import { Command } from 'commander';
import { createInterface } from 'readline';
import { authenticate } from '../api.js';
import { saveCredentials, loadCredentials, clearCredentials } from '../credentials.js';
import { printJson, printTable, formatTimestamp } from '../output.js';

/**
 * Read all stdin lines upfront when not a TTY (piped input).
 */
async function readStdinLines(): Promise<string[]> {
  if (process.stdin.isTTY) return [];
  return new Promise((resolve) => {
    const lines: string[] = [];
    const rl = createInterface({ input: process.stdin, terminal: false });
    rl.on('line', (line) => lines.push(line.trim()));
    rl.on('close', () => resolve(lines));
  });
}

function promptTTY(question: string, hidden: boolean): Promise<string> {
  return new Promise((resolve) => {
    if (hidden) {
      // Disable echo for password
      process.stdout.write(question);
      process.stdin.setRawMode?.(true);
      process.stdin.resume();
      process.stdin.setEncoding('utf8');
      let input = '';
      const onData = (ch: string) => {
        if (ch === '\n' || ch === '\r' || ch === '\u0003') {
          process.stdin.setRawMode?.(false);
          process.stdin.pause();
          process.stdin.removeListener('data', onData);
          process.stdout.write('\n');
          resolve(input);
        } else if (ch === '\u007F') {
          input = input.slice(0, -1);
        } else {
          input += ch;
        }
      };
      process.stdin.on('data', onData);
    } else {
      const rl = createInterface({ input: process.stdin, output: process.stdout });
      rl.question(question, (answer) => {
        rl.close();
        resolve(answer.trim());
      });
    }
  });
}

export function registerAuthCommands(program: Command): void {
  program
    .command('login')
    .description('Log in to Mailcheap and cache credentials')
    .option('--json', 'Output as JSON')
    .action(async (opts) => {
      try {
        let username: string;
        let password: string;

        if (process.stdin.isTTY) {
          username = await promptTTY('Username: ', false);
          password = await promptTTY('Password: ', true);
        } else {
          // Piped/non-interactive: read both lines upfront
          const lines = await readStdinLines();
          username = lines[0] || '';
          password = lines[1] || '';
        }

        if (!username || !password) {
          console.error('Username and password are required.');
          process.exit(1);
        }

        const creds = await authenticate(username, password);
        await saveCredentials(creds);

        if (opts.json) {
          printJson({
            username: creds.username,
            valid_to: creds.valid_to,
            valid_to_human: formatTimestamp(creds.valid_to),
          });
        } else {
          console.log(`✓ Logged in as ${creds.username}`);
          console.log(`  Token valid until: ${formatTimestamp(creds.valid_to)}`);
        }
      } catch (err) {
        console.error(`✗ Login failed: ${(err as Error).message}`);
        process.exit(1);
      }
    });

  program
    .command('logout')
    .description('Clear cached credentials')
    .action(async () => {
      await clearCredentials();
      console.log('✓ Logged out.');
    });

  program
    .command('whoami')
    .description('Show current login status')
    .option('--json', 'Output as JSON')
    .action(async (opts) => {
      const creds = await loadCredentials();

      if (!creds) {
        console.log('Not logged in.');
        process.exit(1);
      }

      const now = Date.now() / 1000;
      const expired = now > creds.valid_to - 60;

      if (opts.json) {
        printJson({
          username: creds.username,
          valid_to: creds.valid_to,
          valid_to_human: formatTimestamp(creds.valid_to),
          expired,
        });
      } else {
        printTable([
          { Field: 'Username', Value: creds.username },
          { Field: 'Token valid until', Value: formatTimestamp(creds.valid_to) },
          { Field: 'Status', Value: expired ? '⚠ Expired' : '✓ Active' },
        ]);
      }
    });
}