package github

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"net/http/httptest"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/jmoiron/sqlx"
	_ "github.com/mattn/go-sqlite3"

	"github.com/kandev/kandev/internal/common/logger"
	"github.com/kandev/kandev/internal/events/bus"
)

func TestParseLinkNext(t *testing.T) {
	tests := []struct {
		link string
		want string
	}{
		{
			link: `<https://api.github.com/repos/o/r/branches?page=2>; rel="next", <https://api.github.com/repos/o/r/branches?page=3>; rel="last"`,
			want: "https://api.github.com/repos/o/r/branches?page=2",
		},
		{
			link: `<https://api.github.com/repos/o/r/branches?page=3>; rel="last"`,
			want: "",
		},
		{link: "", want: ""},
	}
	for _, tc := range tests {
		got := parseLinkNext(tc.link)
		if got != tc.want {
			t.Errorf("parseLinkNext(%q) = %q, want %q", tc.link, got, tc.want)
		}
	}
}

func TestListRepoBranches_Pagination(t *testing.T) {
	page := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		page++
		if page == 1 {
			w.Header().Set("Link", fmt.Sprintf(`<%s/repos/owner/repo/branches?page=2>; rel="next"`, "http://"+r.Host))
			_ = json.NewEncoder(w).Encode([]map[string]any{{"name": "feature-a"}})
		} else {
			_ = json.NewEncoder(w).Encode([]map[string]any{{"name": "main"}})
		}
	}))
	defer srv.Close()

	orig := anonymousAPIBase
	anonymousAPIBase = srv.URL
	defer func() { anonymousAPIBase = orig }()

	svc := &Service{client: &NoopClient{}}
	branches, err := svc.ListRepoBranches(context.Background(), "owner", "repo")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(branches) != 2 {
		t.Fatalf("expected 2 branches across pages, got %d", len(branches))
	}
	// main should appear first regardless of which page it was fetched from.
	if branches[0].Name != "main" {
		t.Errorf("expected main first, got %q; branches: %+v", branches[0].Name, branches)
	}
	if branches[1].Name != "feature-a" {
		t.Errorf("expected feature-a second, got %q", branches[1].Name)
	}
}

func TestListRepoBranches_NoopClientFallback(t *testing.T) {
	// A fake GitHub API that returns two branches for a public repo.
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/repos/owner/repo/branches" {
			http.NotFound(w, r)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode([]map[string]any{
			{"name": "main"},
			{"name": "develop"},
		})
	}))
	defer srv.Close()

	orig := anonymousAPIBase
	anonymousAPIBase = srv.URL
	defer func() { anonymousAPIBase = orig }()

	svc := &Service{client: &NoopClient{}}
	branches, err := svc.ListRepoBranches(context.Background(), "owner", "repo")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(branches) != 2 {
		t.Fatalf("expected 2 branches, got %d", len(branches))
	}
	if branches[0].Name != "main" || branches[1].Name != "develop" {
		t.Errorf("unexpected branches: %+v", branches)
	}
}

func TestListRepoBranches_NoopClientFallback_NotFound(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, `{"message":"Not Found"}`, http.StatusNotFound)
	}))
	defer srv.Close()

	orig := anonymousAPIBase
	anonymousAPIBase = srv.URL
	defer func() { anonymousAPIBase = orig }()

	svc := &Service{client: &NoopClient{}}
	_, err := svc.ListRepoBranches(context.Background(), "owner", "private-repo")
	if err == nil {
		t.Fatal("expected error for private/missing repo")
	}
	var apiErr *GitHubAPIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected GitHubAPIError, got %T: %v", err, err)
	}
	if apiErr.StatusCode != http.StatusNotFound {
		t.Errorf("expected 404 status, got %d", apiErr.StatusCode)
	}
}

func TestGetPRAndIssue_FallBackWithoutClient(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		switch r.URL.Path {
		case "/repos/owner/repo/pulls/7":
			_, _ = w.Write([]byte(`{"number":7,"title":"Public PR","state":"open","head":{"ref":"feature"},"base":{"ref":"main"},"user":{"login":"alice"}}`))
		case "/repos/owner/repo/issues/8":
			_, _ = w.Write([]byte(`{"number":8,"title":"Public issue","state":"open","user":{"login":"alice"}}`))
		default:
			http.NotFound(w, r)
		}
	}))
	defer srv.Close()

	orig := anonymousAPIBase
	anonymousAPIBase = srv.URL
	defer func() { anonymousAPIBase = orig }()

	for _, client := range []Client{nil, &NoopClient{}} {
		svc := &Service{client: client}
		pr, err := svc.GetPR(context.Background(), "owner", "repo", 7)
		if err != nil {
			t.Fatalf("GetPR() error = %v", err)
		}
		if pr.Title != "Public PR" {
			t.Fatalf("GetPR() title = %q, want public PR", pr.Title)
		}

		issue, err := svc.GetIssue(context.Background(), "owner", "repo", 8)
		if err != nil {
			t.Fatalf("GetIssue() error = %v", err)
		}
		if issue.Title != "Public issue" {
			t.Fatalf("GetIssue() title = %q, want public issue", issue.Title)
		}
	}
}

