/*
 * Stairs lighting
 * Copyright 2017 (c) Mark van Renswoude
 *
 * https://git.x2software.net/pub/Stairs
*/
#ifndef __protocol
#define __protocol

#include <stdint.h>


/*
 * There are three classes of messages, these masks provide a way to identify
 * unknown messages if the protocol ever changes.
 *
 * MaskBroadcastCommand:  commands which do not expect a response
 * MaskModuleCommand:     commands which do expect a command. respond with ResponseUhmWhat to satisfy the response requirement.
 * MaskResponse:          responses to commands
*/
const uint8_t MaskMessageType = 0b11000000;

const uint8_t MaskBroadcastCommand = 0b10000000;
const uint8_t MaskModuleCommand = 0b11000000;
const uint8_t MaskResponse = 0b01000000;

const uint8_t ResponseUhmWhat = 0x00 | MaskResponse;


/*
 * Ping:
 *   Aimed at a specific module, which must respond with a
 *   ResponsePing message.
 *
 * Request:
 *   [0]  CommandPing
 *   [1]  Module index
 *
 * Response:
 *   [0]  ResponsePing
 *   [1]  Module index
*/
const uint8_t BasePing = 0x01;
const uint8_t CommandPing = BasePing | MaskModuleCommand;
const uint8_t ResponsePing = BasePing | MaskResponse;


/*
 * Display module index:
 *   Broadcast to all modules which should turn on their display
 *   and show the current settings. No response is expected.
 *
 * Request:
 *   [0]  CommandDisplayModuleIndex
*/
const uint8_t CommandDisplayModuleIndex = 0x02 | MaskBroadcastCommand;



/*
 * Start linking:
 *   Broadcast to all modules which should change to link mode.
 *   During link mode the master will disable all other communication,
 *   allowing the module to respond at will in response to user input.
 *
 *   Each module should send a CommandRequestLink message when user input
 *   is provided.
 *
 * Request:
 *   [0]  CommandStartLink
 *
 * Response (eventually):
 *   See CommandRequestLink
*/
const uint8_t CommandStartLink = 0x10 | MaskBroadcastCommand;


/*
 * Request link:
 *   Sent by a module when user input is provided to link this module
 *   as the next in line. All other modules should disable sending this
 *   message until the currently requesting module receives a response.
 *
 *   The master must respond with the new module index, which the
 *   module must apply and store immediately.
 *
 * Request:
 *   [0]  CommandRequestLink
 *
 * Response:
 *   [0]  ResponseRequestLink
 *   [1]  New module index
*/
const uint8_t BaseRequestLink = 0x11;
const uint8_t CommandRequestLink = BaseRequestLink | MaskBroadcastCommand;
const uint8_t ResponseRequestLink = BaseRequestLink | MaskResponse;


/*
 * Stop linking:
 *   Broadcast to all modules when the master takes back control
 *   over the communication line. No response is expected.
 *
 * Request:
 *   [0]  CommandStopLink
*/
const uint8_t CommandStopLink = 0x12 | MaskBroadcastCommand;


/*
 * Set PWM value:
 *   Aimed at a specific module, which must apply the specified
 *   PWM values to the LED strips and respond with a
 *   ResponseSetPWM message.
 *
 * Request:
 *   [0]    CommandSetPWM
 *   [1]    Module index
 *   [2]    Flags, see below
 *   [3,4]  PWM value for step 1 (0-4095, uint16_t)
 *   [5,6]  PWM value for step 2 (0-4095, uint16_t)
 *
 * Response:
 *   [0]    ResponseSetPWM
 *   [1]    Module index
*/
const uint8_t BaseSetPWM = 0x20;
const uint8_t CommandSetPWM = BaseSetPWM | MaskModuleCommand;
const uint8_t ResponseSetPWM = BaseSetPWM | MaskResponse;

// If included, the on-board verification LEDs should light up with
// the specified PWM values as well. Otherwise they should be off.
const uint8_t SetPWMFlagModuleLEDs = 0x01;


/*
 * Get sensor values:
 *   Aimed at a specific module, which must response with a
 *   ResponseGetSensors message containing the current sensor states.
 *
 * Request:
 *   [0]    CommandGetSensors
 *   [1]    Module index
 *
 * Response:
 *   [0]    ResponseGetSensors
 *   [1]    Module index
 *   [2]    Analog (0-255) or digital (0, 255) value for sensor 1
 *   [3]    Analog (0-255) or digital (0, 255) value for sensor 2
*/
const uint8_t BaseGetSensors = 0x30;
const uint8_t CommandGetSensors = BaseGetSensors | MaskModuleCommand;
const uint8_t ResponseGetSensors = BaseGetSensors | MaskResponse;

#endif