OpenRCT2/src/core/FileScanner.cpp

#pragma region Copyright (c) 2014-2016 OpenRCT2 Developers
/*****************************************************************************
 * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
 *
 * OpenRCT2 is the work of many authors, a full list can be found in contributors.md
 * For more information, visit https://github.com/OpenRCT2/OpenRCT2
 *
 * OpenRCT2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * A full copy of the GNU General Public License can be found in licence.txt
 *****************************************************************************/
#pragma endregion

#include "../common.h"

#ifdef __WINDOWS__
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif

#include <stack>
#include <vector>
#include "FileScanner.h"
#include "Memory.hpp"
#include "Path.hpp"
#include "String.hpp"

extern "C"
{
    #include "../localisation/localisation.h"
    #include "../platform/platform.h"
}

enum DIRECTORY_CHILD_TYPE
{
    DCT_DIRECTORY,
    DCT_FILE,
};

struct DirectoryChild
{
    DIRECTORY_CHILD_TYPE Type;
    std::string Name;

    // Files only
    uint64 Size;
    uint64 LastModified;
};

static bool MatchWildcard(const utf8 * fileName, const utf8 * pattern);

class FileScannerBase : public IFileScanner
{
private:
    struct DirectoryState
    {
        std::string                 Path;
        std::vector<DirectoryChild> Listing;
        sint32                      Index;
    };

    // Options
    utf8 *      _rootPath;
    utf8 * *    _patterns;
    size_t      _numPatterns;
    bool        _recurse;

    // State
    bool                        _started;
    std::stack<DirectoryState>  _directoryStack;

    // Current
    FileInfo    * _currentFileInfo;
    utf8        * _currentPath;

public:
    FileScannerBase(const utf8 * pattern, bool recurse)
    {
        _rootPath = Memory::Allocate<utf8>(MAX_PATH);
        Path::GetDirectory(_rootPath, MAX_PATH, pattern);
        _recurse = recurse;
        _numPatterns = GetPatterns(&_patterns, Path::GetFileName(pattern));

        _currentPath = Memory::Allocate<utf8>(MAX_PATH);
        _currentFileInfo = Memory::Allocate<FileInfo>();

        Reset();
    }

    ~FileScannerBase() override
    {
        Memory::Free(_rootPath);
        Memory::FreeArray(_patterns, _numPatterns);
        Memory::Free(_currentPath);
        Memory::Free(_currentFileInfo);
    }

    const FileInfo * GetFileInfo() const override
    {
        return _currentFileInfo;
    }

    const utf8 * GetPath() const override
    {
        return _currentPath;
    }

    void Reset() override
    {
        _started = false;
        _directoryStack = std::stack<DirectoryState>();
        _currentPath[0] = 0;
    }

    bool Next() override
    {
        if (!_started)
        {
            _started = true;
            PushState(_rootPath);
        }

        while (_directoryStack.size() != 0)
        {
            DirectoryState * state = &_directoryStack.top();
            state->Index++;
            if (state->Index >= state->Listing.size())
            {
                _directoryStack.pop();
            }
            else
            {
                const DirectoryChild * child = &state->Listing[state->Index];
                if (child->Type == DCT_DIRECTORY)
                {
                    utf8 childPath[MAX_PATH];
                    String::Set(childPath, sizeof(childPath), state->Path.c_str());
                    Path::Append(childPath, sizeof(childPath), child->Name.c_str());
                    PushState(childPath);
                }
                else if (PatternMatch(child->Name.c_str()))
                {
                    String::Set(_currentPath, MAX_PATH, state->Path.c_str());
                    Path::Append(_currentPath, MAX_PATH, child->Name.c_str());

                    _currentFileInfo->Name = child->Name.c_str();
                    _currentFileInfo->Size = child->Size;
                    _currentFileInfo->LastModified = child->LastModified;
                    return true;
                }
            }
        }
        return false;
    }

private:
    void PushState(const utf8 * directory)
    {
        DirectoryState newState;
        newState.Path = std::string(directory);
        newState.Index = -1;
        GetDirectoryChildren(newState.Listing, directory);
        _directoryStack.push(newState);
    }

    bool PatternMatch(const utf8 * fileName)
    {
        for (size_t i = 0; i < _numPatterns; i++)
        {
            if (MatchWildcard(fileName, _patterns[i]))
            {
                return true;
            }
        }
        return false;
    }

