/*
 * Main driver program for hardlink to directory program.
 * Written by Michael Rywalt - 2569
 * Operating System Concepts
 */
#include "../Common/file.h"

int main(int argc, char **argv)
{
    void *pFileSystem;
    tsSuperBlock *pSuperBlock;
    tsDirEntry sDirEntry;
    tsInode *pInode;
    int iBlockSize;
    int iFileSystemSize;
    int iRetVal = 0;

    /* We must have the correct number of arguments to proceed. */
    if(argc < 4)
    {
        printf("usage: lnhdir <filesystem> <targetDir> <hardLinkName>\n");
        return EXIT_FAILURE;
    }

    pFileSystem = LoadFileSystem(argv[1]);

    if(pFileSystem == NULL)
    {
        printf("Error: Filesystem not found, or too small.\n");
        return EXIT_FAILURE;
    }

    pSuperBlock = (tsSuperBlock*)((char*)pFileSystem + SUPERBLOCK_OFFSET);

    /* Verify that we're looking at a real EXT2 filesystem. */
    if(!VerifyFSMagicNumber(pSuperBlock))
    {
        FreeFileSystem(pFileSystem);
        printf("Filesystem is not EXT2, or has been corrupted.\n");
        return EXIT_FAILURE;
    }

    printf("lnhdir: attempting to hardlink %s to %s...\n", argv[3], argv[2]);

    /* Get the filesystem size. */
    iFileSystemSize = GetFileSize(argv[1]);

    /* Get our block size. */
    iBlockSize = GetFSBlockSize(pSuperBlock);

    /* We want to get the root directory inode. 0 is our starting inode table entry. */
    pInode = GetInode(1, pFileSystem); 

    /* We are now finding an inode based on the file/dir name. This is the second argument to the program. */
    pInode = GetMatchingInode(argv[2], pInode, pFileSystem);

    /* Add a new entry into the current directory's table which points to the current directory's inode.
     * This is our hard link to the directory.
     */
    iRetVal = InsertHardLink(argv[1], argv[3], pInode, pFileSystem);

    if(iRetVal == 1)
    {
        /* Save the newly modified filesystem to disk. */
        SaveModifiedFileSystemData(argv[1], pFileSystem, iFileSystemSize);

        printf("Directory %s now has hard-link %s inside.\nHere is the new directory listing for %s:\n", 
                argv[2], argv[3], argv[2]);

        /* Print the directory listing showing our new entry. */
        PrintDirectoryListing(pInode, pFileSystem);
    }
    else if(iRetVal == -1)
    {
        printf("Sorry, %s is not a directory, as it should be! Quitting without modifying filesystem...\n", argv[2]);
    }
    else if(iRetVal == -2)
    {
        printf("Error: Filename already exists in directory %s.\n", argv[2]);
    }

    return 0;
}