File content as of revision 0:4eaf82806f06:

#include "TransferService.h"
#include "Logger.h"
#include "Configuration.h"

namespace Transfer {
// Transfer base UUID: ADC710C2-xxxx-4BF5-8244-3CEAAA0F87F5
#define transfer_UUID(x)   {0xAD, 0xC7, 0x10, 0xC2, (((x) & 0xFF00) >> 8), ((x) & 0xFF), 0x4B, 0xF5, 0x82, 0x44, 0x3C, 0xEA, 0xAA, 0x0F, 0x87, 0xF5}

// UUID byte arrays
static const uint8_t transferServiceUUID[]     = transfer_UUID(0xACDC);
static const uint8_t transferFileInfoUUID[]    = transfer_UUID(0xACDF);
static const uint8_t transferFileBlockUUID[16] = transfer_UUID(0xACE0);

// Storage for the value of the characteristics
struct fileInfo_t {
    uint16_t length;
    uint16_t crc16;
};
static struct fileInfo_t            fileInfo;
struct fileBlock_t {
    uint16_t blockNumber;
    uint8_t data[16];
};
static struct fileBlock_t           fileBlock;

// Other things needed for operation
static BLEDevice*                   ble;
static Timer                        downloadTimer;

static uint16_t expectingBlock = 0;

static bool acceptFile         = true; // additional condition whether to accept a file upload or not, currently always accept
static bool downloadInProgress = false; // indicates if we are downloading a file from the phone

static GattCharacteristic transferFileInfo(transferFileInfoUUID,
                                           (uint8_t *)&fileInfo,
                                           sizeof(fileInfo),
                                           sizeof(fileInfo),
                                           GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);

static GattCharacteristic transferFileBlock(transferFileBlockUUID,
                                            (uint8_t *)&fileBlock,
                                            sizeof(fileBlock_t),
                                            sizeof(fileBlock_t),
                                            GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE |
                                            GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE_WITHOUT_RESPONSE);

static GattCharacteristic *allChars[] = {&transferFileInfo, &transferFileBlock};
static GattService transferService(transferServiceUUID, allChars, sizeof(allChars) / sizeof(GattCharacteristic *));

void init(BLEDevice &bleDevice)
{
    downloadInProgress = false;
    ble                = &bleDevice;
    ble->addService(transferService);
    DEBUG("Added transfer service\r\n");
}

void reset()
{
    // reset internal state on new connection
    downloadInProgress = false;
}

const uint8_t *getServiceUUIDp()
{
    return transferServiceUUID;
}

void requestBlock(uint16_t); // prototype declaration
void sendFileInfo();
void refuseFile();
void sendFileDownloadedSuccessfully();

void handleDataWritten(uint16_t handle)
{
    if (!ble) {
        return;
    }

    if (handle == transferFileInfo.getHandle()) {
        uint16_t len = sizeof(fileInfo);
        ble->readCharacteristicValue(handle, (uint8_t *) &fileInfo, &len);

        if ((fileInfo.length == 0) && (fileInfo.crc16 == 0)) {
            // signal to cancel pending upload
            downloadInProgress = false;
            downloadTimer.reset();
            expectingBlock = 0;
            DEBUG("Download RESET\r\n");
            return;
        }

        DEBUG("Offered file len=%d, crc=0x%04x, acceptFile=%d, downloadInProgress=%d\r\n", fileInfo.length, fileInfo.crc16, acceptFile, downloadInProgress);

        // Now we must decide whether to accept it or not
        if (acceptFile && !downloadInProgress) {
            downloadTimer.reset();
            downloadTimer.start();
            downloadInProgress = true;
            requestBlock(0);
        } else {
            refuseFile();
        }
    } else if (handle == transferFileBlock.getHandle()) {
        uint16_t len = sizeof(fileBlock);
        ble->readCharacteristicValue(handle, (uint8_t *) &fileBlock, &len);

        // DEBUG("received blk %u (total %u): ", fileBlock.blockNumber, fileInfo.length / Config::blockSize);
        // uint8_t byte;
        // for (int i = 2; i < len; i++) {
        //     byte = *(((uint8_t*) &fileBlock) + i);
        //     DEBUG("%02x ", byte);
        // }
        // DEBUG("\r\n");

        if (fileBlock.blockNumber != expectingBlock) {
            DEBUG("Expected blk %d, not %d!\r\n", expectingBlock, fileBlock.blockNumber);
            requestBlock(expectingBlock);
            return;
        } else {
            // DEBUG("."); // one dot = one successfully received packet
        }

        if (fileBlock.blockNumber > (fileInfo.length / Config::blockSize)) {
            DEBUG("Error: block %d is out of range\r\n", fileBlock.blockNumber);
            return;
        }

        // "processing" step disabled
        //uint16_t offset = fileBlock.blockNumber * Config::blockSize;
        //memcpy(downloadLocation, fileBlock[0].data, Config::blockSize);

        // request next block if needed
        uint16_t nextBlock = fileBlock.blockNumber + 1;
        if (nextBlock <= fileInfo.length / Config::blockSize) {
            requestBlock(nextBlock);
        } else {
            sendFileDownloadedSuccessfully();
        }
    } else {
        DEBUG("Got data on unexpected characteristic handle %u!\r\n", handle);
    }
}

void requestBlock(uint16_t blockNumber)
{
    // Requesting a block by sending notification is disabled for speed
    //ble->updateCharacteristicValue(transferFileBlocks[0].getHandle(), (uint8_t*) &blockNumber, sizeof(blockNumber), false);
    //DEBUG("BlockReq %d --> PHONE\r\n", blockNumber);
    expectingBlock = blockNumber;
}

void sendFileInfo(uint32_t value)
{
    // refusal is indicated by sending a fileInfo with all zeros
    ble->updateCharacteristicValue(transferFileInfo.getHandle(), (uint8_t *) &value, sizeof(value), false);
}

void refuseFile()
{
    sendFileInfo(0);
}

void sendFileDownloadedSuccessfully()
{
    sendFileInfo(1);
    downloadInProgress = false;
    downloadTimer.stop();
    DEBUG("File transfer took %0.1f sec\r\n", downloadTimer.read());
}
} // namespace transfer