<?php

namespace Menking\Meshcore;

use Exception;
use Menking\Meshcore\Model\AdvertPathResponse;
use Menking\Meshcore\Model\AdvertResponse;
use Menking\Meshcore\Model\AppStartResponse;
use Menking\Meshcore\Model\BinaryResponse;
use Menking\Meshcore\Model\ChannelResponse;
use Menking\Meshcore\Model\CodeSentResponse;
use Menking\Meshcore\Model\CurrentTimeResponse;
use Menking\Meshcore\Model\DeviceInfoResponse;
use Menking\Meshcore\Model\ErrorResponse;
use Menking\Meshcore\Model\LoginResponse;
use Menking\Meshcore\Model\LogReceiveResponse;
use Menking\Meshcore\Model\BatteryStorageResponse;
use Menking\Meshcore\Model\CodeStatusResponse;
use Menking\Meshcore\Model\ContactResponse;
use Menking\Meshcore\Model\ContactsFullResponse;
use Menking\Meshcore\Model\MessageResponse;
use Menking\Meshcore\Model\MessagesWaitingResponse;
use Menking\Meshcore\Model\NoMoreMessagesResponse;
use Menking\Meshcore\Model\OkResponse;

class CoreParser {
    /**
     * 
     * @param string $payload 
     * @throws Exception 
     */
    public static function parseResponse(string $payload): mixed {
        switch(ord($payload[0])) {
            case CoreProtocol::RESP_CODE_OK: 
                return self::parseOk($payload);
            case CoreProtocol::RESP_CODE_ERR:
                //throw new \Exception("Protocol error: " . CoreProtocol::getErrorText(ord($payload[1])));
                return self::parseError($payload);
            case CoreProtocol::RESP_CODE_CONTACT:
                return self::getContact($payload);
            case CoreProtocol::RESP_CODE_SELF_INFO:
                return self::parseAppStart($payload);
            case CoreProtocol::RESP_CODE_SENT:
                return self::parseCodeSent($payload);
            case CoreProtocol::PUSH_CODE_LOGIN_SUCCESS:
                return self::parseLoginSuccess($payload);
            case CoreProtocol::PUSH_CODE_LOG_RX_DATA:
                return self::parseLogRxData($payload);
            case CoreProtocol::PUSH_CODE_LOGIN_FAIL:
                return self::parseLoginFail($payload);
            case CoreProtocol::RESP_CODE_CURR_TIME:
                return self::parseCurrentTime($payload);
            case CoreProtocol::PUSH_CODE_BINARY_RESPONSE:
                return self::parseBinaryResponse($payload);
            case CoreProtocol::RESP_CODE_BATT_AND_STORAGE:
                return self::parseBatteryAndStorage($payload);
            case CoreProtocol::RESP_CODE_NO_MORE_MESSAGES:
                return new NoMoreMessagesResponse();
            case CoreProtocol::RESP_CODE_ADVERT_PATH:
                return self::parseAdvertPathResponse($payload);
            case CoreProtocol::RESP_CODE_STATS:
                return self::parseCodeStatusResponse($payload);
            case CoreProtocol::RESP_CODE_DEVICE_INFO:
                return self::parseDeviceInfoResponse($payload);
            case CoreProtocol::RESP_CODE_CHANNEL_INFO:
                return self::parseChannelInfoResponse($payload);
            case CoreProtocol::PUSH_CODE_MSG_WAITING:
                return new MessagesWaitingResponse();
            case CoreProtocol::RESP_CODE_CONTACT_MSG_RECV_V3:
            case CoreProtocol::RESP_CODE_CHANNEL_MSG_RECV_V3:
            case CoreProtocol::RESP_CODE_CHANNEL_MSG_RECV:
                return self::parseMsg($payload);
            case CoreProtocol::PUSH_CODE_ADVERT:
            case CoreProtocol::PUSH_CODE_NEW_ADVERT:
                return self::parseAdvert($payload);
            case CoreProtocol::PUSH_CODE_CONTACTS_FULL:
                return new ContactsFullResponse();
            default:
                echo "Unparsed response: " . \Menking\Meshcore\Util\Debug::hexDump($payload) . "\n";
                return $payload;
        }
    }

    protected static function parseOk(string $payload): OkResponse {
        $m = new OkResponse();
        $m->code = ord($payload[0]);

        return $m;
    }

    protected static function parseMsg(string $payload): mixed {
        $m = new MessageResponse();

