#include "ch390_runtime.h"

#include "CH390.h"
#include "CH390_Interface.h"
#include "SEGGER_RTT.h"
#include "ethernetif.h"
#include "stm32f1xx_hal.h"
#include "lwip/etharp.h"
#include "lwip/pbuf.h"
#include "lwip/stats.h"

#include <string.h>

static void ch390_runtime_dispatch_frame(struct netif *netif, struct pbuf *p)
{
    if ((p != NULL) && (netif->input(p, netif) != ERR_OK)) {
        pbuf_free(p);
    }
}

static uint8_t ch390_runtime_drain_rx(struct netif *netif, uint8_t max_frames)
{
    struct pbuf *p;
    uint8_t drained = 0u;

    while (drained < max_frames) {
        p = ch390_runtime_input_frame(netif);
        if (p == NULL) {
            break;
        }
        ch390_runtime_dispatch_frame(netif, p);
        drained++;
    }

    return drained;
}

static volatile uint8_t g_ch390_irq_pending;
static uint8_t g_ch390_ready;
static ch390_diag_t g_diag;

static uint8_t ch390_runtime_probe_identity(void)
{
    g_diag.vendor_id = ch390_get_vendor_id();
    g_diag.product_id = ch390_get_product_id();
    g_diag.revision = ch390_get_revision();
    g_diag.phy_bmcr = ch390_read_phy(CH390_PHY_BMCR);
    g_diag.phy_bmsr = ch390_read_phy(CH390_PHY_BMSR);
    g_diag.phy_id1 = ch390_read_phy(CH390_PHY_PHYID1);
    g_diag.phy_id2 = ch390_read_phy(CH390_PHY_PHYID2);
    g_diag.phy_anar = ch390_read_phy(CH390_PHY_ANAR);
    g_diag.phy_anlpar = ch390_read_phy(CH390_PHY_ANLPAR);
    g_diag.phy_aner = ch390_read_phy(CH390_PHY_ANER);
    g_diag.nsr = ch390_read_reg(CH390_NSR);
    g_diag.ncr = ch390_read_reg(CH390_NCR);
    g_diag.rcr = ch390_read_reg(CH390_RCR);
    g_diag.imr = ch390_read_reg(CH390_IMR);
    g_diag.intcr = ch390_read_reg(CH390_INTCR);
    g_diag.gpr = ch390_read_reg(CH390_GPR);
    g_diag.isr = ch390_read_reg(CH390_ISR);
    g_diag.phy_speed_10m = 0u;
    g_diag.phy_full_duplex = 0u;
    g_diag.link_up = (uint8_t)0u;
    g_diag.id_valid = (uint8_t)((g_diag.vendor_id != 0x0000u) &&
                                (g_diag.vendor_id != 0xFFFFu) &&
                                (g_diag.product_id != 0x0000u) &&
                                (g_diag.product_id != 0xFFFFu));
    return g_diag.id_valid;
}

static void ch390_runtime_refresh_diag(void)
{
    uint8_t id_valid = ch390_runtime_probe_identity();
    g_diag.int_pin = (uint8_t)ch390_get_int_pin();

    if (id_valid != 0u) {
        g_diag.phy_speed_10m = (uint8_t)ch390_get_phy_speed();
        g_diag.phy_full_duplex = (uint8_t)ch390_get_duplex_mode();
        g_diag.link_up = (uint8_t)ch390_get_link_status();
    }
}

struct pbuf *ch390_runtime_input_frame(struct netif *netif)
{
    struct ethernetif *ethernetif = (struct ethernetif *)netif->state;
    struct pbuf *p = NULL;
    struct pbuf *q;
    uint16_t len;
    uint16_t frame_len;
    uint8_t rcr;
    uint8_t rx_ready;
    uint8_t rx_header[4];
    ch390_read_reg(CH390_MRCMDX);
    rx_ready = ch390_read_reg(CH390_MRCMDX);

    if (rx_ready & CH390_PKT_ERR) {
        rcr = ch390_read_reg(CH390_RCR);
        ch390_write_reg(CH390_RCR, (uint8_t)(rcr & (uint8_t)(~RCR_RXEN)));
        ch390_write_reg(CH390_MPTRCR, 0x01u);
        ch390_write_reg(CH390_MRRH, 0x0Cu);
        ch390_delay_us(1000u);
        ch390_write_reg(CH390_RCR, rcr);
        ethernetif->rx_len = 0u;
        LINK_STATS_INC(link.drop);
        g_diag.rx_packets_drop++;
        return NULL;
    }

