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) Repository[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]) GetByID(id int) (*T, error) {
	var entity T

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

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

	return &entity, nil
}

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)
	for rows.Next() {
		var entity T
		if err := rows.Scan(entity); err != nil {
			return nil, err
		}
		entities = append(entities, entity)
	}

	if err = rows.Err(); err != nil {
		return nil, err
	}

	return entities, nil
}

func (r *baseRepository[T]) Delete(id int) error {
	query := r.BuildQuery("DELETE %s WHERE id = ? LIMIT 1")
	_, err := r.db.Exec(query, id)
	return err
}