package remdeshid

import "fmt"

//Convert a HIDCommand to bytes that can be sent over the USBKVM device
func ConvHIDCommandToBytes(cmd HIDCommand) ([]byte, error) {
	// Convert the HID command to bytes
	var data []byte
	if cmd.EventType == FRONTEND_OPR_TYPE_KEYBOARD_WRITE {
		data = []byte{OPR_TYPE_KEYBOARD_WRITE}

		/* Keyboard Subtypes */
		if len(cmd.Data) == 1 && cmd.Data[0] >= 32 && cmd.Data[0] <= 127 {
			//Valid ASCII character
			if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_DOWN {
				data = append(data, SUBTYPE_KEYBOARD_ASCII_PRESS)
			} else if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_UP {
				data = append(data, SUBTYPE_KEYBOARD_ASCII_RELEASE)
			} else {
				//Key Click
				data = append(data, SUBTYPE_KEYBOARD_ASCII_WRITE)
			}
			data = append(data, cmd.Data[0])
			return data, nil
		} else if isFuncKey(cmd.Data) {
			//Function Key
			if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_DOWN {
				data = append(data, SUBTYPE_KEYBOARD_FUNCTKEY_PRESS)
			} else {
				data = append(data, SUBTYPE_KEYBOARD_FUNCTKEY_RELEASE)
			}
			data = append(data, funcKeyToByte(cmd.Data))
			if data[0] == 0xFF {
				return nil, fmt.Errorf("invalid function key: %v", cmd.Data)
			}
			return data, nil
		} else if isModifierKey(cmd.Data) {
			//Modifier Key
			if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_DOWN {
				data = append(data, SUBTYPE_KEYBOARD_MODIFIER_PRESS)
			} else {
				data = append(data, SUBTYPE_KEYBOARD_MODIFIER_RELEASE)
			}
			data = append(data, modifierKeyToByte(cmd.Data))
			if data[0] == 0xFF {
				return nil, fmt.Errorf("invalid modifier key: %v", cmd.Data)
			}
			return data, nil
		} else if isOtherKeys(cmd.Data) {
			//Other Keys
			if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_DOWN {
				data = append(data, SUBTYPE_KEYBOARD_OTHERKEY_PRESS)
			} else if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_UP {
				data = append(data, SUBTYPE_KEYBOARD_OTHERKEY_RELEASE)
			} else {
				return nil, fmt.Errorf("invalid HID command subtype: %v", cmd.Data)
			}
			data = append(data, nonAsciiKeysToBytes(cmd.Data)...)
			return data, nil
		} else if isNumpadKey(cmd.Data) {
			//Numpad Keys
			if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_DOWN {
				data = append(data, SUBTYPE_KEYBOARD_NUMPAD_PRESS)
			} else if cmd.EventSubType == FRONTEND_SUBTYPE_KEYBOARD_KEY_UP {
				data = append(data, SUBTYPE_KEYBOARD_NUMPAD_RELEASE)
			} else {
				return nil, fmt.Errorf("invalid HID command subtype: %v", cmd.Data)
			}
			data = append(data, numpadKeyToByte(string(cmd.Data)))
			return data, nil
		} else if cmd.Data == "NumLock" {
			//Special Key: NumLock
			//TODO: Implement NumLock
			return nil, fmt.Errorf("numLock not implemented")
		} else if cmd.Data == "ContextMenu" {
			//Special Key: ContextMenu
			//TODO: Implement ContextMenu
			return nil, fmt.Errorf("ContextMenu not implemented")
		} else if cmd.Data == "Ctrl+Alt+Del" {
			//Special Key: Ctrl+Alt+Del
			data = append(data, SUBTYPE_KEYBOARD_SPECIAL_CTRLALTDEL)
			data = append(data, 0x00)
			return data, nil
		} else {
			return nil, fmt.Errorf("invalid HID command subtype: %v", cmd.Data)
		}

	} else if cmd.EventType == FRONTEND_OPR_TYPE_MOUSE_WRITE {
		/* Mouse Write Event */
		data = []byte{OPR_TYPE_MOUSE_WRITE}
	} else {
		return nil, fmt.Errorf("invalid HID command type: %s", cmd.EventType)
	}

	return data, nil
}