<?php

/**
 * DomFramework
 * @package domframework
 * @author Dominique Fournier <dominique@fournier38.fr>
 * @license BSD
 */

namespace Domframework;

/**
 * The logger class permit to log the information from the soft
 * It allow to debug too
 */
class Logger
{
    /* The logger class can be used with :
       $d=new logger;
       $d->timezone = "Europe/Paris";
       $d->logtype="display|file";
       $d->logfile="/tmp/toto.log";
       $d->logwrite ("Super log default");
       $d->logwrite ("Super log DEBUG", $d::DEBUG);
       $d->logwrite ("Super log NOTICE", $d::NOTICE);
 */
    // TODO : Add SQL support
    /**
     * The method to log.
     * Can be display, file, syslog, stderr, session
     * Can be merged with a pipe : "display|syslog|file" or put in array
     */
    public $logtype = "stderr";
    /**
     * For logtype=file, the filename to use
     */
    public $logfile = false;
    /**
     * Timezone use to save the logs
     */
    public $timezone = "UTC";
    /**
     * Minimum log level in the logs
     */
    public $loglevelmin = LOG_NOTICE;
    /**
     * In Syslog mode, the facility to use
     * See http://fr2.php.net/manual/en/function.openlog.php for $syslogFacility
     */
    public $syslogFacility = LOG_USER;
    /**
     * In Syslog, prefix the log by the text
     */
    public $syslogPrefix = false;
    /**
     * Remove X entries of backtrace to see the right file generating the error
     */
    public $backTraceSkip = 1;
    /**
     * Display the backtrace in all the messages
     */
    public $backtraceDisplay = false;

    /**
     * The priorities which can be used in the priorities
     * LOG_EMERG   system is unusable
     * LOG_ALERT   action must be taken immediately
     * LOG_CRIT    critical conditions
     * LOG_ERR     error conditions
     * LOG_WARNING warning conditions
     * LOG_NOTICE  normal, but significant, condition
     * LOG_INFO    informational message
     * LOG_DEBUG   debug-level message
     */
    private $priorities = [
        LOG_EMERG   => "EMERG",
        LOG_ALERT   => "ALERT",
        LOG_CRIT    => "CRITICAL",
        LOG_ERR     => "ERROR",
        LOG_WARNING => "WARNING",
        LOG_NOTICE  => "NOTICE",
        LOG_INFO    => "INFO",
        LOG_DEBUG   => "DEBUG",
    ];

    /**
     * Catch all the messages raised by the PHP, in trigger_error
     * Use the properties of the logger to save the logs
     */
    public function catchAll()
    {
        set_error_handler([&$this, "errorHandler"]);
    }

    /**
     * The error handler to log
     * @param integer $errno The error number to use
     * @param string $errstr The error message to save
     * @param string $errfile The file which generate the error
     * @param integer $errline The line where the error is generated
     */
    public function errorHandler($errno, $errstr, $errfile, $errline)
    {
        if (!(error_reporting() & $errno)) {
            // This error code is not included in error_reporting
            return;
        }
        $priority = LOG_ERR;
        switch ($errno) {
            case E_ERROR:
                $priority = LOG_ERR;
                break;
            case E_WARNING:
                $priority = LOG_WARNING;
                break;
            case E_PARSE:
                $priority = LOG_ERR;
                break;
            case E_NOTICE:
                $priority = LOG_NOTICE;
                break;
            case E_CORE_ERROR:
                $priority = LOG_ERR;
                break;
            case E_CORE_WARNING:
                $priority = LOG_WARNING;
                break;
            case E_COMPILE_ERROR:
                $priority = LOG_ERR;
                break;
            case E_COMPILE_WARNING:
                $priority = LOG_WARNING;
                break;
            case E_USER_ERROR:
                $priority = LOG_ERR;
                break;
            case E_USER_WARNING:
                $priority = LOG_WARNING;
                break;
            case E_USER_NOTICE:
                $priority = LOG_NOTICE;
                break;
            case E_STRICT:
                $priority = LOG_WARNING;
                break;
            case E_RECOVERABLE_ERROR:
                $priority = LOG_ERR;
                break;
            case E_DEPRECATED:
                $priority = LOG_WARNING;
                break;
            case E_USER_DEPRECATED:
                $priority = LOG_WARNING;
                break;
        }
        $this->log($priority, $errstr);
    }

