/*
 *  mms_client_journals.c
 *
 *  Copyright 2016 Michael Zillgith
 *
 *  This file is part of libIEC61850.
 *
 *  libIEC61850 is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  libIEC61850 is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with libIEC61850.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  See COPYING file for the complete license text.
 */

#include "libiec61850_platform_includes.h"
#include "stack_config.h"
#include "mms_common.h"
#include "mms_client_connection.h"
#include "byte_buffer.h"

#include "mms_client_internal.h"
#include "ber_encoder.h"
#include "ber_decode.h"
#include "conversions.h"
#include "mms_value_internal.h"

//TODO add event-based API to parse journal entries

static bool
parseJournalVariable(uint8_t* buffer, int bufPos, int maxLength, MmsJournalVariable journalVariable)
{
    int maxBufPos = bufPos + maxLength;

    while (bufPos < maxBufPos) {

        uint8_t tag = buffer[bufPos++];

        int length;

        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

        if  ((bufPos < 0) || ((bufPos + length) > maxBufPos)) { /* check length field for validity */
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

            return false;
        }

        switch (tag) {
        case 0x80: /* variableTag */

            if (journalVariable->tag == NULL) {
                journalVariable->tag = (char*) GLOBAL_MALLOC(length + 1);
                memcpy(journalVariable->tag, buffer + bufPos, length);
                journalVariable->tag[length] = 0;
            }

            break;

        case 0xa1: /* valueSpec */

            if (journalVariable->value == NULL) {
                journalVariable->value = MmsValue_decodeMmsData(buffer, bufPos, length, NULL);
            }

            break;

        default:
            break;

        }

        bufPos += length;
    }

    return true;
}

static bool
parseJournalVariables(uint8_t* buffer, int bufPos, int maxLength, MmsJournalEntry journalEntry)
{
    int maxBufPos = bufPos + maxLength;

    while (bufPos < maxBufPos) {

        int length;
        uint8_t tag = buffer[bufPos++];
        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

        if ((bufPos < 0) || ((bufPos + length) > maxBufPos)) { /* check length field for validity */
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

            return false;
        }

        MmsJournalVariable journalVariable;

        switch (tag) {
        case 0x30: /* journalVariable */

            journalVariable = (MmsJournalVariable)
                GLOBAL_CALLOC(1, sizeof(struct sMmsJournalVariable));

            parseJournalVariable(buffer, bufPos, length, journalVariable);

            LinkedList_add(journalEntry->journalVariables, (void*) journalVariable);

            break;

        default:
            break;

        }

        bufPos += length;
    }

    return true;
}

static bool
parseData(uint8_t* buffer, int bufPos, int maxLength, MmsJournalEntry journalEntry)
{
    int maxBufPos = bufPos + maxLength;

    while (bufPos < maxBufPos) {

        int length;
        uint8_t tag = buffer[bufPos++];
        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

        if ((bufPos < 0) || ((bufPos + length) > maxBufPos)) { /* check length field for validity */
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

            return false;
        }

        switch (tag) {
        case 0xa1: /* journalVariables */

            journalEntry->journalVariables = LinkedList_create();

            parseJournalVariables(buffer, bufPos, length, journalEntry);

            break;

        default:
            break;

        }

        bufPos += length;
    }

    return true;
}

static bool
parseEntryContent(uint8_t* buffer, int bufPos, int maxLength, MmsJournalEntry journalEntry)
{
    int maxBufPos = bufPos + maxLength;

    while (bufPos < maxBufPos) {

       int length;
       uint8_t tag = buffer[bufPos++];
       bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

       if ((bufPos < 0) ||((bufPos + length) > maxBufPos)) { /* check length field for validity */
           if (DEBUG_MMS_CLIENT)
               printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

           return false;
       }

       switch (tag) {
       case 0x80: /* occurenceTime */
           if (length == 6)
               journalEntry->occurenceTime = MmsValue_newBinaryTime(false);
           else if (length == 4)
               journalEntry->occurenceTime = MmsValue_newBinaryTime(true);
           else
               break;

