package user_test

import (
	"context"
	"encoding/json"
	"fmt"
	"testing"
	"time"

	"github.com/food-ai/backend/internal/domain/user"
)

func ptrStr(s string) *string     { return &s }
func ptrInt(i int) *int           { return &i }
func ptrFloat(f float64) *float64 { return &f }

// mockUserRepo is an in-test mock implementing user.UserRepository.
type mockUserRepo struct {
	getByIDFn             func(ctx context.Context, id string) (*user.User, error)
	updateFn              func(ctx context.Context, id string, req user.UpdateProfileRequest) (*user.User, error)
	updateInTxFn          func(ctx context.Context, id string, profileReq user.UpdateProfileRequest, caloriesReq *user.UpdateProfileRequest) (*user.User, error)
	upsertByFirebaseUIDFn func(ctx context.Context, uid, email, name, avatarURL string) (*user.User, error)
	setRefreshTokenFn     func(ctx context.Context, id, token string, expiresAt time.Time) error
	findByRefreshTokenFn  func(ctx context.Context, token string) (*user.User, error)
	clearRefreshTokenFn   func(ctx context.Context, id string) error
}

func (m *mockUserRepo) UpsertByFirebaseUID(ctx context.Context, uid, email, name, avatarURL string) (*user.User, error) {
	return m.upsertByFirebaseUIDFn(ctx, uid, email, name, avatarURL)
}
func (m *mockUserRepo) GetByID(ctx context.Context, id string) (*user.User, error) {
	return m.getByIDFn(ctx, id)
}
func (m *mockUserRepo) Update(ctx context.Context, id string, req user.UpdateProfileRequest) (*user.User, error) {
	return m.updateFn(ctx, id, req)
}
func (m *mockUserRepo) UpdateInTx(ctx context.Context, id string, profileReq user.UpdateProfileRequest, caloriesReq *user.UpdateProfileRequest) (*user.User, error) {
	return m.updateInTxFn(ctx, id, profileReq, caloriesReq)
}
func (m *mockUserRepo) SetRefreshToken(ctx context.Context, id, token string, expiresAt time.Time) error {
	return m.setRefreshTokenFn(ctx, id, token, expiresAt)
}
func (m *mockUserRepo) FindByRefreshToken(ctx context.Context, token string) (*user.User, error) {
	return m.findByRefreshTokenFn(ctx, token)
}
func (m *mockUserRepo) ClearRefreshToken(ctx context.Context, id string) error {
	return m.clearRefreshTokenFn(ctx, id)
}

func TestGetProfile_Success(t *testing.T) {
	repo := &mockUserRepo{
		getByIDFn: func(ctx context.Context, id string) (*user.User, error) {
			return &user.User{ID: id, Email: "test@example.com", Plan: "free"}, nil
		},
	}
	svc := user.NewService(repo)

	u, getError := svc.GetProfile(context.Background(), "user-1")
	if getError != nil {
		t.Fatalf("unexpected error: %v", getError)
	}
	if u.ID != "user-1" {
		t.Errorf("expected user-1, got %s", u.ID)
	}
}

func TestGetProfile_NotFound(t *testing.T) {
	repo := &mockUserRepo{
		getByIDFn: func(ctx context.Context, id string) (*user.User, error) {
			return nil, fmt.Errorf("not found")
		},
	}
	svc := user.NewService(repo)

	_, getError := svc.GetProfile(context.Background(), "nonexistent")
	if getError == nil {
		t.Fatal("expected error")
	}
}

func TestUpdateProfile_NameOnly(t *testing.T) {
	repo := &mockUserRepo{
		updateFn: func(ctx context.Context, id string, req user.UpdateProfileRequest) (*user.User, error) {
			return &user.User{ID: id, Name: *req.Name, Plan: "free"}, nil
		},
	}
	svc := user.NewService(repo)

	u, updateError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{Name: ptrStr("New Name")})
	if updateError != nil {
		t.Fatalf("unexpected error: %v", updateError)
	}
	if u.Name != "New Name" {
		t.Errorf("expected 'New Name', got %q", u.Name)
	}
}

