/*
 * Mr. 4th Dimention - Allen Webster
 *
 * 18.07.2017
 *
 * General win32 functions
 *
 */

// TOP

//
// 4ed path
//

internal
Sys_Get_4ed_Path_Sig(system_get_4ed_path){
    i32 size = GetModuleFileName_utf8(0, (u8*)out, capacity);
    if (size < capacity - 1){
        String str = make_string(out, size);
        remove_last_folder(&str);
        terminate_with_null(&str);
        size = str.size;
    }
    return(size);
}

//
// Logging
//

internal
Sys_Log_Sig(system_log){
    if (plat_settings.use_log){
        u8 space[4096];
        String str = make_fixed_width_string(space);
        str.size = system_get_4ed_path(str.str, str.memory_size);
        append_sc(&str, "4coder_log.txt");
        terminate_with_null(&str);
        HANDLE file = CreateFile_utf8(space, GENERIC_WRITE, 0, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
        if (file != INVALID_HANDLE_VALUE){
            SetFilePointer(file, win32vars.log_position, 0, FILE_BEGIN);
            win32vars.log_position += length;
            DWORD written = 0;
            DWORD total_written = 0;
            do{
                WriteFile(file, message + total_written, length - total_written, &written, 0);
                total_written += written;
            }while(total_written < length);
            CloseHandle(file);
        }
    }
}

//
// Shared system functions (system_shared.h)
//

internal
Sys_File_Can_Be_Made_Sig(system_file_can_be_made){
    HANDLE file = CreateFile_utf8(filename, FILE_APPEND_DATA, 0, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
    b32 result = false;
    if (file != 0 && file != INVALID_HANDLE_VALUE){
        CloseHandle(file);
        result = true;
    }
    return(result);
}

//
// Memory
//

internal
Sys_Memory_Allocate_Sig(system_memory_allocate){
    void *result = VirtualAlloc(0, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
    return(result);
}

internal
Sys_Memory_Set_Protection_Sig(system_memory_set_protection){
    bool32 result = false;
    DWORD old_protect = 0;
    DWORD protect = 0;
    
    switch (flags & 0x7){
        case 0:                                                   protect = PAGE_NOACCESS; break;
        case MemProtect_Read:                                     protect = PAGE_READONLY; break;
        case MemProtect_Write:                                    /* below */
        case MemProtect_Write|MemProtect_Read:                    protect = PAGE_READWRITE; break;
        case MemProtect_Execute:                                  protect = PAGE_EXECUTE; break;
        case MemProtect_Execute|MemProtect_Read:                  protect = PAGE_EXECUTE_READ; break;
        case MemProtect_Execute|MemProtect_Write:                 /* below */
        case MemProtect_Execute|MemProtect_Write|MemProtect_Read: protect = PAGE_EXECUTE_READWRITE; break;
    }
    
    VirtualProtect(ptr, size, protect, &old_protect);
    return(result);
}

internal
Sys_Memory_Free_Sig(system_memory_free){
    VirtualFree(ptr, 0, MEM_RELEASE);
}

//
// Files
//

internal
Sys_Set_File_List_Sig(system_set_file_list){
    b32 clear_list = true;
    if (directory != 0){
        char dir_space[MAX_PATH + 32];
        String dir = make_string_cap(dir_space, 0, MAX_PATH + 32);
        append_sc(&dir, directory);
        terminate_with_null(&dir);
        
        HANDLE dir_handle = CreateFile_utf8((u8*)dir.str, FILE_LIST_DIRECTORY, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, 0);
        
        if (dir_handle != INVALID_HANDLE_VALUE){
            DWORD final_length = GetFinalPathNameByHandle_utf8(dir_handle, (u8*)dir_space, sizeof(dir_space), 0);
            CloseHandle(dir_handle);
            
            if (final_length < sizeof(dir_space)){
                u8 *c_str_dir = (u8*)dir_space;
                
                final_length -= 4;
                memmove(c_str_dir, c_str_dir+4, final_length);
                c_str_dir[final_length] = '\\';
                c_str_dir[final_length+1] = '*';
                c_str_dir[final_length+2] = 0;
                
                if (canon_directory_out != 0){
                    if (final_length+1 < canon_directory_max){
                        memcpy(canon_directory_out, c_str_dir, final_length);
                        if (canon_directory_out[final_length-1] != '\\'){
                            canon_directory_out[final_length++] = '\\';
                        }
                        canon_directory_out[final_length] = 0;
                        *canon_directory_size_out = final_length;
                    }
                    else{
                        u32 length = copy_fast_unsafe_cc(canon_directory_out, directory);
                        canon_directory_out[length] = 0;
                        *canon_directory_size_out = length;
                    }
                }
                