           memcpy(journalEntry->occurenceTime->value.binaryTime.buf, buffer + bufPos, length);

           break;

       case 0xa2: /* data */

           parseData(buffer, bufPos, length, journalEntry);

           break;

       default:
           if (DEBUG_MMS_CLIENT)
               printf("MMS_CLIENT: parseReadJournalResponse: ignore unknown tag %02x\n", tag);
           break;
       }

       bufPos += length;
    }

    return true;
}

static bool
parseJournalEntry(uint8_t* buffer, int bufPos, int maxLength, LinkedList journalEntries)
{
    int maxBufPos = bufPos + maxLength;

    MmsJournalEntry journalEntry = (MmsJournalEntry) GLOBAL_CALLOC(1, sizeof(struct sMmsJournalEntry));
    LinkedList_add(journalEntries, (void*) journalEntry);

    while (bufPos < maxBufPos) {

        int length;
        uint8_t tag = buffer[bufPos++];
        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

        if ((bufPos + length) > maxBufPos) { /* check length field for validity */
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

            return false;
        }

        switch (tag) {

        case 0x80: /* entryID */
            journalEntry->entryID = MmsValue_newOctetString(length, length);
            MmsValue_setOctetString(journalEntry->entryID, buffer + bufPos, length);
            break;

        case 0xa1: /* originatingApplication */
            /* ignore */
            break;

        case 0xa2: /* entryContent */
            if (parseEntryContent(buffer, bufPos, length, journalEntry) == false)
                return false;

            break;

        default:
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: unknown tag %02x\n", tag);

            return false;
        }

        bufPos += length;
    }

    return true;
}

static bool
parseListOfJournalEntries(uint8_t* buffer, int bufPos, int maxLength, LinkedList journalEntries)
{
    int maxBufPos = bufPos + maxLength;


    while (bufPos < maxBufPos) {

        int length;
        uint8_t tag = buffer[bufPos++];
        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);

        if ((bufPos < 0) || ((bufPos + length) > maxBufPos)) { /* check length field for validity */
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: invalid length field\n");

            return false;
        }

        switch (tag) {
        case 0x30:
            if (parseJournalEntry(buffer, bufPos, length, journalEntries) == false)
                return false;
            break;

        default:
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: parseReadJournalResponse: unknown tag %02x\n", tag);

            return false;
        }

        bufPos += length;
    }

    return true;
}

bool
mmsClient_parseReadJournalResponse(MmsConnection self, bool* moreFollows, LinkedList* result)
{
    uint8_t* buffer = self->lastResponse->buffer;
    int maxBufPos = self->lastResponse->size;
    int bufPos = self->lastResponseBufPos;
    int length;

    uint8_t tag = buffer[bufPos++];

    if (tag != 0xbf) {
        if (DEBUG_MMS_CLIENT)
            printf("MMS_CLIENT: mmsClient_parseReadJournalResponse: unknown tag %02x\n", tag);
        return false;
    }

    tag = buffer[bufPos++];

    if (moreFollows)
        *moreFollows = false;

    if (tag != 0x41) {
        if (DEBUG_MMS_CLIENT)
            printf("MMS_CLIENT: mmsClient_parseReadJournalResponse: unknown tag %02x\n", tag);
        return false;
    }

    bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);
    if (bufPos < 0) return false;

    int endPos = bufPos + length;

    if (endPos > maxBufPos) {
        if (DEBUG_MMS_CLIENT)
            printf("MMS_CLIENT: mmsClient_parseReadJournalResponse: message to short (length:%i maxBufPos:%i)!\n", length, maxBufPos);
        return false;
    }