        $idx = 0;
        $m->code = ord($payload[$idx]);
        $idx++;

        $m->snr = 0;

        if( $m->code == CoreProtocol::RESP_CODE_CHANNEL_MSG_RECV_V3 ) {
            $m->snr = ord($payload) / 4;
            $idx += 1;
            // two reserved bytes
            $idx += 2;
        }

        $m->channel_idx = ord($payload[$idx]);
        $m->path_len = ord($payload[$idx+1]);
        $m->type = ord($payload[$idx+2]);
        $m->timestamp = unpack('V', substr($payload, $idx+3, 4))[1];
        $m->message = substr($payload, $idx+7);

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return mixed 
     */
    protected static function parseAdvert(string $payload): mixed {
        $m = new AdvertResponse();

        $m->code = ord($payload[0]);
        $m->pub_key = self::formatPublicKey(substr($payload, 1, CoreProtocol::PUB_KEY_SIZE));
 
        if( strlen($payload) > CoreProtocol::PUB_KEY_SIZE + 2 ) {
            $m->type = ord($payload[33]);
            $m->flags = ord($payload[34]);
            $m->out_path = self::formatPublicKey(substr($payload, 35, CoreProtocol::MAX_PATH_SIZE+1));
            $m->name = rtrim(substr($payload, 100, 32));

            if( strlen($payload) > 132 ) {
                $m->last_advert_time = unpack('V', substr($payload, 132, 4))[1];
                $m->lat = unpack('V', substr($payload, 136, 4))[1];
                $m->lon = unpack('V', substr($payload, 140, 4))[1];
                $m->last_mod = unpack('V', substr($payload, 144, 4))[1];
            }
        }

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return BinaryResponse 
     */
    protected static function parseBinaryResponse(string $payload): BinaryResponse {
        $data = new BinaryResponse();

        $data->code = ord($payload[0]);
        $data->reserved = ord($payload[1]);
        $data->tag = unpack('V', substr($payload, 2, 4))[1];
        $data->lpp = [];

        $lpp = substr($payload, 6);
        // Cayenne LPP proto
        $offset = 0;
        while($offset < strlen($lpp) ) {
            $block = substr($lpp, $offset, 4);
            $q = [
                'channel' => ord($block[0]),
                'type' => ord($block[1]),
                'type_name'=>CoreProtocol::getLppType(ord($block[1])),
                'value' => unpack('n', substr($block, 2, 2))[1]
            ];

            switch($q['type']) {
                case CoreProtocol::LPP_VOLTAGE:
                    $q['value'] /= 100;
                    break;
                case CoreProtocol::LPP_TEMP:
                    $q['value'] /= 10;
                    $q['fahrenheit'] = (($q['value'] * 9.0 / 5.0) + 32.0);
                    break;
            }

            $offset += 4;

            if( $q['channel'] != 0 && $q['type'] != 0 ) {
                $data->lpp[] = $q;            
            }
        }

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return ErrorResponse 
     */
    protected static function parseError(string $payload): ErrorResponse {
        $e = new ErrorResponse();
        $e->code = ord($payload[0]);
        $e->error_code = ord($payload[1]);
        $e->error_text = CoreProtocol::getErrorText(ord($payload[1]));

        return $e;
    }

    /**
     * 
     * @param string $payload 
     * @return CurrentTimeResponse 
     */
    protected static function parseCurrentTime(string $payload): CurrentTimeResponse {
        $data = new CurrentTimeResponse();

        $data->code = ord($payload[0]);
        $data->current_time = unpack('V', substr($payload, 1, 4))[1];

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return LoginResponse 
     */
    protected static function parseLoginFail(string $payload): LoginResponse {
        $data = new LoginResponse();

        $data->code = ord($payload[0]);
        $data->status = false;
        $data->is_admin = ord($payload[1]);
        $data->pub_key_prefix = self::formatPublicKey(substr($payload, 2, 6));

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return LoginResponse 
     */
    protected static function parseLoginSuccess(string $payload): LoginResponse {
        $data = new LoginResponse();

