package repository

import (
	"context"

	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/model"
)

// NotificationPreferenceRepo implements GORM repository for NotificationPreference.
// Reference: Chatwoot app/models/notification_preference.rb
type NotificationPreferenceRepo struct {
	db *gorm.DB
}

// NewNotificationPreferenceRepo creates a new NotificationPreference repository.
func NewNotificationPreferenceRepo(db *gorm.DB) *NotificationPreferenceRepo {
	return &NotificationPreferenceRepo{db: db}
}

// FindByID retrieves a notification preference by primary key.
func (r *NotificationPreferenceRepo) FindByID(ctx context.Context, id uint) (*model.NotificationPreference, error) {
	var pref model.NotificationPreference
	err := r.db.WithContext(ctx).First(&pref, id).Error
	if err != nil {
		return nil, err
	}
	return &pref, nil
}

// ListByUserAndAccount retrieves all notification preferences for a user within an account.
func (r *NotificationPreferenceRepo) ListByUserAndAccount(ctx context.Context, userID uint, accountID uint) ([]model.NotificationPreference, error) {
	var prefs []model.NotificationPreference
	err := r.db.WithContext(ctx).
		Where("user_id = ? AND account_id = ?", userID, accountID).
		Find(&prefs).Error
	return prefs, err
}

// Upsert creates or updates a notification preference (unique constraint on user+account+channel+event).
func (r *NotificationPreferenceRepo) Upsert(ctx context.Context, pref *model.NotificationPreference) error {
	result := r.db.WithContext(ctx).
		Where("user_id = ? AND account_id = ? AND channel = ? AND event_type = ?",
			pref.UserID, pref.AccountID, pref.Channel, pref.EventType).
		Assign(map[string]interface{}{
			"enabled":     pref.Enabled,
			"preferences": pref.Preferences,
		}).
		FirstOrCreate(pref)

	if result.Error != nil {
		return result.Error
	}

	if result.RowsAffected == 0 {
		// Record already existed, update it
		return r.db.WithContext(ctx).Save(pref).Error
	}
	return nil
}

// BatchUpsert creates or updates multiple notification preferences at once.
func (r *NotificationPreferenceRepo) BatchUpsert(ctx context.Context, prefs []model.NotificationPreference) error {
	for i := range prefs {
		if err := r.Upsert(ctx, &prefs[i]); err != nil {
			return err
		}
	}
	return nil
}

// DeleteByUserAndAccount removes all notification preferences for a user within an account.
func (r *NotificationPreferenceRepo) DeleteByUserAndAccount(ctx context.Context, userID uint, accountID uint) error {
	return r.db.WithContext(ctx).
		Where("user_id = ? AND account_id = ?", userID, accountID).
		Delete(&model.NotificationPreference{}).Error
}