<?php

class DB_Record extends Object {
    // protected $db;
    protected $table;
    protected $primaryKey;
    protected $fields;
    // protected $copy;

    public function __construct($table) {
        // $this->db = db::getConnection();
        $this->table = $table;
        $stm = db::query('DESCRIBE ' . $this->table);
        $cols = $stm->fetchAll(PDO::FETCH_OBJ);
        foreach ($cols as $col) {
            if ($col->Key == 'PRI') {
                $this->primaryKey = $col->Field;
            }
            $this->fields[$col->Field] = $col->Default;
        }
    }

    public function load($id) {
        if (preg_match('/^[1-9]\d*$/', $id)) {
            $stm = db::query("SELECT * FROM `{$this->table}` WHERE `{$this->primaryKey}`=$id");
            $data = $stm->fetch(PDO::FETCH_ASSOC);
            if (count($data)) {
                $this->data = $data;
                $this->copy = $data;
                return true;
            }
        }
        return false;
    }

    public function save() {
        // INSERT
        if ($this->isNew()) {
            $fields = $this->matchFields();
            $sql = "INSERT INTO \"{$this->table}\"";
            $sql .= ' ("' . implode('","', array_keys($fields)) . '"")';
            $sql .= ' VALUES (' . substr(str_repeat('?,', count($fields)), 0 , -1) . ')';
            echo $sql . '<br>';
            $stm = db::prepare($sql);
            $stm->execute(array_values($fields));
            return db::lastInsertId();
        }
        // UPDATE
        // if ($this->isChanged()) {
            $fields = $this->matchFields();
            $id = $fields[$this->primaryKey];
            unset($fields[$this->primaryKey]);
            $sql = "UPDATE `{$this->table}` SET ";
            $parts = array();
            foreach ($fields as $k => $v) {
                $parts[] = "`$k`=:$k";
            }
            $sql .= implode(',', $parts) . " WHERE `{$this->primaryKey}`=$id";
            echo $sql . '<br>';
            $stm = db::prepare($sql);
            $stm->execute($fields);
            return (bool) $stm->rowCount();
            // return true;
        // }
        // return false;
    }

    protected function isNew() {
        return !$this->copy;
    }

    // protected function isChanged() {
    //     if ($this->copy) {
    //         foreach ($this->copy as $k => $v) {
    //             if (!isset($this->data[$k]) || $this->data[$k] !== $this->copy[$k]) {
    //                 return true;
    //             }
    //         }
    //     }
    //     return false;
    // }

    protected function matchFields() {
        $ret = array();
        foreach ($this->fields as $field => $default) {
            $ret[$field] = isset($this->data[$field]) ? $this->data[$field] : $default;
        }
        return $ret;

    }
}