                WIN32_FIND_DATA find_data;
                HANDLE search = FindFirstFile_utf8(c_str_dir, &find_data);
                
                if (search != INVALID_HANDLE_VALUE){            
                    u32 character_count = 0;
                    u32 file_count = 0;
                    BOOL more_files = true;
                    do{
                        b32 nav_dir =
                            (find_data.cFileName[0] == '.' && find_data.cFileName[1] == 0) ||(find_data.cFileName[0] == '.' && find_data.cFileName[1] == '.' && find_data.cFileName[2] == 0);
                        if (!nav_dir){
                            ++file_count;
                            u32 size = 0;
                            for(;find_data.cFileName[size];++size);
                            character_count += size + 1;
                        }
                        more_files = FindNextFile(search, &find_data);
                    }while(more_files);
                    FindClose(search);
                    
                    u32 remaining_size = character_count*2;
                    u32 required_size = remaining_size + file_count*sizeof(File_Info);
                    if (file_list->block_size < required_size){
                        system_memory_free(file_list->block, 0);
                        file_list->block = system_memory_allocate(required_size);
                        file_list->block_size = required_size;
                    }
                    
                    file_list->infos = (File_Info*)file_list->block;
                    u8 *name = (u8*)(file_list->infos + file_count);
                    u32 corrected_file_count = 0;
                    if (file_list->block != 0){
                        search = FindFirstFile_utf8(c_str_dir, &find_data);
                        
                        if (search != INVALID_HANDLE_VALUE){
                            File_Info *info = file_list->infos;
                            more_files = true;
                            do{
                                b32 nav_dir =
                                    (find_data.cFileName[0] == '.' && find_data.cFileName[1] == 0) ||(find_data.cFileName[0] == '.' && find_data.cFileName[1] == '.' && find_data.cFileName[2] == 0);
                                
                                if (!nav_dir){
                                    u32 attribs = find_data.dwFileAttributes;
                                    info->folder = (attribs & FILE_ATTRIBUTE_DIRECTORY) != 0;
                                    info->filename = (char*)name;
                                    
                                    u16 *src = (u16*)find_data.cFileName;
                                    u32 src_len = 0;
                                    for (;src[src_len];++src_len);
                                    
                                    u8 *dst = name;
                                    u32 max = remaining_size-1;
                                    
                                    b32 error = false;
                                    u32 length = (u32)utf16_to_utf8_minimal_checking(dst, max, src, src_len, &error);
                                    
                                    if (length <= max && !error){
                                        name += length;
                                        
                                        info->filename_len = length;
                                        *name++ = 0;
                                        String fname = make_string_cap(info->filename, length, length+1);
                                        replace_char(&fname, '\\', '/');
                                        ++info;
                                        ++corrected_file_count;
                                    }
                                }
                                more_files = FindNextFile(search, &find_data);
                            }while(more_files);
                            FindClose(search);
                            
                            file_list->count = corrected_file_count;
                            clear_list = false;
                        }
                    }
                }
            }
        }
    }
    
    if (clear_list){
        system_memory_free(file_list->block, 0);
        file_list->block = 0;
        file_list->block_size = 0;
        file_list->infos = 0;
        file_list->count = 0;
    }
}

internal
Sys_Get_Canonical_Sig(system_get_canonical){
    u32 result = 0;
    
    char src_space[MAX_PATH + 32];
    if (len < sizeof(src_space) && len >= 2 && ((filename[0] >= 'a' && filename[0] <= 'z') || (filename[0] >= 'A' && filename[0] <= 'Z')) && filename[1] == ':'){
        memcpy(src_space, filename, len);
        src_space[len] = 0;
        