    /**
     * Store a new message log in the log manager defined by $logtype
     * The message can be multiple types. An array will be stored in textual form
     * but it will accept only one depth.
     * The $message is not fixed, you can pass the number of parameters you want
     * @param integer|null $priority Priority to use
     * @param mixed ...$message Message to log
     */
    public function log($priority, $message)
    {
        if ($priority === null) {
            $priority = LOG_NOTICE;
        }
        if (! is_int($priority)) {
            switch ($priority) {
                case "LOG_EMERG":
                    $priority = LOG_EMERG;
                    break;
                case "LOG_ALERT":
                    $priority = LOG_ALERT;
                    break;
                case "LOG_CRIT":
                    $priority = LOG_CRIT;
                    break;
                case "LOG_ERR":
                    $priority = LOG_ERR;
                    break;
                case "LOG_WARNING":
                    $priority = LOG_WARNING;
                    break;
                case "LOG_NOTICE":
                    $priority = LOG_NOTICE;
                    break;
                case "LOG_INFO":
                    $priority = LOG_INFO;
                    break;
                case "LOG_DEBUG":
                    $priority = LOG_DEBUG;
                    break;
            }
        }
        if (! is_int($this->loglevelmin)) {
            switch ($this->loglevelmin) {
                case "LOG_EMERG":
                    $this->loglevelmin = LOG_EMERG;
                    break;
                case "LOG_ALERT":
                    $this->loglevelmin = LOG_ALERT;
                    break;
                case "LOG_CRIT":
                    $this->loglevelmin = LOG_CRIT;
                    break;
                case "LOG_ERR":
                    $this->loglevelmin = LOG_ERR;
                    break;
                case "LOG_WARNING":
                    $this->loglevelmin = LOG_WARNING;
                    break;
                case "LOG_NOTICE":
                    $this->loglevelmin = LOG_NOTICE;
                    break;
                case "LOG_INFO":
                    $this->loglevelmin = LOG_INFO;
                    break;
                case "LOG_DEBUG":
                    $this->loglevelmin = LOG_DEBUG;
                    break;
            }
        }
        if ($this->loglevelmin < $priority) {
            return;
        }
        $back = [];
        $backtrace = debug_backtrace();
        for ($i = 0; $i <= $this->backTraceSkip; $i++) {
            $back = array_shift($backtrace);
        }
        while (! array_key_exists("file", $back) && count($backtrace) > 0) {
            $back = array_shift($backtrace);
        }
        $msg = "";
        if (isset($_SERVER["HTTP_X_FORWARDED_FOR"])) {
            $msg .= "[" . $_SERVER["HTTP_X_FORWARDED_FOR"] . "] ";
        } elseif (isset($_SERVER["REMOTE_ADDR"])) {
            $msg .= "[" . $_SERVER["REMOTE_ADDR"] . "] ";
        }

        // The messages are all the parameters of the function except the first,
        // which is the priority
        $messages = func_get_args();
        array_shift($messages);
        // Convert each part of message to text
        foreach ($messages as $m) {
            if (is_array($m)) {
                $msg .= "[";
                foreach ($m as $key => $val) {
                    if (is_array($val)) {
                        foreach ($val as $key2 => $val2) {
                            $msg .= "$key2=>$val2,";
                        }
                    } else {
                        $msg .= "$key=>$val,";
                    }
                }
                $msg .= "]";
            } else {
                $msg .= $m;
            }
        }

        // Add the filename which generate the error
        $msg .= " [" . basename($back["file"]) . ":" . $back["line"] . "]";

        // Display the backtrace if it is needed
        if ($this->backtraceDisplay) {
            $e = new \Exception();
            $msg .= "\n" . ($e->getTraceAsString());
        }

        $logsType = [];
        if (is_string($this->logtype)) {
            $logsType = explode("|", $this->logtype);
        } elseif (is_array($this->logtype)) {
            $logsType = $this->logtype;
        }
        if (in_array("display", $logsType, true)) {
            $this->logdisplay($msg, $priority);
        }
        if (in_array("stderr", $logsType, true)) {
            $this->logstderr($msg, $priority);
        }
        if (in_array("file", $logsType, true)) {
            $this->logfile($msg, $priority);
        }
        if (in_array("syslog", $logsType, true)) {
            $this->logsyslog($msg, $priority);
        }
        if (in_array("session", $logsType, true)) {
            $this->logsession($msg, $priority);
        }
    }