        $data->code = ord($payload[0]);
        $data->status = true;
        $data->is_admin = ord($payload[1]);
        $data->pub_key_prefix = self::formatPublicKey(substr($payload, 2, 6));

        if( strlen($payload) > 8 ) {
            $data->timestamp = unpack('V', substr($payload, 8, 4))[1];
            $data->acl = ord($payload[12]);
            $data->firmware_version = ord($payload[13]);
        }

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return LogReceiveResponse 
     */
    protected static function parseLogRxData(string $payload): LogReceiveResponse {
        $data = new LogReceiveResponse();

        $data->code = ord($payload[0]);
        $data->snr = ord($payload[1]) / 4;
        $data->rssi = (ord($payload[2]) >= 128) ? (ord($payload[2]) - 256): ord($payload[2]);

        //$data->flags = ord($payload[1]);
        //$data->snr = ord($payload[2]) / 4;
        $data->raw = base64_encode(substr($payload, 3, strlen($payload)));

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return CodeSentResponse 
     */
    protected static function parseCodeSent(string $payload): CodeSentResponse {
        $data = new CodeSentResponse();

        $data->code = ord($payload[0]);
        $data->sent_as_flood = ord($payload[1]);
        $data->tag= unpack('V', substr($payload, 2, 4))[1];
        $data->est_timeout = unpack('V', substr($payload, 6, 4))[1];
        
        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return DeviceInfoResponse 
     */
    protected static function parseDeviceInfo(string $payload): DeviceInfoResponse {
        $data = new DeviceInfoResponse();

        $data->code = ord($payload[0]);
        $data->firmware_version = ord($payload[1]);
        $data->max_contacts_raw = ord($payload[2]);
        $data->max_channels = ord($payload[3]);
        $data->ble_pin = unpack('v', substr($payload, 4, 4))[1];
        $data->firmware_build = trim(substr($payload, 8, 12));
        $data->model = trim(substr($payload, 20, 40));
        $data->version = trim(substr($payload, 60, 20));
        $data->client_repeat_enabled = ord($payload[80]);
        $data->path_hash_mode = ord($payload[81]);

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return BatteryStorageResponse 
     */
    protected static function parseBatteryAndStorage(string $payload): BatteryStorageResponse {
        $data = new BatteryStorageResponse();

        $data->code = ord($payload[0]);
        $data->battery_millivolt = unpack('v', substr($payload, 1, 2))[1];
        $data->storage_used = unpack('V', substr($payload, 3, 4))[1];
        $data->storage_total = unpack('V', substr($payload, 7, 4))[1];

        return $data;
    }

    /**
     * 
     * @param string $payload 
     * @return ContactResponse 
     */
    public static function getContact(string $payload): ContactResponse {
        $m = new ContactResponse();
        
        $m->code = ord($payload[0]);
        $m->pub_key = self::formatPublicKey(substr($payload, 1, CoreProtocol::PUB_KEY_SIZE));
        $m->type = ord($payload[33]);
        $m->flags = ord($payload[34]);
        $m->out_path_len = ord($payload[35]);
        $m->out_path = self::formatPublicKey(substr($payload, 36, 64));
        $m->name = trim(substr($payload, 100, 32), ' ');
        $m->last_advert_timestamp = date('r', unpack('V', substr($payload, 132, 4))[1]);
        $m->lat = unpack('l', substr($payload, 136, 4))[1] / 1000000.0;
        $m->lon = unpack('l', substr($payload, 140, 4))[1] / 1000000.0;
        $m->lastmod = date('r', unpack('V', substr($payload, 144, 4))[1]);

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return AppStartResponse 
     */
    protected static function parseAppStart(string $payload): AppStartResponse {    
        $m = new AppStartResponse();
        
        $m->code = ord($payload[0]);
        $m->advert_type = ord($payload[1]);
        $m->tx_power_dbm = ord($payload[2]);
        $m->max_tx_power = ord($payload[3]);
        $m->pub_key = self::formatPublicKey(substr($payload, 4, CoreProtocol::PUB_KEY_SIZE));
        $m->lat = unpack('l', substr($payload, 36, 4))[1] / 1000000.0;
        $m->lon = unpack('l', substr($payload, 40, 4))[1] / 1000000.0;
        $m->multi_acks = ord($payload[44]);
        $m->advert_loc_policy = ord($payload[45]);

