<?php

/**
 * 處理歐噴公司相關 API 的使用統計以及認證
 */
class OpenFunAPIHelper
{
    protected static $_db = null;
    public static function getDb()
    {
        if (is_null(self::$_db)) {
            if (!$database_url = getenv('API_COUNTER_DATABASE_URL')) {
                throw new Exception('API_COUNTER_DATABASE_URL not set');
            }
            $url = parse_url($database_url);
            $dsn = "{$url['scheme']}:host={$url['host']};port={$url['port']};dbname=" . ltrim($url['path'], '/');
            self::$_db = new PDO($dsn, $url['user'], $url['pass']);
            self::$_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        return self::$_db;
    }

    protected static $_api_options = null;
    public static function checkUsage($options)
    {
        self::$_api_options = $options;
        if ($_GET['token'] ?? false) {
            $token = $_GET['token'];
            $token_data = self::getTokenData($token);
        }
        // TODO: 檢查是否有到用量限制
    }

    public static function errorJson($message)
    {
        header('Content-Type: application/json');
        echo json_encode([
            'error' => true,
            'message' => $message,
        ]);
        exit;
    }

    public static function getTokenData($token)
    {
        $db = self::getDb();
        $sql = "SELECT * FROM token WHERE token = :token";
        $stmt = $db->prepare($sql);
        $stmt->execute([':token' => $token]);
        $row = $stmt->fetch(PDO::FETCH_ASSOC);
        if (!$row) {
            $project = self::$_api_options['project'] ?? 'unknown';
            $class = self::$_api_options['class'] ?? 'unknown';
            $counts = [];
            $counts[] = ['error', "token-not-found", 1];
            $counts[] = ['error-ip', "token-not-found:ip:{$_SERVER['REMOTE_ADDR']}", 1];
            self::counterInc($counts);
            return self::errorJson('Token not found');
        }
        self::$_api_options['token_id'] = $row['id'];
        self::$_api_options['token_user_id'] = $row['user_id'];
        $config = json_decode($row['config']);
        if ($config->type == 'referer' and $_SERVER['HTTP_REFERER'] ?? false) {
            $match = false;
            $referer_obj = parse_url($_SERVER['HTTP_REFERER']);
            foreach ($config->referer as $referer) {
                if (strpos($referer, '/') === false) {
                    $domain = $referer;
                    $path = '';
                } else {
                    $domain = explode('/', $referer, 2)[0];
                    $path = substr($referer, strpos($referer, '/'));
                }
                if ($domain !== $referer_obj['host']) {
                    continue;
                }
                if (strlen($path) and isset($referer_obj['path']) and strpos($referer_obj['path'], $path) !== 0) {
                    continue;
                }
                $match = true;
            }
            if (!$match) {
                $project = self::$_api_options['project'] ?? 'unknown';
                $class = self::$_api_options['class'] ?? 'unknown';
                $counts = [];
                $counts[] = ['error', "token-referer-not-match", 1];
                $counts[] = ['error-ip', "token-referer-not-match:ip:{$_SERVER['REMOTE_ADDR']}", 1];
                self::counterInc($counts);
                return self::errorJson('Token referer not match');
            }
        }
    }

    public static function apiDone($options)
    {
        $size = $options['size'] ?? 0;
        $project = self::$_api_options['project'] ?? 'unknown';
        $class = self::$_api_options['class'] ?? 'unknown';
        $ip = $_SERVER['REMOTE_ADDR'] ?? 'unknown';
        $referer = $_SERVER['HTTP_REFERER'] ?? 'unknown';
        $counts = [];
        $counts[] = ['project-count', "project-count", 1];
        $counts[] = ['project-size', "project-size", $size];
        $counts[] = ['call-count-class', "call-count:class:{$class}", 1];
        $counts[] = ['call-size-class', "call-size:class:{$class}", $size];
        if (self::$_api_options['token_id'] ?? false) {
            $token_id = self::$_api_options['token_id'];
            $token_user_id = self::$_api_options['token_user_id'];
            $counts[] = ['call-count-token', "call-count:token:{$token_id}", 1];
            $counts[] = ['call-size-token', "call-size:token:{$token_id}", $size];
            $counts[] = ['call-count-token-user', "call-count:token-user:{$token_user_id}", 1];
            $counts[] = ['call-size-token-user', "call-size:token-user:{$token_user_id}", $size];
        } else {
            $counts[] = ['call-count-ip', "call-count:ip:{$ip}", 1];
            $counts[] = ['call-size-ip', "call-size:ip:{$ip}", $size];
            if (preg_match('/^https?:\/\/([^\/]+)(.*)$/', $referer, $matches)) {
                $domain = $matches[1];
                $counts[] = ['call-count-referer', "call-count:referer:{$domain}", 1];
                $counts[] = ['call-size-referer', "call-size:referer:{$domain}", $size];
            }
        }
        self::counterInc($counts);
    }

    public static function getMappingId($values)
    {
        // 先查一輪是否有資料
        $checking_values = array_combine($values, $values);
        $found_values = [];

        $db = self::getDb();
        $sql = "SELECT id, value FROM mapping WHERE (key, value) IN ";
        $terms = [];
        $params = [];
        foreach ($values as $idx => $value) {
            $terms[] = "(:key_{$idx}, :value_{$idx})";
            $params[":key_{$idx}"] = crc32($value);
            $params[":value_{$idx}"] = $value;
        }
        $sql .= '(' . implode(',', $terms) . ')';
        $stmt = $db->prepare($sql);
        $stmt->execute($params);
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
        foreach ($rows as $row) {
            $found_values[$row['value']] = $row['id'];
            unset($checking_values[$row['value']]);
        }

        if (!count($checking_values)) {
            // 如果 $checking_values 沒有值，表示都已經找到對應的 id
            return $found_values;
        }

