/**
 * Completion Command
 * Generate shell completion scripts for bash/zsh
 */

import { COMMANDS } from '@celilo/core';
import { generateBashCompletion, generateFishCompletion } from '../completion';
import { generateRichZshCompletion } from '../generate-zsh-completion';
import { celiloIntro } from '../prompts';
import type { CommandResult } from '../types';

/**
 * Handle completion command
 *
 * @param args - Command arguments: [shell]
 * @param flags - Command flags
 */
export async function handleCompletion(
  args: string[],
  _flags: Record<string, boolean | string> = {},
): Promise<CommandResult> {
  try {
    const shell = args[0];

    if (!shell) {
      celiloIntro('Shell Completion');

      return {
        success: false,
        error: `Shell argument required.

Usage:
  celilo completion bash    Generate bash completion script
  celilo completion zsh     Generate zsh completion script
  celilo completion fish    Generate fish completion script

Install zsh completions:
  celilo completion zsh > ~/.zsh/completions/_celilo
  exec zsh
`,
      };
    }

    if (shell === 'bash') {
      return { success: true, message: generateBashCompletion() };
    }

    if (shell === 'zsh') {
      return { success: true, message: generateRichZshCompletion(COMMANDS) };
    }

    if (shell === 'fish') {
      return { success: true, message: generateFishCompletion() };
    }

    celiloIntro('Shell Completion');

    return {
      success: false,
      error: `Unknown shell: ${shell}

Supported shells:
  bash  Generate bash completion script
  zsh   Generate zsh completion script
  fish  Generate fish completion script

Usage:
  # Bash
  celilo completion bash > /etc/bash_completion.d/celilo
  # OR for user install:
  celilo completion bash >> ~/.bashrc

  # Zsh
  celilo completion zsh > ~/.zsh/completions/_celilo
  # OR for user install:
  celilo completion zsh > /usr/local/share/zsh/site-functions/_celilo

  # Fish
  celilo completion fish > ~/.config/fish/completions/celilo.fish
`,
    };
  } catch (error) {
    return {
      success: false,
      error: `Failed to generate completion script: ${error instanceof Error ? error.message : String(error)}`,
    };
  }
}