<?php

require_once 'analytics_interface.php';

class MySQLAnalyticsHandler
    implements AnalyticsInterface {

    private $sql_connection;
    private $hostname;

    function __construct($sql_connection, $hostname) {
        $this->sql_connection = $sql_connection;
        $this->hostname = $hostname;
    }

    private function _exec($qery, $argtypes = '', ...$args) {
		$stmt = $this->sql_connection->prepare($qery);
		
        if($argtypes != ""){
			$stmt->bind_param($argtypes, ...$args);
		}
		$stmt->execute();

		return $stmt->get_result();
	}

    public function get_current_timestamp() {
        return (int)($this->_exec(
            "SELECT unix_timestamp(NOW()) AS ctime"
        )->fetch_assoc()['ctime']);
    }

    public function increment_counter($tags, $counter, $value = 1, $timestamp = null) {
        $timestamp ??= $this->get_current_timestamp();

        $qry =
        "INSERT INTO analytics_summations
            (
                time_bucket,
                metric,
                tags, 
                metric_value
            )
        VALUES
            (
                from_unixtime(floor(? / 300) * 300),
                ?,
                ?,
                ?
            ) AS new
        ON DUPLICATE KEY
            UPDATE metric_value=analytics_summations.metric_value + new.metric_value;
        ";

        $this->_exec($qry,
            "dssd",
            $timestamp, $counter, json_encode($tags), $value);
    }

    public function insert_event($event_tags, $event_text) {
        $qry =
        "INSERT INTO analytics_events (
            event_time, tags, event_text
        )
        VALUES (NOW(), ?, ?)";

        $this->_exec($qry, "ss",
            json_encode($event_tags), $event_text);
    }

    public function log_path_access(
        $path,
        $agent,
        $referrer,
        $time, $status = 200) {
        
        if(strlen($path) == 0) {
            $path = '/';
        }

        $this->increment_counter([
            'host' => $this->hostname,
            'path' => $path,
            'agent' => $agent,
            'referrer' => $referrer,
            'status' => $status
        ], 'access_sum');

        $this->increment_counter([
            'host' => $this->hostname,
            'path' => $path
        ], 'runtime', $time);
    }

    public function log_path_errcode(
        $path, $code, $message) {

        $this->insert_event([
            'host' => $this->hostname,
            'path' => $path,
            'code' => $code
        ], $message);
    }

    public function generate_lp_line($table, $tags, $values, $timestamp) {
        $out_str = $table;

        $line_tags = [];
        foreach($tags AS $tag_key => $tag_value) {
            if(!preg_match('/^[\w_]+$/', $tag_key)) {
                throw new Exception('Invalid line tag key (' . $tag_key . ')!');
            }

            $tag_value = preg_replace('/([,=\s])/', '\\\\$0', $tag_value);
            
            $line_tags []= $tag_key . '=' . $tag_value;
        }

        $line_values = [];
        foreach($values AS $tag_key => $tag_value) {
            if(!preg_match('/^[\w_]+$/', $tag_key)) {
                throw new Exception('Invalid line value key (' . $tag_key . ')!');
            }

            if(gettype($tag_value) == 'string') {
                $tag_value = preg_replace('/(["\])/', '\\\\$0', $tag_value);
                $tag_value = preg_replace('/\n/', '\\\\n', $tag_value);
                $tag_value = '"' . $tag_value . '"';
            }
            elseif (gettype($tag_value) == 'integer') {
                $tag_value = $tag_value . 'i';
            }
            
            $line_values []= $tag_key . '=' . $tag_value;
        }
        
        return $table 
            . ',' . implode(',', $line_tags) 
            . ' ' . implode(',', $line_values)
            . ' ' . $timestamp;
    }

    public function pop_analytics($delete = true) {
        $this->sql_connection->begin_transaction();

        try {  
            $barrier_time = $this->_exec("SELECT NOW() - INTERVAL 6 MINUTE AS ctime")->fetch_assoc()['ctime'];
            
            $result = $this->_exec("
            SELECT *
            FROM analytics_summations
            WHERE time_bucket < ?
            ORDER BY metric, time_bucket DESC", "s", $barrier_time);

            $data_category = "access_metrics";

            $row = $result->fetch_assoc();
            $out_str = '';

            while(isset($row)) {
                $row_tags  = json_decode($row['tags']);
                $row_value = $row['metric_value'];

                $row_metric = $row['metric'];

                $out_str .= $this->generate_lp_line($data_category, $row_tags, [
                    $row_metric => $row_value
                ], strtotime($row['time_bucket']) . "000000000") . "\n";

                $row = $result->fetch_assoc();
            }

            $result = $this->_exec("
            SELECT *
            FROM analytics_events
            WHERE event_time < ?
            ORDER BY event_time DESC", "s", $barrier_time);

            while(isset($row)) {
                $row_tags  = json_decode($row['tags']);
                $row_value = $row['event_text'];

