/**
 * @file lwrb.h
 * \brief           LwRB - Lightweight ring buffer
 */

/*
 * Copyright (c) 2024 Tilen MAJERLE
 *
 * 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.
 *
 * This file is part of LwRB - Lightweight ring buffer library.
 *
 * Author:          Tilen MAJERLE <tilen@majerle.eu>
 * Version:         v3.2.0
 */
#ifndef LWRB_HDR_H
#define LWRB_HDR_H

#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "lib.h"

// #define LWRB_DISABLE_ATOMIC

#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */

    /**
     * \defgroup        LWRB Lightweight ring buffer manager
     * \brief           Lightweight ring buffer manager
     * \{
     */

#if defined(LWRB_DISABLE_ATOMIC) || __DOXYGEN__
#include <stdatomic.h>

    /**
     * \brief           Atomic type for size variable.
     * Default value is set to be `unsigned 32-bits` type
     */
    typedef atomic_ulong lwrb_sz_atomic_t;

    /**
     * \brief           Size variable for all library operations.
     * Default value is set to be `unsigned 32-bits` type
     */
    typedef unsigned long lwrb_sz_t;
#else
typedef unsigned long lwrb_sz_atomic_t;
typedef unsigned long lwrb_sz_t;
#endif

    /**
     * \brief           Event type for buffer operations
     */
    typedef enum
    {
        LWRB_EVT_READ,  /*!< Read event */
        LWRB_EVT_WRITE, /*!< Write event */
        LWRB_EVT_RESET, /*!< Reset event */
    } lwrb_evt_type_t;

    /**
     * \brief           Buffer structure forward declaration
     */
    struct lwrb;

    /**
     * \brief           Event callback function type
     * \param[in]       buff: Buffer handle for event
     * \param[in]       evt: Event type
     * \param[in]       bp: Number of bytes written or read (when used), depends on event type
     */
    typedef void (*lwrb_evt_fn)(struct lwrb *buff, lwrb_evt_type_t evt, lwrb_sz_t bp);

/* List of flags */
#define LWRB_FLAG_READ_ALL ((uint16_t)0x0001)
#define LWRB_FLAG_WRITE_ALL ((uint16_t)0x0001)

    /**
     * \brief           Buffer structure
     */
    typedef struct lwrb
    {
        uint8_t *buff;          /*!< Pointer to buffer data. Buffer is considered initialized when `buff != NULL` and `size > 0` */
        lwrb_sz_t size;         /*!< Size of buffer data. Size of actual buffer is `1` byte less than value holds */
        lwrb_sz_atomic_t r_ptr; /*!< Next read pointer.
                                    Buffer is considered empty when `r == w` and full when `w == r - 1` */
        lwrb_sz_atomic_t w_ptr; /*!< Next write pointer.
                                    Buffer is considered empty when `r == w` and full when `w == r - 1` */
        lwrb_evt_fn evt_fn;     /*!< Pointer to event callback function */
        void *arg;              /*!< Event custom user argument */
    } lwrb_t;

    uint8_t lwrb_init(lwrb_t *buff, void *buffdata, lwrb_sz_t size);
    uint8_t lwrb_is_ready(lwrb_t *buff);
    void lwrb_free(lwrb_t *buff);
    void lwrb_reset(lwrb_t *buff);
    void lwrb_set_evt_fn(lwrb_t *buff, lwrb_evt_fn fn);
    void lwrb_set_arg(lwrb_t *buff, void *arg);
    void *lwrb_get_arg(lwrb_t *buff);

    /* Read/Write functions */
    lwrb_sz_t lwrb_write(lwrb_t *buff, const void *data, lwrb_sz_t btw);
    lwrb_sz_t lwrb_read(lwrb_t *buff, void *data, lwrb_sz_t btr);
    lwrb_sz_t lwrb_peek(const lwrb_t *buff, lwrb_sz_t skip_count, void *data, lwrb_sz_t btp);

    /* Extended read/write functions */
    uint8_t lwrb_write_ex(lwrb_t *buff, const void *data, lwrb_sz_t btw, lwrb_sz_t *bwritten, uint16_t flags);
    uint8_t lwrb_read_ex(lwrb_t *buff, void *data, lwrb_sz_t btr, lwrb_sz_t *bread, uint16_t flags);

    /* Buffer size information */
    lwrb_sz_t lwrb_get_free(const lwrb_t *buff);
    lwrb_sz_t lwrb_get_full(const lwrb_t *buff);

    /* Read data block management */
    void *lwrb_get_linear_block_read_address(const lwrb_t *buff);
    lwrb_sz_t lwrb_get_linear_block_read_length(const lwrb_t *buff);
    lwrb_sz_t lwrb_skip(lwrb_t *buff, lwrb_sz_t len);

    /* Write data block management */
    void *lwrb_get_linear_block_write_address(const lwrb_t *buff);
    lwrb_sz_t lwrb_get_linear_block_write_length(const lwrb_t *buff);
    lwrb_sz_t lwrb_advance(lwrb_t *buff, lwrb_sz_t len);

    /* Search in buffer */
    uint8_t lwrb_find(const lwrb_t *buff, const void *bts, lwrb_sz_t len, lwrb_sz_t start_offset, lwrb_sz_t *found_idx);
    lwrb_sz_t lwrb_overwrite(lwrb_t *buff, const void *data, lwrb_sz_t btw);
    lwrb_sz_t lwrb_move(lwrb_t *dest, lwrb_t *src);

    /**
     * \}
     */

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* LWRB_HDR_H */