/****************************************************************************

Copyright(c) 2019 by Aerospace C.Power (Chongqing) Microelectronics. ALL RIGHTS RESERVED.

This Information is proprietary to Aerospace C.Power (Chongqing) Microelectronics and MAY NOT
be copied by any method or incorporated into another program without
the express written consent of Aerospace C.Power. This Information or any portion
thereof remains the property of Aerospace C.Power. The Information contained herein
is believed to be accurate and Aerospace C.Power assumes no responsibility or
liability for its use in any way and conveys no license or title under
any patent or copyright and makes no representation or warranty that this
Information is free from patent or copyright infringement.

****************************************************************************/

/* os shim includes */
#include "os_types.h"

#include "iot_ringbuf.h"

void iot_ringbuf_init(struct ringbuf *r, uint8_t *dataptr, uint32_t size)
{
    r->data = dataptr;
    r->mask = size - 1;
    r->put_ptr = 0;
    r->get_ptr = 0;
}

uint32_t IRAM_ATTR iot_get_ring_pos(int32_t pos, struct ringbuf *r)
{
    uint32_t value = 0;
    if (pos < 0)
        value = iot_ringbuf_size(r) + pos;
    else if ((uint32_t)pos > r->mask)
        value = pos - iot_ringbuf_size(r);
    else
        value = pos;
    if (value > (uint32_t)iot_ringbuf_size(r)){
        IOT_ASSERT(0);
    }
    return value;
}

int IRAM_ATTR iot_ringbuf_put(struct ringbuf *r, uint8_t c)
{
    /* Check if buffer is full. If it is full, return 0 to indicate that
     the element was not inserted into the buffer.
    */
    if (iot_ringbuf_elements(r) == r->mask) {
        return 0;
    }
    r->data[r->put_ptr] = c;
    r->put_ptr = iot_get_ring_pos(r->put_ptr + 1, r);
    return 1;
}

int IRAM_ATTR iot_ringbuf_get(struct ringbuf *r)
{
    uint8_t c;

    /* Check if there are bytes in the buffer. If so, we return the
       first one and increase the pointer. If there are no bytes left, we
       return -1.
    */
        if (iot_ringbuf_elements(r) > 0) {
        c = r->data[r->get_ptr];
        r->get_ptr = iot_get_ring_pos(r->get_ptr + 1, r);
        return c;
    } else {
        return -1;
    }
}

uint32_t iot_ringbuf_gets(struct ringbuf *r, uint8_t *seq, uint32_t len)
{
    int c;
    uint32_t i = 0;
    IOT_ASSERT(seq);

    if (!seq)
        return 0;

    while(i < len){
        c = iot_ringbuf_get(r);
        if(c < 0 ){
            break;
        }
        *(seq+i) = (uint8_t)c;
        i++;
    }

    return i;
}

uint32_t iot_ringbuf_drop(struct ringbuf *r, uint32_t len)
{
    uint32_t move_len;

    if (len > 0){
        move_len = len > iot_ringbuf_elements(r) ?
            iot_ringbuf_elements(r) : len;

        r->get_ptr = iot_get_ring_pos(r->get_ptr + move_len, r);
        return move_len;
    }
    return 0;
}


uint32_t iot_ringbuf_puts(struct ringbuf *r, uint8_t *seq, uint32_t len)
{
    uint8_t c;
    uint32_t i = 0;

    while(i < len){
        c = *(seq+i);
        if(iot_ringbuf_put(r, c) == 0){
            break;
        }
        i++;
    }
    return i;
}

uint32_t iot_ringbuf_offset_add(ringbuf_t *r, uint32_t origin_pos,
        uint32_t add)
{
   IOT_ASSERT(origin_pos <= r->mask);
   return iot_get_ring_pos(origin_pos + add, r);
}

uint32_t iot_ringbuf_dummy_gets(ringbuf_t *r, uint8_t *buf,
    uint32_t len, uint32_t pos)
{
    int c;
    uint32_t i = 0, get_dummy;
    IOT_ASSERT(buf);
    if (!buf || pos > r->mask)
        return 0;
    if (iot_get_ring_pos(pos - r->get_ptr, r) >
        iot_get_ring_pos(r->put_ptr - r->get_ptr, r))
        get_dummy = r->get_ptr;
    else
        get_dummy = pos;
    /* check if there are bytes in the buffer. If so, we return the
     * first one and increase the pointer.
     */
    while (i < len && get_dummy != r->put_ptr) {
        c = r->data[get_dummy];
        get_dummy = iot_get_ring_pos((get_dummy + 1), r);
        buf[i] = (uint8_t)c;
        i++;
    }
    return i;
}

int IRAM_ATTR iot_ringbuf_size(struct ringbuf *r)
{
    return r->mask + 1;
}

uint32_t IRAM_ATTR iot_ringbuf_elements(struct ringbuf *r)
{
    if (r->put_ptr >= r->get_ptr)
        return r->put_ptr - r->get_ptr;
    else
        return iot_ringbuf_size(r) - (r->get_ptr - r->put_ptr);
}