<?php

use EventEspresso\core\services\database\TableAnalysis;
use EventEspresso\core\services\database\TableManager;

/**
 * Class EE_Data_Migration_Class_Base
 *
 * Base class for common functionality between EE_Data_migration_Script_base and EE_Data_migration_Script_Stage.
 *
 * @package               Event Espresso
 * @subpackage            core
 * @author                Mike Nelson
 * @since                 4.0
 *
 */
abstract class EE_Data_Migration_Class_Base
{

    /**
     * @var $records_to_migrate int count of all that have been migrated
     */
    protected $_records_to_migrate = 0;

    /**
     *
     * @var $records_migrated int
     */
    protected $_records_migrated = 0;

    /**
     * Whether this migration script is done or not. This COULD be deduced by
     * _records_to_migrate and _records_migrated, but that might nto be accurate
     *
     * @var string one of EE_Data_migration_Manager::status_* constants
     */
    protected $_status = null;

    /**
     * internationalized name of this class. Convention is to NOT restate that
     * this class if a migration script or a migration script stage
     *
     * @var string (i18ned)
     */
    protected $_pretty_name = null;

    /**
     * @var array
     */
    protected $_errors = array();

    /**
     * @var \EventEspresso\core\services\database\TableManager $table_manager
     */
    protected $_table_manager;

    /**
     * @var \EventEspresso\core\services\database\TableAnalysis $table_analysis
     */
    protected $_table_analysis;


    /**
     * Just initializes the status of the migration
     *
     * @param TableManager  $table_manager
     * @param TableAnalysis $table_analysis
     */
    public function __construct(TableManager $table_manager = null, TableAnalysis $table_analysis = null)
    {
        $this->_table_manager = $table_manager;
        $this->_table_analysis = $table_analysis;
        $this->set_status(EE_Data_Migration_Manager::status_continue);
    }


    /**
     * Just gets the pretty name for this migration script or stage
     *
     * @throws EE_Error
     * @return string
     */
    public function pretty_name()
    {
        if ($this->_pretty_name === null) {
            throw new EE_Error(
                sprintf(
                    __(
                        "Please give a pretty name to the migration script stage %s by assigning the property _pretty_name in the constructor",
                        "event_espresso"
                    ),
                    get_class($this)
                )
            );
        }
        return $this->_pretty_name;
    }

    /**
     *
     * @return int
     */
    public function count_records_to_migrate()
    {
        if ($this->_records_to_migrate == null) {
            $this->_records_to_migrate = $this->_count_records_to_migrate();
        }
        return $this->_records_to_migrate;
    }

    /**
     * Counts records already migrated. This should only be implemented by EE_Data_Migration_Script_base and
     * EE_Data_migration_Script_Stage
     *
     * @return int
     */
    abstract public function count_records_migrated();

    /**
     * Counts the records to migrate; the public version may cache it
     *
     * @return int
     */
    abstract protected function _count_records_to_migrate();

    /**
     * Returns a string indicating the migration script's status.
     *
     * @return string one of EE_Data_Migration_Manager::status_* constants
     * @throws EE_Error
     */
    public function get_status()
    {
        if ($this->_status === null) {
            throw new EE_Error(
                sprintf(
                    __(
                        "Trying to get status of Migration class %s, but it has not been initialized yet. It should be set in the constructor.",
                        "event_espresso"
                    ),
                    get_class($this)
                )
            );
        }
        return $this->_status;
    }

    /**
     *
     * @param string $status
     * @return void
     */
    protected function set_status($status)
    {
        $this->_status = $status;
    }

    /**
     * @return array of strings
     */
    abstract public function get_errors();

    /**
     * Returns the last error that occurred. If none occurred, returns null
     *
     * @return string
     */
    public function get_last_error()
    {
        $errors = $this->get_errors();
        if ($errors) {
            return end($errors);
        } else {
            return null;
        }
    }

    /**
     * Adds an error to the array of errors on this class.
     *
     * @param string  $error a string describing the error that will be useful for debugging. Consider including all
     *                       the data that led to the error, and a stack trace etc.
     * @param boolean $force force the error to be added (because otherwise we have a limit). If forcing and errors are
     *                       already at their limit, we will purposefully forget the first half
     */
    public function add_error($error, $force = false)
    {
        if (! defined('EE_DMS_ERROR_LIMIT')) {
            $limit = 50;
        } else {
            $limit = EE_DMS_ERROR_LIMIT;
        }
        // make sure errors is an array, see ticket #8261
        if (is_string($this->_errors)) {
            $this->_errors = array($this->_errors);
        }
        if (count($this->_errors) >= $limit) {
            if ($force) {
                // get rid of the first half of the errors and any above the limit
                $this->_errors = array_slice($this->_errors, $limit / 2, $limit / 2);
                $this->_errors[] = "Limit reached; removed first half of errors to save space";
                $this->_errors[] = $error;
            } else {
                $this->_errors[ $limit ] = 'More, but limit reached...';
            }
        } else {
            $this->_errors[] = $error;
        }
    }

    /**
     * Indicates there was a fatal error and the migration cannot possibly continue
     *
     * @return boolean
     */
    public function is_broken()
    {
        return $this->get_status() == EE_Data_Migration_Manager::status_fatal_error;
    }