func TestUpdateProfile_WithCaloriesRecalculation(t *testing.T) {
	dob := time.Now().AddDate(-30, 0, 0).Format("2006-01-02")
	profileReq := user.UpdateProfileRequest{
		HeightCM:    ptrInt(180),
		WeightKG:    ptrFloat(80),
		DateOfBirth: &dob,
		Gender:      ptrStr("male"),
		Activity:    ptrStr("moderate"),
		Goal:        ptrStr("maintain"),
	}
	finalUser := &user.User{
		ID:            "user-1",
		HeightCM:      ptrInt(180),
		WeightKG:      ptrFloat(80),
		DateOfBirth:   &dob,
		Gender:        ptrStr("male"),
		Activity:      ptrStr("moderate"),
		Goal:          ptrStr("maintain"),
		DailyCalories: ptrInt(2759),
		Plan:          "free",
	}

	repo := &mockUserRepo{
		// Service calls GetByID first to merge current values for calorie calculation
		getByIDFn: func(ctx context.Context, id string) (*user.User, error) {
			return &user.User{ID: id, Plan: "free"}, nil
		},
		updateInTxFn: func(ctx context.Context, id string, pReq user.UpdateProfileRequest, cReq *user.UpdateProfileRequest) (*user.User, error) {
			if cReq == nil {
				t.Error("expected caloriesReq to be non-nil")
			} else if *cReq.DailyCalories != 2759 {
				t.Errorf("expected calories 2759, got %d", *cReq.DailyCalories)
			}
			return finalUser, nil
		},
	}
	svc := user.NewService(repo)

	u, updateError := svc.UpdateProfile(context.Background(), "user-1", profileReq)
	if updateError != nil {
		t.Fatalf("unexpected error: %v", updateError)
	}
	if u.DailyCalories == nil {
		t.Fatal("expected daily_calories to be set")
	}
	if *u.DailyCalories != 2759 {
		t.Errorf("expected 2759, got %d", *u.DailyCalories)
	}
}

func TestUpdateProfile_InvalidHeight_TooLow(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{HeightCM: ptrInt(50)})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidHeight_TooHigh(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{HeightCM: ptrInt(300)})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidWeight_TooLow(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{WeightKG: ptrFloat(10)})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidWeight_TooHigh(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{WeightKG: ptrFloat(400)})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidDOB_TooRecent(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})
	dob := time.Now().AddDate(-5, 0, 0).Format("2006-01-02")

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{DateOfBirth: &dob})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidDOB_TooOld(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})
	dob := time.Now().AddDate(-150, 0, 0).Format("2006-01-02")

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{DateOfBirth: &dob})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidDOB_BadFormat(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})
	dob := "not-a-date"

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{DateOfBirth: &dob})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidGender(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{Gender: ptrStr("other")})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidActivity(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{Activity: ptrStr("extreme")})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_InvalidGoal(t *testing.T) {
	svc := user.NewService(&mockUserRepo{})

	_, validationError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{Goal: ptrStr("bulk")})
	if validationError == nil {
		t.Fatal("expected validation error")
	}
}

func TestUpdateProfile_Preferences(t *testing.T) {
	prefs := json.RawMessage(`{"cuisines":["russian"]}`)
	repo := &mockUserRepo{
		updateFn: func(ctx context.Context, id string, req user.UpdateProfileRequest) (*user.User, error) {
			return &user.User{
				ID:          id,
				Plan:        "free",
				Preferences: *req.Preferences,
				UpdatedAt:   time.Now(),
			}, nil
		},
	}
	svc := user.NewService(repo)

	u, updateError := svc.UpdateProfile(context.Background(), "user-1", user.UpdateProfileRequest{Preferences: &prefs})
	if updateError != nil {
		t.Fatalf("unexpected error: %v", updateError)
	}
	if string(u.Preferences) != `{"cuisines":["russian"]}` {
		t.Errorf("unexpected preferences: %s", u.Preferences)
	}
}