#include "StrImageLoader.h"

#include <fstream>
#include <filesystem>

StrImageLoader::StrImageLoader(object_id_t objectId) : SystemObject(objectId){

}

StrImageLoader::~StrImageLoader() {
}

ReturnValue_t StrImageLoader::initialize() {
    sdcMan = SdCardManager::instance();
    if (sdcMan == nullptr) {
        sif::warning << "StrImageLoader::initialize: Invalid SD Card Manager" << std::endl;
        return RETURN_FAILED;
    }
    return RETURN_OK;
}

ReturnValue_t StrImageLoader::performOperation(uint8_t operationCode) {
    ReturnValue_t result = RETURN_OK;
    semaphore.acquire();
    while(true) {
        switch(internalState) {
        case InternalState::IDLE: {
            semaphore.acquire();
            break;
        }
        case InternalState::UPLOAD_IMAGE: {
            result = performImageUpload();
            if (result == RETURN_OK){
                triggerEvent(IMAGE_UPLOAD_SUCCESSFUL);
            }
            internalState = InternalState::IDLE;
            break;
        }
        case InternalState::DOWNLOAD_IMAGE:
            result = performImageDownload();
            if (result == RETURN_OK){
                triggerEvent(IMAGE_DOWNLOAD_SUCCESSFUL);
            }
            internalState = InternalState::IDLE;
            break;
        }
    }
}

void StrImageLoader::setComIF(DeviceCommunicationIF* communicationInterface_) {
    communicationInterface = communicationInterface_;
}

void StrImageLoader::setComCookie(CookieIF* comCookie_) {
    comCookie = comCookie_;
}

ReturnValue_t StrImageLoader::startImageUpload(std::string image) {
    // Check if file is stored on SD card and if associated SD card is mounted
    if (image.substr(0, sizeof(SdCardManager::SD_0_MOUNT_POINT))
            == std::string(SdCardManager::SD_0_MOUNT_POINT)) {
        if (!sdcMan->isSdCardMounted(sd::SLOT_0)) {
            sif::warning << "StrImageLoader::getImageLocation: SD card 0 not mounted" << std::endl;
            return SD_NOT_MOUNTED;
        }
    } else if (image.substr(0, sizeof(SdCardManager::SD_1_MOUNT_POINT))
            == std::string(SdCardManager::SD_1_MOUNT_POINT)) {
        if (!sdcMan->isSdCardMounted(sd::SLOT_0)) {
            sif::warning << "StrImageLoader::getImageLocation: SD card 1 not mounted" << std::endl;
            return SD_NOT_MOUNTED;
        }
    }
    uploadImage = image;
    if(not std::filesystem::exists(uploadImage)) {
        return FILE_NOT_EXISTS;
    }
    internalState = InternalState::UPLOAD_IMAGE;
    semaphore.release();
    return RETURN_OK;
}

void StrImageLoader::startImageDownload(std::string downloadImage_) {
    downloadImage = downloadImage_;
    internalState = InternalState::DOWNLOAD_IMAGE;
    semaphore.release();
}

ReturnValue_t StrImageLoader::performImageDownload() {
    ReturnValue_t result;
    struct DownloadActionRequest downloadReq;
    uint32_t size = 0;
    std::ofstream file(downloadImage, std::ios_base::app | std::ios_base::out);
    while(downloadReq.position < LAST_POSITION) {
        arc_pack_download_action_req(&downloadReq, commandBuffer, &size);
        result = sendAndRead(size, downloadReq.position);
        if (result != RETURN_OK) {
            file.close();
            return result;
        }
        result = checkReply();
        if (result != RETURN_OK) {
            file.close();
            return result;
        }
        result = checkReplyPosition(downloadReq.position);
        if (result != RETURN_OK) {
            file.close();
            return result;
        }
        file.write(reinterpret_cast<const char*>(datalinkLayer.getReply() + DATA_OFFSET),
                IMAGE_DATA_SIZE);
        downloadReq.position++;
    }
    file.close();
    return RETURN_OK;
}

