/****************************************************************************
 * USB Loader GX Team
 * openingbnr
 *
 * Extract opening.bnr/banner.bin/sound.bin/icon.bin
 *
 * Copyright 2008 Magicus <magicus@gmail.com>
 * Licensed under the terms of the GNU GPL, version 2
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
 * Version 1.0 Initial release
 ***************************************************************************/

#define _GNU_SOURCE

#include <ogcsys.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "libfat/fat.h"

#include "MD5.h"
#include "banner.h"
#include "openingbnr.h"
#include "../ramdisk/ramdisk.h"
#include "../listfiles.h"

u16 be16( const u8 *p )
{
    return ( p[0] << 8 ) | p[1];
}

u32 be32( const u8 *p )
{
    return ( p[0] << 24 ) | ( p[1] << 16 ) | ( p[2] << 8 ) | p[3];
}

u64 be64( const u8 *p )
{
    return ( ( u64 )be32( p ) << 32 ) | be32( p + 4 );
}

u64 be34( const u8 *p )
{
    return 4 * ( u64 )be32( p );
}

void wbe16( u8 *p, u16 x )
{
    p[0] = x >> 8;
    p[1] = x;
}

void wbe32( u8 *p, u32 x )
{
    wbe16( p, x >> 16 );
    wbe16( p + 2, x );
}

void wbe64( u8 *p, u64 x )
{
    wbe32( p, x >> 32 );
    wbe32( p + 4, x );
}

void md5( u8 *data, u32 len, u8 *hash )
{
    MD5( hash, data, len );
}


typedef struct
{
    u8 zeroes[0x40];
    u32 imet; // "IMET"
    u8 zero_six_zero_three[8];  // fixed, unknown purpose
    u32 sizes[3];
    u32 flag1;
    u16 name_jp[0x2a]; // might be empty
    u16 name_en[0x2a];
    u16 name_de[0x2a];
    u16 name_fr[0x2a];
    u16 name_es[0x2a];
    u16 name_it[0x2a];
    u16 name_nl[0x2a];
    u8 zeroes_2[0x348];
    u8 crypto[0x10];
} imet_data_t;

typedef struct
{
    u32 imd5_tag; // 0x494D4435 "IMD5";
    u32 size;  // size of the rest of part B, starting from next field.
    u8 zeroes[8];
    u8 md5[16];
    u32 payload_tag; // 0x4C5A3737 "LZ77" if this is lz77
    u32 payload_data;
}  imd5_header_t;

typedef struct
{
    u16 type;
    u16 name_offset;
    u32 data_offset; // == absolut offset från U.8- headerns början
    u32 size; // last included file num for directories
} U8_node;

typedef struct
{
    u32 tag; // 0x55AA382D "U.8-"
    u32 rootnode_offset; // offset to root_node, always 0x20.
    u32 header_size; // size of header from root_node to end of string table.
    u32 data_offset; // offset to data -- this is rootnode_offset + header_size, aligned to 0x40.
    u8 zeroes[16];
} U8_archive_header;

static int write_file( void* data, size_t size, char* name )
{
    size_t written = 0;
    FILE *out;
    out = fopen( name, "wb" );
    if ( out )
    {
        written = fwrite( data, 1, size, out );
        fclose( out );
    }
    return ( written == size ) ? 1 : -1;
}

u8* decompress_lz77( u8 *data, size_t data_size, size_t* decompressed_size )
{
    u8 *data_end;
    u8 *decompressed_data;
    size_t unpacked_size;
    u8 *in_ptr;
    u8 *out_ptr;
    u8 *out_end;

    in_ptr = data;
    data_end = data + data_size;

    // Assume this for now and grow when needed
    unpacked_size = data_size;

    decompressed_data = malloc( unpacked_size );
    out_end = decompressed_data + unpacked_size;

    out_ptr = decompressed_data;

    while ( in_ptr < data_end )
    {
        int bit;
        u8 bitmask = *in_ptr;

        in_ptr++;
        for ( bit = 0x80; bit != 0; bit >>= 1 )
        {
            if ( bitmask & bit )
            {
                // Next section is compressed
                u8 rep_length;
                u16 rep_offset;

                rep_length = ( *in_ptr >> 4 ) + 3;
                rep_offset = *in_ptr & 0x0f;
                in_ptr++;
                rep_offset = *in_ptr | ( rep_offset << 8 );
                in_ptr++;
                if ( out_ptr - decompressed_data < rep_offset )
                {
                    return NULL;
                }

                for ( ; rep_length > 0; rep_length-- )
                {
                    *out_ptr = out_ptr[-rep_offset-1];
                    out_ptr++;
                    if ( out_ptr >= out_end )
                    {
                        // Need to grow buffer
                        decompressed_data = realloc( decompressed_data, unpacked_size * 2 );
                        out_ptr = decompressed_data + unpacked_size;
                        unpacked_size *= 2;
                        out_end = decompressed_data + unpacked_size;
                    }
                }
            }
            else
            {
                // Just copy byte
                *out_ptr = *in_ptr;
                out_ptr++;
                if ( out_ptr >= out_end )
                {
                    // Need to grow buffer
                    decompressed_data = realloc( decompressed_data, unpacked_size * 2 );
                    out_ptr = decompressed_data + unpacked_size;
                    unpacked_size *= 2;
                    out_end = decompressed_data + unpacked_size;
                }
                in_ptr++;
            }
        }
    }