func TestGetPRAndIssue_AuthenticatedErrorsAreAuthoritative(t *testing.T) {
	orig := anonymousAPIBase
	anonymousAPIBase = "http://127.0.0.1:1"
	defer func() { anonymousAPIBase = orig }()

	prErr := &GitHubAPIError{StatusCode: http.StatusForbidden}
	issueErr := &GitHubAPIError{StatusCode: http.StatusNotFound}
	svc := &Service{client: &stubClient{
		getPRFunc: func(context.Context, string, string, int) (*PR, error) { return nil, prErr },
		getIssueFunc: func(context.Context, string, string, int) (*Issue, error) {
			return nil, issueErr
		},
	}}

	if _, err := svc.GetPR(context.Background(), "owner", "repo", 7); !errors.Is(err, prErr) {
		t.Fatalf("GetPR() error = %v, want authenticated 403", err)
	}
	if _, err := svc.GetIssue(context.Background(), "owner", "repo", 8); !errors.Is(err, issueErr) {
		t.Fatalf("GetIssue() error = %v, want authenticated 404", err)
	}
}

func TestGetPRAndIssue_AnonymousStatusIsPreserved(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.Path, "/pulls/") {
			w.WriteHeader(http.StatusForbidden)
			return
		}
		w.WriteHeader(http.StatusNotFound)
	}))
	defer srv.Close()

	orig := anonymousAPIBase
	anonymousAPIBase = srv.URL
	defer func() { anonymousAPIBase = orig }()

	svc := &Service{}
	for _, request := range []struct {
		name   string
		call   func() error
		status int
	}{
		{name: "PR", call: func() error { _, err := svc.GetPR(t.Context(), "owner", "repo", 7); return err }, status: http.StatusForbidden},
		{name: "issue", call: func() error { _, err := svc.GetIssue(t.Context(), "owner", "repo", 8); return err }, status: http.StatusNotFound},
	} {
		t.Run(request.name, func(t *testing.T) {
			err := request.call()
			var apiErr *GitHubAPIError
			if !errors.As(err, &apiErr) || apiErr.StatusCode != request.status {
				t.Fatalf("error = %v, want GitHub API status %d", err, request.status)
			}
		})
	}
}

func TestSortBranchesMainFirst(t *testing.T) {
	tests := []struct {
		input []string
		want  []string
	}{
		{
			input: []string{"feature-b", "main", "feature-a", "master"},
			want:  []string{"main", "master", "feature-a", "feature-b"},
		},
		{
			input: []string{"develop", "master"},
			want:  []string{"master", "develop"},
		},
		{
			input: []string{"feature-a", "feature-b"},
			want:  []string{"feature-a", "feature-b"},
		},
		{
			input: []string{"main"},
			want:  []string{"main"},
		},
		{
			input: []string{},
			want:  []string{},
		},
	}
	for _, tc := range tests {
		branches := make([]RepoBranch, len(tc.input))
		for i, n := range tc.input {
			branches[i] = RepoBranch{Name: n}
		}
		sortBranchesMainFirst(branches)
		for i, b := range branches {
			if b.Name != tc.want[i] {
				t.Errorf("input=%v: got[%d]=%q, want %q", tc.input, i, b.Name, tc.want[i])
			}
		}
	}
}

func TestGetPRFeedback_NilClient(t *testing.T) {
	svc := &Service{client: nil}
	_, err := svc.GetPRFeedback(context.Background(), "owner", "repo", 1)
	if err == nil {
		t.Fatal("expected error when client is nil")
	}
	if !strings.Contains(err.Error(), "github client not available") {
		t.Errorf("unexpected error: %v", err)
	}
}

func TestParsePRURL(t *testing.T) {
	tests := []struct {
		name       string
		url        string
		wantOwner  string
		wantRepo   string
		wantNumber int
		wantErr    bool
	}{
		{
			name:       "standard URL",
			url:        "https://github.com/owner/repo/pull/123",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 123,
		},
		{
			name:       "trailing slash",
			url:        "https://github.com/owner/repo/pull/456/",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 456,
		},
		{
			name:       "with query params",
			url:        "https://github.com/owner/repo/pull/789?diff=unified",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 789,
		},
		{
			name:       "with fragment",
			url:        "https://github.com/owner/repo/pull/42#discussion_r123",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 42,
		},
		{
			name:       "with query and fragment",
			url:        "https://github.com/owner/repo/pull/10?a=b#frag",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 10,
		},
		{
			name:       "with whitespace",
			url:        "  https://github.com/owner/repo/pull/5  \n",
			wantOwner:  "owner",
			wantRepo:   "repo",
			wantNumber: 5,
		},
		{
			name:    "no pull segment",
			url:     "https://github.com/owner/repo/issues/1",
			wantErr: true,
		},
		{
			name:    "invalid PR number",
			url:     "https://github.com/owner/repo/pull/abc",
			wantErr: true,
		},
		{
			name:    "zero PR number",
			url:     "https://github.com/owner/repo/pull/0",
			wantErr: true,
		},
		{
			name:    "negative PR number",
			url:     "https://github.com/owner/repo/pull/-1",
			wantErr: true,
		},
		{
			name:    "too short path",
			url:     "/pull/1",
			wantErr: true,
		},
		{
			name:    "empty owner",
			url:     "https://github.com//repo/pull/1",
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			owner, repo, number, err := parsePRURL(tt.url)
			if tt.wantErr {
				if err == nil {
					t.Errorf("expected error, got nil")
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if owner != tt.wantOwner {
				t.Errorf("owner = %q, want %q", owner, tt.wantOwner)
			}
			if repo != tt.wantRepo {
				t.Errorf("repo = %q, want %q", repo, tt.wantRepo)
			}
			if number != tt.wantNumber {
				t.Errorf("number = %d, want %d", number, tt.wantNumber)
			}
		})
	}
}