    /**
     * @deprecated since 4.6.12
     */
    public function is_borked()
    {
        EE_Error::doing_it_wrong(
            'is_borked',
            __(
                'The cheeky "is_borked" method had been replaced with the more proper "is_broken"',
                'event_espresso'
            ),
            '4.6.12'
        );
        return $this->is_broken();
    }

    /**
     * Sets the status to as having a fatal error
     */
    public function set_broken()
    {
        $this->_status = EE_Data_Migration_Manager::status_fatal_error;
    }

    /**
     *
     * @deprecated since 4.6.12
     */
    public function set_borked()
    {
        EE_Error::doing_it_wrong(
            'is_borked',
            __(
                'The cheeky "is_borked" method had been replaced with the more proper "is_broken"',
                'event_espresso'
            ),
            '4.6.12'
        );
        return $this->set_broken();
    }

    /**
     * Checks if this thing believes it is completed
     *
     * @return boolean
     */
    public function is_completed()
    {
        return $this->get_status() == EE_Data_Migration_Manager::status_completed;
    }

    /**
     * Checks if the current script has more to do or not (ie, if it's status is CONTINUE)
     *
     * @return boolean
     */
    public function has_more_to_do()
    {
        return $this->get_status() == EE_Data_Migration_Manager::status_continue;
    }

    /**
     * Marks that we believe this migration thing is completed
     */
    public function set_completed()
    {
        $this->_status = EE_Data_Migration_Manager::status_completed;
    }

    /**
     * Marks that we think this migration class can continue to migrate
     */
    public function reattempt()
    {
        $this->_status = EE_Data_Migration_Manager::status_continue;
        $this->add_error(__('Reattempt migration', 'event_espresso'), true);
    }

    /**
     * A lot like "__sleep()" magic method in purpose, this is meant for persisting this class'
     * properties to the DB. However, we don't want to use __sleep() because its quite
     * possible that this class is defined when it goes to sleep, but NOT available when it
     * awakes (eg, this class is part of an addon that is deactivated at some point).
     */
    public function properties_as_array()
    {
        $properties = get_object_vars($this);
        $properties['class'] = get_class($this);
        unset($properties['_migration_script']);
        unset($properties['_table_manager']);
        unset($properties['_table_analysis']);
        return $properties;
    }

    /**
     * Sets all of the properties of this script stage to match what's in the array, which is assumed
     * to have been made from the properties_as_array() function.
     *
     * @param array $array_of_properties like what's produced from properties_as_array() method
     */
    abstract public function instantiate_from_array_of_properties($array_of_properties);

    /**
     * Convenience method for showing a database insertion error
     *
     * @param string $old_table
     * @param array  $old_row_as_array
     * @param string $new_table
     * @param array  $new_row_as_array columns=>values like used in wpdb->insert
     * @param array  $data_types       numerically indexed
     * @return string
     */
    protected function _create_error_message_for_db_insertion(
        $old_table,
        $old_row_as_array,
        $new_table,
        $new_row_as_array,
        $data_types
    ) {
        global $wpdb;
        $old_columns_and_values_for_string = array();
        foreach ($old_row_as_array as $column => $value) {
            $old_columns_and_values_for_string[] = "$column => $value";
        }
        $new_columns_and_values_for_string = array();
        $count = 0;
        foreach ($new_row_as_array as $column => $value) {
            $new_columns_and_values_for_string[] = " $column => $value (" . $data_types[ $count++ ] . ")";
        }
        return sprintf(
            __(
                'Received error "%6$s" inserting row %5$s %1$s %5$s into table %2$s.%5$s Data used was %5$s %3$s %5$s from table %4$s.',
                'event_espresso'
            ),
            implode(", ", $new_columns_and_values_for_string),
            $new_table,
            implode(", ", $old_columns_and_values_for_string),
            $old_table,
            '<br/>',
            $wpdb->last_error
        );
    }


    /**
     * Same as json_encode, just avoids putting
     * serialized arrays into the http build query, as that would
     *
     * @param array $array_of_data
     * @return string
     */
    protected function _json_encode($array_of_data)
    {
        // we'd rather NOT serialize the transaction details
        $fields_to_include = array();
        foreach ($array_of_data as $name => $value) {
            $unserialized_data = @unserialize($value);
            if ($unserialized_data === false) {
                $fields_to_include[ $name ] = $value;
            }
        }
        return wp_json_encode($fields_to_include);
    }

    /**
     * Gets the table manager (or throws an exception if it cannot be retrieved)
     *
     * @return TableManager
     * @throws EE_Error
     */
    protected function _get_table_manager()
    {
        if ($this->_table_manager instanceof TableManager) {
            return $this->_table_manager;
        } else {
            throw new EE_Error(
                sprintf(
                    __('Table manager on migration class %1$s is not set properly.', 'event_espresso'),
                    get_class($this)
                )
            );
        }
    }

    /**
     * Gets the injected table analyzer, or throws an exception
     *
     * @return TableAnalysis
     * @throws EE_Error
     */
    protected function _get_table_analysis()
    {
        if ($this->_table_analysis instanceof TableAnalysis) {
            return $this->_table_analysis;
        } else {
            throw new EE_Error(
                sprintf(
                    __('Table analysis class on migration class %1$s is not set properly.', 'event_espresso'),
                    get_class($this)
                )
            );
        }
    }
}
