package repositories

import (
	"learnsteam/cslms-api/internal/models"

	"gorm.io/gorm"
)

type paperRepository struct {
	DB *gorm.DB
}

func NewPaperRepository(db *gorm.DB) PaperRepository {
	return &paperRepository{
		DB: db,
	}
}

type PaperRepository interface {
	List(int64, string, int, int) (*[]models.PaperResponse, error)
	Total(int64, string) (int64, error)

	Find(int64) (*models.PaperResponse, error)
	Get(int64) (*models.Paper, error)
	Update(*models.Paper) (*models.Paper, error)
}

func (r *paperRepository) List(user_id int64, q string, page int, limit int) (*[]models.PaperResponse, error) {
	var rows *[]models.PaperResponse
	var err error
	offset := limit * (page - 1)
	if q != "" {
		err = r.DB.Offset(offset).Limit(limit).Order("UserQuizPapers.created_at DESC").
			Table("UserQuizPapers").
			Select("UserQuizPapers.*", "Users.first_name", "Users.last_name", "QuizPapers.title", "QuizPapers.category").
			Joins("LEFT JOIN Users ON Users.id = UserQuizPapers.user_id").
			Joins("LEFT JOIN QuizPapers ON QuizPapers.id = UserQuizPapers.quiz_paper_id").
			Where("QuizPapers.title LIKE ? OR QuizPapers.category LIKE ? OR CONCAT(first_name, last_name) LIKE ?", "%"+q+"%", "%"+q+"%", "%"+q+"%").
			Where("UserQuizPapers.user_id = ?", user_id).
			Find(&rows).Error
	} else {
		err = r.DB.Offset(offset).Limit(limit).Order("UserQuizPapers.created_at DESC").
			Table("UserQuizPapers").
			Select("UserQuizPapers.*", "Users.first_name", "Users.last_name", "QuizPapers.title", "QuizPapers.category").
			Joins("LEFT JOIN Users ON Users.id = UserQuizPapers.user_id").
			Joins("LEFT JOIN QuizPapers ON QuizPapers.id = UserQuizPapers.quiz_paper_id").
			Where("UserQuizPapers.user_id = ?", user_id).
			Find(&rows).Error
	}
	return rows, err
}

func (r *paperRepository) Total(user_id int64, q string) (int64, error) {
	var total int64
	var err error
	if q != "" {
		err = r.DB.Model(&models.Paper{}).
			Joins("LEFT JOIN Users ON Users.id = UserQuizPapers.user_id").
			Joins("LEFT JOIN QuizPapers ON QuizPapers.id = UserQuizPapers.quiz_paper_id").
			Where("QuizPapers.title LIKE ? OR QuizPapers.category LIKE ? OR CONCAT(first_name, last_name) LIKE ?", "%"+q+"%", "%"+q+"%", "%"+q+"%").
			Where("UserQuizPapers.user_id = ?", user_id).
			Count(&total).
			Error
	} else {
		err = r.DB.Model(&models.Paper{}).
			Where("user_id = ?", user_id).
			Count(&total).
			Error
	}

	return total, err
}

func (r *paperRepository) Find(id int64) (*models.PaperResponse, error) {
	var row *models.PaperResponse
	err := r.DB.
		Table("UserQuizPapers").
		Select("UserQuizPapers.*", "Users.first_name", "Users.last_name", "QuizPapers.title", "QuizPapers.category").
		Joins("LEFT JOIN Users ON Users.id = UserQuizPapers.user_id").
		Joins("LEFT JOIN QuizPapers ON QuizPapers.id = UserQuizPapers.quiz_paper_id").
		Where("UserQuizPapers.id = ?", id).First(&row).Error
	return row, err
}

func (r *paperRepository) Get(id int64) (*models.Paper, error) {
	var row *models.Paper
	if err := r.DB.Where("id=?", id).First(&row).Error; err != nil {
		return nil, err
	}
	return row, nil
}

func (r *paperRepository) Update(paper *models.Paper) (*models.Paper, error) {
	var row *models.Paper
	if err := r.DB.Where("id=?", paper.ID).First(&row).Error; err != nil {
		return nil, err
	}

	err := r.DB.Model(&row).Select("*").Updates(&paper).Error
	return row, err
}