<?php
/**
 * Piwik - Open source web analytics
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 * @category Piwik_Plugins
 * @package Goals
 */
namespace Piwik\Plugins\Goals;

use Exception;
use Piwik\Archive;
use Piwik\Metrics;
use Piwik\Piwik;
use Piwik\Common;
use Piwik\DataTable;
use Piwik\Site;
use Piwik\Db;
use Piwik\Tracker\Cache;
use Piwik\Tracker\GoalManager;
use Piwik\Plugins\Goals\Goals;
use Piwik\Plugins\Goals\Archiver;

/**
 * Goals API lets you Manage existing goals, via "updateGoal" and "deleteGoal", create new Goals via "addGoal",
 * or list existing Goals for one or several websites via "getGoals"
 *
 * If you are <a href='http://piwik.org/docs/ecommerce-analytics/' target='_blank'>tracking Ecommerce orders and products</a> on your site, the functions "getItemsSku", "getItemsName" and "getItemsCategory"
 * will return the list of products purchased on your site, either grouped by Product SKU, Product Name or Product Category. For each name, SKU or category, the following
 * metrics are returned: Total revenue, Total quantity, average price, average quantity, number of orders (or abandoned carts) containing this product, number of visits on the Product page,
 * Conversion rate.
 *
 * By default, these functions return the 'Products purchased'. These functions also accept an optional parameter &abandonedCarts=1.
 * If the parameter is set, it will instead return the metrics for products that were left in an abandoned cart therefore not purchased.
 *
 * The API also lets you request overall Goal metrics via the method "get": Conversions, Visits with at least one conversion, Conversion rate and Revenue.
 * If you wish to request specific metrics about Ecommerce goals, you can set the parameter &idGoal=ecommerceAbandonedCart to get metrics about abandoned carts (including Lost revenue, and number of items left in the cart)
 * or &idGoal=ecommerceOrder to get metrics about Ecommerce orders (number of orders, visits with an order, subtotal, tax, shipping, discount, revenue, items ordered)
 *
 * See also the documentation about <a href='http://piwik.org/docs/tracking-goals-web-analytics/' target='_blank'>Tracking Goals</a> in Piwik.
 *
 * @package Goals
 */
class API
{
    static private $instance = null;

    /**
     * @return \Piwik\Plugins\Goals\API
     */
    static public function getInstance()
    {
        if (self::$instance == null) {
            self::$instance = new self;
        }
        return self::$instance;
    }

    /**
     * Returns all Goals for a given website, or list of websites
     *
     * @param string|array $idSite Array or Comma separated list of website IDs to request the goals for
     * @return array Array of Goal attributes
     */
    public function getGoals($idSite)
    {
        //TODO calls to this function could be cached as static
        // would help UI at least, since some UI requests would call this 2-3 times..
        $idSite = Site::getIdSitesFromIdSitesString($idSite);
        if (empty($idSite)) {
            return array();
        }
        Piwik::checkUserHasViewAccess($idSite);
        $goals = Db::fetchAll("SELECT *
								FROM " . Common::prefixTable('goal') . "
								WHERE idsite IN (" . implode(", ", $idSite) . ")
									AND deleted = 0");
        $cleanedGoals = array();
        foreach ($goals as &$goal) {
            if ($goal['match_attribute'] == 'manually') {
                unset($goal['pattern']);
                unset($goal['pattern_type']);
                unset($goal['case_sensitive']);
            }
            $cleanedGoals[$goal['idgoal']] = $goal;
        }
        return $cleanedGoals;
    }

    /**
     * Creates a Goal for a given website.
     *
     * @param int $idSite
     * @param string $name
     * @param string $matchAttribute 'url', 'title', 'file', 'external_website' or 'manually'
     * @param string $pattern eg. purchase-confirmation.htm
     * @param string $patternType 'regex', 'contains', 'exact'
     * @param bool $caseSensitive
     * @param bool|float $revenue If set, default revenue to assign to conversions
     * @param bool $allowMultipleConversionsPerVisit By default, multiple conversions in the same visit will only record the first conversion.
     *                         If set to true, multiple conversions will all be recorded within a visit (useful for Ecommerce goals)
     * @return int ID of the new goal
     */
    public function addGoal($idSite, $name, $matchAttribute, $pattern, $patternType, $caseSensitive = false, $revenue = false, $allowMultipleConversionsPerVisit = false)
    {
        Piwik::checkUserHasAdminAccess($idSite);
        $this->checkPatternIsValid($patternType, $pattern);
        $name = $this->checkName($name);
        $pattern = $this->checkPattern($pattern);

