<?php

namespace Menking\Meshcore;

use Exception;
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;

class CoreParser {
    /**
     * 
     * @param string $payload 
     * @throws Exception 
     */
    public static function parseResponse(string $payload): mixed {
        switch(ord($payload[0])) {
            case CoreProtocol::RESP_CODE_OK: 
                return true;
            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($payload);
            case CoreProtocol::RESP_CODE_NO_MORE_MESSAGES:
                return (object)['code'=>CoreProtocol::RESP_CODE_NO_MORE_MESSAGES];
            case CoreProtocol::RESP_CODE_ADVERT_PATH:
                return self::parseAdvertPathResponse($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 ['code'=>CoreProtocol::PUSH_CODE_MSG_WAITING];
            case CoreProtocol::RESP_CODE_CONTACT_MSG_RECV_V3:
            case CoreProtocol::RESP_CODE_CHANNEL_MSG_RECV_V3:
            case CoreProtocol::RESP_CODE_CHANNEL_MSG_RECV:
                return $payload;
            default:
                echo "Unparsed response: " . \Menking\Meshcore\Util\Debug::hexDump($payload) . "\n";
                return $payload;
        }
    }

    /**
     * 
     * @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]);
        $data->pub_key_prefix = base64_encode(substr($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]);
        $data->pub_key_prefix = base64_encode(substr($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]);
        $data->log = base64_encode(substr($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 ChannelResponse 
     */
    protected static function parseGetChannel(string $payload): ChannelResponse {
        $detail = explode("\0", substr($payload, 2, 32));

        $data = new ChannelResponse();

        $data->code = ord($payload[0]);
        $data->channel_idx = ord($payload[1]);
        $data->detail = $detail;
        $data->channel_secret = base64_encode(substr($payload, 34, 16));

        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;
    }

    public static function getContact(string $payload) {
        $contact = [
            'code'=>ord($payload[0]),
            'pub_key'=>base64_encode(substr($payload, 1, CoreProtocol::PUB_KEY_SIZE)),
            'type'=>ord($payload[33]),
            'flags'=>ord($payload[34]),
            'out_path_len'=>ord($payload[35]),
            'out_path'=>trim(substr($payload, 36, 64)),
            'contact_name'=>trim(substr($payload, 100, 32)),
            'last_advert_timestamp'=>date('r', unpack('V', substr($payload, 132, 4))[1]),
            'gps_lat'=>unpack('l', substr($payload, 136, 4))[1] / 1000000.0,
            'gps_lon'=>unpack('l', substr($payload, 140, 4))[1] / 1000000.0,
            'lastmod'=>date('r', unpack('V', substr($payload, 144, 4))[1])
        ];

        return $contact;
    }

    public static function parseAppStart(string $payload) {
        $info = [
            'response_code'=>ord($payload[0]),
            'advert_type'=>ord($payload[1]),
            'tx_power_dbm'=>ord($payload[2]),
            'max_tx_power'=>ord($payload[3]),
            'public_key'=>base64_encode(substr($payload, 4, CoreProtocol::PUB_KEY_SIZE)),
            'lat'=>unpack('l', substr($payload, 36, 4))[1] / 1000000.0,
            'long'=>unpack('l', substr($payload, 40, 4))[1] / 1000000.0,
            'multi_acks'=>ord($payload[44]),
            'advert_loc_policy'=>ord($payload[45]),
        ];
        
        return $info;
    }

    public static function parseAdvertPathResponse(string $payload) {
        $info = [
            'code'=>ord($payload[0]),
            'received_timestamp'=>unpack('V', substr($payload, 1, 4))[1],
            'path_len'=>ord($payload[5]),
            'path'=>substr($payload, 6, ord($payload[5]))
        ];

        return $info;
    }

    public static function parseCodeStatusResponse(string $payload) {
        $info = [
            'code'=>ord($payload[0]),
            'type'=>ord($payload[1]),
        ];

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

        return $info;
    }

    public static function parseDeviceInfoResponse(string $payload) {
        $info = [
            'code'=>ord($payload[0]),
            'fw_ver_code'=>ord($payload[1]),
            'max_contacts'=>ord($payload[2]) * 2,
            'max_group_channels'=>ord($payload[3]),
            'ble_pin'=>unpack('V', substr($payload, 4, 4))[1],
            'fw_build_date'=>trim(substr($payload, 8, 12)),
            'manufacturer_name'=>trim(substr($payload, 20, 40)),
            'fw_version'=>trim(substr($payload, 60, 20)),
            'client_repeat'=>ord($payload[80]),
            'path_hash_mode'=>ord($payload[81])
        ];

        return $info;
    }

    public static function parseChannelInfoResponse(string $payload) {
        $info = [
            'code'=>ord($payload[0]),
            'channel_idx'=>ord($payload[1]),
            'channel_name'=>self::readCstring(substr($payload, 2, 32)),
            'channel_secret'=>substr($payload, 34, 16)
        ];

        return $info;
    }

    public static function parseMessage(string $payload) {
        $data = [
            'code'=>ord($payload[0]),
            'channel_idx'=>ord($payload[1]),
            'path_len'=>ord($payload[2]),
            'type'=>ord($payload[3]),
            'timestamp'=>date('r', unpack('V', substr($payload, 4, 4))[1]),
            'message'=>substr($payload, 8, strlen($payload))
        ];

        return $data;
    }

    public static function readCstring($str) {
        $x = strpos($str, "\0");

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