func TestComputeOverallCheckStatus(t *testing.T) {
	tests := []struct {
		name   string
		checks []CheckRun
		want   string
	}{
		{"empty", nil, ""},
		{
			"all completed success",
			[]CheckRun{
				{Status: "completed", Conclusion: "success"},
				{Status: "completed", Conclusion: "success"},
			},
			"success",
		},
		{
			"one failure",
			[]CheckRun{
				{Status: "completed", Conclusion: "success"},
				{Status: "completed", Conclusion: "failure"},
			},
			"failure",
		},
		{
			"failure takes priority over pending",
			[]CheckRun{
				{Status: "in_progress"},
				{Status: "completed", Conclusion: "failure"},
			},
			"failure",
		},
		{
			"pending when in progress",
			[]CheckRun{
				{Status: "completed", Conclusion: "success"},
				{Status: "in_progress"},
			},
			"pending",
		},
		{
			"all in progress",
			[]CheckRun{
				{Status: "queued"},
				{Status: "in_progress"},
			},
			"pending",
		},
		{
			// Regression for the "CI pending" badge bug: GitHub shows
			// "All checks have passed — 1 skipped, 20 successful" but
			// we were returning pending because the skipped runs weren't
			// treated as completed-successful.
			"AllSkipped mixed with success returns success",
			func() []CheckRun {
				checks := make([]CheckRun, 21)
				for i := 0; i < 20; i++ {
					checks[i] = CheckRun{Status: "completed", Conclusion: "success"}
				}
				checks[20] = CheckRun{Status: "completed", Conclusion: "skipped"}
				return checks
			}(),
			"success",
		},
		{
			"only skipped returns empty (no signal)",
			[]CheckRun{
				{Status: "completed", Conclusion: "skipped"},
				{Status: "completed", Conclusion: "skipped"},
			},
			"",
		},
		{
			"only neutral returns empty (no signal)",
			[]CheckRun{
				{Status: "completed", Conclusion: "neutral"},
				{Status: "completed", Conclusion: "neutral"},
			},
			"",
		},
		{
			"unknown future conclusion treated as passing",
			[]CheckRun{
				{Status: "completed", Conclusion: "stale"}, // hypothetical future enum
			},
			"success",
		},
		{
			"neutral conclusion is ignored like skipped",
			[]CheckRun{
				{Status: "completed", Conclusion: "success"},
				{Status: "completed", Conclusion: "neutral"},
			},
			"success",
		},
		{
			"cancelled conclusion counts as failure",
			[]CheckRun{
				{Status: "completed", Conclusion: "success"},
				{Status: "completed", Conclusion: "cancelled"},
			},
			"failure",
		},
		{
			"timed_out conclusion counts as failure",
			[]CheckRun{
				{Status: "completed", Conclusion: "timed_out"},
			},
			"failure",
		},
		{
			"action_required conclusion counts as failure",
			[]CheckRun{
				{Status: "completed", Conclusion: "action_required"},
			},
			"failure",
		},
		{
			"in_progress plus skipped returns pending (skipped ignored)",
			[]CheckRun{
				{Status: "in_progress"},
				{Status: "completed", Conclusion: "skipped"},
			},
			"pending",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := computeOverallCheckStatus(tt.checks)
			if got != tt.want {
				t.Errorf("computeOverallCheckStatus() = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestComputeOverallReviewState(t *testing.T) {
	t1 := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
	t2 := time.Date(2025, 1, 2, 0, 0, 0, 0, time.UTC)

	tests := []struct {
		name    string
		reviews []PRReview
		want    string
	}{
		{"empty", nil, ""},
		{
			"all approved",
			[]PRReview{
				{Author: "alice", State: "APPROVED", CreatedAt: t1},
				{Author: "bob", State: "APPROVED", CreatedAt: t1},
			},
			"approved",
		},
		{
			"changes requested",
			[]PRReview{
				{Author: "alice", State: "APPROVED", CreatedAt: t1},
				{Author: "bob", State: "CHANGES_REQUESTED", CreatedAt: t1},
			},
			"changes_requested",
		},
		{
			"latest per author wins",
			[]PRReview{
				{Author: "alice", State: "CHANGES_REQUESTED", CreatedAt: t1},
				{Author: "alice", State: "APPROVED", CreatedAt: t2},
			},
			"approved",
		},
		{
			"pending when not all approved",
			[]PRReview{
				{Author: "alice", State: "APPROVED", CreatedAt: t1},
				{Author: "bob", State: "COMMENTED", CreatedAt: t1},
			},
			"pending",
		},
		{
			"changes requested takes priority over pending",
			[]PRReview{
				{Author: "alice", State: "COMMENTED", CreatedAt: t1},
				{Author: "bob", State: "CHANGES_REQUESTED", CreatedAt: t1},
			},
			"changes_requested",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := computeOverallReviewState(tt.reviews)
			if got != tt.want {
				t.Errorf("computeOverallReviewState() = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestCountPendingReviews(t *testing.T) {
	t1 := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
	t2 := time.Date(2025, 1, 2, 0, 0, 0, 0, time.UTC)

