/*
 * Copyright (C) 2007-2023 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#define _FILE_OFFSET_BITS 64
#define FUSE_USE_VERSION 26

#include <fuse.h>

#include <string.h>
#include <errno.h>

#include <bu/file.h>
#include <bu/myriadfs.h>
#include <bu/myriadstream.h>
#include <bu/hash.h>

Bu::File *pF = NULL;
Bu::MyriadFs *pFs = NULL;

typedef Bu::Hash<int64_t, Bu::MyriadStream> FileHash;
FileHash hOpenFiles;
int64_t iNextFileId = 0;

#define TRACE

extern "C" {
    static int myriadfs_getattr( const char *sPath, struct stat *stbuf )
    {
#ifdef TRACE
        printf("myriadfs_getattr(\"%s\", ... );\n", sPath );
#endif
        try
        {
            Bu::MyriadFs::Stat st;
            pFs->stat( sPath, st );
            stbuf->st_ino = st.iNode;
            stbuf->st_mode = st.uPerms;
            stbuf->st_nlink = st.iLinks;
            stbuf->st_uid = st.iUser;
            stbuf->st_gid = st.iGroup;
            stbuf->st_rdev = Bu::MyriadFs::devToSys( st.uDev );
            stbuf->st_size = st.iSize;
            stbuf->st_blocks = 8;
            stbuf->st_atime = st.iATime;
            stbuf->st_mtime = st.iMTime;
            stbuf->st_ctime = st.iCTime;
            return 0;
        }
        catch(...)
        {
            return -ENOENT;
        }
    }

    static int myriadfs_readdir( const char *sPath, void *buf,
            fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_readdir(\"%s\", ... );\n", sPath );
#endif
        Bu::MyriadFs::Dir lDir = pFs->readDir( sPath );
        filler( buf, ".", NULL, 0 );
        filler( buf, "..", NULL, 0 );
        for( Bu::MyriadFs::Dir::iterator i = lDir.begin(); i; i++ )
        {
            filler( buf, (*i).sName.getStr(), NULL, 0 );
        }

        return 0;
    }

    static int myriadfs_mkdir( const char *sPath, mode_t uMode )
    {
#ifdef TRACE
        printf("myriadfs_mkdir(\"%s\", 0%o );\n", sPath, uMode );
#endif
        pFs->mkDir( sPath, uMode );
        return 0;
    }

    static int myriadfs_open( const char *sPath, struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_open(\"%s\", ... );\n", sPath );
#endif
        try
        {
            Bu::MyriadStream ms = pFs->open( sPath, 0 );
            fi->fh = iNextFileId;
            hOpenFiles.insert( iNextFileId++, ms );
//          printf("File '%s' opened, %d files open now.\n",
//              sPath, hOpenFiles.getSize() );
            return 0;
        }
        catch(...)
        {
            return -EACCES;
        }
    }

    static int myriadfs_read( const char *sPath, char *buf, size_t iSize,
            off_t iOffset, struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_read(\"%s\", ..., %d, %d, ... );\n", sPath, iSize,
                iOffset );
#endif
        Bu::MyriadStream &ms = hOpenFiles.get( fi->fh );
        ms.setPos( iOffset );
        return ms.read( buf, iSize );
    }

    static int myriadfs_write( const char *sPath, const char *buf, size_t iSize,
            off_t iOffset, struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_write(\"%s\", ..., %d, %d, ... );\n", sPath, iSize,
                iOffset );
#endif
        Bu::MyriadStream &ms = hOpenFiles.get( fi->fh );
        ms.setPos( iOffset );
        return ms.write( buf, iSize );
    }

    static int myriadfs_create( const char *sPath, mode_t uPerms,
            struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_create(\"%s\", 0%o, ... );\n", sPath, uPerms );
#endif
        try
        {
            Bu::MyriadStream ms = pFs->open( sPath, 0, uPerms );
            fi->fh = iNextFileId;
            hOpenFiles.insert( iNextFileId++, ms );
//          printf("File '%s' created, %d files open now.\n",
//              sPath, hOpenFiles.getSize() );
            return 0;
        }
        catch(...)
        {
            return -EACCES;
        }
    }
    
    static int myriadfs_mknod( const char *sPath, mode_t uPerms, dev_t Dev )
    {
#ifdef TRACE
        printf("myriadfs_mknod(\"%s\", 0%o, %x );\n", sPath, uPerms, Dev );
#endif
        try
        {
            pFs->create( sPath, uPerms, Bu::MyriadFs::sysToDev( Dev ) );
            return 0;
        }
        catch(...)
        {
            return -EACCES;
        }
    }