    LinkedList journalEntries = NULL;

    while (bufPos < endPos) {
        tag = buffer[bufPos++];
        bufPos = BerDecoder_decodeLength(buffer, &length, bufPos, maxBufPos);
        if (bufPos < 0) return false;

        switch (tag) {
        case 0xa0: /* listOfJournalEntry */
            journalEntries = LinkedList_create();

            if (!parseListOfJournalEntries(buffer, bufPos, length, journalEntries))
                return false;
            break;

        case 0x81: /* moreFollows */
            if (moreFollows)
                *moreFollows = BerDecoder_decodeBoolean(buffer, bufPos);
            break;

        default:
            if (DEBUG_MMS_CLIENT)
                printf("MMS_CLIENT: mmsClient_parseReadJournalResponse: message contains unknown tag %02x!\n", tag);

            return false;
        }

        bufPos += length;
    }

    *result = journalEntries;

    return true;
}

void
mmsClient_createReadJournalRequestWithTimeRange(uint32_t invokeId, ByteBuffer* request, const char* domainId, const char* itemId,
        MmsValue* startingTime, MmsValue* endingTime)
{
    /* calculate sizes */
    uint32_t invokeIdSize = BerEncoder_UInt32determineEncodedSize(invokeId);

    uint32_t domainIdStringSize = strlen(domainId);
    uint32_t domainIdSize = 1 + BerEncoder_determineLengthSize(domainIdStringSize) + domainIdStringSize;

    uint32_t itemIdStringSize = strlen(itemId);
    uint32_t itemIdSize = 1 + BerEncoder_determineLengthSize(itemIdStringSize) + itemIdStringSize;

    uint32_t objectIdSize = domainIdSize + itemIdSize;

    uint32_t journalNameSize =  1 + BerEncoder_determineLengthSize(objectIdSize) + (objectIdSize);

    uint32_t startingTimeSize = 2 + startingTime->value.binaryTime.size;

    uint32_t rangeStartSpecSize = 2 + startingTimeSize;

    uint32_t endingTimeSize = 2 + endingTime->value.binaryTime.size;

    uint32_t rangeEndSpecSize = 2 + endingTimeSize;

    uint32_t journalReadContentSize = journalNameSize + rangeStartSpecSize + rangeEndSpecSize;

    uint32_t journalReadSize = 1 + BerEncoder_determineLengthSize(journalReadContentSize) + (journalReadContentSize);

    uint32_t confirmedRequestPduSize = 1 + 2 + 2  + invokeIdSize + journalReadSize;

    /* encode to buffer */
    int bufPos = 0;
    uint8_t* buffer = request->buffer;

    bufPos = BerEncoder_encodeTL(0xa0, confirmedRequestPduSize, buffer, bufPos);
    bufPos = BerEncoder_encodeTL(0x02, invokeIdSize, buffer, bufPos);
    bufPos = BerEncoder_encodeUInt32(invokeId, buffer, bufPos);

    /* encode read journal tag (context | structured ) [65 = 41h] */
    buffer[bufPos++] = 0xbf;
    buffer[bufPos++] = 0x41;

    bufPos = BerEncoder_encodeLength(journalReadSize, buffer, bufPos);

    /* encode journalName */
    bufPos = BerEncoder_encodeTL(0xa0, journalNameSize, buffer, bufPos);

    bufPos = BerEncoder_encodeTL(0xa1, objectIdSize, buffer, bufPos);

    bufPos = BerEncoder_encodeOctetString(0x1a, (uint8_t*) domainId, domainIdStringSize, buffer, bufPos);
    bufPos = BerEncoder_encodeOctetString(0x1a, (uint8_t*) itemId, itemIdStringSize, buffer, bufPos);

    /* encode rangeStartSpecification|startingTime */
    bufPos = BerEncoder_encodeTL(0xa1, startingTimeSize, buffer, bufPos);
    bufPos = BerEncoder_encodeOctetString(0x80, startingTime->value.binaryTime.buf,
            startingTime->value.binaryTime.size, buffer, bufPos);

