import { execSync } from 'child_process';
import { Relace } from './client';

function ensureGitAvailable() {
  try {
    execSync('git --version', { stdio: 'ignore' });
  } catch {
    throw new Error('Git CLI is not installed or not found in PATH.');
  }
}

/**
 * Helper class that provides Git operations to the SDK.
 */
class GitHelper {
  constructor(
    private client: Relace,
    private rootPath: string,
  ) {}

  /**
   * Clone a Git repository.
   */
  clone(options: { repoId: string; depth?: number; branch?: string; quiet?: boolean; args?: string[] }) {
    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    const { repoId, depth = 1, branch, quiet = true, args = [] } = options;

    const branchArg = branch ? `-b ${branch}` : '';
    const quietArg = quiet ? '--quiet' : '';
    const extraArgs = args.join(' ');

    // Access API token from the client
    const apiToken = this.client.apiKey;
    const repoUrl = `https://token:${apiToken}@api.relace.run/v1/repo/${repoId}.git`;

    ensureGitAvailable();

    const cmd = `git clone ${branchArg} --depth ${depth} ${quietArg} ${extraArgs} ${repoUrl} ${this.rootPath}`;

    execSync(cmd, { stdio: 'inherit' });
  }

  /**
   * Fetch updates from remote repository (optionally for a specific branch)
   */
  fetch(options?: { branch?: string }) {
    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    const { branch } = options || {};
    const branchArg = branch ? branch : '';
    const cmd =
      branchArg ? `git -C ${this.rootPath} fetch origin ${branchArg}` : `git -C ${this.rootPath} fetch`;

    ensureGitAvailable();
    execSync(cmd, { stdio: 'inherit' });
  }

  /**
   * Stage files for commit
   */
  add(options: { files?: string | string[] } = {}) {
    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    const { files = '.' } = options;
    const filesArg = Array.isArray(files) ? files.join(' ') : files;

    ensureGitAvailable();
    execSync(`git -C ${this.rootPath} add ${filesArg}`, { stdio: 'inherit' });

    return this;
  }

  /**
   * Commit staged files
   */
  commit(options: { message: string }) {
    const { message } = options;

    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    if (!message) {
      throw new Error('Please specify a commit message');
    }

    ensureGitAvailable();
    execSync(`git -C ${this.rootPath} commit -m "${message}"`, { stdio: 'inherit' });

    return this;
  }

  /**
   * Push commits to remote
   */
  push(options: { branch?: string } = {}) {
    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    ensureGitAvailable();

    const { branch } = options;
    const branchArg =
      branch ? branch : execSync(`git -C ${this.rootPath} rev-parse --abbrev-ref HEAD`, { encoding: 'utf8' });

    execSync(`git -C ${this.rootPath} push -u origin ${branchArg}`, { stdio: 'inherit' });
  }

  /**
   * Pull a repo (optionally from a specific branch)
   */
  pull(options?: { branch?: string }) {
    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }
    const { branch } = options || {};

    const branchArg = branch ? branch : '';
    const cmd =
      branchArg ? `git -C ${this.rootPath} pull origin ${branchArg}` : `git -C ${this.rootPath} pull`;

    ensureGitAvailable();
    execSync(cmd, { stdio: 'inherit' });
  }

  /**
   * Checkout a Git branch.
   */
  checkoutBranch(options: { branch: string; newBranch?: boolean }) {
    const { branch, newBranch } = options;

    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    const args = newBranch ? '-b' : '';

    ensureGitAvailable();
    execSync(`git -C ${this.rootPath} checkout ${args} ${branch}`, { stdio: 'inherit' });
  }

  /**
   * Run a generic git command.
   */
  command(options: { cmd: string }) {
    const { cmd } = options;

    if (!this.rootPath) {
      throw new Error('No repository path provided. Please specify in git');
    }

    if (!cmd) {
      throw new Error('Please provide a Git command to execute.');
    }

    ensureGitAvailable();
    execSync(`git -C ${this.rootPath} ${cmd}`, { stdio: 'inherit' });

    return this;
  }
}

/**
 * Attach git helpers to the SDK prototype.
 */
export function attachGitSupport(ClientClass: typeof Relace) {
  (ClientClass.prototype as any).git = function (repoPath: string) {
    return new GitHelper(this, repoPath);
  };
}

export { GitHelper };