#include "arm11/acl.h"
#include "fs.h"

typedef struct
{
    uint32_t    typeloc;
    uint32_t    cfgid;
} CheatCfg;

typedef struct
{
    FHandle     fd;                 // acl文件
    uint16_t    serc;               // serial前3字节总数量
    CheatCfg   *list;               // 调用select_game后保存serial对应的一组cheat配置
    uint16_t    listc;              // list的个数
    uint32_t    setid;              // 选中的cheat_set的id
} CheatLib;

typedef struct
{
    uint32_t    entid;              // entry的id
    uint32_t    offset;             // entry对应数据在cheat_set的偏移
    uint32_t    datasz;             // 此entry对应的数据长度(hole对应key数量，key对应gamecode数量)
} CheatEntry;

typedef struct 
{
    uint32_t    seek;               // 在acl文件中的基础偏移
    uint32_t    entc;               // 此cheat_set所有的entry总数
    CheatEntry  entry;              // 当选选中的entry的数据
    char       *strings;            // 字符串表
    void       *entdata;            // 当前选中的entry对应的列表数据
} CheatSet;

static CheatLib gblcht = {0, 0, NULL, 0, 0};
static CheatSet gblset = {0, 0, {0,0,0}, NULL};

#define ACL_MAGIC_CODE 0x4c4341
#define ACL_GBA_CODELEN 4
#define ACL_HEADER_LEN 8
#define ACL_SERIAL_LEN(n) ((n)*3)
#define ACL_INDEX_OFFSET(i) ((i)*sizeof(uint16_t))
#define ACL_CONFIG_OFFSET(i) ((i)*sizeof(CheatCfg))

#define serial_count(n) ((n) & 0xffff)
#define max_cheat_count(n) ((n) >> 16) 

acl_error_t acl_open_lib( acl_text_t filename )
{
    FHandle cheatfile;
    uint32_t readed;
    if( RES_OK != fOpen(&cheatfile, filename, FA_OPEN_EXISTING | FA_READ) )
        return ACHTLIB_NOT_FOUND;
    
    // 验证magic number
    uint32_t num;
    if( RES_OK != fRead(cheatfile, &num, sizeof(num), &readed) 
        || readed != sizeof(num) )
    {
        fClose( cheatfile );
        return ACHTLIB_INVALID;
    }

    if ( (num & 0xffffff) != ACL_MAGIC_CODE )
    {
        fClose( cheatfile );
        return ACHTLIB_INVALID;
    }
    
    if( RES_OK != fRead( cheatfile, &num, sizeof(num), &readed) 
        || readed != sizeof( num ) )
    {
        fClose( cheatfile );
        return ACHTLIB_INVALID;
    }

    CheatCfg *cfglist = (CheatCfg*)malloc( max_cheat_count(num)  * sizeof(CheatCfg) );
    if( cfglist == NULL )
    {
        fClose( cheatfile );
        return ACHTLIB_NOMEM;
    }
    cfglist[0].cfgid = 0;

    gblcht.fd = cheatfile;
    gblcht.serc = serial_count(num);
    gblcht.list = cfglist;
    
    return ACHTLIB_SUCCESS;
}

acl_error_t acl_close_lib( void )
{
    if( gblcht.serc != 0 )
    {
        fClose( gblcht.fd );
        gblcht.fd = 0;

        free( gblcht.list );
        gblcht.list = NULL;

        gblcht.serc = gblcht.listc = 0;

        if( gblset.strings ){
            free( gblset.strings );
            gblset.strings = NULL;
        }

        if( gblset.entdata ){
            free( gblset.entdata );
            gblset.entdata = NULL;
        }
        
        return ACHTLIB_SUCCESS;
    }
    else return ACHTLIB_INVALID;
}

static int32_t bin_search( acl_text_t game )
{
    if( RES_OK != fLseek(gblcht.fd, ACL_HEADER_LEN) ){
        return -ACHTLIB_INVALID;
    }

    int size = ACL_SERIAL_LEN(gblcht.serc);
    char *serials = (char*)malloc( size );
    if( serials == NULL ){
        return -ACHTLIB_NOMEM;
    }

    uint32_t readed;
    if( RES_OK != fRead(gblcht.fd, serials, size, &readed) 
        || readed != size )
    {
        free( serials );
        return -ACHTLIB_INVALID;
    }

    int start = 0, end = gblcht.serc - 1;
    size = ACL_SERIAL_LEN(1);
    int found = -1;
    while( start <= end )
    {
        int mid = (start+end) >> 1;
        int res = strncmp( game, serials+ACL_SERIAL_LEN(mid), size );
        if( res == 0 )
        {
            found = mid;
            break;
        }
        else if( res > 0 )// serial < game
        {
            start = mid + 1;
        }
        else end = mid - 1;
    }
    free( serials );

    if( found >= 0 )
    {
        return found;
    }
    else return -ACHTLIB_NOT_FOUND;
}

