package repository

import (
	"database/sql"
	"fmt"
)

type baseRepository[T any] struct {
	db        *sql.DB
	tableName string
}

func NewBaseRepository[T any](db *sql.DB, tableName string) *baseRepository[T] {
	return &baseRepository[T]{
		db:        db,
		tableName: tableName,
	}
}

func (r *baseRepository[T]) BuildQuery(baseQuery string) string {
	return fmt.Sprintf(baseQuery, r.tableName)
}

func (r *baseRepository[T]) GetDB() *sql.DB {
	return r.db
}

func (r *baseRepository[T]) GetAll() ([]T, error) {
	query := r.BuildQuery("SELECT * FROM %s ORDER BY id DESC")

	rows, err := r.db.Query(query)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	entities := make([]T, 0)
	rowsErr := ScanRows(rows, &entities)

	if rowsErr != nil {
		return nil, err
	}

	return entities, nil
}

func (r *baseRepository[T]) GetByID(id int) (*T, error) {
	var entity T

	query := r.BuildQuery("SELECT * FROM %s WHERE id = ?")
	row := r.db.QueryRow(
		query,
		id,
	)
	err := scanRow(row, &entity)

	if err != nil {
		if err == sql.ErrNoRows {
			return nil, nil
		}
		return nil, err
	}

	return &entity, nil
}

func (r *baseRepository[T]) Delete(id int) (int64, error) {
	query := r.BuildQuery("DELETE FROM %s WHERE id = ?")
	res, err := r.db.Exec(query, id)
	if err != nil {
		return 0, err
	}
	return res.RowsAffected()
}