#include "Limelight-internal.h"

#define MAX_OPTION_NAME_LEN 128

#define MAX_SDP_HEADER_LEN 128
#define MAX_SDP_TAIL_LEN 128

typedef struct _SDP_OPTION {
	char name[MAX_OPTION_NAME_LEN+1];
	void* payload;
	int payloadLen;
	struct _SDP_OPTION *next;
} SDP_OPTION, *PSDP_OPTION;

/* Cleanup the attribute list */
static void freeAttributeList(PSDP_OPTION head) {
	PSDP_OPTION next;
	while (head != NULL) {
		next = head->next;
		free(head);
		head = next;
	}
}

/* Get the size of the attribute list */
static int getSerializedAttributeListSize(PSDP_OPTION head) {
	PSDP_OPTION currentEntry = head;
	size_t size = 0;
	while (currentEntry != NULL) {
		size += strlen("a=");
		size += strlen(currentEntry->name);
		size += strlen(":");
		size += currentEntry->payloadLen;
		size += strlen(" \r\n");

		currentEntry = currentEntry->next;
	}
	return (int)size;
}

/* Populate the serialized attribute list into a string */
static int fillSerializedAttributeList(char* buffer, PSDP_OPTION head) {
	PSDP_OPTION currentEntry = head;
	int offset = 0;
	while (currentEntry != NULL) {
		offset += sprintf(&buffer[offset], "a=%s:", currentEntry->name);
		memcpy(&buffer[offset], currentEntry->payload, currentEntry->payloadLen);
		offset += currentEntry->payloadLen;
		offset += sprintf(&buffer[offset], " \r\n");

		currentEntry = currentEntry->next;
	}
	return offset;
}

/* Add an attribute */
static int addAttributeBinary(PSDP_OPTION *head, char* name, const void* payload, int payloadLen) {
	PSDP_OPTION option, currentOption;

	option = malloc(sizeof(*option) + payloadLen);
	if (option == NULL) {
		return -1;
	}

	option->next = NULL;
	option->payloadLen = payloadLen;
	strcpy(option->name, name);
	option->payload = (void*)(option + 1);
	memcpy(option->payload, payload, payloadLen);

	if (*head == NULL) {
		*head = option;
	}
	else {
		currentOption = *head;
		while (currentOption->next != NULL) {
			currentOption = currentOption->next;
		}
		currentOption->next = option;
	}

	return 0;
}

/* Add an attribute string */
static int addAttributeString(PSDP_OPTION *head, char* name, const char* payload) {
	// We purposefully omit the null terminating character
	return addAttributeBinary(head, name, payload, (int)strlen(payload));
}

static int addGen3Options(PSDP_OPTION *head, char* addrStr) {
    int payloadInt;
    int err = 0;
    
    err |= addAttributeString(head, "x-nv-general.serverAddress", addrStr);
    
    payloadInt = htonl(0x42774141);
    err |= addAttributeBinary(head,
                              "x-nv-general.featureFlags", &payloadInt, sizeof(payloadInt));

    
    payloadInt = htonl(0x41514141);
    err |= addAttributeBinary(head,
                              "x-nv-video[0].transferProtocol", &payloadInt, sizeof(payloadInt));
    err |= addAttributeBinary(head,
                              "x-nv-video[1].transferProtocol", &payloadInt, sizeof(payloadInt));
    err |= addAttributeBinary(head,
                              "x-nv-video[2].transferProtocol", &payloadInt, sizeof(payloadInt));
    err |= addAttributeBinary(head,
                              "x-nv-video[3].transferProtocol", &payloadInt, sizeof(payloadInt));
    
    payloadInt = htonl(0x42414141);
    err |= addAttributeBinary(head,
                              "x-nv-video[0].rateControlMode", &payloadInt, sizeof(payloadInt));
    payloadInt = htonl(0x42514141);
    err |= addAttributeBinary(head,
                              "x-nv-video[1].rateControlMode", &payloadInt, sizeof(payloadInt));
    err |= addAttributeBinary(head,
                              "x-nv-video[2].rateControlMode", &payloadInt, sizeof(payloadInt));
    err |= addAttributeBinary(head,
                              "x-nv-video[3].rateControlMode", &payloadInt, sizeof(payloadInt));
    
    err |= addAttributeString(head, "x-nv-vqos[0].bw.flags", "14083");
    
    err |= addAttributeString(head, "x-nv-vqos[0].videoQosMaxConsecutiveDrops", "0");
    err |= addAttributeString(head, "x-nv-vqos[1].videoQosMaxConsecutiveDrops", "0");
    err |= addAttributeString(head, "x-nv-vqos[2].videoQosMaxConsecutiveDrops", "0");
    err |= addAttributeString(head, "x-nv-vqos[3].videoQosMaxConsecutiveDrops", "0");
    
    return err;
}

static int addGen4Options(PSDP_OPTION *head, char* addrStr) {
    char payloadStr[92];
    int err = 0;
    
    sprintf(payloadStr, "rtsp://%s:48010", addrStr);
    err |= addAttributeString(head, "x-nv-general.serverAddress", payloadStr);
    
    err |= addAttributeString(head, "x-nv-video[0].rateControlMode", "4");
    
