package handlers

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

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

	"git.threesix.ai/jordan/slate-v3-1770514618/pkg/app"
	"git.threesix.ai/jordan/slate-v3-1770514618/pkg/auth"
	"git.threesix.ai/jordan/slate-v3-1770514618/pkg/logging"
	"git.threesix.ai/jordan/slate-v3-1770514618/services/preferences-api/internal/adapter/memory"
	"git.threesix.ai/jordan/slate-v3-1770514618/services/preferences-api/internal/service"
)

func newTestPreferencesHandler() *Preferences {
	repo := memory.NewPreferencesRepository()
	svc := service.NewPreferencesService(repo, logging.Nop())
	return NewPreferences(svc)
}

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 setupRouter(handler *Preferences) *chi.Mux {
	r := chi.NewRouter()
	r.Get("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Get))
	r.Put("/api/preferences-api/preferences/{user_id}", app.Wrap(handler.Update))
	return r
}

func TestPreferences_Get_NotFound(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404, got %d", w.Code)
	}
}

func TestPreferences_Get_InvalidUUID(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/not-a-uuid", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected 400, got %d", w.Code)
	}
}

func TestPreferences_Get_Forbidden(t *testing.T) {
	handler := newTestPreferencesHandler()

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

	req := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", nil)
	req = withAuthUser(req, "different-user-id")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusForbidden {
		t.Errorf("expected 403, got %d", w.Code)
	}
}

func TestPreferences_Get_AdminAccess(t *testing.T) {
	handler := newTestPreferencesHandler()

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

	body := `{"preferences":{"theme":"dark"}}`
	putReq := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	putReq.Header.Set("Content-Type", "application/json")
	putReq = withAuthUser(putReq, "550e8400-e29b-41d4-a716-446655440000")
	putW := httptest.NewRecorder()
	r.ServeHTTP(putW, putReq)

	// Admin accesses another user's prefs
	getReq := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", nil)
	getReq = withAuthUser(getReq, "admin-user-id", "admin")
	getW := httptest.NewRecorder()
	r.ServeHTTP(getW, getReq)

	if getW.Code != http.StatusOK {
		t.Errorf("expected 200 for admin access, got %d", getW.Code)
	}
}

func TestPreferences_Update_CreateNew(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	body := `{"preferences":{"theme":"dark","language":"fr"}}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Errorf("expected 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")
	}

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

	if prefs["theme"] != "dark" {
		t.Errorf("expected theme 'dark', got %v", prefs["theme"])
	}
	if prefs["language"] != "fr" {
		t.Errorf("expected language 'fr', got %v", prefs["language"])
	}
}

func TestPreferences_Update_MergeExisting(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)
	userID := "550e8400-e29b-41d4-a716-446655440000"

	// Create initial
	body1 := `{"preferences":{"theme":"dark","language":"fr"}}`
	req1 := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/"+userID, bytes.NewBufferString(body1))
	req1.Header.Set("Content-Type", "application/json")
	w1 := httptest.NewRecorder()
	router.ServeHTTP(w1, req1)

	// Update only theme
	body2 := `{"preferences":{"theme":"light"}}`
	req2 := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/"+userID, bytes.NewBufferString(body2))
	req2.Header.Set("Content-Type", "application/json")
	w2 := httptest.NewRecorder()
	router.ServeHTTP(w2, req2)

	if w2.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d; body: %s", w2.Code, w2.Body.String())
	}

	var resp map[string]any
	_ = json.NewDecoder(w2.Body).Decode(&resp)
	data := resp["data"].(map[string]any)
	prefs := data["preferences"].(map[string]any)

	if prefs["theme"] != "light" {
		t.Errorf("expected theme 'light', got %v", prefs["theme"])
	}
	if prefs["language"] != "fr" {
		t.Errorf("expected language 'fr' preserved, got %v", prefs["language"])
	}
}

func TestPreferences_Update_InvalidTheme(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	body := `{"preferences":{"theme":"blue"}}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected 400, got %d", w.Code)
	}
}

func TestPreferences_Update_UnknownPreferenceKey(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	body := `{"preferences":{"theme":"dark","unknown_key":"value"}}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

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

func TestPreferences_Update_MissingPreferencesField(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	body := `{"theme":"dark"}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

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

func TestPreferences_Update_EmptyBody(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", nil)
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected 400 for empty body, got %d", w.Code)
	}
}

func TestPreferences_Update_Forbidden(t *testing.T) {
	handler := newTestPreferencesHandler()

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

	body := `{"preferences":{"theme":"dark"}}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/550e8400-e29b-41d4-a716-446655440000", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	req = withAuthUser(req, "different-user-id")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusForbidden {
		t.Errorf("expected 403, got %d", w.Code)
	}
}

func TestPreferences_Update_InvalidUUID(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)

	body := `{"preferences":{"theme":"dark"}}`
	req := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/not-valid", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Errorf("expected 400, got %d", w.Code)
	}
}

func TestPreferences_GetAfterUpdate(t *testing.T) {
	handler := newTestPreferencesHandler()
	router := setupRouter(handler)
	userID := "550e8400-e29b-41d4-a716-446655440000"

	// Create via PUT
	body := `{"preferences":{"theme":"dark"}}`
	putReq := httptest.NewRequest(http.MethodPut, "/api/preferences-api/preferences/"+userID, bytes.NewBufferString(body))
	putReq.Header.Set("Content-Type", "application/json")
	putW := httptest.NewRecorder()
	router.ServeHTTP(putW, putReq)

	// GET
	getReq := httptest.NewRequest(http.MethodGet, "/api/preferences-api/preferences/"+userID, nil)
	getW := httptest.NewRecorder()
	router.ServeHTTP(getW, getReq)

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

	var resp map[string]any
	_ = json.NewDecoder(getW.Body).Decode(&resp)
	data := resp["data"].(map[string]any)
	prefs := data["preferences"].(map[string]any)

	if prefs["theme"] != "dark" {
		t.Errorf("expected theme 'dark', got %v", prefs["theme"])
	}
	if prefs["language"] != "en" {
		t.Errorf("expected default language 'en', got %v", prefs["language"])
	}
}