        // save in db
        $db = Db::get();
        $idGoal = $db->fetchOne("SELECT max(idgoal) + 1
								FROM " . Common::prefixTable('goal') . "
								WHERE idsite = ?", $idSite);
        if ($idGoal == false) {
            $idGoal = 1;
        }
        $db->insert(Common::prefixTable('goal'),
            array(
                 'idsite'          => $idSite,
                 'idgoal'          => $idGoal,
                 'name'            => $name,
                 'match_attribute' => $matchAttribute,
                 'pattern'         => $pattern,
                 'pattern_type'    => $patternType,
                 'case_sensitive'  => (int)$caseSensitive,
                 'allow_multiple'  => (int)$allowMultipleConversionsPerVisit,
                 'revenue'         => (float)$revenue,
                 'deleted'         => 0,
            ));
        Cache::regenerateCacheWebsiteAttributes($idSite);
        return $idGoal;
    }

    /**
     * Updates a Goal description.
     * Will not update or re-process the conversions already recorded
     *
     * @see addGoal() for parameters description
     * @param int $idSite
     * @param int $idGoal
     * @param $name
     * @param $matchAttribute
     * @param string $pattern
     * @param string $patternType
     * @param bool $caseSensitive
     * @param bool|float $revenue
     * @param bool $allowMultipleConversionsPerVisit
     * @return void
     */
    public function updateGoal($idSite, $idGoal, $name, $matchAttribute, $pattern, $patternType, $caseSensitive = false, $revenue = false, $allowMultipleConversionsPerVisit = false)
    {
        Piwik::checkUserHasAdminAccess($idSite);
        $name = $this->checkName($name);
        $pattern = $this->checkPattern($pattern);
        $this->checkPatternIsValid($patternType, $pattern);
        Db::get()->update(Common::prefixTable('goal'),
            array(
                 'name'            => $name,
                 'match_attribute' => $matchAttribute,
                 'pattern'         => $pattern,
                 'pattern_type'    => $patternType,
                 'case_sensitive'  => (int)$caseSensitive,
                 'allow_multiple'  => (int)$allowMultipleConversionsPerVisit,
                 'revenue'         => (float)$revenue,
            ),
            "idsite = '$idSite' AND idgoal = '$idGoal'"
        );
        Cache::regenerateCacheWebsiteAttributes($idSite);
    }

    private function checkPatternIsValid($patternType, $pattern)
    {
        if ($patternType == 'exact'
            && substr($pattern, 0, 4) != 'http'
        ) {
            throw new Exception(Piwik_TranslateException('Goals_ExceptionInvalidMatchingString', array("http:// or https://", "http://www.yourwebsite.com/newsletter/subscribed.html")));
        }
    }

    private function checkName($name)
    {
        return urldecode($name);
    }

    private function checkPattern($pattern)
    {
        return urldecode($pattern);
    }

    /**
     * Soft deletes a given Goal.
     * Stats data in the archives will still be recorded, but not displayed.
     *
     * @param int $idSite
     * @param int $idGoal
     * @return void
     */
    public function deleteGoal($idSite, $idGoal)
    {
        Piwik::checkUserHasAdminAccess($idSite);
        Db::query("UPDATE " . Common::prefixTable('goal') . "
										SET deleted = 1
										WHERE idsite = ?
											AND idgoal = ?",
            array($idSite, $idGoal));
        Db::deleteAllRows(Common::prefixTable("log_conversion"), "WHERE idgoal = ?", "idvisit", 100000, array($idGoal));
        Cache::regenerateCacheWebsiteAttributes($idSite);
    }

    /**
     * Returns a datatable of Items SKU/name or categories and their metrics
     * If $abandonedCarts set to 1, will return items abandoned in carts. If set to 0, will return items ordered
     */
    protected function getItems($recordName, $idSite, $period, $date, $abandonedCarts)
    {
        Piwik::checkUserHasViewAccess($idSite);
        $recordNameFinal = $recordName;
        if ($abandonedCarts) {
            $recordNameFinal = Archiver::getItemRecordNameAbandonedCart($recordName);
        }
        $archive = Archive::build($idSite, $period, $date);
        $dataTable = $archive->getDataTable($recordNameFinal);

        $dataTable->filter('Sort', array(Metrics::INDEX_ECOMMERCE_ITEM_REVENUE));
        $dataTable->queueFilter('ReplaceColumnNames');
        $dataTable->queueFilter('ReplaceSummaryRowLabel');

