package app

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

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

func seedRepoWithFeatureBranch(t *testing.T, bare string) {
	t.Helper()
	if err := gitInitBare(bare); err != nil {
		t.Fatal(err)
	}
	work := filepath.Join(t.TempDir(), "work")
	if err := runGit("", "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 := runGit(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 := runGit(work, "add", "README.md"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "commit", "-m", "initial"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "push", "origin", "HEAD:main"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "checkout", "-b", "feature"); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(work, "feature.txt"), []byte("feature\n"), 0644); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "add", "feature.txt"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "commit", "-m", "feature"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "push", "origin", "HEAD:feature"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "tag", "v1.0.0"); err != nil {
		t.Fatal(err)
	}
	if err := runGit(work, "push", "origin", "v1.0.0"); err != nil {
		t.Fatal(err)
	}
}

func TestAppGitRefsDiffAndMerge(t *testing.T) {
	requireGitForApp(t)
	s, mock, cleanup := newMockServer(t)
	defer cleanup()
	bare := s.repoPath("alice", "demo")
	if err := os.MkdirAll(filepath.Dir(bare), 0755); err != nil {
		t.Fatal(err)
	}
	seedRepoWithFeatureBranch(t, bare)
	repo := Repository{ID: 10, OwnerUserID: 1, Owner: "alice", Name: "demo", Visibility: "public", DefaultBranch: "main"}

	expectLoadRepo(mock, "alice", "demo", repo)
	rr := httptest.NewRecorder()
	s.handleRepoBranches(rr, httptest.NewRequest(http.MethodGet, "/api/repos/alice/demo/branches", nil), "alice", "demo")
	if rr.Code != http.StatusOK {
		t.Fatalf("branches status=%d body=%s", rr.Code, rr.Body.String())
	}
	var refs []RefInfo
	if err := json.Unmarshal(rr.Body.Bytes(), &refs); err != nil {
		t.Fatal(err)
	}
	if len(refs) < 2 {
		t.Fatalf("expected main and feature refs, got %#v", refs)
	}

	expectLoadRepo(mock, "alice", "demo", repo)
	rr = httptest.NewRecorder()
	s.handleRepoTags(rr, httptest.NewRequest(http.MethodGet, "/api/repos/alice/demo/tags", nil), "alice", "demo")
	if rr.Code != http.StatusOK || !strings.Contains(rr.Body.String(), "v1.0.0") {
		t.Fatalf("tags status=%d body=%s", rr.Code, rr.Body.String())
	}

	pr := PullRequest{Number: 1, TargetOwner: "alice", TargetRepo: "demo", TargetBranch: "main", SourceOwner: "alice", SourceRepo: "demo", SourceBranch: "feature"}
	diff, err := s.prDiff(pr)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(diff, "feature.txt") {
		t.Fatalf("diff missing feature file: %s", diff)
	}
	if err := s.mergePR(pr); err != nil {
		t.Fatal(err)
	}
	if !gitBranchExists(bare, "main") {
		t.Fatal("main branch should exist after merge")
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatal(err)
	}
}