import type { GitHubClient } from "../api/client";
import { GITEA_SERVER_URL } from "../api/config";
import {
  branchHasChanges,
  fetchBranch,
  branchExists,
  remoteBranchExists,
} from "../utils/local-git";

export async function checkAndDeleteEmptyBranch(
  client: GitHubClient,
  owner: string,
  repo: string,
  claudeBranch: string | undefined,
  baseBranch: string,
): Promise<{ shouldDeleteBranch: boolean; branchLink: string }> {
  let branchLink = "";
  let shouldDeleteBranch = false;

  if (claudeBranch) {
    // Check if we're using Gitea or GitHub
    const giteaApiUrl = process.env.GITEA_API_URL?.trim();
    const isGitea =
      giteaApiUrl &&
      giteaApiUrl !== "" &&
      !giteaApiUrl.includes("api.github.com") &&
      !giteaApiUrl.includes("github.com");

    if (isGitea) {
      // Use local git operations for Gitea
      console.log("Using local git commands for branch check (Gitea mode)");

      try {
        // Fetch latest changes from remote
        await fetchBranch(claudeBranch);
        await fetchBranch(baseBranch);

        // Check if branch exists and has changes
        const { hasChanges, branchSha, baseSha } = await branchHasChanges(
          claudeBranch,
          baseBranch,
        );

        if (branchSha && baseSha) {
          if (hasChanges) {
            console.log(
              `Branch ${claudeBranch} appears to have commits (different SHA from base)`,
            );
            const branchUrl = `${GITEA_SERVER_URL}/${owner}/${repo}/src/branch/${claudeBranch}`;
            branchLink = `\n[View branch](${branchUrl})`;
          } else {
            console.log(
              `Branch ${claudeBranch} has same SHA as base, marking for deletion`,
            );
            shouldDeleteBranch = true;
          }
        } else {
          // If we can't get SHAs, check if branch exists at all
          const localExists = await branchExists(claudeBranch);
          const remoteExists = await remoteBranchExists(claudeBranch);

          if (localExists || remoteExists) {
            console.log(
              `Branch ${claudeBranch} exists but SHA comparison failed, assuming it has commits`,
            );
            const branchUrl = `${GITEA_SERVER_URL}/${owner}/${repo}/src/branch/${claudeBranch}`;
            branchLink = `\n[View branch](${branchUrl})`;
          } else {
            console.log(
              `Branch ${claudeBranch} does not exist yet - this is normal during workflow`,
            );
            branchLink = "";
          }
        }
      } catch (error: any) {
        console.error("Error checking branch with git commands:", error);
        // For errors, assume the branch has commits to be safe
        console.log("Assuming branch exists due to git command error");
        const branchUrl = `${GITEA_SERVER_URL}/${owner}/${repo}/src/branch/${claudeBranch}`;
        branchLink = `\n[View branch](${branchUrl})`;
      }
    } else {
      // Use API calls for GitHub
      console.log("Using API calls for branch check (GitHub mode)");

      try {
        // Get the branch info to see if it exists and has commits
        const branchResponse = await client.api.getBranch(
          owner,
          repo,
          claudeBranch,
        );

        // Get base branch info for comparison
        const baseResponse = await client.api.getBranch(
          owner,
          repo,
          baseBranch,
        );

        const branchSha = branchResponse.data.commit.sha;
        const baseSha = baseResponse.data.commit.sha;

        // If SHAs are different, assume there are commits
        if (branchSha !== baseSha) {
          console.log(
            `Branch ${claudeBranch} appears to have commits (different SHA from base)`,
          );
          const branchUrl = `${GITEA_SERVER_URL}/${owner}/${repo}/src/branch/${claudeBranch}`;
          branchLink = `\n[View branch](${branchUrl})`;
        } else {
          console.log(
            `Branch ${claudeBranch} has same SHA as base, marking for deletion`,
          );
          shouldDeleteBranch = true;
        }
      } catch (error: any) {
        console.error("Error checking branch:", error);

        // Handle 404 specifically - branch doesn't exist
        if (error.status === 404) {
          console.log(
            `Branch ${claudeBranch} does not exist yet - this is normal during workflow`,
          );
          // Don't add branch link since branch doesn't exist
          branchLink = "";
        } else {
          // For other errors, assume the branch has commits to be safe
          console.log("Assuming branch exists due to non-404 error");
          const branchUrl = `${GITEA_SERVER_URL}/${owner}/${repo}/src/branch/${claudeBranch}`;
          branchLink = `\n[View branch](${branchUrl})`;
        }
      }
    }
  }

  // Delete the branch if it has no commits
  if (shouldDeleteBranch && claudeBranch) {
    console.log(
      `Skipping branch deletion - not reliably supported across all Git platforms: ${claudeBranch}`,
    );
    // Skip deletion to avoid compatibility issues
  }

  return { shouldDeleteBranch, branchLink };
}