<?php

namespace Libs;

use Libs\Database;

class ModelMySQL {
  
  public $id;
  
  protected $primaryKey = 'id';
  protected $ignoreSave = ['id'];
  protected $forceSave = [];
  
  static protected $table;
  static protected $tableSufix = 's';
  static protected $db;
  static protected $querySelect = [
                    'select' => '*',
                    'where' => '',
                    'leftJoin' => '',
                    'rightJoin' => '',
                    'on' => '',
                    'AndOr' => '',
                    'orderBy'=>'',
                    'groupBy'=>'',
                    'limit' => '',
                   ];
                   
  private static function db(){
    if (is_null(self::$db))
      self::$db = Database::getConnection();

    return self::$db;
  }
  
  private static function query($query){
    $db = self::db();
    
    $result = $db->query($query);
    if ($db->errno){
      	echo 'Fallo al consultar la base de datos.<br>
      	      Errno: ' . addslashes ($db->errno).'<br>
      	      Error: ' . addslashes ($db->error).'<br>'.$query;
      exit();
    }
    
    return $result;
  }
  
  private static function resetQuery(){
    self::$querySelect = [
                    'select' => '*',
                    'where' => '',
                    'leftJoin' => '',
                    'rightJoin' => '',
                    'on' => '',
                    'AndOr' => '',
                    'orderBy'=>'',
                    'groupBy'=>'',
                    'limit' => '',
                   ];
  }
  
  private static function buildQuery(){
    $sql = 'SELECT '.self::$querySelect['select'].' FROM '.self::table();
    
    if (self::$querySelect['leftJoin'] != ''){
      $sql .= ' LEFT JOIN ' . self::$querySelect['leftJoin'];
      $sql .= ' ON '. self::$querySelect['on'];
    } elseif(self::$querySelect['rightJoin'] != ''){
      $sql .= ' RIGHT JOIN ' . self::$querySelect['leftJoin'];
      $sql .= ' ON '. self::$querySelect['on'];
    }
    
    if (self::$querySelect['where'] != ''){
      $sql .= ' WHERE '.self::$querySelect['where'];
      
      if (self::$querySelect['AndOr'] != ''){
        $sql .= self::$querySelect['AndOr'];
      }
    }
    
    if (self::$querySelect['groupBy'] != ''){
      $sql .= ' GROUP BY '.self::$querySelect['groupBy'];
    }
    
    if (self::$querySelect['orderBy'] != ''){
      $sql .= ' ORDER BY '.self::$querySelect['orderBy'];
    }
    
    if (self::$querySelect['limit'] != ''){
      $sql .= ' LIMIT '.self::$querySelect['limit'];
    }
    
    self::resetQuery();
    
    return $sql;
  }
  
  
  public function getInstance($elem = []){
    $class = get_called_class();
    $instace = new $class;
    
    foreach ($elem as $key => $value){
      $instace->$key = $value;
    }
    
    return $instace;
  }


  private function getVars(){ // Source: https://stackoverflow.com/questions/10009015/show-all-public-attributes-name-and-value-of-an-object
    $get_vars_proxy = create_function('$obj', 'return get_object_vars($obj);');
    $result = $get_vars_proxy($this);
    foreach ($this->ignoreSave as $del){
      unset($result[$del]);
    }
    
    foreach ($this->forceSave as $value){
      $result[$value] = $this->$value;
    }
    
    return $result;
  }
  
  
  public static function className(){
    return strtolower(substr(strrchr(get_called_class(), '\\'), 1));
  }
  
  
  private static function table(){
    if (isset(self::$table))
      return self::$table;
    return self::className().self::$tableSufix;
  }


  private function update(){
    $atts = $this->getVars();
    
    foreach ($atts as $key => $value){
      $value = self::db()->real_escape_string($value);
      $set[]="$key='$value'";
    }
    
    $table = self::table();
    $pk = $this->primaryKey;
    $pkv = $this->$pk;
    $sql = "UPDATE $table SET ".join(', ', $set)." WHERE $pk='$pkv'";
    self::query($sql);
  }
  
  
  private function add(){
    $db = self::db();
    $atts = $this->getVars();
    
    foreach ($atts as $key => $value){
      $into[] = "`$key`";
      $values[] = "'".$db->real_escape_string($value)."'";
    }
    
    $table = self::table();
    $sql = "INSERT INTO $table (".join(', ', $into).") VALUES (".join(', ', $values).")";
    self::query($sql);
    
    $pk = $this->primaryKey;
    $this->$pk = $db->insert_id;
  }
  
  
  public function save(){
    $pk = $this->primaryKey;
    if (isset($this->$pk))
      $this->update();
    else
      $this->add();
  }
  
  
  public function delete(){
    $atts = $this->getVars();
    
    foreach ($atts as $key => $value){
      $value = self::db()->real_escape_string($value);
      $set[]="$key='$value'";
    }
    
