<?php

// (c) Copyright by authors of the Tiki Wiki CMS Groupware Project
//
// All Rights Reserved. See copyright.txt for details and a complete list of authors.
// Licensed under the GNU LESSER GENERAL PUBLIC LICENSE. See license.txt for details.
// $Id$

// TODO: product_id is meant for storing some information about the product
// purchased that led to the credits being added.

/**
 * CreditsLib
 *
 * @uses TikiLib
 */
class CreditsLib extends TikiLib
{

    public function getRawCredits($userId)
    {
        $result = $this->query(
            "SELECT `creditId`, `credit_type`, `creation_date`, `expiration_date`, `total_amount`, `used_amount`" .
            " FROM `tiki_credits` WHERE `userId` = ? ORDER BY `credit_type`, `creation_date`, `expiration_date`",
            [$userId]
        );

        $credits = [];

        while ($row = $result->fetchRow()) {
            $credits[$row['creditId']] = $row;
        }

        return $credits;
    }

    public function getRawCreditsByType($userId, $credit_type)
    {
        $result = $this->query(
            "SELECT `creditId`, `creation_date`, `expiration_date`, `total_amount`, `used_amount`" .
            " FROM `tiki_credits`" .
            " WHERE `userId` = ? AND `credit_type` = ? ORDER BY `credit_type`, `creation_date`, `expiration_date`",
            [$userId, $credit_type]
        );

        $credits = [];

        while ($row = $result->fetchRow()) {
            $credits[$row['creditId']] = $row;
        }

        return $credits;
    }

    public function updateCreditType($credit_type, $display_text, $unit_text, $is_static_level = 'n', $scaling_divisor = 1)
    {
        $bindvars = [$credit_type, $display_text, $unit_text, $is_static_level, $scaling_divisor];
        $result = $this->query(
            "REPLACE INTO `tiki_credits_types`" .
            " (`credit_type`, `display_text`, `unit_text`, `is_static_level`, `scaling_divisor`)" .
            " VALUES (?, ?, ?, ?, ?)",
            $bindvars
        );

        return $result;
    }

    public function getCreditTypes($staticonly = false)
    {
        $result = $this->query("SELECT `credit_type`, `display_text`, `unit_text`, `is_static_level`, `scaling_divisor` FROM `tiki_credits_types`");
        $creditTypes = [];

        while ($row = $result->fetchRow()) {
            if ($staticonly && $row['is_static_level'] == 'y') {
                $creditTypes[ $row['credit_type'] ] = $row;
            } elseif (! $staticonly) {
                $creditTypes[ $row['credit_type'] ] = $row;
            }
        }

        return $creditTypes;
    }

    public function getCredits($userId)
    {
        $result = $this->query(
            "SELECT `credit_type`, SUM(`total_amount`) total_amount, SUM(`used_amount`) used_amount" .
            " FROM `tiki_credits`" .
            " WHERE" .
            " `userId` = ?" .
            " AND (`expiration_date` IS NULL OR `expiration_date` > NOW())" .
            " AND `creation_date` <= NOW()" .
            " GROUP BY `credit_type`",
            [$userId]
        );

        $credits = [];

        while ($row = $result->fetchRow()) {
            $credits[$row['credit_type']] = [
                'remain' => $row['total_amount'] - $row['used_amount'],
                'used' => $row['used_amount'],
                'total' => $row['total_amount'],
            ];
        }
        // Handle level-type credits in a different manner
        // Level of used amount stored in user preferences
        // Total used (flow) from credits table
        $userlib = TikiLib::lib('user');
        $tikilib = TikiLib::lib('tiki');
        $info = $userlib->get_userid_info($userId);

        $creditTypes = $this->getCreditTypes();

        foreach ($credits as $type => $crVal) {
            if ($creditTypes[$type]['is_static_level'] == 'y') {
                $prefName = "credits_level_" . $type;
                $credits[$type]['used'] = (float) $tikilib->get_user_preference($info['login'], $prefName);
                $credits[$type]['remain'] = $credits[$type]['total'] - $credits['used'];
            }
        }

        // set zero for creditTypes that user does not have
        foreach ($creditTypes as $k => $c) {
            if (! array_key_exists($k, $credits)) {
                $credits[$k]['used'] = 0;
                $credits[$k]['remain'] = 0;
                $credits[$k]['total'] = 0;
            }
        }
        return $credits;
    }

    public function getScaledCredits($userId)
    {
        $creditTypes = $this->getCreditTypes();
        $credits = $this->getCredits($userId);

        foreach ($credits as $type => &$data) {
            $factor = 1;
            if (isset($creditTypes[$type]) && $creditTypes[$type]['scaling_divisor']) {
                $factor = $creditTypes[$type]['scaling_divisor'];
            }
            if (isset($creditTypes[$type]) && $display_text = $creditTypes[$type]['display_text']) {
                $data['display_text'] = $display_text;
            } else {
                $data['display_text'] = $type;
            }
            if (isset($creditTypes[$type]) && $unit_text = $creditTypes[$type]['unit_text']) {
                $data['unit_text'] = $unit_text;
            } else {
                $data['unit_text'] = '';
            }