	tests := []struct {
		name    string
		reviews []PRReview
		want    int
	}{
		{"empty", nil, 0},
		{
			"no pending",
			[]PRReview{
				{Author: "alice", State: "APPROVED", CreatedAt: t1},
			},
			0,
		},
		{
			"one pending",
			[]PRReview{
				{Author: "alice", State: "PENDING", CreatedAt: t1},
			},
			1,
		},
		{
			"commented counts as pending",
			[]PRReview{
				{Author: "alice", State: "COMMENTED", CreatedAt: t1},
			},
			1,
		},
		{
			"latest per author wins",
			[]PRReview{
				{Author: "alice", State: "COMMENTED", CreatedAt: t1},
				{Author: "alice", State: "APPROVED", CreatedAt: t2},
			},
			0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := countPendingReviews(tt.reviews)
			if got != tt.want {
				t.Errorf("countPendingReviews() = %d, want %d", got, tt.want)
			}
		})
	}
}

func TestCountPendingRequestedReviewers(t *testing.T) {
	tests := []struct {
		name string
		pr   *PR
		want int
	}{
		{"nil pr", nil, 0},
		{"none", &PR{}, 0},
		{
			"with requested reviewers",
			&PR{
				RequestedReviewers: []RequestedReviewer{
					{Login: "alice", Type: reviewerTypeUser},
					{Login: "core-team", Type: reviewerTypeTeam},
				},
			},
			2,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := countPendingRequestedReviewers(tt.pr)
			if got != tt.want {
				t.Errorf("countPendingRequestedReviewers() = %d, want %d", got, tt.want)
			}
		})
	}
}

func TestDeriveReviewSyncState(t *testing.T) {
	t1 := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
	tests := []struct {
		name      string
		pr        *PR
		reviews   []PRReview
		wantState string
		wantCount int
	}{
		{
			name:      "uses requested reviewers before review-derived pending",
			pr:        &PR{RequestedReviewers: []RequestedReviewer{{Login: "alice", Type: reviewerTypeUser}}},
			reviews:   []PRReview{{Author: "alice", State: reviewStateCommented, CreatedAt: t1}},
			wantState: computedReviewStatePending,
			wantCount: 1,
		},
		{
			name:      "fallback to review-derived pending when no requests",
			pr:        &PR{},
			reviews:   []PRReview{{Author: "alice", State: reviewStateCommented, CreatedAt: t1}},
			wantState: computedReviewStatePending,
			wantCount: 1,
		},
		{
			name:      "no submitted reviews but pending requests yields pending state",
			pr:        &PR{RequestedReviewers: []RequestedReviewer{{Login: "core", Type: reviewerTypeTeam}}},
			reviews:   nil,
			wantState: computedReviewStatePending,
			wantCount: 1,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			gotState, gotCount := deriveReviewSyncState(tt.pr, tt.reviews)
			if gotState != tt.wantState {
				t.Errorf("deriveReviewSyncState() state = %q, want %q", gotState, tt.wantState)
			}
			if gotCount != tt.wantCount {
				t.Errorf("deriveReviewSyncState() pending count = %d, want %d", gotCount, tt.wantCount)
			}
		})
	}
}

func TestFindLatestCommentTime(t *testing.T) {
	t1 := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
	t2 := time.Date(2025, 1, 5, 0, 0, 0, 0, time.UTC)
	t3 := time.Date(2025, 1, 3, 0, 0, 0, 0, time.UTC)

	tests := []struct {
		name     string
		comments []PRComment
		want     *time.Time
	}{
		{"empty", nil, nil},
		{
			"single",
			[]PRComment{{UpdatedAt: t1}},
			&t1,
		},
		{
			"multiple",
			[]PRComment{
				{UpdatedAt: t1},
				{UpdatedAt: t2},
				{UpdatedAt: t3},
			},
			&t2,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := findLatestCommentTime(tt.comments)
			if tt.want == nil {
				if got != nil {
					t.Errorf("expected nil, got %v", got)
				}
				return
			}
			if got == nil {
				t.Fatal("expected non-nil, got nil")
			}
			if !got.Equal(*tt.want) {
				t.Errorf("got %v, want %v", *got, *tt.want)
			}
		})
	}
}

// --- mockEventBus shared by SyncTaskPR and review-watch tests ---

type mockEventBus struct {
	mu          sync.Mutex
	events      []*bus.Event
	publishedCh chan struct{}
	err         error
}

func (m *mockEventBus) Publish(_ context.Context, _ string, event *bus.Event) error {
	if m.err != nil {
		return m.err
	}
	m.mu.Lock()
	m.events = append(m.events, event)
	m.mu.Unlock()
	if m.publishedCh != nil {
		select {
		case m.publishedCh <- struct{}{}:
		default:
		}
	}
	return nil
}

func (m *mockEventBus) Subscribe(string, bus.EventHandler) (bus.Subscription, error) {
	return nil, nil
}

func (m *mockEventBus) QueueSubscribe(string, string, bus.EventHandler) (bus.Subscription, error) {
	return nil, nil
}

func (m *mockEventBus) Request(context.Context, string, *bus.Event, time.Duration) (*bus.Event, error) {
	return nil, nil
}

func (m *mockEventBus) Close() {}

func (m *mockEventBus) IsConnected() bool { return true }

func (m *mockEventBus) publishedCount() int {
	m.mu.Lock()
	defer m.mu.Unlock()
	return len(m.events)
}

