<?php
/**
 * Schema database management for CakePHP.
 *
 * PHP 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       cake.libs.model
 * @since         CakePHP(tm) v 1.2.0.5550
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */
App::import('Core', 'Model');
App::import('Core', 'ConnectionManager');

/**
 * Base Class for Schema management
 *
 * @package       cake.libs.model
 */
class CakeSchema extends Object {

/**
 * Name of the schema
 *
 * @var string
 * @access public
 */
	public $name = null;

/**
 * Path to write location
 *
 * @var string
 * @access public
 */
	public $path = null;

/**
 * File to write
 *
 * @var string
 * @access public
 */
	public $file = 'schema.php';

/**
 * Connection used for read
 *
 * @var string
 * @access public
 */
	public $connection = 'default';

/**
 * plugin name.
 *
 * @var string
 */
	public $plugin = null;

/**
 * Set of tables
 *
 * @var array
 * @access public
 */
	public $tables = array();

/**
 * Constructor
 *
 * @param array $options optional load object properties
 */
	function __construct($options = array()) {
		parent::__construct();

		if (empty($options['name'])) {
			$this->name = preg_replace('/schema$/i', '', get_class($this));
		}
		if (!empty($options['plugin'])) {
			$this->plugin = $options['plugin'];
		}

		if (strtolower($this->name) === 'cake') {
			$this->name = Inflector::camelize(Inflector::slug(Configure::read('App.dir')));
		}

		if (empty($options['path'])) {
			$this->path = CONFIGS . 'schema';
		}

		$options = array_merge(get_object_vars($this), $options);
		$this->build($options);
	}

/**
 * Builds schema object properties
 *
 * @param array $data loaded object properties
 * @return void
 */
	public function build($data) {
		$file = null;
		foreach ($data as $key => $val) {
			if (!empty($val)) {
				if (!in_array($key, array('plugin', 'name', 'path', 'file', 'connection', 'tables', '_log'))) {
					if ($key[0] === '_') {
						continue;
					}
					$this->tables[$key] = $val;
					unset($this->{$key});
				} elseif ($key !== 'tables') {
					if ($key === 'name' && $val !== $this->name && !isset($data['file'])) {
						$file = Inflector::underscore($val) . '.php';
					}
					$this->{$key} = $val;
				}
			}
		}
		if (file_exists($this->path . DS . $file) && is_file($this->path . DS . $file)) {
			$this->file = $file;
		} elseif (!empty($this->plugin)) {
			$this->path = App::pluginPath($this->plugin) . 'config' . DS . 'schema';
		}
	}

/**
 * Before callback to be implemented in subclasses
 *
 * @param array $events schema object properties
 * @return boolean Should process continue
 */
	public function before($event = array()) {
		return true;
	}

/**
 * After callback to be implemented in subclasses
 *
 * @param array $events schema object properties
 */
	public function after($event = array()) {
	}

/**
 * Reads database and creates schema tables
 *
 * @param array $options schema object properties
 * @return array Set of name and tables
 */
	public function load($options = array()) {
		if (is_string($options)) {
			$options = array('path' => $options);
		}

		$this->build($options);
		extract(get_object_vars($this));

		$class =  $name .'Schema';

		if (!class_exists($class)) {
			if (file_exists($path . DS . $file) && is_file($path . DS . $file)) {
				require_once($path . DS . $file);
			} elseif (file_exists($path . DS . 'schema.php') && is_file($path . DS . 'schema.php')) {
				require_once($path . DS . 'schema.php');
			}
		}

		if (class_exists($class)) {
			$Schema = new $class($options);
			return $Schema;
		}

		return false;
	}

/**
 * Reads database and creates schema tables
 *
 * Options
 *
 * - 'connection' - the db connection to use
 * - 'name' - name of the schema
 * - 'models' - a list of models to use, or false to ignore models
 *
 * @param array $options schema object properties
 * @return array Array indexed by name and tables
 */
	public function read($options = array()) {
		extract(array_merge(
			array(
				'connection' => $this->connection,
				'name' => $this->name,
				'models' => true,
			),
			$options
		));
		$db = ConnectionManager::getDataSource($connection);

		App::import('Model', 'AppModel');
		if (isset($this->plugin)) {
			App::import('Model', Inflector::camelize($this->plugin) . 'AppModel');
		}

		$tables = array();
		$currentTables = $db->listSources();

