package handlers

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/go-chi/chi/v5"

	"git.threesix.ai/jordan/slack5-1770574304/pkg/app"
	"git.threesix.ai/jordan/slack5-1770574304/pkg/auth"
	"git.threesix.ai/jordan/slack5-1770574304/pkg/logging"
	"git.threesix.ai/jordan/slack5-1770574304/services/preferences-api/internal/adapter/memory"
	"git.threesix.ai/jordan/slack5-1770574304/services/preferences-api/internal/domain"
	"git.threesix.ai/jordan/slack5-1770574304/services/preferences-api/internal/service"
)

func newTestPreferenceHandler() (*Preference, *memory.PreferenceRepository) {
	repo := memory.NewPreferenceRepository()
	svc := service.NewPreferenceService(repo, logging.Nop())
	handler := NewPreference(svc, logging.Nop())
	return handler, repo
}

// withAuthUser adds an authenticated user to the request context.
func withAuthUser(r *http.Request, userID string, roles ...string) *http.Request {
	user := &auth.User{
		ID:    userID,
		Roles: roles,
	}
	ctx := auth.SetUser(r.Context(), user)
	return r.WithContext(ctx)
}

func TestPreference_Get_SelfAccess(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Get("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Get))

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/user-1", nil)
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Errorf("expected status 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}

	data, ok := resp["data"].(map[string]any)
	if !ok {
		t.Fatal("expected 'data' field in response")
	}

	// Should return defaults
	if data["theme"] != "system" {
		t.Errorf("expected default theme system, got %v", data["theme"])
	}
	if data["language"] != "en" {
		t.Errorf("expected default language en, got %v", data["language"])
	}
	if data["user_id"] != "user-1" {
		t.Errorf("expected user_id user-1, got %v", data["user_id"])
	}
	// Defaults should not have updated_at
	if _, exists := data["updated_at"]; exists && data["updated_at"] != "" {
		// updated_at may be present but empty for defaults
	}
}

func TestPreference_Get_AdminAccess(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Get("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Get))

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/user-1", nil)
	req = withAuthUser(req, "admin-user", "admin")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Errorf("expected status 200 for admin, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Get_Forbidden(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Get("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Get))

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/user-1", nil)
	req = withAuthUser(req, "other-user")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusForbidden {
		t.Errorf("expected status 403, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Update_SelfAccess(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	body := UpdatePreferencesRequest{
		Theme:    "dark",
		Language: "fr",
		Notifications: UpdateNotificationsRequest{
			Email:  true,
			Push:   false,
			Digest: "daily",
		},
	}
	bodyBytes, _ := json.Marshal(body)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Errorf("expected status 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}

	data, ok := resp["data"].(map[string]any)
	if !ok {
		t.Fatal("expected 'data' field in response")
	}

	if data["theme"] != "dark" {
		t.Errorf("expected theme dark, got %v", data["theme"])
	}
	if data["language"] != "fr" {
		t.Errorf("expected language fr, got %v", data["language"])
	}

	notifications, ok := data["notifications"].(map[string]any)
	if !ok {
		t.Fatal("expected 'notifications' nested object")
	}
	if notifications["push"] != false {
		t.Errorf("expected notifications.push false, got %v", notifications["push"])
	}
	if notifications["digest"] != "daily" {
		t.Errorf("expected notifications.digest daily, got %v", notifications["digest"])
	}
}

func TestPreference_Update_Forbidden(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	body := UpdatePreferencesRequest{
		Theme:    "dark",
		Language: "en",
		Notifications: UpdateNotificationsRequest{
			Email:  true,
			Push:   true,
			Digest: "weekly",
		},
	}
	bodyBytes, _ := json.Marshal(body)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "other-user")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusForbidden {
		t.Errorf("expected status 403, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Update_AdminForbidden(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	body := UpdatePreferencesRequest{
		Theme:    "dark",
		Language: "en",
		Notifications: UpdateNotificationsRequest{
			Email:  true,
			Push:   true,
			Digest: "weekly",
		},
	}
	bodyBytes, _ := json.Marshal(body)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "admin-user", "admin")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	// Even admins cannot modify another user's preferences
	if w.Code != http.StatusForbidden {
		t.Errorf("expected status 403 for admin write, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Update_InvalidBody(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	// Invalid: missing required fields
	bodyBytes := []byte(`{"theme": "dark"}`)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected status 400 for invalid body, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Update_UnknownFields(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	bodyBytes := []byte(`{"theme":"dark","language":"en","notifications":{"email":true,"push":true,"digest":"weekly"},"unknown_field":"value"}`)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected status 400 for unknown fields, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Update_InvalidThemeValue(t *testing.T) {
	handler, _ := newTestPreferenceHandler()

	router := chi.NewRouter()
	router.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))

	bodyBytes := []byte(`{"theme":"invalid","language":"en","notifications":{"email":true,"push":true,"digest":"weekly"}}`)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/user-1", bytes.NewReader(bodyBytes))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected status 400 for invalid theme, got %d; body: %s", w.Code, w.Body.String())
	}
}

func TestPreference_Get_ExistingPreferences(t *testing.T) {
	handler, repo := newTestPreferenceHandler()

	// Seed existing preferences
	existing := &domain.UserPreferences{
		UserID:   "user-1",
		Theme:    domain.ThemeDark,
		Language: "ja",
		Notifications: domain.NotificationPreferences{
			Email:  false,
			Push:   false,
			Digest: domain.DigestNone,
		},
	}
	_ = repo.Upsert(nil, existing)

	router := chi.NewRouter()
	router.Get("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Get))

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/user-1", nil)
	req = withAuthUser(req, "user-1")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Errorf("expected status 200, got %d; body: %s", w.Code, w.Body.String())
	}

	var resp map[string]any
	if err := json.NewDecoder(w.Body).Decode(&resp); err != nil {
		t.Fatalf("failed to decode response: %v", err)
	}

	data := resp["data"].(map[string]any)
	if data["theme"] != "dark" {
		t.Errorf("expected theme dark, got %v", data["theme"])
	}
	if data["language"] != "ja" {
		t.Errorf("expected language ja, got %v", data["language"])
	}
}