/*
 * Copyright (c) 2016 Nordic Semiconductor ASA
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>

#include <zephyr/kernel.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/l2cap.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/buf.h>
#include <zephyr/bluetooth/hci_raw.h>

// Nordic NDK
#include "nrf.h"

// BTstack
#include "btstack_debug.h"
#include "btstack_event.h"
#include "btstack_memory.h"
#include "hci.h"
#include "hci_dump.h"
#include "hci_dump_embedded_stdout.h"
#include "hci_transport.h"

#include "btstack_tlv.h"
#include "btstack_tlv_none.h"
#include "ble/le_device_db_tlv.h"

static K_FIFO_DEFINE(tx_queue);
static K_FIFO_DEFINE(rx_queue);

//
// hci_transport_zephyr.c
//

static void (*transport_packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size);

/**
 * init transport
 * @param transport_config
 */
static void transport_init(const void *transport_config){
	/* startup Controller */
	bt_enable_raw(&rx_queue);
}

/**
 * open transport connection
 */
static int transport_open(void){
    return 0;
}

/**
 * close transport connection
 */
static int transport_close(void){
    return 0;
}

/**
 * register packet handler for HCI packets: ACL, SCO, and Events
 */
static void transport_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
    transport_packet_handler = handler;
}

static void send_hardware_error(uint8_t error_code){
    // hci_outgoing_event[0] = HCI_EVENT_HARDWARE_ERROR;
    // hci_outgoing_event[1] = 1;
    // hci_outgoing_event[2] = error_code;
    // hci_outgoing_event_ready = 1;
}

static int transport_send_packet(uint8_t packet_type, uint8_t *packet, int size){
	struct net_buf *buf;
    switch (packet_type){
        case HCI_COMMAND_DATA_PACKET:
		    buf = bt_buf_get_tx(BT_BUF_CMD, K_NO_WAIT, packet, size);
			if (!buf) {
				log_error("No available command buffers!\n");
                break;
			}

			memcpy(net_buf_add(buf, size), packet, size);
			bt_send(buf);
            break;
        case HCI_ACL_DATA_PACKET:
		    buf = bt_buf_get_tx(BT_BUF_ACL_OUT, K_NO_WAIT, packet, size);
			if (!buf) {
				log_error("No available ACL buffers!\n");
                break;
			}

			memcpy(net_buf_add(buf, size), packet, size);
			bt_send(buf);
            break;
        default:
            send_hardware_error(0x01);  // invalid HCI packet
            break;
    }

    return 0;
}

static const hci_transport_t transport = {
    /* const char * name; */                                        "zephyr",
    /* void   (*init) (const void *transport_config); */            &transport_init,
    /* int    (*open)(void); */                                     &transport_open,
    /* int    (*close)(void); */                                    &transport_close,
    /* void   (*register_packet_handler)(void (*handler)(...); */   &transport_register_packet_handler,
    /* int    (*can_send_packet_now)(uint8_t packet_type); */       NULL,
    /* int    (*send_packet)(...); */                               &transport_send_packet,
    /* int    (*set_baudrate)(uint32_t baudrate); */                NULL,
    /* void   (*reset_link)(void); */                               NULL,
};

static const hci_transport_t * transport_get_instance(void){
	return &transport;
}

static void transport_deliver_controller_packet(struct net_buf * buf){
		uint16_t    size = buf->len;
		uint8_t * packet = buf->data;
		switch (bt_buf_get_type(buf)) {
			case BT_BUF_ACL_IN:
				transport_packet_handler(HCI_ACL_DATA_PACKET, packet, size);
				break;
			case BT_BUF_EVT:
				transport_packet_handler(HCI_EVENT_PACKET, packet, size);
				break;
			default:
				log_error("Unknown type %u\n", bt_buf_get_type(buf));
				break;
		}
		net_buf_unref(buf);
}

// btstack_run_loop_zephry.c

// the run loop
//static btstack_linked_list_t timers;