// setupSyncTest creates a Service backed by in-memory SQLite and a mock event bus.
func setupSyncTest(t *testing.T) (*Service, *Store, *mockEventBus) {
	t.Helper()

	rawDB, err := sql.Open("sqlite3", ":memory:")
	if err != nil {
		t.Fatalf("open sqlite: %v", err)
	}
	rawDB.SetMaxOpenConns(1)
	rawDB.SetMaxIdleConns(1)
	sqlxDB := sqlx.NewDb(rawDB, "sqlite3")
	t.Cleanup(func() { _ = sqlxDB.Close() })

	store, err := NewStore(sqlxDB, sqlxDB)
	if err != nil {
		t.Fatalf("new store: %v", err)
	}

	log, _ := logger.NewLogger(logger.LoggingConfig{Level: "error", Format: "console"})
	eb := &mockEventBus{}
	svc := NewService(nil, "pat", nil, store, eb, log)

	return svc, store, eb
}

func TestSyncTaskPR_PublishesEventOnChange(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()

	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:     "t1",
		Owner:      "owner",
		Repo:       "repo",
		PRNumber:   1,
		PRURL:      "https://github.com/owner/repo/pull/1",
		PRTitle:    "Initial",
		HeadBranch: "feat",
		BaseBranch: "main",
		State:      "open",
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}

	status := &PRStatus{
		PR: &PR{
			Number:    1,
			Title:     "Updated title",
			State:     "open",
			RepoOwner: "owner",
			RepoName:  "repo",
		},
	}

	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync task PR: %v", err)
	}

	if got := eb.publishedCount(); got != 1 {
		t.Errorf("expected 1 event after change, got %d", got)
	}
}

func TestSyncTaskPR_NoEventWhenUnchanged(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()

	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:      "t1",
		Owner:       "owner",
		Repo:        "repo",
		PRNumber:    1,
		PRURL:       "https://github.com/owner/repo/pull/1",
		PRTitle:     "Same title",
		HeadBranch:  "feat",
		BaseBranch:  "main",
		State:       "open",
		Additions:   10,
		Deletions:   5,
		ReviewState: "approved",
		ChecksState: "success",
		ReviewCount: 2,
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}

	status := &PRStatus{
		PR: &PR{
			Number:    1,
			Title:     "Same title",
			State:     "open",
			Additions: 10,
			Deletions: 5,
			RepoOwner: "owner",
			RepoName:  "repo",
		},
		ReviewState: "approved",
		ChecksState: "success",
		ReviewCount: 2,
	}

	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync task PR: %v", err)
	}

	if got := eb.publishedCount(); got != 0 {
		t.Errorf("expected 0 events when unchanged, got %d", got)
	}
}

func TestSyncTaskPR_SecondIdenticalSyncNoEvent(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()

	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:     "t1",
		Owner:      "owner",
		Repo:       "repo",
		PRNumber:   1,
		PRURL:      "https://github.com/owner/repo/pull/1",
		PRTitle:    "Original",
		HeadBranch: "feat",
		BaseBranch: "main",
		State:      "open",
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}

	status := &PRStatus{
		PR: &PR{
			Number:    1,
			Title:     "Changed",
			State:     "open",
			RepoOwner: "owner",
			RepoName:  "repo",
		},
	}

	// First sync: data changed -> event.
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("first sync: %v", err)
	}
	if got := eb.publishedCount(); got != 1 {
		t.Fatalf("expected 1 event after first sync, got %d", got)
	}

	// Second sync with same data -> no additional event.
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("second sync: %v", err)
	}
	if got := eb.publishedCount(); got != 1 {
		t.Errorf("expected still 1 event after identical second sync, got %d", got)
	}
}