    /* encode rangeStopSpecification|endingTime */
    bufPos = BerEncoder_encodeTL(0xa2, endingTimeSize, buffer, bufPos);
    bufPos = BerEncoder_encodeOctetString(0x80, endingTime->value.binaryTime.buf,
            endingTime->value.binaryTime.size, buffer, bufPos);

    request->size = bufPos;
}

void
mmsClient_createReadJournalRequestStartAfter(uint32_t invokeId, ByteBuffer* request, const char* domainId, const char* itemId,
        MmsValue* timeSpecification, MmsValue* entrySpecification)
{
    /* calculate sizes */
    uint32_t invokeIdSize = BerEncoder_UInt32determineEncodedSize(invokeId);

    uint32_t domainIdStringSize = strlen(domainId);
    uint32_t domainIdSize = 1 + BerEncoder_determineLengthSize(domainIdStringSize) + domainIdStringSize;

    uint32_t itemIdStringSize = strlen(itemId);
    uint32_t itemIdSize = 1 + BerEncoder_determineLengthSize(itemIdStringSize) + itemIdStringSize;

    uint32_t objectIdSize = domainIdSize + itemIdSize;

    uint32_t journalNameSize = 1 + BerEncoder_determineLengthSize(objectIdSize) + (objectIdSize);

    uint32_t timeSpecificationSize = 2 + timeSpecification->value.binaryTime.size;

    uint32_t entrySpecificationSize = 2 + entrySpecification->value.octetString.size;

    uint32_t entryToStartAfterContentSize = timeSpecificationSize + entrySpecificationSize;

    uint32_t entryToStartAfterSize =  1 + BerEncoder_determineLengthSize(entryToStartAfterContentSize)
            + entryToStartAfterContentSize;

    uint32_t journalReadContentSize = journalNameSize + entryToStartAfterSize;

    uint32_t journalReadSize = 1 + BerEncoder_determineLengthSize(journalReadContentSize) + (journalReadContentSize);

    uint32_t confirmedRequestPduSize = 1 + 2 + 2  + invokeIdSize + journalReadSize;

    /* encode to buffer */
    int bufPos = 0;
    uint8_t* buffer = request->buffer;

    bufPos = BerEncoder_encodeTL(0xa0, confirmedRequestPduSize, buffer, bufPos);
    bufPos = BerEncoder_encodeTL(0x02, invokeIdSize, buffer, bufPos);
    bufPos = BerEncoder_encodeUInt32(invokeId, buffer, bufPos);

    /* encode read journal tag (context | structured ) [65 = 41h] */
    buffer[bufPos++] = 0xbf;
    buffer[bufPos++] = 0x41;

    bufPos = BerEncoder_encodeLength(journalReadSize, buffer, bufPos);

    /* encode journalName */
    bufPos = BerEncoder_encodeTL(0xa0, journalNameSize, buffer, bufPos);

    bufPos = BerEncoder_encodeTL(0xa1, objectIdSize, buffer, bufPos);

    bufPos = BerEncoder_encodeOctetString(0x1a, (uint8_t*) domainId, domainIdStringSize, buffer, bufPos);
    bufPos = BerEncoder_encodeOctetString(0x1a, (uint8_t*) itemId, itemIdStringSize, buffer, bufPos);

    /* encode entryToStartAfter */
    bufPos = BerEncoder_encodeTL(0xa5, entryToStartAfterContentSize, buffer, bufPos);

    /* encode entryToStartAfter|timeSpecification */
    bufPos = BerEncoder_encodeOctetString(0x80, timeSpecification->value.binaryTime.buf,
            timeSpecification->value.binaryTime.size, buffer, bufPos);

    /* encode entryToStartAfter|entrySpecification */
    bufPos = BerEncoder_encodeOctetString(0x81, entrySpecification->value.octetString.buf,
            entrySpecification->value.octetString.size, buffer, bufPos);

    request->size = bufPos;
}