import type { Sql } from '../db.js';
import type { FastifyBaseLogger } from 'fastify';
import { sshExec } from './ssh.js';

const KNOWN_AGENTS: Array<{ name: string; supportsAcp: boolean }> = [
  { name: 'opencode', supportsAcp: true },
  { name: 'goose', supportsAcp: true },
  { name: 'claude', supportsAcp: false },
  { name: 'pi', supportsAcp: false },
];

/**
 * Probe for available agents on the HOST via SSH.
 *
 * The boocoder container can't run agents locally — they live on the host.
 * We SSH to the host (same mechanism BooTerm uses) and check which agent
 * binaries are on PATH.
 */
export async function probeAgents(sql: Sql, log: FastifyBaseLogger): Promise<void> {
  log.info('agent-probe: scanning HOST for known agents via SSH');

  for (const agent of KNOWN_AGENTS) {
    try {
      // Check if the agent binary is on the host's PATH
      const whichResult = await sshExec(`which ${agent.name}`, { timeoutMs: 10_000 });
      const installPath = whichResult.stdout.trim();
      if (whichResult.exitCode !== 0 || !installPath) continue;

      // Get version
      let version: string | null = null;
      try {
        const verResult = await sshExec(`${agent.name} --version`, { timeoutMs: 15_000 });
        if (verResult.exitCode === 0) {
          version = verResult.stdout.trim().slice(0, 100);
        }
      } catch {
        // Some agents may not support --version — that's fine
      }

      // For ACP-capable agents, verify ACP mode actually works
      let supportsAcp = agent.supportsAcp;
      if (supportsAcp) {
        try {
          const acpCheck = await sshExec(`${agent.name} acp --help`, { timeoutMs: 10_000 });
          supportsAcp = acpCheck.exitCode === 0;
        } catch {
          supportsAcp = false;
        }
      }

      // UPSERT into available_agents
      await sql`
        INSERT INTO available_agents (name, install_path, version, supports_acp, last_probed_at)
        VALUES (${agent.name}, ${installPath}, ${version}, ${supportsAcp}, clock_timestamp())
        ON CONFLICT (name) DO UPDATE SET
          install_path = EXCLUDED.install_path,
          version = EXCLUDED.version,
          supports_acp = EXCLUDED.supports_acp,
          last_probed_at = EXCLUDED.last_probed_at
      `;
      log.info({ agent: agent.name, version, installPath, supportsAcp }, 'agent-probe: found on host');
    } catch (err) {
      // SSH failed or agent not found — skip silently
      const msg = err instanceof Error ? err.message : String(err);
      log.debug({ agent: agent.name, err: msg }, 'agent-probe: not found or SSH failed');
    }
  }

  log.info('agent-probe: scan complete');
}