/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * Development of the code in this file was sponsored by Microbric Pty Ltd
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2014 Damien P. George
 *
 * 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 <stdio.h>
#include <string.h>
#include <sys/time.h>

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#if MICROPY_ESP_IDF_4
#include "esp32/rom/uart.h"
#else
#include "rom/uart.h"
#endif

#include "py/obj.h"
#include "py/objstr.h"
#include "py/stream.h"
#include "py/mpstate.h"
#include "py/mphal.h"
#include "extmod/misc.h"
#include "lib/timeutils/timeutils.h"
#include "lib/utils/pyexec.h"
#include "mphalport.h"

TaskHandle_t mp_main_task_handle;

STATIC uint8_t stdin_ringbuf_array[256];
ringbuf_t stdin_ringbuf = {stdin_ringbuf_array, sizeof(stdin_ringbuf_array)};

// Check the ESP-IDF error code and raise an OSError if it's not ESP_OK.
void check_esp_err(esp_err_t code) {
    if (code != ESP_OK) {
        // map esp-idf error code to posix error code
        uint32_t pcode = -code;
        switch (code) {
            case ESP_ERR_NO_MEM:
                pcode = MP_ENOMEM;
                break;
            case ESP_ERR_TIMEOUT:
                pcode = MP_ETIMEDOUT;
                break;
            case ESP_ERR_NOT_SUPPORTED:
                pcode = MP_EOPNOTSUPP;
                break;
        }
        // construct string object
        mp_obj_str_t *o_str = m_new_obj_maybe(mp_obj_str_t);
        if (o_str == NULL) {
            mp_raise_OSError(pcode);
            return;
        }
        o_str->base.type = &mp_type_str;
        o_str->data = (const byte *)esp_err_to_name(code); // esp_err_to_name ret's ptr to const str
        o_str->len = strlen((char *)o_str->data);
        o_str->hash = qstr_compute_hash(o_str->data, o_str->len);
        // raise
        mp_obj_t args[2] = { MP_OBJ_NEW_SMALL_INT(pcode), MP_OBJ_FROM_PTR(o_str)};
        nlr_raise(mp_obj_exception_make_new(&mp_type_OSError, 2, 0, args));
    }
}

uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
    uintptr_t ret = 0;
    if ((poll_flags & MP_STREAM_POLL_RD) && stdin_ringbuf.iget != stdin_ringbuf.iput) {
        ret |= MP_STREAM_POLL_RD;
    }
    return ret;
}

int mp_hal_stdin_rx_chr(void) {
    for (;;) {
        int c = ringbuf_get(&stdin_ringbuf);
        if (c != -1) {
            return c;
        }
        MICROPY_EVENT_POLL_HOOK
        ulTaskNotifyTake(pdFALSE, 1);
    }
}

void mp_hal_stdout_tx_str(const char *str) {
    mp_hal_stdout_tx_strn(str, strlen(str));
}

void mp_hal_stdout_tx_strn(const char *str, uint32_t len) {
    // Only release the GIL if many characters are being sent
    bool release_gil = len > 20;
    if (release_gil) {
        MP_THREAD_GIL_EXIT();
    }
    for (uint32_t i = 0; i < len; ++i) {
        uart_tx_one_char(str[i]);
    }
    if (release_gil) {
        MP_THREAD_GIL_ENTER();
    }
    mp_uos_dupterm_tx_strn(str, len);
}

// Efficiently convert "\n" to "\r\n"
void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
    const char *last = str;
    while (len--) {
        if (*str == '\n') {
            if (str > last) {
                mp_hal_stdout_tx_strn(last, str - last);
            }
            mp_hal_stdout_tx_strn("\r\n", 2);
            ++str;
            last = str;
        } else {
            ++str;
        }
    }
    if (str > last) {
        mp_hal_stdout_tx_strn(last, str - last);
    }
}

uint32_t mp_hal_ticks_ms(void) {
    return esp_timer_get_time() / 1000;
}

uint32_t mp_hal_ticks_us(void) {
    return esp_timer_get_time();
}

void mp_hal_delay_ms(uint32_t ms) {
    uint64_t us = ms * 1000;
    uint64_t dt;
    uint64_t t0 = esp_timer_get_time();
    for (;;) {
        uint64_t t1 = esp_timer_get_time();
        dt = t1 - t0;
        if (dt + portTICK_PERIOD_MS * 1000 >= us) {
            // doing a vTaskDelay would take us beyond requested delay time
            break;
        }
        MICROPY_EVENT_POLL_HOOK
        ulTaskNotifyTake(pdFALSE, 1);
    }
    if (dt < us) {
        // do the remaining delay accurately
        mp_hal_delay_us(us - dt);
    }
}

void mp_hal_delay_us(uint32_t us) {
    // these constants are tested for a 240MHz clock
    const uint32_t this_overhead = 5;
    const uint32_t pend_overhead = 150;

    // return if requested delay is less than calling overhead
    if (us < this_overhead) {
        return;
    }
    us -= this_overhead;

    uint64_t t0 = esp_timer_get_time();
    for (;;) {
        uint64_t dt = esp_timer_get_time() - t0;
        if (dt >= us) {
            return;
        }
        if (dt + pend_overhead < us) {
            // we have enough time to service pending events
            // (don't use MICROPY_EVENT_POLL_HOOK because it also yields)
            mp_handle_pending(true);
        }
    }
}

uint64_t mp_hal_time_ns(void) {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    // gettimeofday returns seconds since 2000/1/1
    uint64_t ns = timeutils_seconds_since_2000_to_nanoseconds_since_1970(tv.tv_sec);
    ns += (uint64_t)tv.tv_usec * 1000ULL;
    return ns;
}

// Wake up the main task if it is sleeping
void mp_hal_wake_main_task_from_isr(void) {
    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
    vTaskNotifyGiveFromISR(mp_main_task_handle, &xHigherPriorityTaskWoken);
    if (xHigherPriorityTaskWoken == pdTRUE) {
        portYIELD_FROM_ISR();
    }
}