    if ((rx_ready & CH390_PKT_RDY) == 0u) {
        ethernetif->rx_len = 0u;
        return NULL;
    }

    g_diag.rx_ready_hits++;

    ch390_read_mem(rx_header, 4);
    ethernetif->rx_status = rx_header[1];
    frame_len = (uint16_t)((uint16_t)rx_header[2] | ((uint16_t)rx_header[3] << 8));

    if ((ethernetif->rx_status & 0x3Fu) != 0u || frame_len == 0u || frame_len > CH390_PKT_MAX) {
        ethernetif->rx_len = 0u;
        ch390_drop_packet(frame_len);
        LINK_STATS_INC(link.drop);
        g_diag.rx_packets_drop++;
        return NULL;
    }

    ethernetif->rx_len = frame_len;
    len = ethernetif->rx_len;
#if ETH_PAD_SIZE
    len += ETH_PAD_SIZE;
#endif

    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
    if (p != NULL) {
#if ETH_PAD_SIZE
        pbuf_remove_header(p, ETH_PAD_SIZE);
#endif
        for (q = p; q != NULL; q = q->next) {
            ch390_read_mem((uint8_t *)q->payload, q->len);
        }
#if ETH_PAD_SIZE
        pbuf_add_header(p, ETH_PAD_SIZE);
#endif
        LINK_STATS_INC(link.recv);
        g_diag.rx_packets_ok++;

        g_diag.last_frame_len = frame_len;
        g_diag.last_payload_len = p->tot_len;
    } else {
        ch390_drop_packet(ethernetif->rx_len);
        LINK_STATS_INC(link.memerr);
        LINK_STATS_INC(link.drop);
        g_diag.rx_packets_drop++;
    }

    return p;
}

bool ch390_mac_address_valid(const uint8_t *mac)
{
    if (mac == NULL) {
        return false;
    }
    for (uint8_t i = 0; i < ETHARP_HWADDR_LEN; ++i) {
        if (mac[i] == 0u) {
            return false;
        }
    }
    return true;
}

void ch390_runtime_init(struct netif *netif, const uint8_t *mac)
{
    struct ethernetif *ethernetif = (struct ethernetif *)netif->state;

    SEGGER_RTT_WriteString(0, "ETH init: gpio\r\n");
    ch390_gpio_init();
    SEGGER_RTT_WriteString(0, "ETH init: spi\r\n");
    ch390_spi_init();
    SEGGER_RTT_WriteString(0, "ETH init: reset\r\n");
    ch390_hardware_reset();

    SEGGER_RTT_WriteString(0, "ETH init: probe\r\n");
    g_ch390_ready = ch390_runtime_probe_identity();
    if (g_ch390_ready == 0u) {
        netif->hwaddr_len = ETHARP_HWADDR_LEN;
        netif->mtu = 1500;
        netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET;

        ethernetif->rx_len = 0u;
        ethernetif->rx_status = 0u;

        netif_set_link_down(netif);
        SEGGER_RTT_WriteString(0, "ETH init: invalid chip id\r\n");
        return;
    }

    SEGGER_RTT_WriteString(0, "ETH init: default\r\n");
    ch390_default_config();
    SEGGER_RTT_WriteString(0, "ETH init: mac\r\n");
    if (ch390_mac_address_valid(mac)) {
        ch390_set_mac_address((uint8_t *)mac);
    }
    else {
        if (mac != NULL) {
            ch390_get_mac((uint8_t *)mac);
            SEGGER_RTT_printf(0, "ETH init: invalid MAC in config, using hardware MAC: %02X:%02X:%02X:%02X:%02X:%02X\r\n",
                                  mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
        }
        else {
            SEGGER_RTT_WriteString(0, "ETH init: no MAC in config\r\n");
        }
    }

    netif->hwaddr_len = ETHARP_HWADDR_LEN;
    SEGGER_RTT_WriteString(0, "ETH init: getmac\r\n");
    ch390_get_mac(netif->hwaddr);
    netif->mtu = 1500;
    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET;

    ethernetif->rx_len = 0u;
    ethernetif->rx_status = 0u;

    ch390_runtime_refresh_diag();
    g_ch390_ready = g_diag.id_valid;