        $ordersColumn = 'orders';
        if ($abandonedCarts) {
            $ordersColumn = 'abandoned_carts';
            $dataTable->renameColumn(Metrics::INDEX_ECOMMERCE_ORDERS, $ordersColumn);
        }

        // Average price = sum product revenue / quantity
        $dataTable->queueFilter('ColumnCallbackAddColumnQuotient', array('avg_price', 'price', $ordersColumn, GoalManager::REVENUE_PRECISION));

        // Average quantity = sum product quantity / abandoned carts
        $dataTable->queueFilter('ColumnCallbackAddColumnQuotient', array('avg_quantity', 'quantity', $ordersColumn, $precision = 1));
        $dataTable->queueFilter('ColumnDelete', array('price'));

        // Enrich the datatable with Product/Categories views, and conversion rates
        $customVariables = \Piwik\Plugins\CustomVariables\API::getInstance()->getCustomVariables($idSite, $period, $date, $segment = false, $expanded = false,
            $_leavePiwikCoreVariables = true);
        $mapping = array(
            'Goals_ItemsSku'      => '_pks',
            'Goals_ItemsName'     => '_pkn',
            'Goals_ItemsCategory' => '_pkc',
        );
        $reportToNotDefinedString = array(
            'Goals_ItemsSku'      => Piwik_Translate('General_NotDefined', Piwik_Translate('Goals_ProductSKU')), // Note: this should never happen
            'Goals_ItemsName'     => Piwik_Translate('General_NotDefined', Piwik_Translate('Goals_ProductName')),
            'Goals_ItemsCategory' => Piwik_Translate('General_NotDefined', Piwik_Translate('Goals_ProductCategory'))
        );
        $notDefinedStringPretty = $reportToNotDefinedString[$recordName];
        $customVarNameToLookFor = $mapping[$recordName];

        // Handle case where date=last30&period=day
        if ($customVariables instanceof DataTable\Map) {
            $customVariableDatatables = $customVariables->getArray();
            $dataTables = $dataTable->getArray();
            foreach ($customVariableDatatables as $key => $customVariableTableForDate) {
                $dataTableForDate = isset($dataTables[$key]) ? $dataTables[$key] : new DataTable();

                // we do not enter the IF
                // if case idSite=1,3 AND period=day&date=datefrom,dateto,
                if (isset($customVariableTableForDate->metadata['period'])) {
                    $dateRewrite = $customVariableTableForDate->metadata['period']->getDateStart()->toString();
                    $row = $customVariableTableForDate->getRowFromLabel($customVarNameToLookFor);
                    if ($row) {
                        $idSubtable = $row->getIdSubDataTable();
                        $this->enrichItemsDataTableWithItemsViewMetrics($dataTableForDate, $idSite, $period, $dateRewrite, $idSubtable);
                    }
                    $dataTable->addTable($dataTableForDate, $key);
                }
                $this->renameNotDefinedRow($dataTableForDate, $notDefinedStringPretty);
            }
        } elseif ($customVariables instanceof DataTable) {
            $row = $customVariables->getRowFromLabel($customVarNameToLookFor);
            if ($row) {
                $idSubtable = $row->getIdSubDataTable();
                $this->enrichItemsDataTableWithItemsViewMetrics($dataTable, $idSite, $period, $date, $idSubtable);
            }
            $this->renameNotDefinedRow($dataTable, $notDefinedStringPretty);
        }

        // Product conversion rate = orders / visits
        $dataTable->queueFilter('ColumnCallbackAddColumnPercentage', array('conversion_rate', $ordersColumn, 'nb_visits', GoalManager::REVENUE_PRECISION));

        return $dataTable;
    }

    protected function renameNotDefinedRow($dataTable, $notDefinedStringPretty)
    {
        if ($dataTable instanceof DataTable\Map) {
            foreach ($dataTable->getArray() as $table) {
                $this->renameNotDefinedRow($table, $notDefinedStringPretty);
            }
            return;
        }
        $rowNotDefined = $dataTable->getRowFromLabel(\Piwik\Plugins\CustomVariables\Archiver::LABEL_CUSTOM_VALUE_NOT_DEFINED);
        if ($rowNotDefined) {
            $rowNotDefined->setColumn('label', $notDefinedStringPretty);
        }
    }

    protected function enrichItemsDataTableWithItemsViewMetrics($dataTable, $idSite, $period, $date, $idSubtable)
    {
        $ecommerceViews = \Piwik\Plugins\CustomVariables\API::getInstance()->getCustomVariablesValuesFromNameId($idSite, $period, $date, $idSubtable, $segment = false, $_leavePriceViewedColumn = true);