            $data['discreet_total'] = $this->scale($data['total'], $factor);
            $data['discreet_used'] = empty($data['discreet_total']) ? 0 : $data['used'] / ($data['total'] / $data['discreet_total']);
            $data['discreet_remain'] = $data['discreet_total'] - $data['discreet_used'];
            $data['empty'] = $data['remain'] <= 0;
            $data['low'] = $data['remain'] <= $data['total'] * .15;
        }

        return $credits;
    }

    private function scale($value, $factor = 1)
    {
        // 1.5 log( (x/fac)^2 + 1 )
        return floor(1.5 * log(($value / $factor) * ($value / $factor) + 1));
    }

    public function removeCreditBlock($creditId)
    {
        $this->query("DELETE FROM `tiki_credits` WHERE `creditId` = ?", [$creditId]);
    }

    public function replaceCredit($creditId, $type, $used, $total, $validFrom, $expirationDate)
    {
        if (! empty($expirationDate)) {
            $expirationDate = date('Y-m-d H:i:s', $time = strtotime($expirationDate));
        }

        if ($time === false) {
            return false;
        }

        $validFrom = date('Y-m-d H:i:s', $time = strtotime($validFrom));

        if ($time === false) {
            return false;
        }

        $this->query(
            "UPDATE `tiki_credits`
            SET `credit_type` = ?, `used_amount` = ?, `total_amount` = ?, `expiration_date` = if (?='',NULL,?), `creation_date` = ?
            WHERE `creditId` = ?",
            [$type, $used, $total, $expirationDate, $expirationDate, $validFrom, $creditId]
        );
    }

    /**
     * Adds a new credits entry for the user.
     */
    public function addCredits($userId, $creditType, $amount, $expirationDate = null, $validFrom = null)
    {
        if (! $amount) {
            return false;
        }

        if (! empty($expirationDate)) {
            $expirationDate = date('Y-m-d H:i:s', $time = strtotime($expirationDate));
        }

        if ($time === false) {
            return false;
        }

        if (! empty($validFrom)) {
            $validFrom = date('Y-m-d H:i:s', $time = strtotime($validFrom));
        }

        if ($time === false) {
            return false;
        }

        $this->query(
            "INSERT INTO `tiki_credits`
            (`userId`, `credit_type`, `total_amount`, `expiration_date`, `creation_date`)
            VALUES(?,?,?,if (? = '', NULL, ?),if (?='', NULL, ?))",
            [$userId, $creditType, $amount, $expirationDate, $expirationDate, $validFrom, $validFrom]
        );

        return true;
    }

    /**
     * Use the user's credits of a certain type. If the user does not have
     * enough credits, the function will return false. Credits may be used from
     * different entries. Entries expiring soon will be used first.
     */
    public function useCredits($userId, $creditType, $amount, $product_id = null)
    {
        if ($amount == 0) {
            return true;
        }

        // Level-type credits
        $creditTypes = $this->getCreditTypes();
        if ($creditTypes[$creditType]['is_static_level'] == 'y') {
            $credits = $this->getCredits($userId);
            if (! array_key_exists($creditType, $credits)) {
                return false;
            }

            if ($credits[$creditType]['remain'] > 0) {
                $userlib = TikiLib::lib('user');
                $tikilib = TikiLib::lib('tiki');
                $info = $userlib->get_userid_info($userId);

                // Expense all credits if not enough
                $toUse = min($credits[$creditType]['used'] + $amount, $credits[$creditType]['remain']);
                $prefName = "credits_level_" . $creditType;

                $tikilib->set_user_preference(
                    $info['login'],
                    $prefName,
                    $toUse
                );

                if ($amount > 0) {
                    $this->_recCredits($userId, $creditType, $amount, $product_id);
                }

                return true;
            }

            return false;
        }

        // Expendable credits
        $result = $this->query(
            "SELECT `creditId`, `product_id`, `total_amount` - `used_amount` as available
            FROM `tiki_credits`
            WHERE
            ( `expiration_date` > NOW() OR `expiration_date` IS NULL )
            AND `creation_date` <= NOW()
            AND `userId` = ?
            AND `credit_type` = ?
            ORDER BY if (`expiration_date` IS NULL, 1000000, DATEDIFF(`expiration_date`, NOW())) ASC",
            [$userId, $creditType]
        );

