import { createInterface } from 'node:readline';
import { writeFileSync } from 'node:fs';
import { resolve } from 'node:path';
import type { Command } from 'commander';
import {
  DEFAULT_LOCAL_CONFIG,
  DEFAULT_TEAM_CONFIG,
  type MosaicConfig,
  type StorageTier,
} from '@mosaic/config';

function ask(rl: ReturnType<typeof createInterface>, question: string): Promise<string> {
  return new Promise((res) => rl.question(question, res));
}

async function runInit(opts: { tier?: string; output: string }): Promise<void> {
  const outputPath = resolve(opts.output);
  let tier: StorageTier;

  if (opts.tier) {
    if (opts.tier !== 'local' && opts.tier !== 'team') {
      console.error(`Invalid tier "${opts.tier}" — expected "local" or "team"`);
      process.exit(1);
    }
    tier = opts.tier;
  } else {
    const rl = createInterface({ input: process.stdin, output: process.stdout });
    const answer = await ask(rl, 'Select tier (local/team) [local]: ');
    rl.close();
    const trimmed = answer.trim().toLowerCase();
    tier = trimmed === 'team' ? 'team' : 'local';
  }

  let config: MosaicConfig;

  if (tier === 'local') {
    config = DEFAULT_LOCAL_CONFIG;
  } else {
    const rl = createInterface({ input: process.stdin, output: process.stdout });
    const dbUrl = await ask(
      rl,
      'DATABASE_URL [postgresql://mosaic:mosaic@localhost:5432/mosaic]: ',
    );
    const valkeyUrl = await ask(rl, 'VALKEY_URL [redis://localhost:6379]: ');
    rl.close();

    config = {
      ...DEFAULT_TEAM_CONFIG,
      storage: {
        type: 'postgres',
        url: dbUrl.trim() || 'postgresql://mosaic:mosaic@localhost:5432/mosaic',
      },
      queue: {
        type: 'bullmq',
        url: valkeyUrl.trim() || 'redis://localhost:6379',
      },
    };
  }

  writeFileSync(outputPath, JSON.stringify(config, null, 2) + '\n');
  console.log(`\nWrote ${outputPath}`);
  console.log('\nNext steps:');
  console.log('  1. Review the generated config');
  console.log('  2. Run: pnpm --filter @mosaic/gateway exec tsx src/main.ts');
}

export function registerGatewayCommand(program: Command): void {
  const gateway = program.command('gateway').description('Gateway management commands');

  gateway
    .command('init')
    .description('Generate a mosaic.config.json for the gateway')
    .option('--tier <tier>', 'Storage tier: local or team (skips interactive prompt)')
    .option('--output <path>', 'Output file path', './mosaic.config.json')
    .action(async (opts: { tier?: string; output: string }) => {
      await runInit(opts);
    });
}