#ifndef __ZVFS_HOOK_H__
#define __ZVFS_HOOK_H__

#include <stdio.h>

#include <spdk/event.h>
#include <spdk/blob.h>
#include <spdk/bdev.h>
#include <spdk/blob_bdev.h>
#include <spdk/env.h>

#define ZVFS_MAX_FILES  1024
#define ZVFS_MAX_FD     64
#define BUFFER_SIZE     (1024*8)

extern const char *json_file;
extern struct spdk_thread *global_thread;
static const int WAITER_MAX_TIME = 10000000;

/* 目录项（内存中的目录） */
typedef struct {
    char        filename[256];
    spdk_blob_id blob_id;
    uint64_t    file_size;          // 文件逻辑大小（字节）
    uint64_t    allocated_clusters; // 已分配的cluster数量
    bool        is_valid;           // false 表示已删除
    int32_t     open_count;         // 打开的文件句柄数量
} zvfs_dirent_t;

/* 文件系统全局结构 */
typedef struct zvfs_s {
    struct spdk_bs_dev      *bs_dev;
    struct spdk_blob_store  *bs;
    struct spdk_io_channel  *channel;
    struct spdk_blob        *super_blob;    // 承载目录日志的blob
    uint64_t                io_unit_size;   // page大小，单位字节

    /* 目录 */
    zvfs_dirent_t           *dirents[ZVFS_MAX_FILES];       // 目录项数组 #define ZVFS_MAX_FILES 1024
    uint32_t                dirent_count;   // 当前有效项数

    /* 伪FD表 */
    struct zvfs_file_s      *fd_table[ZVFS_MAX_FD]; // // e.g., #define ZVFS_MAX_FD 64
    int                     fd_base;                // 伪FD起始值，如1000
	int 					openfd_count;

    /* 元数据 */
    uint32_t                magic;                  // 0x5A563146 (ZV1F)
    uint32_t                version;                // 1


    bool finished;
} zvfs_t;

/* 打开的文件句柄 */
typedef struct zvfs_file_s {
    zvfs_t                  *fs;
	spdk_blob_id            blob_id;
    struct spdk_blob        *blob;
    zvfs_dirent_t           *dirent;        // 指回目录项 file_size/allocated_clusters
    
    uint64_t                current_offset; // 当前读写位置
    int                     flags;          // O_RDONLY / O_RDWR / O_CREAT 等
    int                     pseudo_fd;

    /* 临时DMA缓冲区（可选：每个file一个，避免每次malloc） */
    void                    *dma_buf;
    uint64_t                dma_buf_size;
    
    size_t          actual_io_count;
    const uint8_t  *write_staging_buf; 
    int             aligned;

    size_t                  io_count;
    bool finished;
} zvfs_file_t;

bool waiter(struct spdk_thread *thread, spdk_msg_fn start_fn, void *ctx, bool *finished);

int zvfs_env_setup(void);
int zvfs_mount(struct zvfs_s *fs);
int zvfs_umount(struct zvfs_s *fs);
int zvfs_create(struct zvfs_file_s *file);
int zvfs_open(struct zvfs_file_s *file);
int zvfs_read(struct zvfs_file_s *file, uint8_t *buffer, size_t count);
int zvfs_write(struct zvfs_file_s *file, const uint8_t *buffer, size_t count);
int zvfs_close(struct zvfs_file_s *file);
int zvfs_delete(struct zvfs_file_s *file);

/* POSIX hook API（zvfs_hook.c 实现） */
int     open(const char *path, int flags, ...);
ssize_t read(int fd, void *buf, size_t count);
ssize_t write(int fd, const void *buf, size_t count);
int     close(int fd);
int unlink(const char *name);
off_t lseek(int fd, off_t offset, int whence);

#endif