		$prefix = null;
		if (isset($db->config['prefix'])) {
			$prefix = $db->config['prefix'];
		}

		if (!is_array($models) && $models !== false) {
			if (isset($this->plugin)) {
				$models = App::objects('model', App::pluginPath($this->plugin) . 'models' . DS, false);
			} else {
				$models = App::objects('model');
			}
		}

		if (is_array($models)) {
			foreach ($models as $model) {
				$importModel = $model;
				if (isset($this->plugin)) {
					$importModel = $this->plugin . '.' . $model;
				}
				if (!App::import('Model', $importModel)) {
					continue;
				}
				$vars = get_class_vars($model);
				if (empty($vars['useDbConfig']) || $vars['useDbConfig'] != $connection) {
					continue;
				}

				$Object = ClassRegistry::init(array('class' => $model, 'ds' => $connection));
				$db = $Object->getDataSource();
				if (is_object($Object) && $Object->useTable !== false) {
					$fulltable = $table = $db->fullTableName($Object, false);
					if ($prefix && strpos($table, $prefix) !== 0) {
						continue;
					}
					$table = str_replace($prefix, '', $table);

					if (in_array($fulltable, $currentTables)) {
						$key = array_search($fulltable, $currentTables);
						if (empty($tables[$table])) {
							$tables[$table] = $this->__columns($Object);
							$tables[$table]['indexes'] = $db->index($Object);
							$tables[$table]['tableParameters'] = $db->readTableParameters($fulltable);
							unset($currentTables[$key]);
						}
						if (!empty($Object->hasAndBelongsToMany)) {
							foreach ($Object->hasAndBelongsToMany as $Assoc => $assocData) {
								if (isset($assocData['with'])) {
									$class = $assocData['with'];
								}
								if (is_object($Object->$class)) {
									$withTable = $db->fullTableName($Object->$class, false);
									if ($prefix && strpos($withTable, $prefix) !== 0) {
										continue;
									}
									if (in_array($withTable, $currentTables)) {
										$key = array_search($withTable, $currentTables);
										$noPrefixWith = str_replace($prefix, '', $withTable);
	
										$tables[$noPrefixWith] = $this->__columns($Object->$class);
										$tables[$noPrefixWith]['indexes'] = $db->index($Object->$class);
										$tables[$noPrefixWith]['tableParameters'] = $db->readTableParameters($withTable);
										unset($currentTables[$key]);
									}
								}
							}
						}
					}
				}
			}
		}

		if (!empty($currentTables)) {
			foreach ($currentTables as $table) {
				if ($prefix) {
					if (strpos($table, $prefix) !== 0) {
						continue;
					}
					$table = str_replace($prefix, '', $table);
				}
				$Object = new AppModel(array(
					'name' => Inflector::classify($table), 'table' => $table, 'ds' => $connection
				));

				$systemTables = array(
					'aros', 'acos', 'aros_acos', Configure::read('Session.table'), 'i18n'
				);
				if (in_array($table, $systemTables)) {
					$tables[$Object->table] = $this->__columns($Object);
					$tables[$Object->table]['indexes'] = $db->index($Object);
					$tables[$Object->table]['tableParameters'] = $db->readTableParameters($table);
				} elseif ($models === false) {
					$tables[$table] = $this->__columns($Object);
					$tables[$table]['indexes'] = $db->index($Object);
					$tables[$table]['tableParameters'] = $db->readTableParameters($table);
				} else {
					$tables['missing'][$table] = $this->__columns($Object);
					$tables['missing'][$table]['indexes'] = $db->index($Object);
					$tables['missing'][$table]['tableParameters'] = $db->readTableParameters($table);
				}
			}
		}

		ksort($tables);
		return compact('name', 'tables');
	}

/**
 * Writes schema file from object or options
 *
 * @param mixed $object schema object or options array
 * @param array $options schema object properties to override object
 * @return mixed false or string written to file
 */
	public function write($object, $options = array()) {
		if (is_object($object)) {
			$object = get_object_vars($object);
			$this->build($object);
		}

		if (is_array($object)) {
			$options = $object;
			unset($object);
		}

		extract(array_merge(
			get_object_vars($this), $options
		));

		$out = "class {$name}Schema extends CakeSchema {\n";

		if ($path !== $this->path) {
			$out .= "\tvar \$path = '{$path}';\n\n";
		}

		if ($file !== $this->file) {
			$out .= "\tvar \$file = '{$file}';\n\n";
		}

		if ($connection !== 'default') {
			$out .= "\tvar \$connection = '{$connection}';\n\n";
		}

		$out .= "\tfunction before(\$event = array()) {\n\t\treturn true;\n\t}\n\n\tfunction after(\$event = array()) {\n\t}\n\n";

		if (empty($tables)) {
			$this->read();
		}

		foreach ($tables as $table => $fields) {
			if (!is_numeric($table) && $table !== 'missing') {
				$out .= $this->generateTable($table, $fields);
			}
		}
		$out .= "}\n";

