package service

import (
	"context"
	"testing"

	"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/domain"
)

func strPtr(s string) *string { return &s }
func boolPtr(b bool) *bool    { return &b }

func TestPreferencesService_Get(t *testing.T) {
	repo := memory.NewPreferencesRepository()
	svc := NewPreferencesService(repo, logging.Nop())
	ctx := context.Background()

	t.Run("returns not found when no preferences exist", func(t *testing.T) {
		_, err := svc.Get(ctx, "user-1")
		if err != domain.ErrPreferencesNotFound {
			t.Errorf("expected ErrPreferencesNotFound, got %v", err)
		}
	})

	t.Run("returns preferences after upsert", func(t *testing.T) {
		_, _ = svc.Upsert(ctx, "user-1", &domain.PreferencesUpdate{
			Theme: strPtr("dark"),
		})
		prefs, err := svc.Get(ctx, "user-1")
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if prefs.Theme != "dark" {
			t.Errorf("expected theme 'dark', got '%s'", prefs.Theme)
		}
	})
}

func TestPreferencesService_Upsert(t *testing.T) {
	repo := memory.NewPreferencesRepository()
	svc := NewPreferencesService(repo, logging.Nop())
	ctx := context.Background()

	t.Run("creates new with defaults and merges", func(t *testing.T) {
		prefs, err := svc.Upsert(ctx, "user-new", &domain.PreferencesUpdate{
			Theme: strPtr("light"),
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if prefs.Theme != "light" {
			t.Errorf("expected theme 'light', got '%s'", prefs.Theme)
		}
		if prefs.Language != "en" {
			t.Errorf("expected default language 'en', got '%s'", prefs.Language)
		}
		if !prefs.Notifications.Email {
			t.Error("expected default email=true")
		}
	})

	t.Run("updates existing with merge", func(t *testing.T) {
		// First upsert
		_, _ = svc.Upsert(ctx, "user-merge", &domain.PreferencesUpdate{
			Theme:    strPtr("dark"),
			Language: strPtr("fr"),
		})

		// Second upsert - only change language
		prefs, err := svc.Upsert(ctx, "user-merge", &domain.PreferencesUpdate{
			Language: strPtr("es"),
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if prefs.Theme != "dark" {
			t.Errorf("expected theme 'dark' unchanged, got '%s'", prefs.Theme)
		}
		if prefs.Language != "es" {
			t.Errorf("expected language 'es', got '%s'", prefs.Language)
		}
	})

	t.Run("rejects invalid theme", func(t *testing.T) {
		_, err := svc.Upsert(ctx, "user-invalid", &domain.PreferencesUpdate{
			Theme: strPtr("blue"),
		})
		if err != domain.ErrInvalidTheme {
			t.Errorf("expected ErrInvalidTheme, got %v", err)
		}
	})

	t.Run("rejects invalid language", func(t *testing.T) {
		_, err := svc.Upsert(ctx, "user-invalid2", &domain.PreferencesUpdate{
			Language: strPtr("XYZ"),
		})
		if err != domain.ErrInvalidLanguage {
			t.Errorf("expected ErrInvalidLanguage, got %v", err)
		}
	})

	t.Run("rejects invalid digest", func(t *testing.T) {
		_, err := svc.Upsert(ctx, "user-invalid3", &domain.PreferencesUpdate{
			Notifications: &domain.NotificationSettingsUpdate{
				Digest: strPtr("monthly"),
			},
		})
		if err != domain.ErrInvalidDigest {
			t.Errorf("expected ErrInvalidDigest, got %v", err)
		}
	})

	t.Run("sets UpdatedAt", func(t *testing.T) {
		prefs, err := svc.Upsert(ctx, "user-time", &domain.PreferencesUpdate{
			Theme: strPtr("dark"),
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if prefs.UpdatedAt.IsZero() {
			t.Error("expected non-zero UpdatedAt")
		}
	})

	t.Run("notification sub-field merge preserves unset fields", func(t *testing.T) {
		_, _ = svc.Upsert(ctx, "user-notif", &domain.PreferencesUpdate{
			Notifications: &domain.NotificationSettingsUpdate{
				Email:  boolPtr(false),
				Push:   boolPtr(false),
				Digest: strPtr("daily"),
			},
		})
		prefs, err := svc.Upsert(ctx, "user-notif", &domain.PreferencesUpdate{
			Notifications: &domain.NotificationSettingsUpdate{
				Email: boolPtr(true),
			},
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		if !prefs.Notifications.Email {
			t.Error("expected email=true")
		}
		if prefs.Notifications.Push != false {
			t.Error("expected push=false preserved")
		}
		if prefs.Notifications.Digest != "daily" {
			t.Errorf("expected digest 'daily' preserved, got '%s'", prefs.Notifications.Digest)
		}
	})
}