        HANDLE file = CreateFile_utf8((u8*)src_space, GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
        
        if (file != INVALID_HANDLE_VALUE){
            DWORD final_length = GetFinalPathNameByHandle_utf8(file, (u8*)buffer, max, 0);
            
            if (final_length < max && final_length >= 4){
                if (buffer[final_length-1] == 0){
                    --final_length;
                }
                final_length -= 4;
                memmove(buffer, buffer+4, final_length);
                buffer[final_length] = 0;
                result = final_length;
            }
            
            CloseHandle(file);
        }
        else{
            String src_str = make_string(filename, len);
            String path_str = path_of_directory(src_str);
            String front_str = front_of_directory(src_str);
            
            memcpy(src_space, path_str.str, path_str.size);
            src_space[path_str.size] = 0;
            
            HANDLE dir = CreateFile_utf8((u8*)src_space, FILE_LIST_DIRECTORY, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, 0);
            
            if (dir != INVALID_HANDLE_VALUE){
                DWORD final_length = GetFinalPathNameByHandle_utf8(dir, (u8*)buffer, max, 0);
                
                if (final_length < max && final_length >= 4){
                    if (buffer[final_length-1] == 0){
                        --final_length;
                    }
                    final_length -= 4;
                    memmove(buffer, buffer+4, final_length);
                    buffer[final_length++] = '\\';
                    memcpy(buffer + final_length, front_str.str, front_str.size);
                    final_length += front_str.size;
                    buffer[final_length] = 0;
                    result = final_length;
                }
                
                CloseHandle(dir);
            }
        }
    }
    
    return(result);
}

internal
Sys_Load_Handle_Sig(system_load_handle){
    b32 result = false;
    HANDLE file = CreateFile_utf8((u8*)filename, GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
    
    if (file != INVALID_HANDLE_VALUE){
        *(HANDLE*)handle_out = file;
        result = true;
    }
    
    return(result);
}

internal
Sys_Load_Size_Sig(system_load_size){
    u32 result = 0;
    HANDLE file = *(HANDLE*)(&handle);
    
    DWORD hi = 0;
    DWORD lo = GetFileSize(file, &hi);
    
    if (hi == 0){
        result = lo;
    }
    
    return(result);
}

internal
Sys_Load_File_Sig(system_load_file){
    b32 result = 0;
    HANDLE file = *(HANDLE*)(&handle);
    
    DWORD read_size = 0;
    
    if (ReadFile(file, buffer, size, &read_size, 0)){
        if (read_size == size){
            result = 1;
        }
    }
    
    return(result);
}

internal
Sys_Load_Close_Sig(system_load_close){
    b32 result = 0;
    HANDLE file = *(HANDLE*)(&handle);
    if (CloseHandle(file)){
        result = 1;
    }
    return(result);
}

internal
Sys_Save_File_Sig(system_save_file){
    b32 result = false;
    HANDLE file = CreateFile_utf8((u8*)filename, GENERIC_WRITE, 0, 0, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
    
    if (file != INVALID_HANDLE_VALUE){
        DWORD written_total = 0;
        DWORD written_size = 0;
        
        result = true;
        
        while (written_total < size){
            if (!WriteFile(file, buffer + written_total, size - written_total, &written_size, 0)){
                result = 0;
                break;
            }
            written_total += written_size;
        }
        
        CloseHandle(file);
    }
    
    return(result);
}

//
// File System
//

internal
Sys_File_Exists_Sig(system_file_exists){
    char full_filename_space[1024];
    String full_filename;
    HANDLE file;
    b32 result = 0;
    
    if (len < sizeof(full_filename_space)){
        full_filename = make_fixed_width_string(full_filename_space);
        copy_ss(&full_filename, make_string(filename, len));
        terminate_with_null(&full_filename);
        
        file = CreateFile_utf8((u8*)full_filename.str, GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
        
        if (file != INVALID_HANDLE_VALUE){
            CloseHandle(file);
            result = 1;
        }
    }
    
    return(result);
}

internal b32
system_directory_exists(char *path){
    DWORD attrib = GetFileAttributes_utf8((u8*)path);
    return(attrib != INVALID_FILE_ATTRIBUTES && (attrib & FILE_ATTRIBUTE_DIRECTORY));
}

//
// Time
//

internal
Sys_Now_Time_Sig(system_now_time){
    u64 result = __rdtsc();
    return(result);
}

// BOTTOM