#define config_type(n) ( (n) & 0xff )
acl_error_t acl_select_game( acl_text_t game, acl_boolean_t filter, acl_count_t *n )
{
    CheatLib *inst = (CheatLib*)&gblcht;
    if( inst->serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( strlen(game) != ACL_GBA_CODELEN ) return ACHTLIB_NOT_FOUND;

    int32_t index = bin_search( game );
    if( index < 0 ) return index * -1;

    uint32_t offset = ACL_HEADER_LEN + ACL_SERIAL_LEN(inst->serc);
    offset += ACL_INDEX_OFFSET(index);

    uint32_t readed;
    uint16_t groups[2];
    if( RES_OK != fLseek(inst->fd, offset) )
        return ACHTLIB_INVALID;
    
    if( RES_OK != fRead(inst->fd, groups, sizeof(groups), &readed)
        || readed != sizeof(groups) )
        return ACHTLIB_INVALID;
    
    offset = ACL_HEADER_LEN + ACL_SERIAL_LEN(inst->serc) + ACL_INDEX_OFFSET(inst->serc+1);
    offset += ACL_CONFIG_OFFSET(groups[0]);

    uint32_t gcount = groups[1] - groups[0];
    if( RES_OK != fLseek(inst->fd, offset) )
        return ACHTLIB_INVALID;
    
    CheatCfg *cfg = inst->list;
    if( RES_OK != fRead(inst->fd, cfg, gcount * sizeof(CheatCfg), &readed)  // 可能需要多次fread
        || readed != gcount * sizeof(CheatCfg) )
    {
        return ACHTLIB_INVALID;
    }

    if( filter )
    {
        char reg = game[3];
        index = -1;
        for( int i=0; i < gcount; ++i )
        {
            if( config_type(cfg[i].typeloc) == reg )
            {
                if( index < 0 ) index = i;
            }
            else if( index >= 0 )
            {
                gcount = i-index;
                memcpy( cfg, cfg+index, gcount * sizeof(CheatCfg) );
                break;
            }
        }
    }

    inst->listc = gcount;
    inst->setid = 0;
    *n = gcount;

    return ACHTLIB_SUCCESS;
}

acl_error_t acl_query_cheat_set( acl_index_t index, acl_chtid_t *chtid, acl_region_t *region )
{
    CheatLib *inst = &gblcht;
    if( inst->serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( inst->listc == 0 ) return ACHTLIB_INVALID;

    if( index >= inst->listc ) return ACHTLIB_NOT_FOUND;
    else 
    {
        CheatCfg *cfg = inst->list;
        *chtid = cfg[index].cfgid;
        *region = config_type( cfg[index].typeloc );
        return ACHTLIB_SUCCESS;
    }
}

static acl_error_t init_cheatset( uint32_t offset )
{
    gblset.seek = offset;
    if( gblset.strings )
    {
        free( gblset.strings );
        gblset.strings = NULL;
    }
    if( gblset.entdata )
    {
        free( gblset.entdata );
        gblset.entdata = NULL;
    }

    uint32_t readed;
    if( RES_OK != fLseek(gblcht.fd, offset) )
        return ACHTLIB_INVALID;

    uint16_t entc;
    if( RES_OK != fRead(gblcht.fd, &entc, sizeof(entc), &readed) 
        || readed != sizeof( entc ) )
        return ACHTLIB_INVALID;
    gblset.entc = entc;

    if( RES_OK != fRead(gblcht.fd, &gblset.entry, sizeof(CheatEntry), &readed)
        || readed != sizeof(CheatEntry) )
        return ACHTLIB_INVALID;
    
    if( gblset.entry.entid != 0 ) return ACHTLIB_INVALID;
    offset = gblset.seek + sizeof(entc) + entc*sizeof(CheatEntry);
    if( RES_OK != fLseek(gblcht.fd, offset) )
        return ACHTLIB_INVALID;
    
    uint32_t size = gblset.entry.offset - sizeof(entc) - entc*sizeof(CheatEntry);
    char *table = (char*)malloc( size );
    if( !table ) return ACHTLIB_NOMEM;