        // For Product names and SKU reports, and for Category report
        // Use the Price (tracked on page views)
        // ONLY when the price sold in conversions is not found (ie. product viewed but not sold)
        foreach ($ecommerceViews->getRows() as $rowView) {
            // If there is not already a 'sum price' for this product
            $rowFound = $dataTable->getRowFromLabel($rowView->getColumn('label'));
            $price = $rowFound
                ? $rowFound->getColumn(Metrics::INDEX_ECOMMERCE_ITEM_PRICE)
                : false;
            if (empty($price)) {
                // If a price was tracked on the product page
                if ($rowView->getColumn(Metrics::INDEX_ECOMMERCE_ITEM_PRICE_VIEWED)) {
                    $rowView->renameColumn(Metrics::INDEX_ECOMMERCE_ITEM_PRICE_VIEWED, 'avg_price');
                }
            }
            $rowView->deleteColumn(Metrics::INDEX_ECOMMERCE_ITEM_PRICE_VIEWED);
        }

        $dataTable->addDataTable($ecommerceViews);
    }

    public function getItemsSku($idSite, $period, $date, $abandonedCarts = false)
    {
        return $this->getItems('Goals_ItemsSku', $idSite, $period, $date, $abandonedCarts);
    }

    public function getItemsName($idSite, $period, $date, $abandonedCarts = false)
    {
        return $this->getItems('Goals_ItemsName', $idSite, $period, $date, $abandonedCarts);
    }

    public function getItemsCategory($idSite, $period, $date, $abandonedCarts = false)
    {
        return $this->getItems('Goals_ItemsCategory', $idSite, $period, $date, $abandonedCarts);
    }

    /**
     * Helper function that checks for special string goal IDs and converts them to
     * their integer equivalents.
     *
     * Checks for the following values:
     * Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER
     * Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART
     *
     * @param string|int $idGoal The goal id as an integer or a special string.
     * @return int The numeric goal id.
     */
    protected static function convertSpecialGoalIds($idGoal)
    {
        if ($idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER) {
            return GoalManager::IDGOAL_ORDER;
        } else if ($idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART) {
            return GoalManager::IDGOAL_CART;
        } else {
            return $idGoal;
        }
    }

    /**
     * Returns Goals data
     *
     * @param int $idSite
     * @param string $period
     * @param string $date
     * @param bool $segment
     * @param bool|int $idGoal
     * @param array $columns Array of metrics to fetch: nb_conversions, conversion_rate, revenue
     * @return DataTable
     */
    public function get($idSite, $period, $date, $segment = false, $idGoal = false, $columns = array())
    {
        Piwik::checkUserHasViewAccess($idSite);
        $archive = Archive::build($idSite, $period, $date, $segment);
        $columns = Piwik::getArrayFromApiParameter($columns);

        // Mapping string idGoal to internal ID
        $idGoal = self::convertSpecialGoalIds($idGoal);

        if (empty($columns)) {
            $columns = Goals::getGoalColumns($idGoal);
            if ($idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER) {
                $columns[] = 'avg_order_revenue';
            }
        }
        if (in_array('avg_order_revenue', $columns)
            && $idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER
        ) {
            $columns[] = 'nb_conversions';
            $columns[] = 'revenue';
            $columns = array_values(array_unique($columns));
        }
        $columnsToSelect = array();
        foreach ($columns as &$columnName) {
            $columnsToSelect[] = Archiver::getRecordName($columnName, $idGoal);
        }
        $dataTable = $archive->getDataTableFromNumeric($columnsToSelect);

        // Rewrite column names as we expect them
        foreach ($columnsToSelect as $id => $oldName) {
            $dataTable->renameColumn($oldName, $columns[$id]);
        }
        if ($idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER) {
            if ($dataTable instanceof DataTable\Map) {
                foreach ($dataTable->getArray() as $row) {
                    $this->enrichTable($row);
                }
            } else {
                $this->enrichTable($dataTable);
            }
        }
        return $dataTable;
    }

    protected function enrichTable($table)
    {
        $row = $table->getFirstRow();
        if (!$row) {
            return;
        }
        // AVG order per visit
        if (false !== $table->getColumn('avg_order_revenue')) {
            $conversions = $row->getColumn('nb_conversions');
            if ($conversions) {
                $row->setColumn('avg_order_revenue', round($row->getColumn('revenue') / $conversions, 2));
            }
        }
    }

    protected function getNumeric($idSite, $period, $date, $segment, $toFetch)
    {
        Piwik::checkUserHasViewAccess($idSite);
        $archive = Archive::build($idSite, $period, $date, $segment);
        $dataTable = $archive->getDataTableFromNumeric($toFetch);
        return $dataTable;
    }

