#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]

use core::time::Duration;

use defmt::*;
use embassy_executor::Spawner;
use embassy_stm32::bind_interrupts;
use embassy_stm32::ipcc::{Config, ReceiveInterruptHandler, TransmitInterruptHandler};
use embassy_stm32::rcc::WPAN_DEFAULT;
use embassy_stm32_wpan::hci::event::command::{CommandComplete, ReturnParameters};
use embassy_stm32_wpan::hci::host::uart::{Packet, UartHci};
use embassy_stm32_wpan::hci::host::{AdvertisingFilterPolicy, EncryptionKey, HostHci, OwnAddressType};
use embassy_stm32_wpan::hci::types::AdvertisingType;
use embassy_stm32_wpan::hci::vendor::stm32wb::command::gap::{
    AddressType, AuthenticationRequirements, DiscoverableParameters, GapCommands, IoCapability, LocalName, Pin, Role,
    SecureConnectionSupport,
};
use embassy_stm32_wpan::hci::vendor::stm32wb::command::gatt::{
    AddCharacteristicParameters, AddServiceParameters, CharacteristicEvent, CharacteristicPermission,
    CharacteristicProperty, EncryptionKeySize, GattCommands, ServiceType, UpdateCharacteristicValueParameters, Uuid,
    WriteResponseParameters,
};
use embassy_stm32_wpan::hci::vendor::stm32wb::command::hal::{ConfigData, HalCommands, PowerLevel};
use embassy_stm32_wpan::hci::vendor::stm32wb::event::{self, AttributeHandle, Stm32Wb5xEvent};
use embassy_stm32_wpan::hci::{BdAddr, Event};
use embassy_stm32_wpan::lhci::LhciC1DeviceInformationCcrp;
use embassy_stm32_wpan::sub::ble::Ble;
use embassy_stm32_wpan::TlMbox;
use {defmt_rtt as _, panic_probe as _};

bind_interrupts!(struct Irqs{
    IPCC_C1_RX => ReceiveInterruptHandler;
    IPCC_C1_TX => TransmitInterruptHandler;
});

const BLE_GAP_DEVICE_NAME_LENGTH: u8 = 7;

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    /*
        How to make this work:

        - Obtain a NUCLEO-STM32WB55 from your preferred supplier.
        - Download and Install STM32CubeProgrammer.
        - Download stm32wb5x_FUS_fw.bin, stm32wb5x_BLE_Stack_full_fw.bin, and Release_Notes.html from
          gh:STMicroelectronics/STM32CubeWB@2234d97/Projects/STM32WB_Copro_Wireless_Binaries/STM32WB5x
        - Open STM32CubeProgrammer
        - On the right-hand pane, click "firmware upgrade" to upgrade the st-link firmware.
        - Once complete, click connect to connect to the device.
        - On the left hand pane, click the RSS signal icon to open "Firmware Upgrade Services".
        - In the Release_Notes.html, find the memory address that corresponds to your device for the stm32wb5x_FUS_fw.bin file
        - Select that file, the memory address, "verify download", and then "Firmware Upgrade".
        - Once complete, in the Release_Notes.html, find the memory address that corresponds to your device for the
          stm32wb5x_BLE_Stack_full_fw.bin file. It should not be the same memory address.
        - Select that file, the memory address, "verify download", and then "Firmware Upgrade".
        - Select "Start Wireless Stack".
        - Disconnect from the device.
        - In the examples folder for stm32wb, modify the memory.x file to match your target device.
        - Run this example.

        Note: extended stack versions are not supported at this time. Do not attempt to install a stack with "extended" in the name.
    */

    let mut config = embassy_stm32::Config::default();
    config.rcc = WPAN_DEFAULT;
    let p = embassy_stm32::init(config);
    info!("Hello World!");

    let config = Config::default();
    let mut mbox = TlMbox::init(p.IPCC, Irqs, config);

    let sys_event = mbox.sys_subsystem.read().await;
    info!("sys event: {}", sys_event.payload());

    let _ = mbox.sys_subsystem.shci_c2_ble_init(Default::default()).await;

