#include "inflate.h"

#define CHUNK 1024

int inflateFile( FILE *source, FILE *dest )
{
    int ret;
    unsigned have;
    z_stream strm;
    unsigned char in[CHUNK];
    unsigned char out[CHUNK];

    /* allocate inflate state */
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit( &strm );
    if ( ret != Z_OK )
        return ret;

    /* decompress until deflate stream ends or end of file */
    do
    {
        strm.avail_in = fread( in, 1, CHUNK, source );
        if ( ferror( source ) )
        {
            ( void )inflateEnd( &strm );
            return Z_ERRNO;
        }
        if ( strm.avail_in == 0 )
            break;
        strm.next_in = in;

        /* run inflate() on input until output buffer not full */
        do
        {
            strm.avail_out = CHUNK;
            strm.next_out = out;
            ret = inflate( &strm, Z_NO_FLUSH );
            switch ( ret )
            {
                case Z_NEED_DICT:
                    ( void )inflateEnd( &strm );
                    return -20;
                case Z_DATA_ERROR:
                    ( void )inflateEnd( &strm );
                    return -21;
                case Z_MEM_ERROR:
                    ( void )inflateEnd( &strm );
                    return -22;
            }
            have = CHUNK - strm.avail_out;
            if ( fwrite( out, 1, have, dest ) != have || ferror( dest ) )
            {
                ( void )inflateEnd( &strm );
                return Z_ERRNO;
            }
        }
        while ( strm.avail_out == 0 );
        /* done when inflate() says it's done */
    }
    while ( ret != Z_STREAM_END );
    /* clean up and return */
    ( void )inflateEnd( &strm );
    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}