// TODO: handle 32 bit ms time overrun
static uint32_t btstack_run_loop_zephyr_get_time_ms(void){
	return  k_uptime_get_32();
}

static void btstack_run_loop_zephyr_set_timer(btstack_timer_source_t *ts, uint32_t timeout_in_ms){
    ts->timeout = k_uptime_get_32() + 1 + timeout_in_ms;
}

/**
 * Execute run_loop
 */
static void btstack_run_loop_zephyr_execute(void) {
    while (1) {
        // process timers
        uint32_t now = k_uptime_get_32();
        btstack_run_loop_base_process_timers(now);

        // get time until next timer expires
        k_timeout_t timeout;
        timeout.ticks = btstack_run_loop_base_get_time_until_timeout(now);
        if (timeout.ticks < 0){
            timeout.ticks = K_TICKS_FOREVER;
        }

        // process RX fifo only
        struct net_buf *buf = net_buf_get(&rx_queue, timeout);
		if (buf){
			transport_deliver_controller_packet(buf);
		}
	}
}

static void btstack_run_loop_zephyr_btstack_run_loop_init(void){
    btstack_run_loop_base_init();
}

static const btstack_run_loop_t btstack_run_loop_zephyr = {
    &btstack_run_loop_zephyr_btstack_run_loop_init,
    NULL,
    NULL,
    NULL,
    NULL,
    &btstack_run_loop_zephyr_set_timer,
    &btstack_run_loop_base_add_timer,
    &btstack_run_loop_base_remove_timer,
    &btstack_run_loop_zephyr_execute,
    &btstack_run_loop_base_dump_timer,
    &btstack_run_loop_zephyr_get_time_ms,
};
/**
 * @brief Provide btstack_run_loop_posix instance for use with btstack_run_loop_init
 */
const btstack_run_loop_t * btstack_run_loop_zephyr_get_instance(void){
    return &btstack_run_loop_zephyr;
}

static btstack_packet_callback_registration_t hci_event_callback_registration;

static bd_addr_t static_address;

static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    if (packet_type != HCI_EVENT_PACKET) return;
    if (hci_event_packet_get_type(packet) != BTSTACK_EVENT_STATE) return;
    if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) return;
    printf("BTstack up and running as %s.\n", bd_addr_to_str(static_address));
}

int btstack_main(void);

#if defined(CONFIG_BT_CTLR_ASSERT_HANDLER)
void bt_ctlr_assert_handle(char *file, uint32_t line)
{
	printf("CONFIG_BT_CTLR_ASSERT_HANDLER: file %s, line %u\n", file, line);
	while (1) {
	}
}
#endif /* CONFIG_BT_CTLR_ASSERT_HANDLER */

int main(void)
{
	// configure console UART by replacing CONFIG_UART_NRF5_BAUD_RATE with 115200 in uart_console.c

	printf("BTstack booting up..\n");

	// start with BTstack init - especially configure HCI Transport
    btstack_memory_init();
    btstack_run_loop_init(btstack_run_loop_zephyr_get_instance());

    // enable full log output while porting
    hci_dump_init(hci_dump_embedded_stdout_get_instance());

    const btstack_tlv_t * btstack_tlv_impl = btstack_tlv_none_init_instance();
    // setup global tlv
    btstack_tlv_set_instance(btstack_tlv_impl, NULL);

    // setup LE Device DB using TLV
    le_device_db_tlv_configure(btstack_tlv_impl, NULL);

    // init HCI
    hci_init(transport_get_instance(), NULL);

    // nRF5 chipsets don't have an official public address
    // Instead, a Static Random Address is assigned during manufacturing
    // let's use it as well
    big_endian_store_16(static_address, 0, NRF_FICR->DEVICEADDR[1] | 0xc000);
    big_endian_store_32(static_address, 2, NRF_FICR->DEVICEADDR[0]);
    gap_random_address_set(static_address);

    // inform about BTstack state
    hci_event_callback_registration.callback = &packet_handler;
    hci_add_event_handler(&hci_event_callback_registration);

    // hand over to btstack embedded code 
    btstack_main();

    // go
    btstack_run_loop_execute();

    while (1){};
    return 0;
}