#include <stdio.h>
#include <string.h>
#include <irq.h>
#include <uart.h>
#include <console.h>
#include <system.h>
#include <time.h>
#include <generated/csr.h>
#include <hw/flags.h>

#ifdef CSR_ETHMAC_BASE
#include <netif/etharp.h>
#include <netif/liteethif.h>
#include <lwip/init.h>
#include <lwip/memp.h>
#include <lwip/ip4_addr.h>
#include <lwip/ip4.h>
#include <lwip/netif.h>
#include <lwip/sys.h>
#include <lwip/tcp.h>
#include <lwip/timers.h>
#endif

#include "flash_storage.h"
#include "clock.h"
#include "test_mode.h"
#include "kserver.h"
#include "session.h"

#ifdef CSR_ETHMAC_BASE

u32_t sys_now(void)
{
    return clock_get_ms();
}

static struct netif netif;

static void lwip_service(void)
{
    sys_check_timeouts();
    if(ethmac_sram_writer_ev_pending_read() & ETHMAC_EV_SRAM_WRITER) {
        liteeth_input(&netif);
        ethmac_sram_writer_ev_pending_write(ETHMAC_EV_SRAM_WRITER);
    }
}

unsigned char macadr[6];

static int hex2nib(int c)
{
    if((c >= '0') && (c <= '9'))
        return c - '0';
    if((c >= 'a') && (c <= 'f'))
        return c - 'a' + 10;
    if((c >= 'A') && (c <= 'F'))
        return c - 'A' + 10;
    return -1;
}

static void init_macadr(void)
{
    static const unsigned char default_macadr[6] = {0x10, 0xe2, 0xd5, 0x32, 0x50, 0x00};
    char b[32];
    char fs_macadr[6];
    int i, r, s;

    memcpy(macadr, default_macadr, 6);
    r = fs_read("mac", b, sizeof(b) - 1, NULL);
    if(r <= 0)
        return;
    b[r] = 0;
    for(i=0;i<6;i++) {
        r = hex2nib(b[3*i]);
        s = hex2nib(b[3*i + 1]);
        if((r < 0) || (s < 0))
            return;
        fs_macadr[i] = (r << 4) | s;
    }
    for(i=0;i<5;i++)
        if(b[3*i + 2] != ':')
            return;
    memcpy(macadr, fs_macadr, 6);
}

static void fsip_or_default(struct ip4_addr *d, char *key, int i1, int i2, int i3, int i4)
{
    int r;
    char cp[32];

    IP4_ADDR(d, i1, i2, i3, i4);

    r = fs_read(key, cp, sizeof(cp) - 1, NULL);
    if(r <= 0)
        return;
    cp[r] = 0;
    if(!ip4addr_aton(cp, d))
        return;
}

static void network_init(void)
{
    struct ip4_addr local_ip;
    struct ip4_addr netmask;
    struct ip4_addr gateway_ip;

    init_macadr();
    fsip_or_default(&local_ip, "ip", 192, 168, 0, 42);
    fsip_or_default(&netmask, "netmask", 255, 255, 255, 0);
    fsip_or_default(&gateway_ip, "gateway", 192, 168, 0, 1);

    lwip_init();

    netif_add(&netif, &local_ip, &netmask, &gateway_ip, 0, liteeth_init, ethernet_input);
    netif_set_default(&netif);
    netif_set_up(&netif);
    netif_set_link_up(&netif);
}

static void regular_main(void)
{
    puts("Accepting sessions on Ethernet");
    clock_init();
    network_init();
    kserver_init();

    while(1) {
        lwip_service();
        kserver_service();
    }
}

#else /* CSR_ETHMAC_BASE */

static void reset_serial_session(void)
{
    int i;

    session_end();
    /* Signal end-of-session inband with zero length packet. */
    for(i=0;i<4;i++)
        uart_write(0x5a);
    for(i=0;i<4;i++)
        uart_write(0x00);
    session_start();
}

static void serial_service(void)
{
    char *txdata;
    int txlen;
    static char rxdata;
    static int rxpending;
    int r, i;

    if(!rxpending && uart_read_nonblock()) {
        rxdata = uart_read();
        rxpending = 1;
    }
    if(rxpending) {
        r = session_input(&rxdata, 1);
        if(r > 0)
            rxpending = 0;
        if(r < 0)
            reset_serial_session();
    }

    session_poll((void **)&txdata, &txlen);
    if(txlen > 0) {
        for(i=0;i<txlen;i++)
            uart_write(txdata[i]);
        session_ack_data(txlen);
        session_ack_mem(txlen);
    } else if(txlen < 0)
        reset_serial_session();
}

static void regular_main(void)
{
    puts("Accepting sessions on serial link");
    clock_init();

    /* Open the session for the serial control. */
    session_start();
    while(1)
        serial_service();
}

#endif

static void blink_led(void)
{
    int i, ev, p;

    p = identifier_frequency_read()/10;
    time_init();
    for(i=0;i<3;i++) {
        leds_out_write(1);
        while(!elapsed(&ev, p));
        leds_out_write(0);
        while(!elapsed(&ev, p));
    }
}

static int check_test_mode(void)
{
    char c;

    timer0_en_write(0);
    timer0_reload_write(0);
    timer0_load_write(identifier_frequency_read() >> 2);
    timer0_en_write(1);
    timer0_update_value_write(1);
    while(timer0_value_read()) {
        if(readchar_nonblock()) {
            c = readchar();
            if((c == 't')||(c == 'T'))
                return 1;
        }
        timer0_update_value_write(1);
    }
    return 0;
}

int main(void)
{
    irq_setmask(0);
    irq_setie(1);
    uart_init();

    puts("ARTIQ runtime built "__DATE__" "__TIME__"\n");

    puts("Press 't' to enter test mode...");
    blink_led();

    if(check_test_mode()) {
        puts("Entering test mode.");
        test_main();
    } else {
        puts("Entering regular mode.");
        regular_main();
    }
    return 0;
}