    /**
     * Log $message on file
     * @param string $message Message to log
     * @param integer|null $priority Priority to use
     */
    private function logfile($message, $priority)
    {
        if ($this->logfile === false) {
            throw new \Exception("Undefined file where logging");
        }
        if (!file_exists($this->logfile)) {
            if (! is_dir(dirname($this->logfile))) {
                throw new \Exception("You must create the " . dirname($this->logfile) .
                             "directory");
            }
            if (! is_writable(dirname($this->logfile))) {
                throw new \Exception("The directory " . dirname($this->logfile) . " must"
                            . " be writable to create log file");
            }
        } elseif (!is_writable($this->logfile)) {
            if (function_exists("posix_geteuid")) {
                $user = posix_geteuid();
            } elseif (getenv('USERNAME') !== false) {
                $user = getenv('USERNAME');
            } else {
                $user = "";
            }
            throw new \Exception("Logfile $this->logfile is not writable for user " .
                           $user);
        }

        ini_set("date.timezone", $this->timezone);
        $message = date("Y/m/d H:i:s") . " [" . $this->priorities[$priority] . "] " .
               $message . "\n";
        file_put_contents($this->logfile, $message, FILE_APPEND | LOCK_EX);
    }

    /**
     * Log $message on screen with adding date. Add the HTML flags if not in CLI.
     * @param string $message Message to log
     * @param integer|null $priority Priority to use
     */
    private function logdisplay($message, $priority)
    {
        if (php_sapi_name() !== "cli") {
            echo "<tt>";
        }
        ini_set("date.timezone", $this->timezone);
        $message = date("Y/m/d H:i:s") . " [" . $this->priorities[$priority] . "] " .
               $message;
        if (php_sapi_name() !== "cli") {
            $message = nl2br($message);
        }
        echo "$message";
        if (php_sapi_name() !== "cli") {
            echo "</tt><br/>";
        }
        echo "\n";
    }

    /**
     * Log $message on stderr with adding date. Add the HTML flags if not in CLI.
     * @param string $message Message to log
     * @param integer|null $priority Priority to use
     */
    private function logstderr($message, $priority)
    {
        ini_set("date.timezone", $this->timezone);
        $message = date("Y/m/d H:i:s") . " [" . $this->priorities[$priority] . "] " .
               $message;
        file_put_contents("php://stderr", "$message");
        file_put_contents("php://stderr", "\n");
    }

    /**
     * Log $message on syslog
     * @param string $message Message to log
     * @param integer|null $priority Priority to use
     */
    private function logsyslog($message, $priority)
    {
        if (is_string($this->syslogFacility)) {
            switch ($this->syslogFacility) {
                case "LOG_AUTH":
                    $this->syslogFacility = LOG_AUTH;
                    break;
                case "LOG_AUTHPRIV":
                    $this->syslogFacility = LOG_AUTHPRIV;
                    break;
                case "LOG_DAEMON":
                    $this->syslogFacility = LOG_DAEMON;
                    break;
                case "LOG_KERN":
                    $this->syslogFacility = LOG_KERN;
                    break;
                case "LOG_LOCAL0":
                    $this->syslogFacility = LOG_LOCAL0;
                    break;
                case "LOG_LOCAL1":
                    $this->syslogFacility = LOG_LOCAL1;
                    break;
                case "LOG_LOCAL2":
                    $this->syslogFacility = LOG_LOCAL2;
                    break;
                case "LOG_LOCAL3":
                    $this->syslogFacility = LOG_LOCAL3;
                    break;
                case "LOG_LOCAL4":
                    $this->syslogFacility = LOG_LOCAL4;
                    break;
                case "LOG_LOCAL5":
                    $this->syslogFacility = LOG_LOCAL5;
                    break;
                case "LOG_LOCAL6":
                    $this->syslogFacility = LOG_LOCAL6;
                    break;
                case "LOG_LOCAL7":
                    $this->syslogFacility = LOG_LOCAL7;
                    break;
                case "LOG_LPR":
                    $this->syslogFacility = LOG_LPR;
                    break;
                case "LOG_MAIL":
                    $this->syslogFacility = LOG_MAIL;
                    break;
                case "LOG_NEWS":
                    $this->syslogFacility = LOG_NEWS;
                    break;
                case "LOG_SYSLOG":
                    $this->syslogFacility = LOG_SYSLOG;
                    break;
                case "LOG_USER":
                    $this->syslogFacility = LOG_USER;
                    break;
                case "LOG_UUCP":
                    $this->syslogFacility = LOG_UUCP;
                    break;
            }
        }
        openlog($this->syslogPrefix, null, $this->syslogFacility);
        // Syslog display a #012 when there is a \n : remove it
        $message = str_replace("\n", "", $message);
        syslog($priority, $message);
    }

    /**
     * Log $message on session (for debug)
     * @param string $message Message to log
     * @param integer|null $priority Priority to use
     */
    private function logsession($message, $priority)
    {
        if (! isset($_SESSION)) {
            throw new \Exception("No session available to store the log", 500);
        }
        ini_set("date.timezone", $this->timezone);
        $message = date("Y/m/d H:i:s") . " [" . $this->priorities[$priority] . "] " .
               $message;
        $_SESSION["domframework"]["logger"][] = $message;
    }
}