func TestSyncTaskPR_EquivalentRESTAndGraphQLStatusNoSecondEvent(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()
	createdAt := time.Date(2026, 8, 17, 10, 0, 0, 0, time.UTC)
	updatedAt := createdAt.Add(time.Hour)
	pr := &PR{
		Number:         1,
		Title:          "Same status",
		URL:            "https://github.com/owner/repo/pull/1",
		HTMLURL:        "https://github.com/owner/repo/pull/1",
		State:          "open",
		HeadBranch:     "feat",
		HeadSHA:        "abc",
		BaseBranch:     "main",
		AuthorLogin:    "alice",
		RepoOwner:      "owner",
		RepoName:       "repo",
		Mergeable:      true,
		MergeableState: "clean",
		Additions:      3,
		Deletions:      1,
		CreatedAt:      createdAt,
		UpdatedAt:      updatedAt,
	}
	restStatus := newPRStatus(
		pr,
		[]PRReview{{Author: "alice", State: reviewStateApproved, CreatedAt: updatedAt}},
		[]CheckRun{{Status: checkStatusCompleted, Conclusion: checkConclusionSuccess}},
	)
	raw := &batchedPRResult{
		State:       "OPEN",
		Title:       pr.Title,
		URL:         pr.URL,
		HeadRefName: pr.HeadBranch,
		BaseRefName: pr.BaseBranch,
		HeadRefOid:  pr.HeadSHA,
		Additions:   pr.Additions,
		Deletions:   pr.Deletions,
		CreatedAt:   pr.CreatedAt,
		UpdatedAt:   pr.UpdatedAt,
	}
	raw.Author.Login = pr.AuthorLogin
	raw.Mergeable = "MERGEABLE"
	raw.MergeStatus = "CLEAN"
	raw.Reviews.Nodes = []reviewNode{{State: "APPROVED"}}
	raw.Reviews.Nodes[0].Author.Login = "alice"
	raw.Reviews.Nodes[0].SubmittedAt = updatedAt
	raw.Commits.Nodes = []struct {
		Commit struct {
			StatusCheckRollup *struct {
				State string `json:"state"`
			} `json:"statusCheckRollup"`
		} `json:"commit"`
	}{{}}
	raw.Commits.Nodes[0].Commit.StatusCheckRollup = &struct {
		State string `json:"state"`
	}{State: "SUCCESS"}
	graphqlStatus := convertBatchedPRResult(raw, "owner", "repo", 1)
	if graphqlStatus.ChecksState != restStatus.ChecksState {
		t.Fatalf("GraphQL checks state = %q, REST = %q", graphqlStatus.ChecksState, restStatus.ChecksState)
	}
	if graphqlStatus.ReviewState != restStatus.ReviewState || graphqlStatus.ReviewCount != restStatus.ReviewCount {
		t.Fatalf("GraphQL review summary = (%q, %d), REST = (%q, %d)", graphqlStatus.ReviewState, graphqlStatus.ReviewCount, restStatus.ReviewState, restStatus.ReviewCount)
	}
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:     "t1",
		Owner:      "owner",
		Repo:       "repo",
		PRNumber:   1,
		PRURL:      pr.URL,
		PRTitle:    "Old title",
		HeadBranch: pr.HeadBranch,
		BaseBranch: pr.BaseBranch,
		State:      "open",
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}
	if err := svc.SyncTaskPR(ctx, "t1", restStatus); err != nil {
		t.Fatalf("REST sync: %v", err)
	}
	if err := svc.SyncTaskPR(ctx, "t1", graphqlStatus); err != nil {
		t.Fatalf("GraphQL sync: %v", err)
	}
	if got := eb.publishedCount(); got != 1 {
		t.Fatalf("equivalent REST and GraphQL snapshots published %d events, want 1", got)
	}
}

func TestSyncTaskPR_ChangedFields(t *testing.T) {
	taskPR := &TaskPR{
		State:              "open",
		PRTitle:            "before",
		Additions:          1,
		Deletions:          2,
		ReviewState:        "pending",
		ChecksState:        "pending",
		MergeableState:     "blocked",
		ReviewCount:        1,
		PendingReviewCount: 2,
		ChecksTotal:        3,
		ChecksPassing:      1,
		BaseBranch:         "main",
	}
	status := &PRStatus{PR: &PR{Title: "after", State: "merged", Additions: 4, Deletions: 5, BaseBranch: "release", MergeableState: "clean"}, ReviewState: "approved", ChecksState: "success", ReviewCount: 2, PendingReviewCount: 0, ChecksTotal: 4, ChecksPassing: 4}
	next := taskPRSyncState{
		state: "merged", mergeableState: "clean", reviewCount: 2, pendingReviewCount: 0,
		checksTotal: 4, checksPassing: 4, baseBranch: "release",
	}
	want := []string{"state", "pr_title", "additions", "deletions", "review_state", "checks_state", "mergeable_state", "review_count", "pending_review_count", "checks_total", "checks_passing", "base_branch"}
	got := taskPRChangedFields(taskPR, status, next)
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("taskPRChangedFields() = %#v, want %#v", got, want)
	}
}

func TestSyncTaskPR_PublishesEventOnMergeableStateChange(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()

	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:         "t1",
		Owner:          "owner",
		Repo:           "repo",
		PRNumber:       1,
		PRURL:          "https://github.com/owner/repo/pull/1",
		PRTitle:        "Same",
		HeadBranch:     "feat",
		BaseBranch:     "main",
		State:          "open",
		Additions:      3,
		Deletions:      1,
		ReviewState:    "approved",
		ChecksState:    "success",
		MergeableState: "blocked",
		ReviewCount:    1,
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}

	// Only mergeable_state changes (blocked -> clean); everything else identical.
	status := &PRStatus{
		PR: &PR{
			Number:    1,
			Title:     "Same",
			State:     "open",
			Additions: 3,
			Deletions: 1,
			RepoOwner: "owner",
			RepoName:  "repo",
		},
		ReviewState:    "approved",
		ChecksState:    "success",
		MergeableState: "clean",
		ReviewCount:    1,
	}