    if( RES_OK != fRead(gblcht.fd, table, size, &readed)    // TODO: 多次read
        || readed != size )
    {
        free( table );
        return ACHTLIB_INVALID;
    }

    gblset.strings = table;
    return ACHTLIB_SUCCESS;
}

static acl_error_t load_data()
{
    if( gblset.entdata != NULL )
    {
        free( gblset.entdata );
        gblset.entdata = NULL;
    }

    int elemlen = gblset.entry.entid > 0xffff ? sizeof(uint32_t) : sizeof(uint16_t);
    int total = gblset.entry.datasz * elemlen;
    if( total == 0 ) return ACHTLIB_SUCCESS;

    uint8_t *d = (uint8_t*)malloc( total );
    if( d == NULL ) return ACHTLIB_NOMEM;

    if( RES_OK != fLseek(gblcht.fd, gblset.seek + gblset.entry.offset))
        return ACHTLIB_INVALID;
    
    uint32_t readed;
    if( RES_OK != fRead(gblcht.fd, d, total, &readed) 
        || readed != total )
    {
        free( d );
        return ACHTLIB_INVALID;
    }

    gblset.entdata = d;
    return ACHTLIB_SUCCESS;
}

#define config_offset(n) ( (n & ~0xff) >> 3 )

acl_error_t acl_select_cheat_set( acl_chtid_t id )
{
    CheatLib *inst = &gblcht;
    if( inst->serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( inst->listc == 0 ) return ACHTLIB_INVALID;

    acl_boolean_t found = 0;
    uint32_t offset = 0;
    CheatCfg *cfg = inst->list;
    for( int i=0; i < inst->listc; ++i )
    {
        if( cfg[i].cfgid == id )
        {
            offset = config_offset( cfg[i].typeloc );
            acl_error_t r = init_cheatset( offset );
            if( r == ACHTLIB_SUCCESS )
            {
                found = 1;
                inst->setid = id;
                break;
            }
            else return r;
        }
    }
    if( found ) return load_data();
    else return ACHTLIB_NOT_FOUND;
}

#define READ_CACHE_SIZE 16
acl_error_t acl_select_entry( acl_entryid_t id, acl_elemlen_t *count)
{
    if( gblcht.serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( gblcht.listc == 0 ) return ACHTLIB_INVALID;
    if( gblcht.setid == 0 ) return ACHTLIB_INVALID;
    
    if( gblset.entry.entid != id )
    {
        // update gblset.entry
        if( RES_OK != fLseek(gblcht.fd, gblset.seek + sizeof(uint16_t)) )
            return ACHTLIB_INVALID;
        
        CheatEntry cache[READ_CACHE_SIZE];
        uint32_t readed;
        for( int i = 0; i < gblset.entc; i += READ_CACHE_SIZE )
        {
            if( RES_OK != fRead(gblcht.fd, cache, sizeof(cache), &readed)
                || readed != sizeof(cache) )
                return ACHTLIB_INVALID;
            
            acl_boolean_t found = 0;
            for( int j=0; j < READ_CACHE_SIZE; ++j )
            {
                if( cache[j].entid == id )
                {
                    memcpy( &gblset.entry, &cache[j], sizeof(CheatEntry) );
                    found = 1;
                    break;
                }
            }
            if( found ) break;
        }
    }
    *count = gblset.entry.datasz;
    
    return load_data();
}

acl_error_t acl_entry_get_label( acl_index_t index, acl_text_t *label )
{
    if( gblcht.serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( gblcht.listc == 0 ) return ACHTLIB_INVALID;
    if( gblcht.setid == 0 ) return ACHTLIB_INVALID;
    
    if( index < gblset.entry.datasz )
    {
        uint16_t *d = (uint16_t*)gblset.entdata;
        *label = gblset.strings + d[index];
        return ACHTLIB_SUCCESS;
    }
    else return ACHTLIB_NOT_FOUND;
}

acl_error_t acl_entry_get_armcode( acl_index_t index, acl_armcode_t *code )
{
    if( gblcht.serc == 0 ) return ACHTLIB_NOT_OPEN;
    if( gblcht.listc == 0 ) return ACHTLIB_INVALID;
    if( gblcht.setid == 0 ) return ACHTLIB_INVALID;
    
    if( index < gblset.entry.datasz )
    {
        uint32_t *d = (uint32_t*)gblset.entdata;
        *code = d[index];
        return ACHTLIB_SUCCESS;
    }
    else return ACHTLIB_NOT_FOUND;
}