        $total = 0;
        $list = [];
        while ($row = $result->fetchRow()) {
            $total += $row['available'];
            $list[] = $row;
        }

        if ($total == 0) {
            return false;
        }

        if ($amount > $total) {
            $amount = $total;
        }

        if ($amount > 0) {
            $this->_recCredits($userId, $creditType, $amount, $product_id);
        }

        foreach ($list as $row) {
            $amount = $this->_useCredits($row['creditId'], $row['available'], $amount);
            if ($amount <= 0) {
                return true;
            }
        }

        die("The verification failed in using credits.");
    }

    public function restoreCredits($userId, $creditType, $amount, $product_id = null)
    {
        // Only valid for level-type credits
        if (! array_key_exists($creditType, $this->getCreditTypes(true))) {
            return false;
        }

        $userlib = TikiLib::lib('user');
        $tikilib = TikiLib::lib('tiki');
        $info = $userlib->get_userid_info($userId);

        $prefName = "credits_level_" . $creditType;

        $used = (float) $tikilib->get_user_preference($info['login'], $prefName);
        if ($used === 0) {
            return false;
        }

        $used -= $amount;
        if ($used < 0) {
            $used = 0;
        }

        $tikilib->set_user_preference($info['login'], $prefName, $used);

        if ($amount > 0) {
            $this->_recCredits($userId, $creditType, -1 * $amount, $product_id);
        }

        return true;
    }

    /**
     * Uses up a credit id and returns the amount of credits remaining to use.
     */
    public function _useCredits($creditId, $available, $amount)
    {
        if ($available >= $amount) {
            $this->query(
                "UPDATE `tiki_credits` SET `used_amount` = `used_amount` + ? WHERE `creditId`= ?",
                [$amount, $creditId]
            );

            return 0;
        } else {
            $this->query(
                "UPDATE `tiki_credits` SET `used_amount` = `total_amount` WHERE `creditId`= ?",
                [$creditId]
            );

            return $amount - $available;
        }
    }


    /**
     * Uses up a credit id and returns the amount of credits remaining to use.
     */
    public function _recCredits($userId, $creditType, $amount, $product_id = null)
    {
        return $this->query(
            "INSERT INTO `tiki_credits_usage` (`userId`, `usage_date`, `credit_type`, `used_amount`, `product_id`)" .
            " VALUES (?, NOW(), ?, ?, ?)",
            [$userId, $creditType, $amount, $product_id]
        );
    }


    /**
     * Delete expired credit entries and those completely used up.
     */
    public function purgeCredits()
    {
        $this->query("DELETE FROM `tiki_credits` WHERE `expiration_date` IS NOT NULL AND `expiration_date` < NOW()");
        $this->query("DELETE FROM `tiki_credits` WHERE `total_amount` = `used_amount`");
    }


    public function getPlanExpiry($userId, $creditType)
    {
        $result = $this->getOne(
            "SELECT MAX(`expiration_date`) FROM `tiki_credits` WHERE `userId` = ? AND `expiration_date` IS NOT NULL AND `credit_type` = ?",
            [$userId, $creditType]
        );

        if ($result) {
            return $result;
        } else {
            return '';
        }
    }

    public function getLatestPlanBegin($userId, $creditType)
    {
        $result = $this->getOne(
            "SELECT MAX(`creation_date`) FROM `tiki_credits`" .
            " WHERE `userId` = ? AND `expiration_date` IS NOT NULL AND `expiration_date` > NOW()" .
            " AND `credit_type` = ? AND `creation_date` < NOW()",
            [$userId, $creditType]
        );

        if ($result) {
            return $result;
        } else {
            return '';
        }
    }

    public function getNextPlanBegin($userId, $creditType)
    {
        $result = $this->getOne(
            "SELECT MIN(`creation_date`)" .
            " FROM `tiki_credits`" .
            " WHERE `userId` = ? AND `expiration_date` IS NOT NULL AND `credit_type` = ? AND `creation_date` > NOW()",
            [$userId, $creditType]
        );

        if ($result) {
            return $result;
        } else {
            return '';
        }
    }

    public function getCreditsUsage($target_user_id, $req_type, $start_date, $end_date)
    {
        if ($req_type) {
            $results = $this->query(
                "SELECT * FROM tiki_credits_usage" .
                " WHERE userId = ? AND credit_type = ? AND usage_date > ? AND usage_date <= ?" .
                " ORDER BY `usage_date` desc",
                [$target_user_id, $req_type, $start_date, $end_date]
            );
        } else {
            $results = $this->query(
                "SELECT * FROM tiki_credits_usage WHERE userId = ? AND usage_date > ? AND usage_date <= ? ORDER BY `usage_date` desc",
                [$target_user_id, $start_date, $end_date]
            );
        }
        $consumption_data = [];
        while ($row = $results->fetchRow()) {
            $consumption_data[] = $row;
        }

        return $consumption_data;
    }
}