git.go

package main

import (
	"bytes"
	"context"
	"fmt"
	"os"
	"os/exec"
	"strings"
)

// resolveRepo returns the repo directory, defaulting to cwd, and validates it is a git repo.
func resolveRepo(ctx context.Context, repoDir string) (string, error) {
	if repoDir == "" {
		var err error
		repoDir, err = os.Getwd()
		if err != nil {
			return "", fmt.Errorf("failed to get current directory: %w", err)
		}
	}
	out, err := exec.CommandContext(ctx, "git", "-C", repoDir, "rev-parse", "--git-dir").CombinedOutput()
	if err != nil {
		return "", fmt.Errorf("not a git repository: %s", strings.TrimSpace(string(out)))
	}
	return repoDir, nil
}

// resolveGitDir returns the absolute path to the .git directory for repoDir.
func resolveGitDir(ctx context.Context, repoDir string) (string, error) {
	out, err := exec.CommandContext(ctx, "git", "-C", repoDir, "rev-parse", "--absolute-git-dir").Output()
	if err != nil {
		return "", fmt.Errorf("failed to resolve git dir: %w", err)
	}
	return strings.TrimSpace(string(out)), nil
}

// runGit runs a git command with the full user environment and stdin connected
// to the controlling TTY, so ssh-agent / gpg-agent / pinentry work correctly.
// Stdout and stderr are captured and returned.
func runGit(ctx context.Context, args ...string) (stdout, stderr string, err error) {
	cmd := exec.CommandContext(ctx, "git", args...)
	cmd.Env = os.Environ()
	cmd.Stdin = os.Stdin
	var outBuf, errBuf bytes.Buffer
	cmd.Stdout = &outBuf
	cmd.Stderr = &errBuf
	err = cmd.Run()
	return strings.TrimSpace(outBuf.String()), strings.TrimSpace(errBuf.String()), err
}