		$file = new SplFileObject($path . DS . $file, 'w+');
		$content = "<?php \n/* {$name} schema generated on: " . date('Y-m-d H:i:s') . " : ". time() . "*/\n{$out}?>";
		if ($file->fwrite($content)) {
			return $content;
		}
		return false;
	}

/**
 * Generate the code for a table. Takes a table name and $fields array
 * Returns a completed variable declaration to be used in schema classes
 *
 * @param string $table Table name you want returned.
 * @param array $fields Array of field information to generate the table with.
 * @return string Variable declaration for a schema class
 */
	function generateTable($table, $fields) {
		$out = "\tvar \${$table} = array(\n";
		if (is_array($fields)) {
			$cols = array();
			foreach ($fields as $field => $value) {
				if ($field != 'indexes' && $field != 'tableParameters') {
					if (is_string($value)) {
						$type = $value;
						$value = array('type'=> $type);
					}
					$col = "\t\t'{$field}' => array('type' => '" . $value['type'] . "', ";
					unset($value['type']);
					$col .= join(', ',  $this->__values($value));
				} elseif ($field == 'indexes') {
					$col = "\t\t'indexes' => array(";
					$props = array();
					foreach ((array)$value as $key => $index) {
						$props[] = "'{$key}' => array(" . join(', ',  $this->__values($index)) . ")";
					}
					$col .= join(', ', $props);
				} elseif ($field == 'tableParameters') {
					//@todo add charset, collate and engine here
					$col = "\t\t'tableParameters' => array(";
					$props = array();
					foreach ((array)$value as $key => $param) {
						$props[] = "'{$key}' => '$param'";
					}
					$col .= join(', ', $props);
				}
				$col .= ")";
				$cols[] = $col;
			}
			$out .= join(",\n", $cols);
		}
		$out .= "\n\t);\n";
		return $out;
	}

/**
 * Compares two sets of schemas
 *
 * @param mixed $old Schema object or array
 * @param mixed $new Schema object or array
 * @return array Tables (that are added, dropped, or changed)
 */
	public function compare($old, $new = null) {
		if (empty($new)) {
			$new = $this;
		}
		if (is_array($new)) {
			if (isset($new['tables'])) {
				$new = $new['tables'];
			}
		} else {
			$new = $new->tables;
		}

		if (is_array($old)) {
			if (isset($old['tables'])) {
				$old = $old['tables'];
			}
		} else {
			$old = $old->tables;
		}
		$tables = array();
		foreach ($new as $table => $fields) {
			if ($table == 'missing') {
				continue;
			}
			if (!array_key_exists($table, $old)) {
				$tables[$table]['add'] = $fields;
			} else {
				$diff = $this->_arrayDiffAssoc($fields, $old[$table]);
				if (!empty($diff)) {
					$tables[$table]['add'] = $diff;
				}
				$diff = $this->_arrayDiffAssoc($old[$table], $fields);
				if (!empty($diff)) {
					$tables[$table]['drop'] = $diff;
				}
			}

			foreach ($fields as $field => $value) {
				if (isset($old[$table][$field])) {
					$diff = $this->_arrayDiffAssoc($value, $old[$table][$field]);
					if (!empty($diff) && $field !== 'indexes' && $field !== 'tableParameters') {
						$tables[$table]['change'][$field] = array_merge($old[$table][$field], $diff);
					}
				}

				if (isset($add[$table][$field])) {
					$wrapper = array_keys($fields);
					if ($column = array_search($field, $wrapper)) {
						if (isset($wrapper[$column - 1])) {
							$tables[$table]['add'][$field]['after'] = $wrapper[$column - 1];
						}
					}
				}
			}

			if (isset($old[$table]['indexes']) && isset($new[$table]['indexes'])) {
				$diff = $this->_compareIndexes($new[$table]['indexes'], $old[$table]['indexes']);
				if ($diff) {
					if (!isset($tables[$table])) {
						$tables[$table] = array();
					}
					if (isset($diff['drop'])) {
						$tables[$table]['drop']['indexes'] = $diff['drop'];
					}
					if ($diff && isset($diff['add'])) {
						$tables[$table]['add']['indexes'] = $diff['add'];
					}
				}
			}
			if (isset($old[$table]['tableParameters']) && isset($new[$table]['tableParameters'])) {
				$diff = $this->_compareTableParameters($new[$table]['tableParameters'], $old[$table]['tableParameters']);
				if ($diff) {
					$tables[$table]['change']['tableParameters'] = $diff;
				}
			}
		}
		return $tables;
	}