    static int myriadfs_release( const char *sPath, struct fuse_file_info *fi )
    {
#ifdef TRACE
        printf("myriadfs_release(\"%s\", ... );\n", sPath );
#endif
        hOpenFiles.erase( fi->fh );
//      printf("File '%s' released, %d files open now.\n",
//          sPath, hOpenFiles.getSize() );

        return 0;
    }

    static int myriadfs_utimens( const char *sPath,
            const struct timespec tv[2] )
    {
#ifdef TRACE
        printf("myriadfs_utimens(\"%s\", ... );\n", sPath );
#endif
        try
        {
            pFs->setTimes( sPath, tv[0].tv_sec, tv[1].tv_sec );
        }
        catch(...)
        {
            return -EACCES;
        }
        return 0;
    }

    static int myriadfs_unlink( const char *sPath )
    {
#ifdef TRACE
        printf("myriadfs_unlink(\"%s\");\n", sPath );
#endif
        try
        {
            pFs->unlink( sPath );
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -EACCES;
        }
        return 0;
    }

    static int myriadfs_symlink( const char *sTarget, const char *sPath )
    {
#ifdef TRACE
        printf("myriadfs_symlink(\"%s\", \"%s\");\n", sTarget, sPath );
#endif
        try
        {
            pFs->mkSymLink( sTarget, sPath );
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -EACCES;
        }
        return 0;
    }

    static int myriadfs_readlink( const char *sPath, char *sOut, size_t s )
    {
#ifdef TRACE
        printf("myriadfs_readlink(\"%s\", ... );\n", sPath );
#endif
        try
        {
            Bu::String sTrg = pFs->readSymLink( sPath );
            size_t iLen = (s-1>sTrg.getSize())?(sTrg.getSize()):(s-1);
            memcpy( sOut, sTrg.getStr(), iLen );
            sOut[iLen] = '\0';
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -EACCES;
        }
        return 0;
    }

    static int myriadfs_truncate( const char *sPath, off_t iSize )
    {
#ifdef TRACE
        printf("myriadfs_truncate(\"%s\", %d );\n", sPath, iSize );
#endif

        try
        {
            pFs->setFileSize( sPath, iSize );
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -ENOENT;
        }
        return 0;
    }

    static int myriadfs_link( const char *sTarget, const char *sPath )
    {
#ifdef TRACE
        printf("myriadfs_link(\"%s\", \"%s\");\n", sTarget, sPath );
#endif

        try
        {
            pFs->mkHardLink( sTarget, sPath );
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -EACCES;
        }
        return 0;
    }

    static int myriadfs_rename( const char *sFrom, const char *sTo )
    {
#ifdef TRACE
        printf("myriadfs_rename(\"%s\", \"%s\");\n", sFrom, sTo );
#endif

        try
        {
            pFs->rename( sFrom, sTo );
        }
        catch( Bu::MyriadFsException &e )
        {
            printf("MyriadFsException: %s\n", e.what() );
            return -EACCES;
        }
        return 0;
    }

    static struct fuse_operations myriadfs_oper;

    int main( int argc, char *argv[] )
    {
        pF = new Bu::File("store.myr", Bu::File::Read|Bu::File::Write|Bu::File::Create );
        pFs = new Bu::MyriadFs( *pF, 512 );
        memset( &myriadfs_oper, sizeof(myriadfs_oper), 0 );
        myriadfs_oper.getattr    = myriadfs_getattr;
        myriadfs_oper.readdir    = myriadfs_readdir;
        myriadfs_oper.mkdir      = myriadfs_mkdir;
        myriadfs_oper.open       = myriadfs_open;
        myriadfs_oper.read       = myriadfs_read;
        myriadfs_oper.write      = myriadfs_write;
        myriadfs_oper.create     = myriadfs_create;
        myriadfs_oper.mknod      = myriadfs_mknod;
        myriadfs_oper.release    = myriadfs_release;
        myriadfs_oper.utimens    = myriadfs_utimens;
        myriadfs_oper.unlink     = myriadfs_unlink;
        myriadfs_oper.rmdir      = myriadfs_unlink;
        myriadfs_oper.symlink    = myriadfs_symlink;
        myriadfs_oper.readlink   = myriadfs_readlink;
        myriadfs_oper.truncate   = myriadfs_truncate;
        myriadfs_oper.link       = myriadfs_link;
        myriadfs_oper.rename     = myriadfs_rename;
        printf("Starting fuse_main.\n");
        int iRet = fuse_main( argc, argv, &myriadfs_oper, NULL );
        printf("Done with fuse_main.\n");
        delete pFs;
        delete pF;
        return iRet;
    }
}