                $row_metric = $row['metric'];

                $out_str .= $this->generate_lp_line($data_category, $row_tags, [
                    $row_metric => $row_value
                ], strtotime($row['time_bucket']) . "000000000") . "\n";

                $row = $result->fetch_assoc();
            }

            if($delete) {
                $this->_exec("DELETE FROM analytics_summations WHERE time_bucket <= ?", "s", $barrier_time);
            }

            $this->sql_connection->commit();

            return $out_str;

        } catch (\Throwable $th) {
			$this->sql_connection->rollback();
			throw $th;
		}     
    }
    
    public function pop_analytics_json($delete = true) {
        $this->sql_connection->begin_transaction();

        try {
            $barrier_time = $this->_exec("SELECT NOW() - INTERVAL 6 MINUTE AS ctime")->fetch_assoc()['ctime'];
            
            $out_data = [];

            $result = $this->_exec("
            SELECT *
            FROM analytics_summations
            WHERE time_bucket < ?
            ORDER BY metric, time_bucket DESC", "s", $barrier_time);

            $row = $result->fetch_assoc();

            $current_metric_collection = [];
            $current_time_bucket_collection = [];

            $current_metric = $row['metric'] ?? null;
            $current_time_bucket = $row['time_bucket'] ?? null;

            while(isset($row)) {
                $current_time_bucket_collection[]= [
                    'tags' => json_decode($row['tags']),
                    'value' => floatval($row['metric_value'])
                ];

                $row = $result->fetch_assoc();

                if(!isset($row) 
                    OR ($row['time_bucket'] != $current_time_bucket) 
                    OR ($row['metric'] != $current_metric)) {
                        
                    $current_metric_collection []= [
                        'time' => $current_time_bucket,
                        'data' => $current_time_bucket_collection
                    ];

                    $current_time_bucket_collection = [];
                    $current_time_bucket = $row['time_bucket'] ?? null;
                }
                if(!isset($row) OR ($row['metric'] != $current_metric)) {
                    $out_data []= [
                        'metric' => $current_metric,
                        'data' => $current_metric_collection
                    ];
                    $current_metric_collection = [];
                    $current_metric = $row['metric'] ?? null;
                }
            }

            if($delete) {
                $this->_exec("DELETE FROM analytics_summations WHERE time_bucket <= ?", "s", $barrier_time);
            }

            $this->sql_connection->commit();

            return json_encode($out_data);
            
        } catch (\Throwable $th) {
			$this->sql_connection->rollback();
			throw $th;
		}     
    }

    public function pop_analytics_old($delete = true) {
		$this->sql_connection->begin_transaction();
        $out_data = "";

		try {
            $barrier_time = $this->_exec("SELECT NOW() - INTERVAL 6 MINUTE AS ctime")->fetch_assoc()['ctime'];

			$data = $this->_exec("
                SELECT *
                FROM analytics_access_sums
                WHERE time_bucket < ?
            ", "s", $barrier_time)->fetch_all(MYSQLI_ASSOC);

			$data_prefix="analytics_access_sums";

			foreach($data AS $post_data) {
				$path = $post_data['request_path'];
				if($path == '') {
					$path = '/';
				}
				$out_data .= $data_prefix . ",host=" . $post_data['host'] . ",agent=".$post_data['agent'];
				$out_data .= ",path=".$path.",referrer=".$post_data['referrer'];

				$out_data .= " access_sum=" . $post_data['access_sum'];
				$out_data .= " " . strtotime($post_data['time_bucket']) . "000000000\n";
			}

            $data = $this->_exec("
                SELECT *
                FROM analytics_processing_time_sums
                WHERE time_bucket < ?
            ", "s", $barrier_time)->fetch_all(MYSQLI_ASSOC);

			$data_prefix="analytics_processing_time_sums";

			foreach($data AS $post_data) {
				$path = $post_data['request_path'];
				if($path == '') {
					$path = '/';
				}
				$out_data .= $data_prefix . ",host=" . $post_data['host'];
				$out_data .= ",path=".$path;

				$out_data .= " time_sum=" . $post_data['time_sum'];
				$out_data .= " " . strtotime($post_data['time_bucket']) . "000000000\n";
			}

            if($delete) {
                $this->_exec("DELETE FROM analytics_access_sums WHERE time_bucket <= ?", "s", $barrier_time);
                $this->_exec("DELETE FROM analytics_processing_time_sums WHERE time_bucket <= ?", "s", $barrier_time);
            }

			$this->sql_connection->commit();
			return $out_data;

		} catch (\Throwable $th) {
			$this->sql_connection->rollback();
			
			throw $th;
		}     
    }
}

?>