    *decompressed_size = ( out_ptr - decompressed_data );
    return decompressed_data;
}

static int write_imd5_lz77( u8* data, size_t size, char* outname )
{
    imd5_header_t* header = ( imd5_header_t* ) data;
    u32 tag;
    u32 size_in_imd5;
    u8 md5_calc[16];
    u8 *decompressed_data;
    size_t decompressed_size;

    tag = be32( ( u8* ) & header->imd5_tag );
    if ( tag != 0x494D4435 )
    {
        return -4;
    }

    md5( data + 32, size - 32, md5_calc );
    if ( memcmp( &header->md5, md5_calc, 0x10 ) )
    {
        return -5;
    }

    size_in_imd5 = be32( ( u8* ) & header->size );
    if ( size_in_imd5 != size - 32 )
    {
        return -6;
    }

    tag = be32( ( u8* ) & header->payload_tag );
    if ( tag == 0x4C5A3737 )
    {
        // "LZ77" - uncompress
        decompressed_data = decompress_lz77( data + sizeof( imd5_header_t ), size - sizeof( imd5_header_t ), &decompressed_size );
        if ( decompressed_data == NULL )
            return -7;
        write_file( decompressed_data, decompressed_size, outname );
        //printf(", uncompressed %d bytes, md5 ok", decompressed_size);

        free( decompressed_data );
    }
    else
    {
        write_file( &header->payload_tag, size - 32, outname );
        //printf(", md5 ok");
    }
    return 0;
}

static int do_U8_archive( FILE *fp )
{
    U8_archive_header header;
    U8_node root_node;
    u32 tag;
    u32 num_nodes;
    U8_node* nodes;
    u8* string_table;
    size_t rest_size;
    unsigned int i;
    u32 data_offset;
    u32 current_offset;
    u16 dir_stack[16];
    int dir_index = 0;

    fread( &header, 1, sizeof header, fp );
    tag = be32( ( u8* ) & header.tag );
    if ( tag != 0x55AA382D )
    {
        return -1;
    }

    fread( &root_node, 1, sizeof( root_node ), fp );
    num_nodes = be32( ( u8* ) & root_node.size ) - 1;
    //printf("Number of files: %d\n", num_nodes);

    nodes = malloc( sizeof( U8_node ) * ( num_nodes ) );
    fread( nodes, 1, num_nodes * sizeof( U8_node ), fp );

    data_offset = be32( ( u8* ) & header.data_offset );
    rest_size = data_offset - sizeof( header ) - ( num_nodes + 1 ) * sizeof( U8_node );

    string_table = malloc( rest_size );
    fread( string_table, 1, rest_size, fp );
    current_offset = data_offset;

    for ( i = 0; i < num_nodes; i++ )
    {
        U8_node* node = &nodes[i];
        u16 type = be16( ( u8* ) & node->type );
        u16 name_offset = be16( ( u8* ) & node->name_offset );
        u32 my_data_offset = be32( ( u8* ) & node->data_offset );
        u32 size = be32( ( u8* ) & node->size );
        char* name = ( char* ) & string_table[name_offset];
        u8* file_data;

        if ( type == 0x0100 )
        {
            // Directory
            mkdir( name, 0777 );
            chdir( name );
            dir_stack[++dir_index] = size;
            //printf("%*s%s/\n", dir_index, "", name);
        }
        else
        {
            // Normal file
            u8 padding[32];

            if ( type != 0x0000 )
            {
                free( string_table );
                return -2;
            }

            if ( current_offset < my_data_offset )
            {
                int diff = my_data_offset - current_offset;

                if ( diff > 32 )
                {
                    free( string_table );
                    return -3;
                }
                fread( padding, 1, diff, fp );
                current_offset += diff;
            }

            file_data = malloc( size );
            fread( file_data, 1, size, fp );
            //printf("%*s %s (%d bytes", dir_index, "", name, size);
            int result;
            result = write_imd5_lz77( file_data, size, name );
            if ( result < 0 )
            {
                free( string_table );
                return result;
            }
            //printf(")\n");
            current_offset += size;
        }

        while ( dir_stack[dir_index] == i + 2 && dir_index > 0 )
        {
            chdir( ".." );
            dir_index--;
        }
    }
    free( string_table );
    return 0;
}

static void do_imet_header( FILE *fp )
{
    imet_data_t header;

    fread( &header, 1, sizeof header, fp );

    write_file( &header, sizeof( header ), "header.imet" );
}

void do_U8_archivebanner( FILE *fp )
{
    U8_archive_header header;
    U8_node root_node;
    u32 tag;
    u32 num_nodes;
    U8_node* nodes;
    u8* string_table;
    size_t rest_size;
    unsigned int i;
    u32 data_offset;
    u16 dir_stack[16];
    int dir_index = 0;