    SEGGER_RTT_WriteString(0, "ETH init: irq\r\n");
    ch390_interrupt_init();
    SEGGER_RTT_WriteString(0, "ETH init: done\r\n");
}

void ch390_runtime_set_irq_pending(void)
{
    g_ch390_irq_pending = 1u;
}

uint8_t ch390_runtime_is_irq_pending(void)
{
    return g_ch390_irq_pending;
}

void ch390_runtime_poll(struct netif *netif)
{
    uint8_t int_status;
    uint8_t rx_ready;
    uint8_t rx_budget;
    uint8_t rx_hint;

    if (!g_ch390_ready) {
        return;
    }

    g_diag.rx_poll_calls++;

    rx_budget = 1u;
    rx_hint = 0u;

    if ((g_ch390_irq_pending != 0u) || (ch390_get_int_pin() == GPIO_PIN_RESET)) {
        g_ch390_irq_pending = 0u;
        int_status = ch390_get_int_status();

        if ((int_status & ISR_LNKCHG) != 0u) {
            ch390_runtime_check_link(netif);
        }

        if ((int_status & ISR_ROS) != 0u) {
            LINK_STATS_INC(link.err);
        }

        if ((int_status & (ISR_PR | ISR_ROS | ISR_ROO)) != 0u) {
            rx_hint = 1u;
            rx_budget = 8u;
        }
    }

    ch390_read_reg(CH390_MRCMDX);
    rx_ready = ch390_read_reg(CH390_MRCMDX);
    if ((rx_ready & CH390_PKT_RDY) != 0u) {
        rx_hint = 1u;
        if (rx_budget < 4u) {
            rx_budget = 4u;
        }
    }

    if (rx_hint != 0u) {
        (void)ch390_runtime_drain_rx(netif, rx_budget);
    }
}

void ch390_runtime_check_link(struct netif *netif)
{
    uint8_t link_up;
    static uint8_t s_last_reported = 0xFFu;

    if (!g_ch390_ready) {
        netif_set_link_down(netif);
        return;
    }

    ch390_runtime_refresh_diag();
    link_up = (uint8_t)ch390_get_link_status();

    if (link_up != s_last_reported) {
        SEGGER_RTT_printf(0,
                          "ETH link %s nsr=0x%02X bmsr=0x%04X anlpar=0x%04X\r\n",
                          link_up ? "up" : "down",
                          g_diag.nsr,
                          g_diag.phy_bmsr,
                          g_diag.phy_anlpar);
        s_last_reported = link_up;
    }

    if (link_up) {
        if (!netif_is_link_up(netif)) {
            netif_set_link_up(netif);
        }
    } else if (netif_is_link_up(netif)) {
        netif_set_link_down(netif);
    }
}

err_t ch390_runtime_output(struct netif *netif, struct pbuf *p)
{
    struct pbuf *q;
    uint32_t start_tick;

    LWIP_UNUSED_ARG(netif);

    if (!g_ch390_ready) {
        LINK_STATS_INC(link.drop);
        return ERR_IF;
    }

#if ETH_PAD_SIZE
    pbuf_remove_header(p, ETH_PAD_SIZE);
#endif

    start_tick = HAL_GetTick();
    while (ch390_read_reg(CH390_TCR) & TCR_TXREQ) {
        if ((HAL_GetTick() - start_tick) > 10u) {
#if ETH_PAD_SIZE
            pbuf_add_header(p, ETH_PAD_SIZE);
#endif
            LINK_STATS_INC(link.drop);
            g_diag.tx_packets_timeout++;
            return ERR_TIMEOUT;
        }
    }

    for (q = p; q != NULL; q = q->next) {
        ch390_write_mem((uint8_t *)q->payload, q->len);
    }

    ch390_write_reg(CH390_TXPLL, p->tot_len & 0xFFu);
    ch390_write_reg(CH390_TXPLH, (p->tot_len >> 8) & 0xFFu);
    ch390_send_request();

#if ETH_PAD_SIZE
    pbuf_add_header(p, ETH_PAD_SIZE);
#endif

    LINK_STATS_INC(link.xmit);
    g_diag.tx_packets_ok++;
    return ERR_OK;
}

void ch390_runtime_get_diag(ch390_diag_t *diag)
{
    if (diag != NULL) {
        ch390_runtime_refresh_diag();
        *diag = g_diag;
    }
}

bool ch390_runtime_is_ready(void)
{
    return g_ch390_ready != 0u;
}