package repository

import (
	"carrot_bbs/internal/model"

	"gorm.io/gorm"
)

type ScheduleRepository interface {
	ListByUserID(userID string) ([]*model.ScheduleCourse, error)
	GetByID(id string) (*model.ScheduleCourse, error)
	Create(course *model.ScheduleCourse) error
	Update(course *model.ScheduleCourse) error
	DeleteByID(id string) error
	ExistsColorByUser(userID, color, excludeID string) (bool, error)
}

type scheduleRepository struct {
	db *gorm.DB
}

func NewScheduleRepository(db *gorm.DB) ScheduleRepository {
	return &scheduleRepository{db: db}
}

func (r *scheduleRepository) ListByUserID(userID string) ([]*model.ScheduleCourse, error) {
	var courses []*model.ScheduleCourse
	err := r.db.
		Where("user_id = ?", userID).
		Order("day_of_week ASC, start_section ASC, created_at ASC").
		Find(&courses).Error
	return courses, err
}

func (r *scheduleRepository) Create(course *model.ScheduleCourse) error {
	return r.db.Create(course).Error
}

func (r *scheduleRepository) GetByID(id string) (*model.ScheduleCourse, error) {
	var course model.ScheduleCourse
	if err := r.db.Where("id = ?", id).First(&course).Error; err != nil {
		return nil, err
	}
	return &course, nil
}

func (r *scheduleRepository) Update(course *model.ScheduleCourse) error {
	return r.db.Save(course).Error
}

func (r *scheduleRepository) DeleteByID(id string) error {
	return r.db.Delete(&model.ScheduleCourse{}, "id = ?", id).Error
}

func (r *scheduleRepository) ExistsColorByUser(userID, color, excludeID string) (bool, error) {
	var count int64
	query := r.db.Model(&model.ScheduleCourse{}).
		Where("user_id = ? AND LOWER(color) = LOWER(?)", userID, color)
	if excludeID != "" {
		query = query.Where("id <> ?", excludeID)
	}
	if err := query.Count(&count).Error; err != nil {
		return false, err
	}
	return count > 0, nil
}