/**
 * This is just a test program, it does nothing but just 
 * init the cache first then use get_cache_sector to test
 * the LRU algorithm with 12 fake-sector number.
 *
 * And it work well here
 *
 */
#include <stdio.h>
#include "cache.h"
#include "ext2_fs.h"

#include <fcntl.h>
#include <sys/stat.h>



struct ext2_super_block sb;

int fd;

extern struct cache_struct cache[CACHE_ENTRIES + 1];


/**
 * Just print the sector, and according the LRU algorithm, 
 * Left most value is the most least secotr, and Right most 
 * value is the most Recent sector. I see it's a Left Right Used
 * (LRU) algorithm; Just kidding:)
 */
void print_cache(void)
{
        int i = 0;
        struct cache_struct *cs = cache;
        for (; i < CACHE_ENTRIES; i++) {
                cs = cs->next;
                printf("%d ", cs->block);        
        }

        printf("\n");
}


/* test function */
void print_hex(char *data, int size)
{
        int i = 0;
        while ( size --) {
                
                if ( (i != 0) && (i % 16 == 0) )
                        printf("\n");
                i ++;

                if ( (*data < 0x20 ) || (*data > 0x80 ) ) {
                        printf(".");
                        data ++;
                        continue;
                }
                putc(*data, stdout);
                data++;

        }
        printf("\n");
}


void usage(void)
{
        printf("USAGE: a.out ext2fs.img filename\n");
        printf("---- ext2fs.img means a ext2 filesytem image\n");
        printf("---- filename menas the file you wanna open, it can be \n");
        printf("     in one of the two following forms:\n");
        printf("     /file/name/xy.y, this is a full name, or \n");
        printf("     file/name/xy.z, in this case, the program will search\n");
        printf("     from the directory where the extlinux.sys stored\n");

}




/**
 * well, it's just a test program that test if the fs driver 
 * would work on ext2/3(ext4 not added for now) filesystem 
 * well or not. so it's task is simple,too: open the ext2fs, 
 * then read what you want.
 *
 */
int main(int argc, char *argv[])
{

        int bytes_read = 0;
        int total_bytes = 0;
        int have_more;
        char *ext2fs = argv[1];
        char *filename = argv[2];
        char buf[1024];
        struct cache_struct *cs;
        struct open_file_t *file = NULL;
        

        if (argc != 3 ) {
                usage();
                return 0;
        }

        /* init. the cache */
        cache_init();

        
        fd = open(ext2fs, O_RDONLY);
        if ( fd < 0 ) {
                printf("File %s open error....\n", ext2fs);
                return 0;
        }

        init_fs(&sb);

        file = (struct open_file_t *)open_file(filename);
        if ( ! file ) {
                printf("open file error: file %s not found ....\n", filename);
                close(fd);
                return 0;
        }

        /*
         * The following message may be nosiy, but it told we how is it 
         * going well.
         */
        do {
                bytes_read = read_file(file, buf, 1024, &have_more);
                printf("--------read %d bytes-------\n", bytes_read);
                printf("----------------\n");
                print_hex(buf, bytes_read);
                
                total_bytes += bytes_read;
        }while(have_more);
        
        printf("-------------total read %d bytes------\n", total_bytes);

        close(fd);

        return 0;
}