// Decode decodes an array of bytes into an object.
//  - fPort contains the LoRaWAN fPort number
//  - bytes is an array of bytes, e.g. [225, 230, 255, 0]
//  - variables contains the device variables e.g. {"calibration": "3.5"} (both the key / value are of type string)
// The function must return an object, e.g. {"temperature": 22.5}
function Decode(fPort, bytes, variables) {
    // O5 Door contact sensor
    if (fPort === 4) {
        return [
            {
                led_state: bytes[0] === 0 ? "Off" : "On",
                mtm_code_1: bytes[1],
                mtm_code_2: bytes[2],
                hw_code: bytes[3],
                battery_level: bytes[4] + "%",
                size_value: bytes[5],
                HALL_1_state: bytes[6] === 1 ? "Door_Open" : "Door_Close",
                HALL_2_state: bytes[7] === 1 ? "Door_Open" : "Door_Close",
            }
        ];
    }
    // heart-beat of O5
    else if (fPort === 5) {
        return [
            {
                led_state: (bytes[0] & 0x7f) === 0 ? "Off" : "On",
                battery_level: bytes[4] + " %",
            }
        ];
    }
    // R4 soap/sanitizer sensor
    else if (fPort === 7) {
        return [
            {
                led_state: bytes[0] === 0 ? "Off" : "On",
                mtm_code_1: bytes[1],
                mtm_code_2: bytes[2],
                hw_code: bytes[3],
                battery_level: bytes[4] + "%",
                size_value: bytes[5],
                measure_tech: bytes[6] === 0 ? "Capacitive" : "Other",
                liquid_level_event: bytes[7] === 0 ? "Liquid Detected" : "No Liquid",
            }
        ];
    }
    // R4 soap/sanitizer heart-beat
    else if (fPort === 8) {
        return [
            {
                led_state: (bytes[0] & 0x7f) === 0 ? "Off" : "On",
                battery_level: bytes[1] + " %",
            }
        ];
    }
    // R1D dual roll toilet paper sensor
    else if (fPort === 57) {
        return [
            {
                led_state: bytes[0] === 0 ? "Off" : "On",
                mtm_code_1: bytes[1],
                mtm_code_2: bytes[2],
                hw_code: bytes[3],
                battery_level: bytes[4] + "%",
                size_value: bytes[5],
                distance_1_mm: bytes[6] << 8 | bytes[7],
                distance_2_mm: bytes[8] << 8 | bytes[9],
                distance_unit: "mm",
            }
        ];
    }
    // R1D, Heart-beat 
    else if (fPort === 58) {
        return [
            {
                led_state: (bytes[0] & 0x7f) === 0 ? "Off" : "On",
                battery_level: bytes[4] + " %",
            }
        ];
    }
    // R5 waste bin sensor
    else if (fPort === 11) {
        return [
            {
                led_state: bytes[0] === 0 ? "Off" : "On",
                mtm_code_1: bytes[1],
                mtm_code_2: bytes[2],
                hw_code: bytes[3],
                battery_level: bytes[4] + "%",
                size_value: bytes[5],
                distance_1_mm: (bytes[6] << 8 | bytes[7]),
                //distance_2_mm:bytes[8]*256+bytes[9],        
                //distance_3_mm:bytes[10]*256+bytes[11],        
                distance_unit: "mm",
            }
        ];
    }
    // R5, Heart-beat 
    else if (fPort === 12) {
        return [
            {
                led_state: (bytes[0] & 0x7f) === 0 ? "Off" : "On",
                battery_level: bytes[4] + " %",
            }
        ];
    }
    // UPLINK, RFAC
    else if (fPort === 1) {
        var data = {};
        data.length = bytes.length;
        if (bytes[0] === 0x59) {
            if (bytes[1] === 0x44) {
                data.Uplink_interval = (bytes[2] - 0x30) * 60 + (bytes[3] - 0x30);
                data.Uplink_interval_unit = String.fromCharCode(bytes[4]);
            }
            else if (bytes[1] === 0x53) {
                data.Heart_Beat_interval = (bytes[2] - 0x30) * 60 + (bytes[3] - 0x30);
                data.Heart_Beat_interval_unit = String.fromCharCode(bytes[4]);
            }
        }
        else if ((bytes[0] === 0x41) && (bytes[1] === 0x43)) {
            data.RFAC = "OK";
        }

        return { "Yunhorn_SmarToilets_data": data };
    }
}