#include "MeshBluetoothService.h"
#include "BluetoothUtil.h"
#include <Arduino.h>
#include <BLE2902.h>
#include <assert.h>
#include <esp_gatt_defs.h>

#include "CallbackCharacteristic.h"
#include "MeshService.h"
#include "NodeDB.h"
#include "PowerFSM.h"
#include "configuration.h"
#include "mesh-pb-constants.h"
#include "mesh.pb.h"

#include "GPS.h"

// This scratch buffer is used for various bluetooth reads/writes - but it is safe because only one bt operation can be in
// proccess at once
static uint8_t trBytes[_max(_max(_max(_max(ToRadio_size, RadioConfig_size), User_size), MyNodeInfo_size), FromRadio_size)];

class ProtobufCharacteristic : public CallbackCharacteristic
{
    const pb_msgdesc_t *fields;
    void *my_struct;

  public:
    ProtobufCharacteristic(const char *uuid, uint32_t btprops, const pb_msgdesc_t *_fields, void *_my_struct)
        : CallbackCharacteristic(uuid, btprops), fields(_fields), my_struct(_my_struct)
    {
        setCallbacks(this);
    }

    void onRead(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onRead(c);
        size_t numbytes = pb_encode_to_bytes(trBytes, sizeof(trBytes), fields, my_struct);
        DEBUG_MSG("pbread from %s returns %d bytes\n", c->getUUID().toString().c_str(), numbytes);
        c->setValue(trBytes, numbytes);
    }

    void onWrite(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onWrite(c);
        writeToDest(c, my_struct);
    }

  protected:
    /// like onWrite, but we provide an different destination to write to, for use by subclasses that
    /// want to optionally ignore parts of writes.
    /// returns true for success
    bool writeToDest(BLECharacteristic *c, void *dest)
    {
        // dumpCharacteristic(pCharacteristic);
        std::string src = c->getValue();
        DEBUG_MSG("pbwrite to %s of %d bytes\n", c->getUUID().toString().c_str(), src.length());
        return pb_decode_from_bytes((const uint8_t *)src.c_str(), src.length(), fields, dest);
    }
};

class NodeInfoCharacteristic : public BLECharacteristic, public BLEKeepAliveCallbacks
{
  public:
    NodeInfoCharacteristic()
        : BLECharacteristic("d31e02e0-c8ab-4d3f-9cc9-0b8466bdabe8",
                            BLECharacteristic::PROPERTY_WRITE | BLECharacteristic::PROPERTY_READ)
    {
        setCallbacks(this);
    }

    void onRead(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onRead(c);

        const NodeInfo *info = nodeDB.readNextInfo();

        if (info) {
            DEBUG_MSG("Sending nodeinfo: num=0x%x, lastseen=%u, id=%s, name=%s\n", info->num, info->position.time, info->user.id,
                      info->user.long_name);
            size_t numbytes = pb_encode_to_bytes(trBytes, sizeof(trBytes), NodeInfo_fields, info);
            c->setValue(trBytes, numbytes);
        } else {
            c->setValue(trBytes, 0); // Send an empty response
            DEBUG_MSG("Done sending nodeinfos\n");
        }
    }

    void onWrite(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onWrite(c);
        DEBUG_MSG("Reset nodeinfo read pointer\n");
        nodeDB.resetReadPointer();
    }
};

// wrap our protobuf version with something that forces the service to reload the config
class RadioCharacteristic : public ProtobufCharacteristic
{
  public:
    RadioCharacteristic()
        : ProtobufCharacteristic("b56786c8-839a-44a1-b98e-a1724c4a0262",
                                 BLECharacteristic::PROPERTY_WRITE | BLECharacteristic::PROPERTY_READ, RadioConfig_fields,
                                 &radioConfig)
    {
    }

    void onRead(BLECharacteristic *c)
    {
        DEBUG_MSG("Reading radio config, sdsecs %u\n", radioConfig.preferences.sds_secs);
        ProtobufCharacteristic::onRead(c);
    }

    void onWrite(BLECharacteristic *c)
    {
        DEBUG_MSG("Writing radio config\n");
        ProtobufCharacteristic::onWrite(c);
        service.reloadConfig();
    }
};

// wrap our protobuf version with something that forces the service to reload the owner
class OwnerCharacteristic : public ProtobufCharacteristic
{
  public:
    OwnerCharacteristic()
        : ProtobufCharacteristic("6ff1d8b6-e2de-41e3-8c0b-8fa384f64eb6",
                                 BLECharacteristic::PROPERTY_WRITE | BLECharacteristic::PROPERTY_READ, User_fields, &owner)
    {
    }

    void onWrite(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onWrite(
            c); // NOTE: We do not call the standard ProtobufCharacteristic superclass, because we want custom write behavior

        static User o; // if the phone doesn't set ID we are careful to keep ours, we also always keep our macaddr
        if (writeToDest(c, &o)) {
            int changed = 0;

            if (*o.long_name) {
                changed |= strcmp(owner.long_name, o.long_name);
                strcpy(owner.long_name, o.long_name);
            }
            if (*o.short_name) {
                changed |= strcmp(owner.short_name, o.short_name);
                strcpy(owner.short_name, o.short_name);
            }
            if (*o.id) {
                changed |= strcmp(owner.id, o.id);
                strcpy(owner.id, o.id);
            }