    info!("resetting BLE...");
    mbox.ble_subsystem.reset().await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("config public address...");
    mbox.ble_subsystem
        .write_config_data(&ConfigData::public_address(get_bd_addr()).build())
        .await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("config random address...");
    mbox.ble_subsystem
        .write_config_data(&ConfigData::random_address(get_random_addr()).build())
        .await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("config identity root...");
    mbox.ble_subsystem
        .write_config_data(&ConfigData::identity_root(&get_irk()).build())
        .await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("config encryption root...");
    mbox.ble_subsystem
        .write_config_data(&ConfigData::encryption_root(&get_erk()).build())
        .await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("config tx power level...");
    mbox.ble_subsystem.set_tx_power_level(PowerLevel::ZerodBm).await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("GATT init...");
    mbox.ble_subsystem.init_gatt().await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("GAP init...");
    mbox.ble_subsystem
        .init_gap(Role::PERIPHERAL, false, BLE_GAP_DEVICE_NAME_LENGTH)
        .await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("set IO capabilities...");
    mbox.ble_subsystem.set_io_capability(IoCapability::DisplayConfirm).await;
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("set authentication requirements...");
    mbox.ble_subsystem
        .set_authentication_requirement(&AuthenticationRequirements {
            bonding_required: false,
            keypress_notification_support: false,
            mitm_protection_required: false,
            encryption_key_size_range: (8, 16),
            fixed_pin: Pin::Requested,
            identity_address_type: AddressType::Public,
            secure_connection_support: SecureConnectionSupport::Optional,
        })
        .await
        .unwrap();
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("set scan response data...");
    mbox.ble_subsystem.le_set_scan_response_data(b"TXTX").await.unwrap();
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    info!("set scan response data...");
    mbox.ble_subsystem.le_set_scan_response_data(b"TXTX").await.unwrap();
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    defmt::info!("initializing services and characteristics...");
    let mut ble_context = init_gatt_services(&mut mbox.ble_subsystem).await.unwrap();
    defmt::info!("{}", ble_context);

    let discovery_params = DiscoverableParameters {
        advertising_type: AdvertisingType::ConnectableUndirected,
        advertising_interval: Some((Duration::from_millis(100), Duration::from_millis(100))),
        address_type: OwnAddressType::Public,
        filter_policy: AdvertisingFilterPolicy::AllowConnectionAndScan,
        local_name: Some(LocalName::Complete(b"TXTX")),
        advertising_data: &[],
        conn_interval: (None, None),
    };

    info!("set discoverable...");
    mbox.ble_subsystem.set_discoverable(&discovery_params).await.unwrap();
    let response = mbox.ble_subsystem.read().await;
    defmt::debug!("{}", response);

    loop {
        let response = mbox.ble_subsystem.read().await;
        defmt::debug!("{}", response);

        if let Ok(Packet::Event(event)) = response {
            match event {
                Event::LeConnectionComplete(_) => {
                    defmt::info!("connected");
                }
                Event::DisconnectionComplete(_) => {
                    defmt::info!("disconnected");
                    ble_context.is_subscribed = false;
                    mbox.ble_subsystem.set_discoverable(&discovery_params).await.unwrap();
                }
                Event::Vendor(vendor_event) => match vendor_event {
                    Stm32Wb5xEvent::AttReadPermitRequest(read_req) => {
                        defmt::info!("read request received {}, allowing", read_req);
                        mbox.ble_subsystem.allow_read(read_req.conn_handle).await
                    }
                    Stm32Wb5xEvent::AttWritePermitRequest(write_req) => {
                        defmt::info!("write request received {}, allowing", write_req);
                        mbox.ble_subsystem
                            .write_response(&WriteResponseParameters {
                                conn_handle: write_req.conn_handle,
                                attribute_handle: write_req.attribute_handle,
                                status: Ok(()),
                                value: write_req.value(),
                            })
                            .await
                            .unwrap()
                    }
                    Stm32Wb5xEvent::GattAttributeModified(attribute) => {
                        defmt::info!("{}", ble_context);
                        if attribute.attr_handle.0 == ble_context.chars.notify.0 + 2 {
                            if attribute.data()[0] == 0x01 {
                                defmt::info!("subscribed");
                                ble_context.is_subscribed = true;
                            } else {
                                defmt::info!("unsubscribed");
                                ble_context.is_subscribed = false;
                            }
                        }
                    }
                    _ => {}
                },
                _ => {}
            }
        }
    }
}

fn get_bd_addr() -> BdAddr {
    let mut bytes = [0u8; 6];

    let lhci_info = LhciC1DeviceInformationCcrp::new();
    bytes[0] = (lhci_info.uid64 & 0xff) as u8;
    bytes[1] = ((lhci_info.uid64 >> 8) & 0xff) as u8;
    bytes[2] = ((lhci_info.uid64 >> 16) & 0xff) as u8;
    bytes[3] = lhci_info.device_type_id;
    bytes[4] = (lhci_info.st_company_id & 0xff) as u8;
    bytes[5] = (lhci_info.st_company_id >> 8 & 0xff) as u8;

