import type { Command } from 'commander';

import { DEFAULT_MOSAIC_HOME } from '../constants.js';
import {
  brainToolExists,
  execBrainTool,
  exitStatusFor,
  resolveBrainTool,
} from './brain-dispatch.js';

export { exitStatusFor };

/**
 * `mosaic watch` — dispatch to the brain's agent-watch suite.
 * See brain-dispatch.ts for the architecture and pass-through contract.
 */
export function resolveAgentWatchTool(mosaicHome: string): string {
  return resolveBrainTool(mosaicHome, 'tools/agent-watch/agent-watch.sh');
}

export function registerWatchCommand(program: Command): void {
  const cmd: Command = program
    .command('watch')
    .description('Wake-me-when watchers (agent-watch): start, list, stop')
    // allowUnknownOption + variadic = full ordered pass-through: unknown
    // options (--name, --when, ...) and their values land in args verbatim
    // (commander 13 measured behavior), so the tool owns its own flag
    // surface without the CLI needing passThroughOptions (which would
    // force enablePositionalOptions fleet-wide on the root program).
    .allowUnknownOption()
    // The tool owns help too: without this, commander would intercept
    // --help and answer with wrapper help instead of agent-watch's own
    // (codex review of 18f3dd49).
    .helpOption(false)
    .argument('[args...]', 'args passed through to agent-watch.sh')
    .action(async (args: string[], _opts: unknown, command: Command) => {
      // --mosaic-home is not global in this CLI; walk parents for it and
      // fall back to the default. MOSAIC_BRAIN_HOME (seat launchers export
      // it) wins inside resolveBrainHome regardless.
      let mosaicHome: string | undefined;
      for (let anc: Command | null = command; anc; anc = anc.parent) {
        const v = (anc.opts() as Record<string, string | undefined>)['mosaicHome'];
        if (v !== undefined) {
          mosaicHome = v;
          break;
        }
      }
      const home = mosaicHome ?? DEFAULT_MOSAIC_HOME;

      const tool = resolveAgentWatchTool(home);
      if (!brainToolExists(tool)) {
        console.error(
          `mosaic watch: agent-watch not found (expected ${tool}). ` +
            'The watcher suite lives in the brain tree under tools/agent-watch/; ' +
            'check MOSAIC_BRAIN_HOME or the brain checkout.',
        );
        process.exitCode = 127;
        return;
      }

      process.exitCode = execBrainTool(home, 'tools/agent-watch/agent-watch.sh', args);
    });

  cmd.addHelpText(
    'after',
    '\nEverything after `mosaic watch` is passed through to agent-watch.sh verbatim (args, output, exit code).',
  );
}