/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Damien P. George
 * Copyright (c) 2020 Jim Mussared
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "py/runtime.h"
#include "py/stream.h"
#include "py/mphal.h"
#include "shared/timeutils/timeutils.h"
#include "extmod/misc.h"
#include "ticks.h"
#include "tusb.h"
#include "fsl_snvs_lp.h"
#include "fsl_ocotp.h"

#include CPU_HEADER_H

STATIC uint8_t stdin_ringbuf_array[260];
ringbuf_t stdin_ringbuf = {stdin_ringbuf_array, sizeof(stdin_ringbuf_array), 0, 0};

#if MICROPY_KBD_EXCEPTION

int mp_interrupt_char = -1;

void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char) {
    (void)itf;
    (void)wanted_char;
    tud_cdc_read_char(); // discard interrupt char
    mp_sched_keyboard_interrupt();
}

void mp_hal_set_interrupt_char(int c) {
    mp_interrupt_char = c;
    tud_cdc_set_wanted_char(c);
}

#endif

uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
    uintptr_t ret = 0;
    if ((poll_flags & MP_STREAM_POLL_RD) && ringbuf_peek(&stdin_ringbuf) != -1) {
        ret |= MP_STREAM_POLL_RD;
    }
    if (tud_cdc_connected() && tud_cdc_available()) {
        ret |= MP_STREAM_POLL_RD;
    }
    return ret;
}

int mp_hal_stdin_rx_chr(void) {
    for (;;) {
        // TODO
        // if (USARTx->USART.INTFLAG.bit.RXC) {
        //     return USARTx->USART.DATA.bit.DATA;
        // }
        int c = ringbuf_get(&stdin_ringbuf);
        if (c != -1) {
            return c;
        }
        if (tud_cdc_connected() && tud_cdc_available()) {
            uint8_t buf[1];
            uint32_t count = tud_cdc_read(buf, sizeof(buf));
            if (count) {
                return buf[0];
            }
        }
        MICROPY_EVENT_POLL_HOOK
    }
}

void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
    if (tud_cdc_connected()) {
        for (size_t i = 0; i < len;) {
            uint32_t n = len - i;
            if (n > CFG_TUD_CDC_EP_BUFSIZE) {
                n = CFG_TUD_CDC_EP_BUFSIZE;
            }
            while (n > tud_cdc_write_available()) {
                __WFE();
            }
            uint32_t n2 = tud_cdc_write(str + i, n);
            tud_cdc_write_flush();
            i += n2;
        }
    }
    mp_uos_dupterm_tx_strn(str, len);
    // TODO
    // while (len--) {
    //     while (!(USARTx->USART.INTFLAG.bit.DRE)) { }
    //     USARTx->USART.DATA.bit.DATA = *str++;
    // }
}

uint64_t mp_hal_time_ns(void) {
    snvs_lp_srtc_datetime_t t;
    SNVS_LP_SRTC_GetDatetime(SNVS, &t);
    uint64_t s = timeutils_seconds_since_epoch(t.year, t.month, t.day, t.hour, t.minute, t.second);
    return s * 1000000000ULL;
}

/*******************************************************************************/
// MAC address

void mp_hal_get_unique_id(uint8_t id[]) {
    OCOTP_Init(OCOTP, CLOCK_GetFreq(kCLOCK_IpgClk));
    *(uint32_t *)&id[0] = OCOTP->CFG0;
    *(uint32_t *)&id[4] = OCOTP->CFG1;
}

// Generate a random locally administered MAC address (LAA)
void mp_hal_generate_laa_mac(int idx, uint8_t buf[6]) {
    // Take the MAC addr from the OTP's Configuration and Manufacturing Info
    unsigned char id[8];
    mp_hal_get_unique_id(id);

    uint32_t pt1 = *(uint32_t *)&id[0];
    uint32_t pt2 = *(uint32_t *)&id[4];

    buf[0] = 0x02; // Locally Administered MAC
    *(uint32_t *)&buf[1] = pt1 ^ (pt1 >> 8);
    *(uint16_t *)&buf[4] = (uint16_t)(pt2 ^ pt2 >> 16);
    buf[5] ^= (uint8_t)idx;
}

// A board can override this if needed
MP_WEAK void mp_hal_get_mac(int idx, uint8_t buf[6]) {
    mp_hal_generate_laa_mac(idx, buf);
}

void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest) {
    static const char hexchr[16] = "0123456789ABCDEF";
    uint8_t mac[6];
    mp_hal_get_mac(idx, mac);
    for (; chr_len; ++chr_off, --chr_len) {
        *dest++ = hexchr[mac[chr_off >> 1] >> (4 * (1 - (chr_off & 1))) & 0xf];
    }
}
