#include "ethernet.h"

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

#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "esp_eth.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_mac.h"
#include "esp_netif.h"
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"

static const char *TAG = "ethernet";

// Waveshare ESP32-S3-ETH W5500 wiring (same as matter-esp32-heating-monitor).
#define ETH_SPI_HOST      SPI2_HOST
#define ETH_SPI_SCLK_GPIO 13
#define ETH_SPI_MOSI_GPIO 11
#define ETH_SPI_MISO_GPIO 12
#define ETH_SPI_CS_GPIO   14
#define ETH_SPI_INT_GPIO  10
#define ETH_SPI_RST_GPIO  9
#define ETH_SPI_CLOCK_MHZ 25

#define GOT_IP_BIT BIT0

static EventGroupHandle_t s_events;
static char s_ip[16] = "0.0.0.0";

static void on_eth_event(void *arg, esp_event_base_t base, int32_t id, void *data)
{
    switch (id) {
    case ETHERNET_EVENT_CONNECTED:
        ESP_LOGI(TAG, "Link up");
        break;
    case ETHERNET_EVENT_DISCONNECTED:
        ESP_LOGW(TAG, "Link down");
        xEventGroupClearBits(s_events, GOT_IP_BIT);
        strcpy(s_ip, "0.0.0.0");
        break;
    default:
        break;
    }
}

static void on_got_ip(void *arg, esp_event_base_t base, int32_t id, void *data)
{
    ip_event_got_ip_t *event = (ip_event_got_ip_t *)data;
    snprintf(s_ip, sizeof(s_ip), IPSTR, IP2STR(&event->ip_info.ip));
    ESP_LOGI(TAG, "Got IP %s", s_ip);
    xEventGroupSetBits(s_events, GOT_IP_BIT);
}

esp_err_t ethernet_start(void)
{
    s_events = xEventGroupCreate();

    // The W5500 signals RX through a GPIO interrupt.
    esp_err_t err = gpio_install_isr_service(0);
    if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
        return err;
    }

    esp_netif_config_t netif_cfg = ESP_NETIF_DEFAULT_ETH();
    esp_netif_t *netif = esp_netif_new(&netif_cfg);

    spi_bus_config_t buscfg = {
        .mosi_io_num = ETH_SPI_MOSI_GPIO,
        .miso_io_num = ETH_SPI_MISO_GPIO,
        .sclk_io_num = ETH_SPI_SCLK_GPIO,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
    };
    ESP_ERROR_CHECK(spi_bus_initialize(ETH_SPI_HOST, &buscfg, SPI_DMA_CH_AUTO));

    spi_device_interface_config_t devcfg = {
        .mode = 0,
        .clock_speed_hz = ETH_SPI_CLOCK_MHZ * 1000 * 1000,
        .spics_io_num = ETH_SPI_CS_GPIO,
        .queue_size = 20,
    };

    eth_w5500_config_t w5500_config = ETH_W5500_DEFAULT_CONFIG(ETH_SPI_HOST, &devcfg);
    w5500_config.int_gpio_num = ETH_SPI_INT_GPIO;

    eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();
    esp_eth_mac_t *mac = esp_eth_mac_new_w5500(&w5500_config, &mac_config);

    eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();
    phy_config.reset_gpio_num = ETH_SPI_RST_GPIO;
    esp_eth_phy_t *phy = esp_eth_phy_new_w5500(&phy_config);

    esp_eth_config_t eth_cfg = ETH_DEFAULT_CONFIG(mac, phy);
    esp_eth_handle_t eth = NULL;
    ESP_ERROR_CHECK(esp_eth_driver_install(&eth_cfg, &eth));

    // The W5500 has no MAC of its own; derive one from the SoC eFuse.
    uint8_t mac_addr[6];
    ESP_ERROR_CHECK(esp_read_mac(mac_addr, ESP_MAC_ETH));
    ESP_ERROR_CHECK(esp_eth_ioctl(eth, ETH_CMD_S_MAC_ADDR, mac_addr));

    ESP_ERROR_CHECK(esp_netif_attach(netif, esp_eth_new_netif_glue(eth)));
    ESP_ERROR_CHECK(esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, &on_eth_event, NULL));
    ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_ETH_GOT_IP, &on_got_ip, NULL));
    ESP_ERROR_CHECK(esp_eth_start(eth));

    ESP_LOGI(TAG, "W5500 started");
    return ESP_OK;
}

bool ethernet_wait_for_ip(int timeout_ms)
{
    EventBits_t bits = xEventGroupWaitBits(s_events, GOT_IP_BIT, pdFALSE, pdTRUE, pdMS_TO_TICKS(timeout_ms));
    return (bits & GOT_IP_BIT) != 0;
}

const char *ethernet_ip_string(void)
{
    return s_ip;
}