ReturnValue_t StrImageLoader::performImageUpload() {
    ReturnValue_t result = RETURN_OK;
    uint32_t size = 0;
    uint32_t imageSize = 0;
    struct UploadActionRequest uploadReq;
    uploadReq.position = 0;
    std::memset(&uploadReq.data, 0, sizeof(uploadReq.data));
    if (not std::filesystem::exists(uploadImage)) {
        triggerEvent(IMAGE_FILE_NOT_EXISTS, uploadReq.position);
        internalState = InternalState::IDLE;
        return RETURN_FAILED;
    }
    std::ifstream file(uploadImage, std::ifstream::binary);
    // Set position of next character to end of file input stream
    file.seekg(0, file.end);
    // tellg returns position of character in input stream
    imageSize = file.tellg();
    while((uploadReq.position + 1) * SIZE_IMAGE_PART < imageSize) {
        file.seekg(uploadReq.position * SIZE_IMAGE_PART, file.beg);
        file.read(reinterpret_cast<char*>(uploadReq.data), SIZE_IMAGE_PART);
        arc_pack_upload_action_req(&uploadReq, commandBuffer, &size);
        result = sendAndRead(size, uploadReq.position);
        if (result != RETURN_OK) {
            return RETURN_FAILED;
        }
        result = checkReply();
        if (result != RETURN_OK) {
            return result;
        }
        uploadReq.position++;
    }
    std::memset(uploadReq.data, 0, sizeof(uploadReq.data));
    uint32_t remainder = imageSize - uploadReq.position * SIZE_IMAGE_PART;
    file.seekg(uploadReq.position * SIZE_IMAGE_PART, file.beg);
    file.read(reinterpret_cast<char*>(uploadReq.data), remainder);
    file.close();
    uploadReq.position++;
    arc_pack_upload_action_req(&uploadReq, commandBuffer, &size);
    result = sendAndRead(size, uploadReq.position);
    if (result != RETURN_OK) {
        return RETURN_FAILED;
    }
    result = checkReply();
    if (result != RETURN_OK) {
        return result;
    }
    return RETURN_OK;
}

ReturnValue_t StrImageLoader::sendAndRead(size_t size, uint32_t position) {
    ReturnValue_t result = RETURN_OK;
    ReturnValue_t decResult = RETURN_OK;
    size_t receivedDataLen = 0;
    uint8_t *receivedData = nullptr;
    size_t bytesLeft = 0;
    uint32_t missedReplies = 0;
    datalinkLayer.encodeFrame(commandBuffer, size);
    result = communicationInterface->sendMessage(comCookie, datalinkLayer.getEncodedFrame(),
        datalinkLayer.getEncodedLength());
    if (result != RETURN_OK) {
        sif::warning << "StrImageLoader::sendAndRead: Failed to send packet" << std::endl;
        triggerEvent(IMG_LOADER_SENDING_PACKET_FAILED, result, position);
        return RETURN_FAILED;
    }
    decResult = ArcsecDatalinkLayer::DEC_IN_PROGRESS;
    while (decResult == ArcsecDatalinkLayer::DEC_IN_PROGRESS) {
        result = communicationInterface->requestReceiveMessage(comCookie,
                StarTracker::MAX_FRAME_SIZE * 2 + 2);
        if (result != RETURN_OK) {
            sif::warning << "StrImageLoader::sendAndRead: Failed to request reply" << std::endl;
            triggerEvent(IMG_LOADER_REQUESTING_MSG_FAILED, result, position);
            return RETURN_FAILED;
        }
        result = communicationInterface->readReceivedMessage(comCookie, &receivedData, &receivedDataLen);
        if (result != RETURN_OK) {
            sif::warning << "StrImageLoader::sendAndRead: Failed to read received message" << std::endl;
            triggerEvent(IMG_LOADER_READING_REPLY_FAILED, result, position);
            return RETURN_FAILED;
        }
        if (receivedDataLen == 0 && missedReplies < MAX_POLLS) {
            missedReplies++;
            continue;
        }
        else if ((receivedDataLen == 0) && (missedReplies >= MAX_POLLS)) {
            triggerEvent(IMG_LOADER_NO_REPLY, position);
            return RETURN_FAILED;
        }
        else {
            missedReplies = 0;
        }
        decResult = datalinkLayer.decodeFrame(receivedData, receivedDataLen, &bytesLeft);
        if (bytesLeft != 0) {
            // This should never happen
            sif::warning << "StrImageLoader::sendAndRead: Bytes left after decoding" << std::endl;
            triggerEvent(IMG_LOADER_COM_ERROR, result, position);
            return RETURN_FAILED;
        }
    }
    if (decResult != RETURN_OK) {
        triggerEvent(IMG_LOADER_DEC_ERROR, decResult, position);
        return RETURN_FAILED;
    }
    return RETURN_OK;
}

ReturnValue_t StrImageLoader::checkReply() {
    uint8_t type = datalinkLayer.getReplyFrameType();
    if (type != TMTC_ACTIONREPLY) {
        sif::warning << "StrImageLoader::checkUploadReply: Received reply with invalid type ID"
                << std::endl;
        triggerEvent(INVALID_TYPE_ID);
        return RETURN_FAILED;
    }
    uint8_t status = datalinkLayer.getStatusField();
    if (status != ArcsecDatalinkLayer::STATUS_OK) {
        triggerEvent(STATUS_ERROR);
        sif::warning << "StrImageLoader::checkUploadReply: Status failure" << std::endl;
        return RETURN_FAILED;
    }
    return RETURN_OK;
}

ReturnValue_t StrImageLoader::checkReplyPosition(uint32_t expectedPosition) {
    uint32_t receivedPosition = 0;
    std::memcpy(&receivedPosition, datalinkLayer.getReply() + POS_OFFSET, sizeof(receivedPosition));
    if (receivedPosition != expectedPosition) {
        triggerEvent(POSITION_MISMATCH, receivedPosition);
        return RETURN_FAILED;
    }
    return RETURN_OK;
}