package gitutil

import (
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

func requireGit(t *testing.T) {
	t.Helper()
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("git not installed")
	}
}

func TestRunFailureIncludesCommandOutput(t *testing.T) {
	requireGit(t)
	err := Run("", "definitely-not-a-git-command")
	if err == nil {
		t.Fatal("expected git command to fail")
	}
	if !strings.Contains(err.Error(), "git definitely-not-a-git-command failed") {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestInitBareBranchExistsAndRefs(t *testing.T) {
	requireGit(t)
	root := t.TempDir()
	bare := filepath.Join(root, "repo.git")
	if err := InitBare(bare); err != nil {
		t.Fatal(err)
	}
	head, err := os.ReadFile(filepath.Join(bare, "HEAD"))
	if err != nil {
		t.Fatal(err)
	}
	if strings.TrimSpace(string(head)) != "ref: refs/heads/main" {
		t.Fatalf("HEAD = %q", string(head))
	}
	if BranchExists(bare, "main") {
		t.Fatal("new empty bare repo should not have a main branch commit yet")
	}
	if BranchExists(bare, "bad branch") {
		t.Fatal("invalid branch should not exist")
	}

	work := filepath.Join(root, "work")
	if err := Run("", "clone", bare, work); err != nil {
		t.Fatal(err)
	}
	for _, args := range [][]string{
		{"config", "user.name", "Test User"},
		{"config", "user.email", "test@example.com"},
	} {
		if err := Run(work, args...); err != nil {
			t.Fatal(err)
		}
	}
	if err := os.WriteFile(filepath.Join(work, "README.md"), []byte("hello\n"), 0644); err != nil {
		t.Fatal(err)
	}
	if err := Run(work, "add", "README.md"); err != nil {
		t.Fatal(err)
	}
	if err := Run(work, "commit", "-m", "initial commit"); err != nil {
		t.Fatal(err)
	}
	if err := Run(work, "push", "origin", "HEAD:main"); err != nil {
		t.Fatal(err)
	}
	if err := Run(work, "tag", "v1.0.0"); err != nil {
		t.Fatal(err)
	}
	if err := Run(work, "push", "origin", "v1.0.0"); err != nil {
		t.Fatal(err)
	}
	if !BranchExists(bare, "main") {
		t.Fatal("main branch should exist after push")
	}
	branches, err := Refs(bare, "refs/heads")
	if err != nil {
		t.Fatal(err)
	}
	if len(branches) != 1 || branches[0].Name != "main" || branches[0].Message != "initial commit" {
		t.Fatalf("unexpected branches: %#v", branches)
	}
	tags, err := Refs(bare, "refs/tags")
	if err != nil {
		t.Fatal(err)
	}
	if len(tags) != 1 || tags[0].Name != "v1.0.0" {
		t.Fatalf("unexpected tags: %#v", tags)
	}
}

func TestRefsInvalidRepo(t *testing.T) {
	requireGit(t)
	if _, err := Refs(filepath.Join(t.TempDir(), "missing.git"), "refs/heads"); err == nil {
		t.Fatal("expected missing repo refs to fail")
	}
}