package git

import (
	"fmt"
	"os/exec"
	"regexp"
	"strings"
)

// Remote holds the parsed coordinates of a git remote.
type Remote struct {
	Host  string
	Owner string
	Repo  string
}

var (
	httpsRE = regexp.MustCompile(`^https?://(?:[^@]+@)?([^/:]+)(?::\d+)?/([^/]+)/([^/]+?)(?:\.git)?/?$`)
	sshRE   = regexp.MustCompile(`^(?:ssh://)?(?:[^@]+@)?([^/:]+)[:/]([^/]+)/([^/]+?)(?:\.git)?/?$`)
)

// ParseRemoteURL parses a git remote URL into its Host, Owner, and Repo parts.
// Supports https, ssh (git@host:owner/repo), and ssh:// forms.
func ParseRemoteURL(url string) (*Remote, error) {
	trimmed := strings.TrimSpace(url)
	if trimmed == "" {
		return nil, fmt.Errorf("empty remote URL")
	}

	if m := httpsRE.FindStringSubmatch(trimmed); m != nil {
		return &Remote{Host: m[1], Owner: m[2], Repo: m[3]}, nil
	}

	if m := sshRE.FindStringSubmatch(trimmed); m != nil {
		return &Remote{Host: m[1], Owner: m[2], Repo: m[3]}, nil
	}

	return nil, fmt.Errorf("unrecognized remote URL format: %q", trimmed)
}

// DetectRepo resolves the origin remote URL for the given workspace root
// and parses it into a Remote.
func DetectRepo(workspaceRoot string) (*Remote, error) {
	out, err := exec.Command("git", "-C", workspaceRoot, "remote", "get-url", "origin").Output()
	if err != nil {
		return nil, fmt.Errorf("git remote get-url origin: %w", err)
	}
	return ParseRemoteURL(strings.TrimSpace(string(out)))
}