    static size_t GetPatterns(utf8 * * * outPatterns, const utf8 * delimitedPatterns)
    {
        std::vector<utf8 *> patterns;

        const utf8 * start = delimitedPatterns;
        const utf8 * ch = start;
        utf8 c;
        do
        {
            c = *ch;
            if (c == '\0' || c == ';')
            {
                size_t length = (size_t)(ch - start);
                if (length > 0)
                {
                    utf8 * newPattern = Memory::Allocate<utf8>(length + 1);
                    Memory::Copy(newPattern, start, length);
                    newPattern[length] = '\0';
                    patterns.push_back(newPattern);
                }
                start = ch + 1;
            }
            ch++;
        }
        while (c != '\0');

        *outPatterns = Memory::DuplicateArray(patterns.data(), patterns.size());
        return patterns.size();
    }

protected:
    virtual void GetDirectoryChildren(std::vector<DirectoryChild> &children, const utf8 * path) abstract;

};

#ifdef __WINDOWS__

class FileScannerWindows final : public FileScannerBase
{
public:
    FileScannerWindows(const utf8 * pattern, bool recurse)
        : FileScannerBase(pattern, recurse)
    {
    }

protected:
    void GetDirectoryChildren(std::vector<DirectoryChild> &children, const utf8 * path) override
    {
        size_t pathLength = String::SizeOf(path);
        utf8 * pattern = Memory::Duplicate(path, pathLength + 3);
        pattern[pathLength + 0] = '\\';
        pattern[pathLength + 1] = '*';
        pattern[pathLength + 2] = '\0';

        wchar_t * wPattern = utf8_to_widechar(pattern);

        WIN32_FIND_DATAW findData;
        HANDLE hFile = FindFirstFileW(wPattern, &findData);
        if (hFile != INVALID_HANDLE_VALUE)
        {
            do
            {
                if (lstrcmpW(findData.cFileName, L".") != 0 &&
                    lstrcmpW(findData.cFileName, L"..") != 0)
                {
                    DirectoryChild child = CreateChild(&findData);
                    children.push_back(child);
                }
            }
            while (FindNextFileW(hFile, &findData));
            FindClose(hFile);
        }
    }

private:
    static DirectoryChild CreateChild(const WIN32_FIND_DATAW * child)
    {
        DirectoryChild result;

        utf8 * name = widechar_to_utf8(child->cFileName);
        result.Name = std::string(name);
        Memory::Free(name);

        if (child->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
        {
            result.Type = DCT_DIRECTORY;
        }
        else
        {
            result.Type = DCT_FILE;
            result.Size = ((uint64)child->nFileSizeHigh << 32ULL) | (uint64)child->nFileSizeLow;
            result.LastModified = ((uint64)child->ftLastWriteTime.dwHighDateTime << 32ULL) | (uint64)child->ftLastWriteTime.dwLowDateTime;
        }
        return result;
    }
};

#endif // __WINDOWS__

IFileScanner * Path::ScanDirectory(const utf8 * pattern, bool recurse)
{
#ifdef __WINDOWS__
    return new FileScannerWindows(pattern, recurse);
#endif
}

/**
 * Due to FindFirstFile / FindNextFile searching for DOS names as well, *.doc also matches *.docx which isn't what the pattern
 * specified. This will verify if a filename does indeed match the pattern we asked for.
 * @remarks Based on algorithm (http://xoomer.virgilio.it/acantato/dev/wildcard/wildmatch.html)
 */
static bool MatchWildcard(const utf8 * fileName, const utf8 * pattern)
{
    while (*fileName != '\0')
    {
        switch (*pattern) {
        case '?':
            if (*fileName == '.')
            {
                return false;
            }
            break;
        case '*':
            do
            {
                pattern++;
            }
            while (*pattern == '*');
            if (*pattern == '\0')
            {
                return false;
            }
            while (*fileName != '\0')
            {
                if (MatchWildcard(fileName++, pattern))
                {
                    return true;
                }
            }
            return false;
        default:
            if (toupper(*fileName) != toupper(*pattern))
            {
                return false;
            }
            break;
        }
        pattern++;
        fileName++;
    }
    while (*pattern == '*')
    {
        ++fileName;
    }
    return *pattern == '\0';
}