        // 如果 $checking_values 還有值，表示沒有找到對應的 id，需要插入新的資料
        // begin transaction
        $db->beginTransaction();

        // 啟動 transcaction 之後再檢查一次看看有沒有資料
        $sql = "SELECT id, value FROM mapping WHERE (key, value) IN ";
        $terms = [];
        $params = [];
        foreach (array_keys($checking_values) as $idx => $value) {
            $terms[] = "(:key_{$idx}, :value_{$idx})";
            $params[":key_{$idx}"] = crc32($value);
            $params[":value_{$idx}"] = $value;
        }
        $sql .= '(' . implode(',', $terms) . ')';
        $stmt = $db->prepare($sql);
        $stmt->execute($params);
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
        foreach ($rows as $row) {
            $found_values[$row['value']] = $row['id'];
            unset($checking_values[$row['value']]);
        }

        if (!count($checking_values)) {
            // 如果 $checking_values 沒有值，表示都已經找到對應的 id
            $db->commit();
            return $found_values;
        }

        // 剩下的再寫入 maping 中
        $sql = "INSERT INTO mapping (key, value, created_at) VALUES ";
        $terms = [];
        $params = [];
        $params[':created_at'] = time();
        foreach (array_keys($checking_values) as $idx => $value) {
            $terms[] = "(:key_{$idx}, :value_{$idx}, :created_at)";
            $params[":key_{$idx}"] = crc32($value);
            $params[":value_{$idx}"] = $value;
        }
        $sql .= implode(',', $terms);
        $stmt = $db->prepare($sql);
        $stmt->execute($params);

        // 取得剛剛寫入的 id
        $sql = "SELECT id, value FROM mapping WHERE (key, value) IN ";
        $terms = [];
        $params = [];
        foreach (array_keys($checking_values) as $idx => $value) {
            $terms[] = "(:key_{$idx}, :value_{$idx})";
            $params[":key_{$idx}"] = crc32($value);
            $params[":value_{$idx}"] = $value;
        }
        $sql .= '(' . implode(',', $terms) . ')';
        $stmt = $db->prepare($sql);
        $stmt->execute($params);
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
        foreach ($rows as $row) {
            $found_values[$row['value']] = $row['id'];
            unset($checking_values[$row['value']]);
        }

        // commit transaction
        $db->commit();
        return $found_values;
    }

    public static function counterInc($counts)
    {
        try {
            self::counterInc_exec($counts);
        } catch (Exception $e) {
            // 如果有錯誤就不做別的事
            error_log($e->getMessage());
            return false;
        }
    }

    public static function counterInc_exec($counts)
    {
        $project = self::$_api_options['project'] ?? 'unknown';
        $start_time = microtime(true);
        // 先抓取所有 value ，來取得他的 id
        $map = [];
        $map[$project] = null;
        foreach ($counts as $count_list) {
            list($group_val, $count_val, $count) = $count_list;
            $map[$group_val] = null;
            $map[$count_val] = null;
        }
        $map = self::getMappingId(array_keys($map));

        // 取得 id 之後，開始寫入資料
        $db = self::getDb();
        $sql = "INSERT INTO counter (project_id, id, group_id, count) VALUES ";
        $terms = [];
        $params = [];
        $params[':project_id'] = $map[$project];
        foreach ($counts as $idx => $count_list) {
            list($group_val, $count_val, $count) = $count_list;
            $terms[] = "(:project_id, :id_{$idx}, :group_id_{$idx}, :count_{$idx})";
            $params[":id_{$idx}"] = $map[$count_val];
            $params[":group_id_{$idx}"] = $map[$group_val];
            $params[":count_{$idx}"] = $count;
        }
        $sql .= implode(',', $terms);
        $sql .= " ON CONFLICT (project_id, id) DO UPDATE SET count = counter.count + EXCLUDED.count";
        $stmt = $db->prepare($sql);
        $stmt->execute($params);

        // 寫入 hourly, daily
        foreach ([
            'hourly' => date('YmdH'),
            'daily' => date('Ymd'),
        ] as $period => $time) {
            $sql = "INSERT INTO counter_{$period} (project_id, id, group_id, count, time) VALUES ";
            $terms = [];
            $params = [];
            $params[':project_id'] = $map[$project];
            foreach ($counts as $idx => $count_list) {
                list($group_val, $count_val, $count) = $count_list;
                $terms[] = "(:project_id, :id_{$idx}, :group_id_{$idx}, :count_{$idx}, :time_{$idx})";
                $params[":id_{$idx}"] = $map[$count_val];
                $params[":group_id_{$idx}"] = $map[$group_val];
                $params[":count_{$idx}"] = $count;
                $params[":time_{$idx}"] = $time;
            }
            $sql .= implode(',', $terms);
            $sql .= " ON CONFLICT (project_id, id, time) DO UPDATE SET count = counter_{$period}.count + EXCLUDED.count";
            $stmt = $db->prepare($sql);
            $stmt->execute($params);
        }

        $delta = microtime(true) - $start_time;
        $ret = new stdClass();
        $ret->time = $delta;
        $ret->map = $map;
        // 如果沒錯誤就不做別的事
    }
}