import chalk from 'chalk';

const MINT_GREEN = '#18E299';

const mint = chalk.hex(MINT_GREEN);

interface CommandEntry {
  name: string;
  description: string;
}

interface CommandGroup {
  title: string;
  commands: CommandEntry[];
}

const GROUPS: CommandGroup[] = [
  {
    title: 'Preview',
    commands: [
      { name: 'dev', description: 'Start a local preview of your site' },
      { name: 'new', description: 'Scaffold a new documentation site' },
      {
        name: 'deploy',
        description: 'Provision a docs site without login; get Git push instructions',
      },
    ],
  },
  {
    title: 'Quality',
    commands: [
      { name: 'validate', description: 'Validate the site build (strict)' },
      {
        name: 'broken-links',
        description: 'Find broken links before you ship',
      },
      { name: 'a11y', description: 'Check site for accessibility issues' },
      { name: 'score', description: 'Run agent-readiness checks' },
    ],
  },
  {
    title: 'Insights',
    commands: [
      { name: 'analytics', description: 'View analytics for your site' },
      { name: 'automations', description: 'Create and manage automations' },
    ],
  },
  {
    title: 'Account',
    commands: [
      { name: 'login', description: 'Authenticate with Mintlify' },
      { name: 'claim', description: 'Claim a site created with mint deploy' },
      { name: 'logout', description: 'Sign out on this device' },
      { name: 'status', description: 'View authentication status' },
    ],
  },
  {
    title: 'CLI',
    commands: [
      { name: 'config', description: 'Manage CLI configuration' },
      { name: 'update', description: 'Update to the latest version' },
    ],
  },
];

const EXAMPLES: CommandEntry[] = [
  { name: 'dev', description: 'Start a local preview of your site' },
  { name: 'new docs', description: 'Scaffold a new site in ./docs' },
  {
    name: 'claim --email you@example.com',
    description: 'Get a claim link; use the deployment directory',
  },
  { name: 'claim --code <code>', description: 'Finish the claim in the same directory' },
  { name: 'validate', description: 'Validate your site before shipping' },
  { name: 'broken-links', description: 'Find broken links across your site' },
];

const COMMAND_NAME_WIDTH =
  GROUPS.flatMap((group) => group.commands).reduce(
    (max, command) => Math.max(max, command.name.length),
    0
  ) + 2;

// `name  description`, name padded to a shared column and colored mint. Padding
// is computed on the raw name so ANSI codes don't throw off the alignment.
const commandRow = (name: string, description: string, nameWidth: number, indent: number): string =>
  ' '.repeat(indent) + mint(name.padEnd(nameWidth)) + chalk.dim(description);

export interface WelcomeOptions {
  packageName: string;
  version?: string;
  signedIn: boolean;
  subdomain?: string;
}

/**
 * Builds the branded welcome / help screen as a ready-to-print string: the
 * Mintlify leaf beside an identity block, then grouped examples and commands.
 */
export function renderWelcome({
  packageName,
  version,
  signedIn,
  subdomain,
}: WelcomeOptions): string {
  const title = `${packageName.charAt(0).toUpperCase()}${packageName.slice(1)} CLI`;
  // Only prefix "v" for real semver versions; the linked-dev build reports a
  // descriptive string ("linked to local package").
  const versionLabel = version ? (/^\d/.test(version) ? `v${version}` : version) : undefined;

  const identity: string[] = [
    chalk.bold(title) + (versionLabel ? chalk.dim(` ${versionLabel}`) : ''),
    '',
    signedIn
      ? chalk.dim('Signed in to Mintlify')
      : chalk.dim('Run ') + mint(`${packageName} login`) + chalk.dim(' to sign in'),
    ...(subdomain ? [chalk.dim(`Project ${subdomain}`)] : []),
  ];

  const lines: string[] = [''];

  lines.push(...identity);

  // Examples.
  const exampleWidth =
    EXAMPLES.reduce((max, example) => Math.max(max, `${packageName} ${example.name}`.length), 0) +
    2;
  lines.push('', ' ' + chalk.bold('EXAMPLES'));
  for (const example of EXAMPLES) {
    lines.push(commandRow(`${packageName} ${example.name}`, example.description, exampleWidth, 3));
  }

  // Commands, grouped.
  lines.push('', ' ' + chalk.bold('COMMANDS'));
  for (const group of GROUPS) {
    lines.push('', '   ' + chalk.bold(group.title));
    for (const command of group.commands) {
      lines.push(commandRow(command.name, command.description, COMMAND_NAME_WIDTH, 5));
    }
  }

  lines.push(
    '',
    ' ' +
      chalk.dim('Run ') +
      mint(`${packageName} <command> --help`) +
      chalk.dim(' for details on any command.'),
    ''
  );

  return lines.join('\n') + '\n';
}