/**
 * Extended array_diff_assoc noticing change from/to NULL values
 *
 * It behaves almost the same way as array_diff_assoc except for NULL values: if
 * one of the values is not NULL - change is detected. It is useful in situation
 * where one value is strval('') ant other is strval(null) - in string comparing
 * methods this results as EQUAL, while it is not.
 *
 * @param array $array1 Base array
 * @param array $array2 Corresponding array checked for equality
 * @return array Difference as array with array(keys => values) from input array
 *     where match was not found.
 * @access protected
 */
	function _arrayDiffAssoc($array1, $array2) {
		$difference = array();
		foreach ($array1 as $key => $value) {
			if (!array_key_exists($key, $array2)) {
				$difference[$key] = $value;
				continue;
			}
			$correspondingValue = $array2[$key];
			if (is_null($value) !== is_null($correspondingValue)) {
				$difference[$key] = $value;
				continue;
			}
			if (is_bool($value) !== is_bool($correspondingValue)) {
				$difference[$key] = $value;
				continue;
			}
			$compare = strval($value);
			$correspondingValue = strval($correspondingValue);
			if ($compare === $correspondingValue) {
				continue;
			}
			$difference[$key] = $value;
		}
		return $difference;
	}

/**
 * Formats Schema columns from Model Object
 *
 * @param array $values options keys(type, null, default, key, length, extra)
 * @return array Formatted values
 */
	public function __values($values) {
		$vals = array();
		if (is_array($values)) {
			foreach ($values as $key => $val) {
				if (is_array($val)) {
					$vals[] = "'{$key}' => array('" . implode("', '",  $val) . "')";
				} else if (!is_numeric($key)) {
					$val = var_export($val, true);
					$vals[] = "'{$key}' => {$val}";
				}
			}
		}
		return $vals;
	}

/**
 * Formats Schema columns from Model Object
 *
 * @param array $Obj model object
 * @return array Formatted columns
 */
	public function __columns(&$Obj) {
		$db = $Obj->getDataSource();
		$fields = $Obj->schema(true);

		$columns = $props = array();
		foreach ($fields as $name => $value) {
			if ($Obj->primaryKey == $name) {
				$value['key'] = 'primary';
			}
			if (!isset($db->columns[$value['type']])) {
				trigger_error(__('Schema generation error: invalid column type %s does not exist in DBO', $value['type']), E_USER_NOTICE);
				continue;
			} else {
				$defaultCol = $db->columns[$value['type']];
				if (isset($defaultCol['limit']) && $defaultCol['limit'] == $value['length']) {
					unset($value['length']);
				} elseif (isset($defaultCol['length']) && $defaultCol['length'] == $value['length']) {
					unset($value['length']);
				}
				unset($value['limit']);
			}

			if (isset($value['default']) && ($value['default'] === '' || $value['default'] === false)) {
				unset($value['default']);
			}
			if (empty($value['length'])) {
				unset($value['length']);
			}
			if (empty($value['key'])) {
				unset($value['key']);
			}
			$columns[$name] = $value;
		}

		return $columns;
	}

/**
 * Compare two schema files table Parameters
 *
 * @param array $new New indexes
 * @param array $old Old indexes
 * @return mixed False on failure, or an array of parameters to add & drop.
 */
	function _compareTableParameters($new, $old) {
		if (!is_array($new) || !is_array($old)) {
			return false;
		}
		$change = $this->_arrayDiffAssoc($new, $old);
		return $change;
	}

/**
 * Compare two schema indexes
 *
 * @param array $new New indexes
 * @param array $old Old indexes
 * @return mixed false on failure or array of indexes to add and drop
 */
	function _compareIndexes($new, $old) {
		if (!is_array($new) || !is_array($old)) {
			return false;
		}

		$add = $drop = array();

		$diff = $this->_arrayDiffAssoc($new, $old);
		if (!empty($diff)) {
			$add = $diff;
		}

		$diff = $this->_arrayDiffAssoc($old, $new);
		if (!empty($diff)) {
			$drop = $diff;
		}

		foreach ($new as $name => $value) {
			if (isset($old[$name])) {
				$newUnique = isset($value['unique']) ? $value['unique'] : 0;
				$oldUnique = isset($old[$name]['unique']) ? $old[$name]['unique'] : 0;
				$newColumn = $value['column'];
				$oldColumn = $old[$name]['column'];

				$diff = false;

				if ($newUnique != $oldUnique) {
					$diff = true;
				} elseif (is_array($newColumn) && is_array($oldColumn)) {
					$diff = ($newColumn !== $oldColumn);
				} elseif (is_string($newColumn) && is_string($oldColumn)) {
					$diff = ($newColumn != $oldColumn);
				} else {
					$diff = true;
				}
				if ($diff) {
					$drop[$name] = null;
					$add[$name] = $value;
				}
			}
		}
		return array_filter(compact('add', 'drop'));
	}
}