            if (changed) // If nothing really changed, don't broadcast on the network or write to flash
                service.reloadOwner();
        }
    }
};

class ToRadioCharacteristic : public CallbackCharacteristic
{
  public:
    ToRadioCharacteristic() : CallbackCharacteristic("f75c76d2-129e-4dad-a1dd-7866124401e7", BLECharacteristic::PROPERTY_WRITE) {}

    void onWrite(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onWrite(c);
        DEBUG_MSG("Got on write\n");

        service.handleToRadio(c->getValue());
    }
};

class FromRadioCharacteristic : public CallbackCharacteristic
{
  public:
    FromRadioCharacteristic() : CallbackCharacteristic("8ba2bcc2-ee02-4a55-a531-c525c5e454d5", BLECharacteristic::PROPERTY_READ)
    {
    }

    void onRead(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onRead(c);
        MeshPacket *mp = service.getForPhone();

        // Someone is going to read our value as soon as this callback returns.  So fill it with the next message in the queue
        // or make empty if the queue is empty
        if (!mp) {
            DEBUG_MSG("toPhone queue is empty\n");
            c->setValue((uint8_t *)"", 0);
        } else {
            static FromRadio fRadio;

            // Encapsulate as a FromRadio packet
            memset(&fRadio, 0, sizeof(fRadio));
            fRadio.which_variant = FromRadio_packet_tag;
            fRadio.variant.packet = *mp;

            size_t numbytes = pb_encode_to_bytes(trBytes, sizeof(trBytes), FromRadio_fields, &fRadio);
            DEBUG_MSG("delivering toPhone packet to phone %d bytes\n", numbytes);
            c->setValue(trBytes, numbytes);

            service.releaseToPool(mp); // we just copied the bytes, so don't need this buffer anymore
        }
    }
};

class FromNumCharacteristic : public CallbackCharacteristic, public Observer<uint32_t>
{
  public:
    FromNumCharacteristic()
        : CallbackCharacteristic("ed9da18c-a800-4f66-a670-aa7547e34453", BLECharacteristic::PROPERTY_WRITE |
                                                                             BLECharacteristic::PROPERTY_READ |
                                                                             BLECharacteristic::PROPERTY_NOTIFY)
    {
        observe(&service.fromNumChanged);
    }

    void onRead(BLECharacteristic *c)
    {
        BLEKeepAliveCallbacks::onRead(c);
        DEBUG_MSG("FIXME implement fromnum read\n");
    }

    /// If the mesh service tells us fromNum has changed, tell the phone
    virtual int onNotify(uint32_t newValue)
    {
        setValue(newValue);
        notify();
        return 0;
    }
};

class MyNodeInfoCharacteristic : public ProtobufCharacteristic
{
  public:
    MyNodeInfoCharacteristic()
        : ProtobufCharacteristic("ea9f3f82-8dc4-4733-9452-1f6da28892a2", BLECharacteristic::PROPERTY_READ, MyNodeInfo_fields,
                                 &myNodeInfo)
    {
    }

    void onRead(BLECharacteristic *c)
    {
        // update gps connection state
        myNodeInfo.has_gps = gps.isConnected;

        ProtobufCharacteristic::onRead(c);

        myNodeInfo.error_code = 0; // The phone just read us, so throw it away
        myNodeInfo.error_address = 0;
    }
};

FromNumCharacteristic *meshFromNumCharacteristic;

BLEService *meshService;

/*
See bluetooth-api.md for documentation.
 */
BLEService *createMeshBluetoothService(BLEServer *server)
{
    // Create the BLE Service, we need more than the default of 15 handles
    BLEService *service = server->createService(BLEUUID("6ba1b218-15a8-461f-9fa8-5dcae273eafd"), 30, 0);

    assert(!meshFromNumCharacteristic);
    meshFromNumCharacteristic = new FromNumCharacteristic;

    addWithDesc(service, meshFromNumCharacteristic, "fromRadio");
    addWithDesc(service, new ToRadioCharacteristic, "toRadio");
    addWithDesc(service, new FromRadioCharacteristic, "fromNum");
    addWithDesc(service, new MyNodeInfoCharacteristic, "myNode");
    addWithDesc(service, new RadioCharacteristic, "radio");
    addWithDesc(service, new OwnerCharacteristic, "owner");
    addWithDesc(service, new NodeInfoCharacteristic, "nodeinfo");

    meshFromNumCharacteristic->addDescriptor(addBLEDescriptor(new BLE2902())); // Needed so clients can request notification

    service->start();

    // We only add to advertisting once, because the ESP32 arduino code is dumb and that object never dies
    static bool firstTime = true;
    if (firstTime) {
        firstTime = false;
        server->getAdvertising()->addServiceUUID(service->getUUID());
    }

    DEBUG_MSG("*** Mesh service:\n");
    service->dump();

    meshService = service;
    return service;
}

void stopMeshBluetoothService()
{
    assert(meshService);
    meshService->stop();
}

void destroyMeshBluetoothService()
{
    assert(meshService);
    delete meshService;

    meshFromNumCharacteristic = NULL;
}