    $table = self::table();
    $pk = $this->primaryKey;
    $pkv = $this->$pk;
    $sql = "DELETE FROM $table WHERE $pk='$pkv'";
    self::query($sql);
  }
  
  
  public static function select($value){
    $db = self::db();
    $select = [];
    foreach($value as $elem){
      $select[] = $db->real_escape_string($elem);
    }
    
    self::$querySelect['select'] = join(', ', $select);
    
    return new static();
  }
  
  /*
  * Sintaxis permitidas: 
  *  - Class::where(columna, operador, valor)
  *  - Class::where(columna, valor)  // Operador por defecto "="
  */
  
  public static function where($column, $operator, $value=null){
    if (is_null($value)){
      $value = $operator;
      $operator = '=';
    }
    
    $value = self::db()->real_escape_string($value);
    
    self::$querySelect['where'] = "$column$operator'$value'";
    
    return new static();
  }
  
  
  public static function where_in($column,$arr, $in = true){
    foreach($arr as $index => $value){
      $arr[$index] = self::db()->real_escape_string($value);
    }
    
    if ($in)
      self::$querySelect['where'] = "$column IN (".join(', ',$arr).")";
    else
      self::$querySelect['where'] = "$column NOT IN (".join(', ',$arr).")";
    
    return new static();
  }
  
  public static function leftJoin($table, $columnA, $operator, $columnB = null){
    if (is_null($columnB)){
      $columnB = $operator;
      $operator = '=';
    }
    
    $columnA = self::db()->real_escape_string($columnA);
    $columnB = self::db()->real_escape_string($columnB);
    
    self::$querySelect['leftJoin'] = $table;
    self::$querySelect['on'] = "$columnA$operator$columnB";
    
    
    return new static();
  }
  
  public static function rightJoin($table, $columnA, $operator, $columnB = null){
    if (is_null($columnB)){
      $columnB = $operator;
      $operator = '=';
    }
    
    $columnA = self::db()->real_escape_string($columnA);
    $columnB = self::db()->real_escape_string($columnB);
    
    self::$querySelect['rightJoin'] = $table;
    self::$querySelect['on'] = "$columnA$operator$columnB";
    
    
    return new static();
  }
  
  public static function and($column, $operator, $value=null){
    if (is_null($value)){
      $value = $operator;
      $operator = '=';
    }
    
    $value = self::db()->real_escape_string($value);
    
    self::$querySelect['AndOr'] .= " AND $column$operator'$value'";
    
    return new static();
  }
  
  
  public static function or($column, $operator, $value=null){
    if (is_null($value)){
      $value = $operator;
      $operator = '=';
    }
    
    $value = self::db()->real_escape_string($value);
    
    self::$querySelect['AndOr'] .= " OR $column$operator'$value'";
    
    return new static();
  }
  
  public static function groupBy($arr){
    self::$querySelect['groupBy'] = join(', ', $arr);
    return new static();
  }
  
  public static function limit($initial, $final = 0){
    $initial = (int)$initial;
    $final = (int)$final;
  
    if ($final==0)
      self::$querySelect['limit'] = $initial;
    else
      self::$querySelect['limit'] = $initial.', '.$final;
      
    return new static();
  }
  
  
  public static function orderBy($value, $order = 'ASC'){
    if ($value == "RAND"){
      self::$querySelect['orderBy'] = 'RAND()';
      return new static();
    }
    
    $value = self::db()->real_escape_string($value);
    
    if (!(strtoupper($order) == 'ASC' || strtoupper($order) == 'DESC'))
      $order = 'ASC';    
      
    self::$querySelect['orderBy'] = $value.' '.$order;
    
    return new static();
  }
  
  
  public static function count(){
    self::$querySelect['select'] = 'count(*) as quantity';
    $sql = self::buildQuery();
    $result = self::query($sql)->fetch_assoc();
    return $result['quantity'];
  }
  
  
  public static function getById($id){
    return self::where('id', $id)->getFirst();
  }
  
  
  public static function search($search, $in = null){
    $className = get_called_class();
    $objAtts = array_keys((new $className())->getVars());
    
    if ($in == null){
      $in = $objAtts;
    }
    
    $db = self::db();
    
    $search = $db->real_escape_string($search);
    
    $where = [];
    
    foreach($in as $row){
      if(in_array($row, $objAtts))
        $where[] = "$row LIKE '%$search%'";
    }
    
    if (self::$querySelect['where']=='')
      self::$querySelect['where'] = join($where, ' OR ');
    else
      self::$querySelect['where'] = self::$querySelect['where'] .' AND ('.join($where, ' OR ').')';
    
    return new static();
  }
  
  
  public static function get(){ // Devuelve array vacío si no encuentra nada
    $sql = self::buildQuery();
    $result = self::query($sql);
    
    $instaces = [];
    
    while ($row = $result->fetch_assoc()){
      $instaces[] = self::getInstance($row);
    }
                   
    return $instaces;
  }
  
  
  public static function getFirst(){ // Devuelve null si no encuentra nada
    self::limit(1);
    $instaces = self::get();
    return empty($instaces) ? null : $instaces[0];
  }


  public static function all(){
    $sql = 'SELECT * FROM '.self::table();
    
    $result = self::query($sql);
    
    $instaces = [];
    
    while ($row = $result->fetch_assoc()){
      $instaces[] = self::getInstance($row);
    }
    
    return $instaces;
  }
}
?>