<?php

namespace lib\Core;

use Exception;
use PDO;
use PDOException;
use PDOStatement;

abstract class Model
{
    private $_db = null;
    private $_wheres = [];
    private $_primaryKey = false;
    protected $resultMode = 'array';
    protected function __construct(string $primaryKey)
    {
        $this->_primaryKey = $primaryKey;
    } //

    abstract public function getTable();
    final public function getPrimaryKey(): string
    {
        if (!$this->_primaryKey) {
            throw new \Exception("PrimayKey가 지정되지 않았습니다.");
        }
        return $this->_primaryKey;
    }
    final public function getDB()
    {
        if ($this->_db === null) {
            $envs = parse_ini_file(APP . DIRECTORY_SEPARATOR . ".env.ini", true);
            if (!$envs) {
                throw new Exception(var_export($envs, true));
            }
            $this->_db = new PDO($envs['db']['dsn'], $envs['db']['id'], $envs['db']['passwd']);
            // $this->_db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
            $this->_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            // echo "Connected successfully: " . $this->_db->getAttribute(PDO::ATTR_CONNECTION_STATUS) . "\n";
        }
        return $this->_db;
    }

    final public function where($key, $value, $condition = "AND")
    {
        if (is_array($value)) {
            throw new \Exception("Value is Array:" . var_export($value, true));
        }
        $this->_wheres[] = sprintf(
            " %s {$key}=%s",
            count($this->_wheres) ? $condition : "WHERE",
            is_int($value) ? $value : "'{$value}'"
        );
    }

    private function chanegValueToSQLTypeValue($value)
    {
        return  is_int($value)  ? $value : "'{$value}'";
    }
    final public function execute($sql): bool|PDOStatement
    {
        $sql .= implode(" ", $this->_wheres);
        //echo $sql . "\n";
        $stmt = $this->getDB()->prepare($sql);
        if (!$stmt->execute()) {
            throw new Exception("SQL 오류: {$stmt->errorInfo()} \n{$sql}\n");
        }
        $this->_wheres = [];
        return $stmt;
    }

    //SQL문
    final public function select(array $columns = ["*"]): bool|PDOStatement
    {
        $sql = sprintf("SELECT %s FROM %s", implode(",", $columns), $this->getTable());
        return $this->execute($sql);
    }

    final public function insert(array $datas)
    {
        $sqlDatas = [];
        foreach ($datas as $key => $value) {
            $sqlDatas[$key] = $this->chanegValueToSQLTypeValue($value);
        }
        $sql = sprintf("INSERT INTO {$this->getTable()} SET (%s) VALUES (%s}", array_keys($sqlDatas), array_values($sqlDatas));
        return $this->execute($sql);
    }
    final public function update(array $datas)
    {
        $sqlDatas = [];
        foreach ($datas as $key => $value) {
            if ($key === $this->getPrimaryKey()) { //PrimaryKey변경불가
                continue;
            }
            $value      = $this->chanegValueToSQLTypeValue($value);
            $sqlDatas[] = "{$key}={$value}";
        }
        $sql = sprintf("UPDATE {$this->getTable()} SET %s", implode(",", $sqlDatas));
        return $this->execute($sql);
    }
    public function save($entity)
    {
        if ($entity->isChanged()) {
            $pk = $this->getPrimaryKey();
            if ($entity->$pk) {
                $this->where($pk, $entity->$pk);
                $datas = [];
                foreach ($entity->getChangedFields() as $key) {
                    $datas[$key] = $entity->$key;
                }
                $this->update($datas);
                $entity->clearChangedFields();
            } else {
                $datas = [];
                foreach ($entity->getChangedFields() as $key) {
                    $datas[$key] = $entity->$key;
                }
                $this->insert($datas);
                $entity->$pk = $this->getDB()->lastInsertId();
                $entity->clearChangedFields();
            }
        }
        return $entity;
    }

    final public function getEntity()
    {
        $stmt = $this->select();
        if (class_exists($this->resultMode)) {
            $stmt->setFetchMode(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, $this->resultMode);
            return $stmt->fetch();
        }
        return $stmt->fetch(PDO::FETCH_DEFAULT);
    }

    final public function getEntitys()
    {
        $stmt = $this->select();
        if (class_exists($this->resultMode)) {
            $stmt->setFetchMode(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, $this->resultMode);
            return $stmt->fetchAll();
        }
        return $stmt->fetchAll(PDO::FETCH_DEFAULT);
    }
} //Class