import { execa } from "execa";
import chalk from "chalk";
import type {
  PullRequest,
  MergedPullRequest,
  GitHubPRResponse,
} from "./ui/types.js";

/**
 * GitHub CLIがインストールされているかを確認
 * @returns {Promise<boolean>} インストールされている場合true
 */
export async function isGitHubCLIAvailable(): Promise<boolean> {
  try {
    await execa("gh", ["--version"]);
    return true;
  } catch {
    return false;
  }
}

/**
 * マージ済みのプルリクエスト一覧を取得
 * @returns {Promise<MergedPullRequest[]>} マージ済みPRの配列
 */
export async function getMergedPullRequests(): Promise<MergedPullRequest[]> {
  try {
    // リモート情報を更新してから マージ済みPR を取得
    try {
      await execa("git", ["fetch", "--all", "--prune"]);
    } catch (fetchError) {
      if (process.env.DEBUG_CLEANUP) {
        console.log(
          chalk.yellow(
            "Debug: Failed to fetch remote updates, continuing anyway",
          ),
        );
      }
    }

    const { stdout } = await execa("gh", [
      "pr",
      "list",
      "--state",
      "merged",
      "--json",
      "number,title,headRefName,mergedAt,author",
      "--limit",
      "100",
    ]);

    if (!stdout || stdout.trim() === "") {
      if (process.env.DEBUG_CLEANUP) {
        console.log(
          chalk.yellow(
            "Debug: GitHub CLI returned empty response for merged PRs",
          ),
        );
      }
      return [];
    }

    const prs: GitHubPRResponse[] = JSON.parse(stdout);
    if (process.env.DEBUG_CLEANUP) {
      console.log(
        chalk.cyan(`Debug: GitHub CLI returned ${prs.length} merged PRs`),
      );
    }

    return prs.map((pr) => ({
      number: pr.number,
      title: pr.title,
      branch: pr.headRefName,
      mergedAt: pr.mergedAt!,
      author: pr.author?.login || "unknown",
    }));
  } catch (error) {
    const errorMessage = error instanceof Error ? error.message : String(error);
    console.error(chalk.red("Error: Failed to fetch merged pull requests"));
    console.error(chalk.red(`Details: ${errorMessage}`));

    if (
      errorMessage.includes("authentication") ||
      errorMessage.includes("auth")
    ) {
      console.log(
        chalk.yellow(
          'Hint: Try running "gh auth login" to authenticate with GitHub',
        ),
      );
    } else if (
      errorMessage.includes("not found") ||
      errorMessage.includes("404")
    ) {
      console.log(
        chalk.yellow(
          "Hint: Make sure you are in a repository with GitHub remote",
        ),
      );
    }

    if (process.env.DEBUG_CLEANUP) {
      console.error(chalk.red("Debug: Full error details:"), error);
    }

    return [];
  }
}

export async function getPullRequestByBranch(
  branchName: string,
): Promise<PullRequest | null> {
  try {
    const { stdout } = await execa("gh", [
      "pr",
      "list",
      "--head",
      branchName,
      "--state",
      "all",
      "--json",
      "number,title,state,headRefName,mergedAt,author",
      "--limit",
      "1",
    ]);

    const prs: GitHubPRResponse[] = JSON.parse(stdout);
    if (prs.length === 0 || !prs[0]) {
      return null;
    }

    const pr = prs[0];
    return {
      number: pr.number,
      title: pr.title,
      state: pr.state as "OPEN" | "CLOSED" | "MERGED",
      branch: pr.headRefName,
      mergedAt: pr.mergedAt,
      author: pr.author?.login || "unknown",
    };
  } catch (error) {
    return null;
  }
}

export async function checkGitHubAuth(): Promise<boolean> {
  try {
    // gh auth status returns non-zero exit code even when authenticated
    // Check if we can actually use the API instead
    await execa("gh", ["api", "user"]);
    return true;
  } catch {
    console.error(chalk.red("Error: GitHub CLI is not authenticated"));
    console.log(chalk.yellow("Please run: gh auth login"));
    return false;
  }
}