    fread( &header, 1, sizeof header, fp );
    tag = be32( ( u8* ) & header.tag );
    if ( tag != 0x55AA382D )
    {
        //printf("No U8 tag");
        exit( 0 );
    }

    fread( &root_node, 1, sizeof( root_node ), fp );
    num_nodes = be32( ( u8* ) & root_node.size ) - 1;
    printf( "Number of files: %d\n", num_nodes );

    nodes = malloc( sizeof( U8_node ) * ( num_nodes ) );
    fread( nodes, 1, num_nodes * sizeof( U8_node ), fp );

    data_offset = be32( ( u8* ) & header.data_offset );
    rest_size = data_offset - sizeof( header ) - ( num_nodes + 1 ) * sizeof( U8_node );

    string_table = malloc( rest_size );
    fread( string_table, 1, rest_size, fp );

    for ( i = 0; i < num_nodes; i++ )
    {
        U8_node* node = &nodes[i];
        u16 type = be16( ( u8* ) & node->type );
        u16 name_offset = be16( ( u8* ) & node->name_offset );
        u32 my_data_offset = be32( ( u8* ) & node->data_offset );
        u32 size = be32( ( u8* ) & node->size );
        char* name = ( char* ) & string_table[name_offset];
        u8* file_data;

        if ( type == 0x0100 )
        {
            // Directory
            mkdir( name, 0777 );
            chdir( name );
            dir_stack[++dir_index] = size;
            //printf("%*s%s/\n", dir_index, "", name);
        }
        else
        {
            // Normal file

            if ( type != 0x0000 )
            {
                printf( "Unknown type" );
                exit( 0 );
            }

            fseek( fp, my_data_offset, SEEK_SET );
            file_data = malloc( size );
            fread( file_data, 1, size, fp );
            write_file( file_data, size, name );
            free( file_data );
            //printf("%*s %s (%d bytes)\n", dir_index, "", name, size);
        }

        while ( dir_stack[dir_index] == i + 2 && dir_index > 0 )
        {
            chdir( ".." );
            dir_index--;
        }
    }
    free( string_table );
}

int extractbnrfile( const char * filepath, const char * destpath )
{
    int ret = -1;
    FILE *fp = fopen( filepath, "rb" );
    if ( fp )
    {
        subfoldercreate( destpath );
        chdir( destpath );

        do_imet_header( fp );
        ret = do_U8_archive( fp );

        fclose( fp );
    }
    return ret;
}

int unpackBin( const char * filename, const char * outdir )
{
    FILE *fp = fopen( filename, "rb" );;
    if ( fp )
    {
        subfoldercreate( outdir );
        chdir( outdir );

        do_U8_archivebanner( fp );
        fclose( fp );
        return 1;
    }
    return 0;
}

#define TMP_PATH(s) "BANNER:/dump"s
//#define TMP_PATH(s) "SD:/dump"s

int unpackBanner( const u8 *gameid, int what, const char *outdir )
{

    char path[256];
    if ( !ramdiskMount( "BANNER", NULL ) ) return -1;

    subfoldercreate( TMP_PATH( "/" ) );
    s32 ret = dump_banner( gameid, TMP_PATH( "/opening.bnr" ) );
    if ( ret != 1 )
    {
        ret = -1;
        goto error2;
    }

    ret = extractbnrfile( TMP_PATH( "/opening.bnr" ), TMP_PATH( "/" ) );
    if ( ret != 0 )
    {
        ret = -1;
        goto error2;
    }

    if ( what & UNPACK_BANNER_BIN )
    {
        snprintf( path, sizeof( path ), "%sbanner/", outdir );
        ret = unpackBin( TMP_PATH( "/meta/banner.bin" ), path );
        if ( ret != 1 )
        {
            ret = -1;
            goto error2;
        }
    }
    if ( what & UNPACK_ICON_BIN )
    {
        snprintf( path, sizeof( path ), "%sicon/", outdir );
        ret = unpackBin( TMP_PATH( "/meta/icon.bin" ), path );
        if ( ret != 1 )
        {
            ret = -1;
            goto error2;
        }
    }
    if ( what & UNPACK_SOUND_BIN )
    {
        snprintf( path, sizeof( path ), "%ssound.bin", outdir );
        FILE *fp = fopen( TMP_PATH( "/meta/sound.bin" ), "rb" );
        if ( fp )
        {
            size_t size;
            u8 *data;
            fseek( fp, 0, SEEK_END );
            size = ftell( fp );
            if ( !size )
            {
                ret = -1;
                goto error;
            }
            fseek( fp, 0, SEEK_SET );
            data = ( u8 * )malloc( size );
            if ( !data )
            {
                ret = -1;
                goto error;
            }
            if ( fread( data, 1, size, fp ) != size )
            {
                ret = -1;
                goto error;
            }
            ret = write_file( data, size, path );
        }
error:  fclose( fp );
    }
    ramdiskUnmount( "BANNER" );
error2:
    if ( ret < 0 )
        return ret;
    return 1;
}