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return AdvertPathResponse 
     */
    protected static function parseAdvertPathResponse(string $payload): AdvertPathResponse {
        $m = new AdvertPathResponse();

        $m->code = ord($payload[0]);
        $m->received_timestamp = unpack('V', substr($payload, 1, 4))[1];
        $m->path_len = ord($payload[5]);
        $m->path = substr($payload, 6, ord($payload[5]));

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return CodeStatusTypeCoreResponse|CodeStatusTypeRadioResponse|CodeStatusTypePacketResponse 
     */
    protected static function parseCodeStatusResponse(string $payload): CodeStatusResponse {
        $m = null;

        switch(ord($payload[1])) {
            case CoreProtocol::STATS_TYPE_CORE:
                $m = new CodeStatusResponse();
                $m->code =  ord($payload[0]);
                $m->type = CodeStatusResponse::RESP_CORE;
                $m->battery_mv = unpack('v', substr($payload, 2, 2))[1];
                $m->uptime_secs = unpack('V', substr($payload, 4, 4))[1];
                $m->err_flags = unpack('v', substr($payload, 8, 2))[1];
                $m->queue_len = ord($payload[10]);
                break;  
            case CoreProtocol::STATS_TYPE_RADIO:
                $m = new CodeStatusResponse();
                $m->code = ord($payload[0]);
                $m->type = CodeStatusResponse::RESP_RADIO;
                $m->noise_floor = unpack('v', substr($payload, 2, 2))[1];
                $m->last_rssi = (ord($payload[4]) >= 128) ? (ord($payload[4]) - 256): ord($payload[4]); 
                $m->last_snr = ord($payload[5]);;
                $m->tx_air_secs = unpack('V', substr($payload, 6, 4))[1];
                $m->rx_air_secs = unpack('V', substr($payload, 10, 4))[1];
                break;
            case CoreProtocol::STATS_TYPE_PACKETS:
                $m = new CodeStatusResponse();
                $m->code = ord($payload[0]);
                $m->type = CodeStatusResponse::RESP_PACKET;
                $m->recv = unpack('V', substr($payload, 2, 4))[1];
                $m->sent = unpack('V', substr($payload, 6, 4))[1];
                $m->n_sent_flood = unpack('V', substr($payload, 10, 4))[1];
                $m->n_sent_direct = unpack('V', substr($payload, 14, 4))[1];
                $m->n_recv_flood = unpack('V', substr($payload, 18, 4))[1];
                $m->n_recv_direct = unpack('V', substr($payload, 22, 4))[1];
                $m->n_recv_errors = unpack('V', substr($payload, 26, 4))[1];
                break;
        }

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return DeviceInfoResponse 
     */
    protected static function parseDeviceInfoResponse(string $payload): DeviceInfoResponse {
        $m = new DeviceInfoResponse();
        $m->code = ord($payload[0]);
        $m->firmware_version = ord($payload[1]);
        $m->max_contacts_raw = ord($payload[2]) * 2;
        $m->max_channels = ord($payload[3]);
        $m->ble_pin = unpack('V', substr($payload, 4, 4))[1];
        $m->firmware_build = trim(substr($payload, 8, 12));
        $m->model = trim(substr($payload, 20, 40));
        $m->version =trim(substr($payload, 60, 20));
        $m->client_repeat_enabled = ord($payload[80]);
        $m->path_hash_mode = ord($payload[81]);

        return $m;
    }

    /**
     * 
     * @param string $payload 
     * @return ChannelResponse 
     */
    protected static function parseChannelInfoResponse(string $payload): ChannelResponse {
        $m = new ChannelResponse();

        $m->code = ord($payload[0]);
        $m->channel_idx = ord($payload[1]);
        $m->channel_name = self::readCstring(substr($payload, 2, 32));
        $m->channel_secret = substr($payload, 34, 16);

        return $m;
    }

    /**
     * 
     * @param mixed $str 
     * @return null|string 
     */
    public static function readCstring($str) {
        $x = strpos($str, "\0");

        if( $x === false ) {
            return null;
        }
        else {
            return trim(substr($str, 0, $x));
        }
    }

    /**
     * 
     * @param string $pubkey 
     * @return string 
     */
    public static function formatPublicKey(string $pubkey): string {
        return bin2hex($pubkey);
    }
}