package git

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

func TestInitBare(t *testing.T) {
	path := filepath.Join(t.TempDir(), "demo.git")
	if err := InitBare(path, "main"); err != nil {
		t.Fatalf("InitBare: %v", err)
	}

	head, err := os.ReadFile(filepath.Join(path, "HEAD"))
	if err != nil {
		t.Fatalf("read HEAD: %v", err)
	}
	if !strings.Contains(string(head), "ref: refs/heads/main") {
		t.Errorf("HEAD = %q, want ref: refs/heads/main", head)
	}

	cmd := exec.Command("git", "rev-parse", "--is-bare-repository")
	cmd.Dir = path
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("rev-parse: %v: %s", err, out)
	} else if strings.TrimSpace(string(out)) != "true" {
		t.Errorf("is-bare-repository = %q, want true", out)
	}
}

func TestInitBareReportsFailure(t *testing.T) {
	file := filepath.Join(t.TempDir(), "occupied")
	if err := os.WriteFile(file, []byte("x"), 0o644); err != nil {
		t.Fatalf("write file: %v", err)
	}
	if err := InitBare(file, "main"); err == nil {
		t.Error("InitBare over a regular file = nil, want error")
	}
}

func TestInitBareInstallsPostReceive(t *testing.T) {
	path := filepath.Join(t.TempDir(), "demo.git")
	if err := InitBare(path, "main"); err != nil {
		t.Fatalf("InitBare: %v", err)
	}
	hook := filepath.Join(path, "hooks", "post-receive")
	info, err := os.Stat(hook)
	if err != nil {
		t.Fatalf("stat post-receive: %v", err)
	}
	if info.Mode()&0o111 == 0 {
		t.Error("post-receive is not executable")
	}
	script, err := os.ReadFile(hook)
	if err != nil {
		t.Fatalf("read post-receive: %v", err)
	}
	for _, want := range []string{"SIMPLEGIT_BIN", "hook --repo", "dirname"} {
		if !strings.Contains(string(script), want) {
			t.Errorf("post-receive lacks %q: %q", want, script)
		}
	}
}

func TestDefaultBranchRoundTrip(t *testing.T) {
	path := filepath.Join(t.TempDir(), "demo.git")
	if err := InitBare(path, "main"); err != nil {
		t.Fatalf("InitBare: %v", err)
	}
	if branch, err := DefaultBranch(path); err != nil || branch != "main" {
		t.Fatalf("DefaultBranch = %q, %v; want main", branch, err)
	}
	if err := SetDefaultBranch(path, "trunk"); err != nil {
		t.Fatalf("SetDefaultBranch: %v", err)
	}
	if branch, err := DefaultBranch(path); err != nil || branch != "trunk" {
		t.Errorf("DefaultBranch after set = %q, %v; want trunk", branch, err)
	}
}