    BdAddr(bytes)
}

fn get_random_addr() -> BdAddr {
    let mut bytes = [0u8; 6];

    let lhci_info = LhciC1DeviceInformationCcrp::new();
    bytes[0] = (lhci_info.uid64 & 0xff) as u8;
    bytes[1] = ((lhci_info.uid64 >> 8) & 0xff) as u8;
    bytes[2] = ((lhci_info.uid64 >> 16) & 0xff) as u8;
    bytes[3] = 0;
    bytes[4] = 0x6E;
    bytes[5] = 0xED;

    BdAddr(bytes)
}

const BLE_CFG_IRK: [u8; 16] = [
    0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0,
];
const BLE_CFG_ERK: [u8; 16] = [
    0xfe, 0xdc, 0xba, 0x09, 0x87, 0x65, 0x43, 0x21, 0xfe, 0xdc, 0xba, 0x09, 0x87, 0x65, 0x43, 0x21,
];

fn get_irk() -> EncryptionKey {
    EncryptionKey(BLE_CFG_IRK)
}

fn get_erk() -> EncryptionKey {
    EncryptionKey(BLE_CFG_ERK)
}

#[derive(defmt::Format)]
pub struct BleContext {
    pub service_handle: AttributeHandle,
    pub chars: CharHandles,
    pub is_subscribed: bool,
}

#[derive(defmt::Format)]
pub struct CharHandles {
    pub read: AttributeHandle,
    pub write: AttributeHandle,
    pub notify: AttributeHandle,
}

pub async fn init_gatt_services(ble_subsystem: &mut Ble) -> Result<BleContext, ()> {
    let service_handle = gatt_add_service(ble_subsystem, Uuid::Uuid16(0x500)).await?;

    let read = gatt_add_char(
        ble_subsystem,
        service_handle,
        Uuid::Uuid16(0x501),
        CharacteristicProperty::READ,
        Some(b"Hello from embassy!"),
    )
    .await?;

    let write = gatt_add_char(
        ble_subsystem,
        service_handle,
        Uuid::Uuid16(0x502),
        CharacteristicProperty::WRITE_WITHOUT_RESPONSE | CharacteristicProperty::WRITE | CharacteristicProperty::READ,
        None,
    )
    .await?;

    let notify = gatt_add_char(
        ble_subsystem,
        service_handle,
        Uuid::Uuid16(0x503),
        CharacteristicProperty::NOTIFY | CharacteristicProperty::READ,
        None,
    )
    .await?;

    Ok(BleContext {
        service_handle,
        is_subscribed: false,
        chars: CharHandles { read, write, notify },
    })
}

async fn gatt_add_service(ble_subsystem: &mut Ble, uuid: Uuid) -> Result<AttributeHandle, ()> {
    ble_subsystem
        .add_service(&AddServiceParameters {
            uuid,
            service_type: ServiceType::Primary,
            max_attribute_records: 8,
        })
        .await;
    let response = ble_subsystem.read().await;
    defmt::debug!("{}", response);

    if let Ok(Packet::Event(Event::CommandComplete(CommandComplete {
        return_params:
            ReturnParameters::Vendor(event::command::ReturnParameters::GattAddService(event::command::GattService {
                service_handle,
                ..
            })),
        ..
    }))) = response
    {
        Ok(service_handle)
    } else {
        Err(())
    }
}

async fn gatt_add_char(
    ble_subsystem: &mut Ble,
    service_handle: AttributeHandle,
    characteristic_uuid: Uuid,
    characteristic_properties: CharacteristicProperty,
    default_value: Option<&[u8]>,
) -> Result<AttributeHandle, ()> {
    ble_subsystem
        .add_characteristic(&AddCharacteristicParameters {
            service_handle,
            characteristic_uuid,
            characteristic_properties,
            characteristic_value_len: 32,
            security_permissions: CharacteristicPermission::empty(),
            gatt_event_mask: CharacteristicEvent::all(),
            encryption_key_size: EncryptionKeySize::with_value(7).unwrap(),
            is_variable: true,
        })
        .await;
    let response = ble_subsystem.read().await;
    defmt::debug!("{}", response);

    if let Ok(Packet::Event(Event::CommandComplete(CommandComplete {
        return_params:
            ReturnParameters::Vendor(event::command::ReturnParameters::GattAddCharacteristic(
                event::command::GattCharacteristic {
                    characteristic_handle, ..
                },
            )),
        ..
    }))) = response
    {
        if let Some(value) = default_value {
            ble_subsystem
                .update_characteristic_value(&UpdateCharacteristicValueParameters {
                    service_handle,
                    characteristic_handle,
                    offset: 0,
                    value,
                })
                .await
                .unwrap();

            let response = ble_subsystem.read().await;
            defmt::debug!("{}", response);
        }
        Ok(characteristic_handle)
    } else {
        Err(())
    }
}