    /**
     * @ignore
     */
    public function getConversions($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        return $this->getNumeric($idSite, $period, $date, $segment, Archiver::getRecordName('nb_conversions', $idGoal));
    }

    /**
     * @ignore
     */
    public function getNbVisitsConverted($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        return $this->getNumeric($idSite, $period, $date, $segment, Archiver::getRecordName('nb_visits_converted', $idGoal));
    }

    /**
     * @ignore
     */
    public function getConversionRate($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        return $this->getNumeric($idSite, $period, $date, $segment, Archiver::getRecordName('conversion_rate', $idGoal));
    }

    /**
     * @ignore
     */
    public function getRevenue($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        return $this->getNumeric($idSite, $period, $date, $segment, Archiver::getRecordName('revenue', $idGoal));
    }

    /**
     * Utility method that retrieve an archived DataTable for a specific site, date range,
     * segment and goal. If not goal is specified, this method will retrieve and sum the
     * data for every goal.
     *
     * @param string $recordName The archive entry name.
     * @param int|string $idSite The site(s) to select data for.
     * @param string $period The period type.
     * @param string $date The date type.
     * @param string $segment The segment.
     * @param int|bool $idGoal The id of the goal to get data for. If this is set to false,
     *                         data for every goal that belongs to $idSite is returned.
     * @return false|DataTable
     */
    protected function getGoalSpecificDataTable($recordName, $idSite, $period, $date, $segment, $idGoal)
    {
        Piwik::checkUserHasViewAccess($idSite);

        $archive = Archive::build($idSite, $period, $date, $segment);

        // check for the special goal ids
        $realGoalId = $idGoal != true ? false : self::convertSpecialGoalIds($idGoal);

        // get the data table
        $dataTable = $archive->getDataTable(Archiver::getRecordName($recordName, $realGoalId), $idSubtable = null);
        $dataTable->queueFilter('ReplaceColumnNames');

        return $dataTable;
    }

    /**
     * Gets a DataTable that maps ranges of days to the number of conversions that occurred
     * within those ranges, for the specified site, date range, segment and goal.
     *
     * @param int $idSite The site to select data from.
     * @param string $period The period type.
     * @param string $date The date type.
     * @param string|bool $segment The segment.
     * @param int|bool $idGoal The id of the goal to get data for. If this is set to false,
     *                         data for every goal that belongs to $idSite is returned.
     * @return false|DataTable
     */
    public function getDaysToConversion($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        $dataTable = $this->getGoalSpecificDataTable(
            Archiver::DAYS_UNTIL_CONV_RECORD_NAME, $idSite, $period, $date, $segment, $idGoal);

        $dataTable->queueFilter('Sort', array('label', 'asc', true));
        $dataTable->queueFilter(
            'BeautifyRangeLabels', array(Piwik_Translate('General_OneDay'), Piwik_Translate('General_NDays')));

        return $dataTable;
    }

    /**
     * Gets a DataTable that maps ranges of visit counts to the number of conversions that
     * occurred on those visits for the specified site, date range, segment and goal.
     *
     * @param int $idSite The site to select data from.
     * @param string $period The period type.
     * @param string $date The date type.
     * @param string|bool $segment The segment.
     * @param int|bool $idGoal The id of the goal to get data for. If this is set to false,
     *                         data for every goal that belongs to $idSite is returned.
     * @return bool|DataTable
     */
    public function getVisitsUntilConversion($idSite, $period, $date, $segment = false, $idGoal = false)
    {
        $dataTable = $this->getGoalSpecificDataTable(
            Archiver::VISITS_UNTIL_RECORD_NAME, $idSite, $period, $date, $segment, $idGoal);

        $dataTable->queueFilter('Sort', array('label', 'asc', true));
        $dataTable->queueFilter(
            'BeautifyRangeLabels', array(Piwik_Translate('General_OneVisit'), Piwik_Translate('General_NVisits')));

        return $dataTable;
    }
}