#include <memory.h>
#include <malloc.h>
#include "AVRInterface.h"

//AVRInterface::AVRInterface(int (*SendMessage)(const void *buffer, unsigned int bufferSize)) {
//}
AVRInterface::~AVRInterface() {
	FreeMemory();
}

void AVRInterface::Tick(uint32_t now_ms) {
	uint32_t elapsed_ms = now_ms - sentAtTime_ms;

	switch (state) {
	default:
	case AVRState_T::stPoweringUp:
		readyResponsReceived = false;
		ProcessSerialQueue((uint8_t *)"\x11" "000" "\x03", 5);		// Send the Ready Command
		sentAtTime_ms = now_ms;
		readyTries++;
		state = stAwaitingReadyResponse;
		break;
	case stAwaitingReadyResponse:
		if (readyResponsReceived) {
			state = stReady;
		} else if (elapsed_ms > RETRY_INTERVAL_ms) {
			if (readyTries > MAXTRIES) {
				// fail

			} else {
				state = stPoweringUp;
			}
		}
		break;
	case AVRState_T::stInitializing:
		break;
	case AVRState_T::stRetryInitializing:
		break;
	case AVRState_T::stAwaitingResponse:
		break;
	case AVRState_T::stReady:
		ProcessSerialQueue();
		break;
	}
}

bool AVRInterface::HandleMessage(const uint8_t *buffer, uint16_t len) {
	switch (state) {
	case stAwaitingReadyResponse:
		switch (buffer[0]) {
		case 0x02:	// STX <msg> ETX
			break;
		case 0x11:	// DC1 <msg> ETX
			break;
		case 0x12:	// DC2 <msg> ETX
			if (CheckTheChecksum(buffer, len)) {
				readyResponsReceived = true;
			}
			break;
		case 0x14:	// DC4 <extended response> ETX
			break;
		default:
			break;
		}
		readyResponsReceived = true;
		break;
	case stReady:
		break;
	}
	return true;
}

bool AVRInterface::Initialize() {
	return true;
}

bool AVRInterface::IsOnline() {
	return true;
}
bool AVRInterface::Power(AVRPower_T cmd) {
	return true;
}

bool AVRInterface::MasterVolumeButton(AVRVolumeButton_T cmd) {
	return true;
}
bool AVRInterface::Mute(AVRMute_T cmd) {
	return true;
}

bool AVRInterface::ProcessSerialQueue(const uint8_t *p, uint16_t len) {
	bool retVal = false;	// assume fail
	static bool freshData = false;

	if (p && len) {
		if (serialQueueCount < SERIALQUEUESIZE) {
			serialQueue[serialQueueCount].messageToSend = (uint8_t *)malloc(len);
			if (serialQueue[serialQueueCount].messageToSend) {
				memcpy(serialQueue[serialQueueCount].messageToSend, p, len);
				serialQueue[serialQueueCount].len = len;
				serialQueueCount++;
				retVal = true;
				freshData = true;
			}
		}
	}
	if (serialQueueCount) {
		if ((*SendMethod)((const uint8_t *)serialQueue[0].messageToSend, serialQueue[0].len)) {
			--serialQueueCount;
			free(serialQueue[0].messageToSend);
			serialQueue[0].messageToSend = NULL;
			for (int i = 0; i < serialQueueCount; i++) {
				serialQueue[i] = serialQueue[i + 1];
			}
			retVal = true;
		}
	}
	return retVal;
}

void AVRInterface::FreeMemory() {
	for (int i = 0; i < serialQueueCount; i++) {
		if (serialQueue[0].messageToSend)
			free(serialQueue[0].messageToSend);
	}
}


bool AVRInterface::CheckTheChecksum(const uint8_t *szBuffer, uint32_t num) {
	uint8_t sum = 0;
	for (uint16_t i = 1; i < num - 3; i++) {
		sum += szBuffer[i];
	}
	uint8_t cksum = (uint8_t)Hex2Dec(&szBuffer[num - 3], 2);
	//printf("CheckSum: %02X v. %c%c\n", sum, szBuffer[num - 3], szBuffer[num - 2]);
	return (sum == cksum);
}

// Hex2Dec
//
//	All responses are pretty much Hex-ASCII, so
//	we sometimes want to convert it to decimal
//	This takes a buffer and converts the specified
//	number of characters.
//
unsigned long AVRInterface::Hex2Dec(const uint8_t *p, int dig) {
	unsigned long x = 0;
	while (dig--) {
		if (*p >= '0' && *p <= '9')
			x = x * 16 + *p - '0';
		else if (*p >= 'a' && *p <= 'f')
			x = x * 16 + 0x0a + *p - 'a';
		else if (*p >= 'A' && *p <= 'F')
			x = x * 16 + 0x0a + *p - 'A';
		p++;
	}
	return x;
}