/* Virtual File System Server
 * Provides unified interface to different file systems
 * Based on MINIX3 VFS server
 */

#include "../kernel/kernel.h"

extern int printf(const char* format, ...);
extern int receive(int source, message_t* msg);

#define VFS_NAME "Virtual File System"
#define MAX_FILES 256

typedef struct {
    int fd;
    int inode;
    int flags;
    int offset;
} vfs_file_t;

static vfs_file_t file_table[MAX_FILES];

void vfs_init() {
    printf("[%s] Initializing...\n", VFS_NAME);
    
    /* Initialize file table */
    for (int i = 0; i < MAX_FILES; i++) {
        file_table[i].fd = -1;
    }
    
    printf("[%s] Ready\n", VFS_NAME);
}

int vfs_open(const char* path, int flags) {
    /* Find free file descriptor */
    for (int i = 0; i < MAX_FILES; i++) {
        if (file_table[i].fd == -1) {
            file_table[i].fd = i;
            file_table[i].flags = flags;
            file_table[i].offset = 0;
            return i;
        }
    }
    return -1;
}

int vfs_read(int fd, void* buf, size_t count) {
    if (fd < 0 || fd >= MAX_FILES || file_table[fd].fd == -1) {
        return -1;
    }
    
    /* TODO: Actual read implementation */
    return 0;
}

int vfs_write(int fd, const void* buf, size_t count) {
    if (fd < 0 || fd >= MAX_FILES || file_table[fd].fd == -1) {
        return -1;
    }
    
    /* TODO: Actual write implementation */
    return count;
}

void vfs_close(int fd) {
    if (fd >= 0 && fd < MAX_FILES) {
        file_table[fd].fd = -1;
    }
}

void vfs_main() {
    message_t msg;
    
    vfs_init();
    
    /* Main server loop */
    for(;;) {
        receive(-1, &msg);
        
        switch(msg.type) {
            case SYS_OPEN:
                /* Handle open request */
                break;
            case SYS_READ:
                /* Handle read request */
                break;
            case SYS_WRITE:
                /* Handle write request */
                break;
            case SYS_CLOSE:
                /* Handle close request */
                break;
            default:
                printf("[%s] Unknown message type: %d\n", VFS_NAME, msg.type);
        }
    }
}