/******************************************************************************
 * file    lib/management/file_fifo.c 
 * author  YuLiang
 * version 1.0.0
 * date    10-Jun-2025
 * brief   This file provides all the file fifo operation functions.
 *
 ******************************************************************************
 * Attention
 *
 * <h2><center>&copy; COPYRIGHT(c) 2025 LandPower</center></h2>
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *   3. Neither the name of LandPower nor the names of its contributors may be used to 
 *      endorse or promote products derived from this software without specific
 *      prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* 标准C库头文件. */
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <ctype.h>

/* 用户代码头文件. */
#include <file_fifo.h>

/* Private define ------------------------------------------------------------*/

/* Private macro -------------------------------------------------------------*/

/* Private typedef -----------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/

/* Private function prototypes -----------------------------------------------*/

/* Internal functions --------------------------------------------------------*/
/* 创建目录 */
int32_t _file_fifo_dir_create(char *dir)
{
    uint32_t i = 0;
    uint32_t len = 0;
    
    len = strlen(dir);

    /* 循环创建前级目录 */
    for(i = 0; i < len; i++)
    {
        if(dir[i] == '/')
        {
            dir[i] = '\0';
            if(access(dir, 0) != 0)
            {
                mkdir(dir, 744);
            }
            dir[i] ='/';
        }
    }

    /* 创建最后级目录 */
    if(len > 0 && access(dir, 0) != 0)
    {
        mkdir(dir, 744);
    }
    
    return E_NONE;
}

/* Interface functions -------------------------------------------------------*/
/* 写函数 */
int32_t file_fifo_write(file_fifo_t *config, const char *content, int32_t len)
{
    FILE *fp = NULL;
    char filename[FILE_FIFO_PATH_LEN];
    int32_t size = 0;

    if (config->index_max - config->index_min >= config->files_max)
    {
        return E_FULL;
    }

    /* 确认文件名 */
    snprintf(filename, FILE_FIFO_PATH_LEN, "%s/%lld", config->dir, config->index_max);

    /* 写入文件 */
    fp = fopen(filename, "w+");
    if (!fp)
    {
        DBG(DBG_M_FILE_FIFO_ERR, "Open %s ERROR\r\n", filename);
        return E_SYS_CALL;
    }

    size = fwrite(content, 1, len, fp);
    if (size != len)
    {
        fclose(fp);
        DBG(DBG_M_FILE_FIFO_ERR, "Write %s ERROR\r\n", filename);
        return E_SYS_CALL;
    }
    fclose(fp);

    config->index_max++;
    return E_NONE;
}

/* 读函数 */
int32_t file_fifo_read(file_fifo_t *config, char *content, int32_t *len)
{
    FILE *fp = NULL;
    char filename[FILE_FIFO_PATH_LEN];
    int32_t size = 0;

    if (config->index_max == config->index_min)
    {
        return E_EMPTY;
    }

    /* 确认文件名 */
    snprintf(filename, FILE_FIFO_PATH_LEN, "%s/%lld", config->dir, config->index_min);

    /* 打开文件 */
    fp = fopen(filename, "r");
    if (!fp)
    {
        file_fifo_delete_by_min_index(config);
        DBG(DBG_M_FILE_FIFO_ERR, "Open %s ERROR\r\n", filename);
        return E_SYS_CALL;
    }

    size = fread(content, 1, *len, fp);
    if (size <= 0)
    {
        fclose(fp);
        file_fifo_delete_by_min_index(config);
        DBG(DBG_M_FILE_FIFO_ERR, "Read %s ERROR\r\n", filename);
        return E_SYS_CALL;
    }
    *len = size;
    fclose(fp);

    return E_NONE;
}

/* 删除最小索引文件 */
void file_fifo_delete_by_min_index(file_fifo_t *config)
{
    char filename[FILE_FIFO_PATH_LEN];
    
    snprintf(filename, FILE_FIFO_PATH_LEN, "%s/%lld", config->dir, config->index_min);
    remove(filename);
    
    /* 更新最小索引 */
    config->index_min++;
}

/* 初始化最大最小索引, 这套接口不能在不同线程同时调用, 例如 write 接口只能在单一线程调用, read可以在另一个线程调用,
   但是 write 接口不能同时在两个线程调用 */
int32_t file_fifo_init(file_fifo_t *config)
{
    DIR *dir = opendir(config->dir);
    struct dirent *entry;
    uint8_t first = 1;
    int64_t index = 0;

    config->index_max = 0;
    config->index_min = 0;
    
    if (!dir)
    {
        /* 创建目录 */
        _file_fifo_dir_create(config->dir);
    }
    else
    {
        /* 初始化最大最小 index */
        while ((entry = readdir(dir)) != NULL)
        {
            if (entry->d_type != DT_REG)
            {
                continue;
            }

            if (!isdigit(entry->d_name[0]))
            {
                continue;
            }

            index = strtoll(entry->d_name, NULL, 10);
            if (first)
            {
                config->index_max = config->index_min = index;
                first = 0;
            }
            else
            {
                if (index > config->index_max)
                {
                    config->index_max = index;
                }

                if (index < config->index_min)
                {
                    config->index_min = index;
                }
            }
        }

        /* 非空目录最大索引要加一 */
        if (!first)
        {
            config->index_max++;
        }
        
        closedir(dir);
    }
    
    return E_NONE;
}
/************************ (C) COPYRIGHT LandPower ***** END OF FILE ****************/