	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	if got := eb.publishedCount(); got != 1 {
		t.Errorf("expected 1 event after mergeable_state change, got %d", got)
	}

	stored, err := store.GetTaskPR(ctx, "t1")
	if err != nil {
		t.Fatalf("get task PR: %v", err)
	}
	if stored.MergeableState != "clean" {
		t.Errorf("expected stored mergeable_state=clean, got %q", stored.MergeableState)
	}
}

func TestSyncTaskPR_DraftOverridesCleanMergeableState(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()

	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:         "t1",
		Owner:          "owner",
		Repo:           "repo",
		PRNumber:       1,
		PRURL:          "https://github.com/owner/repo/pull/1",
		PRTitle:        "Draft change",
		HeadBranch:     "feat",
		BaseBranch:     "main",
		State:          "open",
		ChecksState:    "success",
		MergeableState: "clean",
	}); err != nil {
		t.Fatalf("create task PR: %v", err)
	}

	status := &PRStatus{
		PR: &PR{
			Number:         1,
			Title:          "Draft change",
			State:          "open",
			Draft:          true,
			RepoOwner:      "owner",
			RepoName:       "repo",
			MergeableState: "clean",
		},
		ChecksState:    "success",
		MergeableState: "clean",
	}

	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	if got := eb.publishedCount(); got != 1 {
		t.Fatalf("expected draft normalization to publish an update, got %d events", got)
	}

	stored, err := store.GetTaskPR(ctx, "t1")
	if err != nil {
		t.Fatalf("get task PR: %v", err)
	}
	if stored.MergeableState != "draft" {
		t.Fatalf("stored mergeable_state = %q, want draft", stored.MergeableState)
	}
}

// TestSyncTaskPR_ChecksPopulated_PreservesOnLightweightSync verifies the
// "preserve when batch sync didn't populate" path: a PRStatus with
// ChecksPopulated=false must NOT clobber the persisted ChecksTotal /
// ChecksPassing, even when status carries 0/0.
func TestSyncTaskPR_ChecksPopulated_PreservesOnLightweightSync(t *testing.T) {
	svc, store, _ := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID:        "t1",
		Owner:         "owner",
		Repo:          "repo",
		PRNumber:      1,
		PRURL:         "https://github.com/owner/repo/pull/1",
		HeadBranch:    "feat",
		BaseBranch:    "main",
		State:         "open",
		ChecksTotal:   10,
		ChecksPassing: 7,
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR:              &PR{Number: 1, State: "open", RepoOwner: "owner", RepoName: "repo"},
		ChecksTotal:     0,
		ChecksPassing:   0,
		ChecksPopulated: false, // batched GraphQL path: didn't count
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, err := store.GetTaskPR(ctx, "t1")
	if err != nil {
		t.Fatalf("get: %v", err)
	}
	if stored.ChecksTotal != 10 || stored.ChecksPassing != 7 {
		t.Fatalf("counts clobbered: total=%d passing=%d (want 10/7)", stored.ChecksTotal, stored.ChecksPassing)
	}
}

// TestSyncTaskPR_ChecksPopulated_AcceptsRealZero verifies the design fix:
// when the rich sync path explicitly reports 0/0 (workflows removed from
// the PR), we DO honor the new value instead of clinging to stale totals.
func TestSyncTaskPR_ChecksPopulated_AcceptsRealZero(t *testing.T) {
	svc, store, _ := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
		HeadBranch: "feat", BaseBranch: "main", State: "open",
		ChecksTotal: 5, ChecksPassing: 5,
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR:              &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
		ChecksTotal:     0,
		ChecksPassing:   0,
		ChecksPopulated: true, // REST path: counted to zero
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, _ := store.GetTaskPR(ctx, "t1")
	if stored.ChecksTotal != 0 || stored.ChecksPassing != 0 {
		t.Fatalf("real-zero not honored: total=%d passing=%d", stored.ChecksTotal, stored.ChecksPassing)
	}
}

// TestSyncTaskPR_ReviewCounts_PreservesOnLightweightSync covers the same
// preserve-on-not-populated dance for ReviewCount/PendingReviewCount as the
// checks/threads variants. A partial sync path (status.ReviewCountsPopulated
// = false) must not reset the popover's "Approved (N)" line to zero.
func TestSyncTaskPR_ReviewCounts_PreservesOnLightweightSync(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
		HeadBranch: "feat", BaseBranch: "main", State: "open",
		ReviewCount: 2, PendingReviewCount: 1,
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR:                    &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
		ReviewCount:           0,
		PendingReviewCount:    0,
		ReviewCountsPopulated: false,
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, _ := store.GetTaskPR(ctx, "t1")
	if stored.ReviewCount != 2 || stored.PendingReviewCount != 1 {
		t.Fatalf("review counts clobbered: review=%d pending=%d (want 2/1)",
			stored.ReviewCount, stored.PendingReviewCount)
	}
	if got := eb.publishedCount(); got != 0 {
		t.Fatalf("expected no event when nothing changed, got %d", got)
	}
}

