix.basename(clean);
  return base || null;
}

function repoExistsInJail(jail: string, repoPath: string): boolean {
  const { ok } = bastille('cmd', jail, 'test', '-d', repoPath);
  return ok;
}

export async function run(_args: string[]): Promise<void> {
  const jailName = GIT_JAIL_NAME;
  const hostname = `git.${AGENT_INTERNAL_DOMAIN}`;
  const repoPath = path.posix.join(GIT_STORAGE_ROOT, GIT_DEFAULT_REPO_NAME);
  const extraMirrorUrls = GIT_MIRROR_URLS.filter((url) => url && url !== REMOTE_GIT_URL);
  const runBastille = (args: string[]) => bastille(...args);

  // Feature gate — skip if git hosting is explicitly disabled
  if (!FEATURE_GIT || CODE_HOSTING_MODE === 'external') {
    emitStatus('SETUP_GIT', {
      STATUS: 'skipped',
      REASON: !FEATURE_GIT ? 'feature_disabled' : 'external_hosting',
      LOG,
    });
    logger.info('Git jail skipped — FEATURE_GIT=%s, CODE_HOSTING_MODE=%s', FEATURE_GIT, CODE_HOSTING_MODE);
    return;
  }

  // Platform gate
  if (getPlatform() !== 'freebsd') {
    emitStatus('SETUP_GIT', {
      STATUS: 'failed',
      ERROR: 'unsupported_platform',
      LOG,
    });
    process.exit(1);
  }

  try {
    const exists = jailExists(jailName);

    // ── Create jail if missing ──────────────────────────────────────
    if (!exists) {
      const release = detectFreeBSDRelease();
      const gateway = process.env.WARDEN_GATEWAY || `${SUBNET_BASE}.1`;
      const bridge = process.env.WARDEN_BRIDGE || 'warden0';

      logger.info({ jailName, ip: GIT_JAIL_IP, release }, 'Creating git jail');

      const create = bastille(
        'create', '-T', '-B',
        '-g', gateway,
        jailName, release, `${GIT_JAIL_IP}/24`, bridge,
      );
      if (!create.ok) {
        throw new Error(`bastille create failed: ${create.output}`);
      }

      // Set hostname and restart so it takes effect
      bastille('config', jailName, 'set', 'host.hostname', hostname);
      bastille('restart', jailName);
    } else {
      logger.info({ jailName }, 'Git jail already exists, skipping creation');
    }

    // ── Install packages ────────────────────────────────────────────
    mountPkgCacheInJail(jailName);

    const packages = loadPackageList('git-jail.txt');
    const pkg = bastille('pkg', jailName, 'install', '-y', ...packages);
    if (!pkg.ok) {
      logger.warn({ output: pkg.output }, 'Package install had warnings');
    }

    maybeEnableTailscaleInJail(runBastille, jailName, jailName);

    // ── Create storage root ─────────────────────────────────────────
    bastille('cmd', jailName, 'install', '-d', '-m', '755', GIT_STORAGE_ROOT);

    // ── Create or mirror repository ─────────────────────────────────
    if (!repoExistsInJail(jailName, repoPath)) {
      let mirrored = false;

      if (REMOTE_GIT_URL) {
        logger.info({ url: REMOTE_GIT_URL }, 'Attempting mirror clone');
        const clone = bastille(
          'cmd', jailName,
          'git', 'clone', '--mirror', REMOTE_GIT_URL, repoPath,
        );
        if (clone.ok) {
          mirrored = true;
        } else {
          logger.warn(
            { output: clone.output },
            'Mirror clone failed — falling back to empty bare repo',
          );
        }
      }

      if (!mirrored) {
        const init = bastille('cmd', jailName, 'git', 'init', '--bare', repoPath);
        if (!init.ok) {
          throw new Error(`git init --bare failed: ${init.output}`);
        }
      }
    } else {
      logger.info({ repoPath }, 'Bare repo already exists, skipping');
    }

    if (extraMirrorUrls.length) {
      for (const mirrorUrl of extraMirrorUrls) {
        const repoName = repoNameFromRemote(mirrorUrl);
        if (!repoName) {
          logger.warn({ mirrorUrl }, 'Unable to derive repo name for mirror URL');
          continue;
        }
        if (repoName === GIT_DEFAULT_REPO_NAME) {
          continue;
        }

        const mirrorRepoPath = path.posix.join(GIT_STORAGE_ROOT, repoName);
        if (repoExistsInJail(jailName, mirrorRepoPath)) {
          logger.info({ mirrorRepoPath }, 'Mirror repo already exists, skipping');
          continue;
        }

        logger.info({ mirrorUrl, mirrorRepoPath }, 'Attempting mirror clone');
        const clone = bastille(
          'cmd', jailName,
          'git', 'clone', '--mirror', mirrorUrl, mirrorRepoPath,
        );
        if (!clone.ok) {
          logger.warn(
            { mirrorUrl, output: clone.output },
            'Mirror clone failed — skipping extra repo',
          );
        }
      }
    }

    // ── Enable on boot ──────────────────────────────────────────────
    try {
      execSync(`sysrc jail_list+="${jailName}"`, { stdio: 'ignore' });
    } catch {
      logger.warn('sysrc jail_list update failed — jail may not start on boot');
    }

    // ── Validate ────────────────────────────────────────────────────
    const gitVer = bastille('cmd', jailName, 'git', '--version');
    if (!gitVer.ok) {
      throw new Error('Validation failed: git not installed in jail');
    }

    const isBare = bastille(
      'cmd', jailName,
      'git', '--git-dir', repoPath, 'rev-parse', '--is-bare-repository',
    );
    if (!isBare.ok || !isBare.output.includes('true')) {
      throw new Error(`Validation failed: ${repoPath} is not a valid bare repository`);
    }

    emitStatus('SETUP_GIT', {
      STATUS: 'success',
      JAIL_NAME: jailName,
      JAIL_IP: GIT_JAIL_IP,
      GIT_STORAGE_ROOT,
      GIT_REPO: GIT_DEFAULT_REPO_NAME,
      MIRROR_SOURCE: REMOTE_GIT_URL || 'none',
      MIRROR_EXTRAS: extraMirrorUrls.join(',') || 'none',
      LOG,
    });

    logger.info({ jailName, ip: GIT_JAIL_IP, repoPath }, 'Git jail provisioned');
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error);
    emitStatus('SETUP_GIT', {
      STATUS: 'failed',
      ERROR: message,
      LOG,
    });
    throw error;
  }
}