// Buttplug Rust Source Code File - See https://buttplug.io for more info.
//
// Copyright 2016-2024 Nonpolynomial Labs LLC. All rights reserved.
//
// Licensed under the BSD 3-Clause license. See LICENSE file in the project root
// for full license information.

use crate::device::{
  hardware::{Hardware, HardwareCommand, HardwareReadCmd, HardwareWriteCmd},
  protocol::{
    ProtocolHandler,
    ProtocolIdentifier,
    ProtocolInitializer,
    generic_protocol_initializer_setup,
  },
};
use async_trait::async_trait;
use buttplug_core::errors::ButtplugDeviceError;
use buttplug_server_device_config::Endpoint;
use buttplug_server_device_config::{
  ProtocolCommunicationSpecifier,
  ServerDeviceDefinition,
  UserDeviceIdentifier,
};
use std::sync::Arc;
use uuid::{Uuid, uuid};

generic_protocol_initializer_setup!(Ankni, "ankni");

const ANKNI_PROTOCOL_UUID: Uuid = uuid!("9859232d-57ee-4135-a93c-c8988bf8cbbf");

#[derive(Default)]
pub struct AnkniInitializer {}

#[async_trait]
impl ProtocolInitializer for AnkniInitializer {
  async fn initialize(
    &mut self,
    hardware: Arc<Hardware>,
    _: &ServerDeviceDefinition,
  ) -> Result<Arc<dyn ProtocolHandler>, ButtplugDeviceError> {
    let msg = HardwareReadCmd::new(ANKNI_PROTOCOL_UUID, Endpoint::Generic0, 16, 100);
    let reading = hardware.read_value(&msg).await?;

    // No mac address on PnP characteristic, assume no handshake required
    if reading.data().len() > 6 {
      return Ok(Arc::new(Ankni::default()));
    }

    let mut addrdata = Vec::with_capacity(7);
    addrdata.push(0x01);
    addrdata.extend(reading.data());

    let check = ((crc16(addrdata) & 0xff00) >> 8) as u8;
    debug!("Ankni Checksum: {:#02X}", check);

    let msg = HardwareWriteCmd::new(
      &[ANKNI_PROTOCOL_UUID],
      Endpoint::Tx,
      vec![
        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
        0x01, 0x01, 0x01, 0x01, 0x01,
      ],
      true,
    );
    hardware.write_value(&msg).await?;
    let msg = HardwareWriteCmd::new(
      &[ANKNI_PROTOCOL_UUID],
      Endpoint::Tx,
      vec![
        0x01, 0x02, check, check, check, check, check, check, check, check, check, check, check,
        check, check, check, check, check, 0x00, 0x00,
      ],
      true,
    );
    hardware.write_value(&msg).await?;
    Ok(Arc::new(Ankni::default()))
  }
}

#[derive(Default)]
pub struct Ankni {}

impl ProtocolHandler for Ankni {
  fn handle_output_vibrate_cmd(
    &self,
    _feature_index: u32,
    feature_id: Uuid,
    speed: u32,
  ) -> Result<Vec<HardwareCommand>, ButtplugDeviceError> {
    Ok(vec![
      HardwareWriteCmd::new(
        &[feature_id],
        Endpoint::Tx,
        vec![
          0x03,
          0x12,
          speed as u8,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
          0x00,
        ],
        true,
      )
      .into(),
    ])
  }
}

fn crc16(advert_data: Vec<u8>) -> u16 {
  let mut remain: u16 = 0;
  for byte in advert_data {
    remain ^= (byte as u16) << 8;
    for _ in 0..8 {
      if (remain & (1 << (u16::BITS - 1))) != 0 {
        remain <<= 1;
        remain ^= 0x1021;
      } else {
        remain <<= 1;
      }
    }
  }
  remain
}