    // Use slicing for increased performance on some decoders
    err |= addAttributeString(head, "x-nv-video[0].videoEncoderSlicesPerFrame", "4");
    
    return err;
}

static PSDP_OPTION getAttributesList(char *urlSafeAddr) {
	PSDP_OPTION optionHead;
	char payloadStr[92];
	int err;

	optionHead = NULL;
	err = 0;

	sprintf(payloadStr, "%d", StreamConfig.width);
	err |= addAttributeString(&optionHead, "x-nv-video[0].clientViewportWd", payloadStr);
	sprintf(payloadStr, "%d", StreamConfig.height);
	err |= addAttributeString(&optionHead, "x-nv-video[0].clientViewportHt", payloadStr);

	sprintf(payloadStr, "%d", StreamConfig.fps);
	err |= addAttributeString(&optionHead, "x-nv-video[0].maxFPS", payloadStr);
    
    sprintf(payloadStr, "%d", StreamConfig.packetSize);
    err |= addAttributeString(&optionHead, "x-nv-video[0].packetSize", payloadStr);

	err |= addAttributeString(&optionHead, "x-nv-video[0].rateControlMode", "4");
    
    // FIXME: Remote optimizations
    if (StreamConfig.bitrate <= 13000) {
        err |= addAttributeString(&optionHead, "x-nv-video[0].averageBitrate", "9");
        err |= addAttributeString(&optionHead, "x-nv-video[0].peakBitrate", "9");
    }

	err |= addAttributeString(&optionHead, "x-nv-video[0].timeoutLengthMs", "7000");
	err |= addAttributeString(&optionHead, "x-nv-video[0].framesWithInvalidRefThreshold", "0");
    
    // Lock the bitrate since we're not scaling resolution so the picture doesn't get too bad
    if (StreamConfig.height >= 1080 && StreamConfig.fps >= 60) {
        if (StreamConfig.bitrate < 10000) {
            sprintf(payloadStr, "%d", StreamConfig.bitrate);
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", payloadStr);
        }
        else {
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", "10000");
        }
    }
    else if (StreamConfig.height >= 1080 || StreamConfig.fps >= 60) {
        if (StreamConfig.bitrate < 7000) {
            sprintf(payloadStr, "%d", StreamConfig.bitrate);
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", payloadStr);
        }
        else {
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", "7000");
        }
    }
    else {
        if (StreamConfig.bitrate < 3000) {
            sprintf(payloadStr, "%d", StreamConfig.bitrate);
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", payloadStr);
        }
        else {
            err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.minimumBitrate", "3000");
        }
    }

	sprintf(payloadStr, "%d", StreamConfig.bitrate);
	err |= addAttributeString(&optionHead, "x-nv-vqos[0].bw.maximumBitrate", payloadStr);

    // Using FEC turns padding on which makes us have to take the slow path
    // in the depacketizer, not to mention exposing some ambiguous cases with
    // distinguishing padding from valid sequences. Since we can only perform
    // execute an FEC recovery on a 1 packet frame, we'll just turn it off completely.
    err |= addAttributeString(&optionHead, "x-nv-vqos[0].fec.enable", "0");

	err |= addAttributeString(&optionHead, "x-nv-vqos[0].videoQualityScoreUpdateTime", "5000");
    
    // FIXME: Remote optimizations
	err |= addAttributeString(&optionHead, "x-nv-vqos[0].qosTrafficType", "5");
	err |= addAttributeString(&optionHead, "x-nv-aqos.qosTrafficType", "4");
    
    if (ServerMajorVersion == 3) {
        err |= addGen3Options(&optionHead, urlSafeAddr);
    }
    else {
        err |= addGen4Options(&optionHead, urlSafeAddr);
    }

	if (err == 0) {
		return optionHead;
	}

	freeAttributeList(optionHead);
	return NULL;
}

/* Populate the SDP header with required information */
static int fillSdpHeader(char* buffer, int rtspClientVersion, char *urlSafeAddr) {
	return sprintf(buffer,
		"v=0\r\n"
		"o=android 0 %d IN %s %s\r\n"
		"s=NVIDIA Streaming Client\r\n",
                   rtspClientVersion,
                   RemoteAddr.ss_family == AF_INET ? "IPv4" : "IPv6",
                   urlSafeAddr);
}

/* Populate the SDP tail with required information */
static int fillSdpTail(char* buffer) {
	return sprintf(buffer,
		"t=0 0\r\n"
		"m=video %d  \r\n",
                   ServerMajorVersion < 4 ? 47996 : 47998);
}

/* Get the SDP attributes for the stream config */
char* getSdpPayloadForStreamConfig(int rtspClientVersion, int *length) {
	PSDP_OPTION attributeList;
	int offset;
	char* payload;
    char urlSafeAddr[URLSAFESTRING_LEN];
    
    addrToUrlSafeString(&RemoteAddr, urlSafeAddr);

	attributeList = getAttributesList(urlSafeAddr);
	if (attributeList == NULL) {
		return NULL;
	}

	payload = malloc(MAX_SDP_HEADER_LEN + MAX_SDP_TAIL_LEN +
		getSerializedAttributeListSize(attributeList));
	if (payload == NULL) {
		freeAttributeList(attributeList);
		return NULL;
	}

	offset = fillSdpHeader(payload, rtspClientVersion, urlSafeAddr);
	offset += fillSerializedAttributeList(&payload[offset], attributeList);
	offset += fillSdpTail(&payload[offset]);

	freeAttributeList(attributeList);
	*length = offset;
	return payload;
}