// TestSyncTaskPR_ReviewCounts_AcceptsRealZero is the symmetric case: when the
// caller actually counted reviewers and reports zero, we honor it (e.g. all
// approvals dismissed) instead of clinging to the previous non-zero values.
func TestSyncTaskPR_ReviewCounts_AcceptsRealZero(t *testing.T) {
	svc, store, _ := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
		HeadBranch: "feat", BaseBranch: "main", State: "open",
		ReviewCount: 2, PendingReviewCount: 1,
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR:                    &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
		ReviewCount:           0,
		PendingReviewCount:    0,
		ReviewCountsPopulated: true,
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, _ := store.GetTaskPR(ctx, "t1")
	if stored.ReviewCount != 0 || stored.PendingReviewCount != 0 {
		t.Fatalf("real-zero not honored: review=%d pending=%d",
			stored.ReviewCount, stored.PendingReviewCount)
	}
}

// TestSyncTaskPR_UnresolvedThreads_PreservesOnLightweightSync verifies the
// REST single-PR poller (which doesn't fetch review threads) does NOT
// clobber the value set by the GraphQL batched poller. Without the
// UnresolvedReviewThreadsPopulated guard, every REST sync would flip the
// count to 0 and emit a spurious github.task_pr.updated event.
func TestSyncTaskPR_UnresolvedThreads_PreservesOnLightweightSync(t *testing.T) {
	svc, store, eb := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
		HeadBranch: "feat", BaseBranch: "main", State: "open",
		UnresolvedReviewThreads: 3,
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR:                               &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
		UnresolvedReviewThreads:          0,
		UnresolvedReviewThreadsPopulated: false, // REST path: didn't look
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, _ := store.GetTaskPR(ctx, "t1")
	if stored.UnresolvedReviewThreads != 3 {
		t.Fatalf("threads clobbered: got %d, want 3", stored.UnresolvedReviewThreads)
	}
	if got := eb.publishedCount(); got != 0 {
		t.Fatalf("expected no event when nothing changed, got %d", got)
	}
}

// TestSyncTaskPR_BaseBranchRetarget covers the case where a PR is retargeted
// to a different base branch upstream — the new branch must be persisted so
// future branch-protection lookups key off the right value.
func TestSyncTaskPR_BaseBranchRetarget(t *testing.T) {
	svc, store, _ := setupSyncTest(t)
	ctx := context.Background()
	if err := store.CreateTaskPR(ctx, &TaskPR{
		TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
		HeadBranch: "feat", BaseBranch: "main", State: "open",
	}); err != nil {
		t.Fatalf("create: %v", err)
	}
	status := &PRStatus{
		PR: &PR{
			Number: 1, State: "open", RepoOwner: "o", RepoName: "r",
			BaseBranch: "develop",
		},
	}
	if err := svc.SyncTaskPR(ctx, "t1", status); err != nil {
		t.Fatalf("sync: %v", err)
	}
	stored, _ := store.GetTaskPR(ctx, "t1")
	if stored.BaseBranch != "develop" {
		t.Fatalf("base branch not updated: got %q want develop", stored.BaseBranch)
	}
}

// TestSyncTaskPR_NewFieldsPublishEvent guards that a change to any of the
// CI-popover-relevant fields (UnresolvedReviewThreads, RequiredReviews,
// ChecksTotal, ChecksPassing) triggers a github.task_pr.updated event so the
// frontend popover refreshes via WS.
func TestSyncTaskPR_NewFieldsPublishEvent(t *testing.T) {
	required2 := 2
	cases := []struct {
		name   string
		init   TaskPR
		status PRStatus
	}{
		{
			name: "unresolved threads change",
			init: TaskPR{TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
				HeadBranch: "feat", BaseBranch: "main", State: "open"},
			status: PRStatus{
				PR:                               &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
				UnresolvedReviewThreads:          3,
				UnresolvedReviewThreadsPopulated: true,
			},
		},
		{
			name: "required reviews change",
			init: TaskPR{TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
				HeadBranch: "feat", BaseBranch: "main", State: "open"},
			status: PRStatus{
				PR:              &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
				RequiredReviews: &required2,
			},
		},
		{
			name: "checks total change",
			init: TaskPR{TaskID: "t1", Owner: "o", Repo: "r", PRNumber: 1, PRURL: "u",
				HeadBranch: "feat", BaseBranch: "main", State: "open"},
			status: PRStatus{
				PR:              &PR{Number: 1, State: "open", RepoOwner: "o", RepoName: "r"},
				ChecksTotal:     5,
				ChecksPassing:   3,
				ChecksPopulated: true,
			},
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			svc, store, eb := setupSyncTest(t)
			ctx := context.Background()
			if err := store.CreateTaskPR(ctx, &tc.init); err != nil {
				t.Fatalf("create: %v", err)
			}
			if err := svc.SyncTaskPR(ctx, "t1", &tc.status); err != nil {
				t.Fatalf("sync: %v", err)
			}
			if got := eb.publishedCount(); got != 1 {
				t.Fatalf("expected 1 event, got %d", got)
			}
		})
	}
}

func TestTimeEqual(t *testing.T) {
	now := time.Now()
	later := now.Add(time.Second)

	tests := []struct {
		name string
		a, b *time.Time
		want bool
	}{
		{"both nil", nil, nil, true},
		{"a nil", nil, &now, false},
		{"b nil", &now, nil, false},
		{"equal", &now, &now, true},
		{"not equal", &now, &later, false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := timeEqual(tt.a, tt.b); got != tt.want {
				t.Errorf("timeEqual() = %v, want %v", got, tt.want)
			}
		})
	}
}