// Copyright (C) 2003 Dolphin Project.

// This program 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, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

#ifndef _POINTERWRAP_H_
#define _POINTERWRAP_H_

// Extremely simple serialization framework.

// (mis)-features:
// + Super fast
// + Very simple
// + Same code is used for serialization and deserializaition (in most cases)
// - Zero backwards/forwards compatibility
// - Serialization code for anything complex has to be manually written.

#include <map>
#include <vector>
#include <deque>
#include <string>
#include <list>
#include <set>
#ifndef __SYMBIAN32__
#if defined(IOS) || defined(MACGNUSTD)
#include <tr1/type_traits>
#else
#include <type_traits>
#endif
#endif

#include "common.h"
#include "file_util.h"
//#include "../ext/snappy/snappy-c.h"

#if defined(IOS) || defined(MACGNUSTD)
namespace std {
    using tr1::is_pointer;
}
#endif
#ifdef __SYMBIAN32__
namespace std {
    template <bool bool_value>
    struct bool_constant {
        typedef bool_constant<bool_value> type;
        static const bool value = bool_value;
    };
    template <bool bool_value> const bool bool_constant<bool_value>::value;
    template <typename T> struct is_pointer : public bool_constant<false> {};
    template <typename T> struct is_pointer<T*> : public bool_constant<true> {};
}
#endif

template <class T>
struct LinkedListItem : public T
{
    LinkedListItem<T> *next;
};

class PointerWrap;

class PointerWrapSection
{
public:
    PointerWrapSection(PointerWrap &p, int ver, const char *title) : p_(p), ver_(ver), title_(title) {
    }
    ~PointerWrapSection();
    
    bool operator == (const int &v) const { return ver_ == v; }
    bool operator != (const int &v) const { return ver_ != v; }
    bool operator <= (const int &v) const { return ver_ <= v; }
    bool operator >= (const int &v) const { return ver_ >= v; }
    bool operator <  (const int &v) const { return ver_ < v; }
    bool operator >  (const int &v) const { return ver_ > v; }

    operator bool() const  {
        return ver_ > 0;
    }

private:
    PointerWrap &p_;
    int ver_;
    const char *title_;
};

// Wrapper class
class PointerWrap
{
    // This makes it a compile error if you forget to define DoState() on non-POD.
    // Which also can be a problem, for example struct tm is non-POD on linux, for whatever reason...
#ifdef _MSC_VER
    template<typename T, bool isPOD = std::is_pod<T>::value, bool isPointer = std::is_pointer<T>::value>
#else
    template<typename T, bool isPOD = __is_pod(T), bool isPointer = std::is_pointer<T>::value>
#endif
    struct DoHelper
    {
        static void DoArray(PointerWrap *p, T *x, int count)
        {
            for (int i = 0; i < count; ++i)
                p->Do(x[i]);
        }

        static void Do(PointerWrap *p, T &x)
        {
            p->DoClass(x);
        }
    };

    template<typename T>
    struct DoHelper<T, true, false>
    {
        static void DoArray(PointerWrap *p, T *x, int count)
        {
            p->DoVoid((void *)x, sizeof(T) * count);
        }

        static void Do(PointerWrap *p, T &x)
        {
            p->DoVoid((void *)&x, sizeof(x));
        }
    };

public:
    enum Mode {
        MODE_READ = 1, // load
        MODE_WRITE, // save
        MODE_MEASURE, // calculate size
        MODE_VERIFY, // compare
    };

    enum Error {
        ERROR_NONE = 0,
        ERROR_WARNING = 1,
        ERROR_FAILURE = 2,
    };

    u8 **ptr;
    Mode mode;
    Error error;

public:
    PointerWrap(u8 **ptr_, Mode mode_) : ptr(ptr_), mode(mode_), error(ERROR_NONE) {}
    PointerWrap(unsigned char **ptr_, int mode_) : ptr((u8**)ptr_), mode((Mode)mode_), error(ERROR_NONE) {}

    PointerWrapSection Section(const char *title, int ver) {
        return Section(title, ver, ver);
    }

    // The returned object can be compared against the version that was loaded.
    // This can be used to support versions as old as minVer.
    // Version = 0 means the section was not found.
    PointerWrapSection Section(const char *title, int minVer, int ver) {
        char marker[16] = {0};
        int foundVersion = ver;

        strncpy(marker, title, sizeof(marker));
        if (!ExpectVoid(marker, sizeof(marker)))
        {
            // Might be before we added name markers for safety.
            if (foundVersion == 1 && ExpectVoid(&foundVersion, sizeof(foundVersion)))
                DoMarker(title);
            // Wasn't found, but maybe we can still load the state.
            else
                foundVersion = 0;
        }
        else
            Do(foundVersion);

        if (error == ERROR_FAILURE || foundVersion < minVer || foundVersion > ver) {
            WARN_LOG(COMMON, "Savestate failure: wrong version %d found for %s", foundVersion, title);
            SetError(ERROR_FAILURE);
            return PointerWrapSection(*this, -1, title);
        }
        return PointerWrapSection(*this, foundVersion, title);
    }

    void SetMode(Mode mode_) {mode = mode_;}
    Mode GetMode() const {return mode;}
    u8 **GetPPtr() {return ptr;}
    void SetError(Error error_)
    {
        if (error < error_)
            error = error_;
        if (error > ERROR_WARNING)
            mode = PointerWrap::MODE_MEASURE;
    }

    bool ExpectVoid(void *data, int size)
    {
        switch (mode) {
        case MODE_READ:    if (memcmp(data, *ptr, size) != 0) return false; break;
        case MODE_WRITE: memcpy(*ptr, data, size); break;
        case MODE_MEASURE: break;  // MODE_MEASURE - don't need to do anything
        case MODE_VERIFY: for(int i = 0; i < size; i++) _dbg_assert_msg_(COMMON, ((u8*)data)[i] == (*ptr)[i], "Savestate verification failure: %d (0x%X) (at %p) != %d (0x%X) (at %p).\n", ((u8*)data)[i], ((u8*)data)[i], &((u8*)data)[i], (*ptr)[i], (*ptr)[i], &(*ptr)[i]); break;
        default: break;  // throw an error?
        }
        (*ptr) += size;
        return true;
    }

    void DoVoid(void *data, int size)
    {
        switch (mode) {
        case MODE_READ:    memcpy(data, *ptr, size); break;
        case MODE_WRITE: memcpy(*ptr, data, size); break;
        case MODE_MEASURE: break;  // MODE_MEASURE - don't need to do anything
        case MODE_VERIFY: for(int i = 0; i < size; i++) _dbg_assert_msg_(COMMON, ((u8*)data)[i] == (*ptr)[i], "Savestate verification failure: %d (0x%X) (at %p) != %d (0x%X) (at %p).\n", ((u8*)data)[i], ((u8*)data)[i], &((u8*)data)[i], (*ptr)[i], (*ptr)[i], &(*ptr)[i]); break;
        default: break;  // throw an error?
        }
        (*ptr) += size;
    }
    
    template<class K, class T>
    void Do(std::map<K, T *> &x)
    {
        if (mode == MODE_READ)
        {
            for (auto it = x.begin(), end = x.end(); it != end; ++it)
            {
                if (it->second != NULL)
                    delete it->second;
            }
        }
        T *dv = NULL;
        DoMap(x, dv);
    }

    template<class K, class T>
    void Do(std::map<K, T> &x)
    {
        T dv = T();
        DoMap(x, dv);
    }

    template<class K, class T>
    void DoMap(std::map<K, T> &x, T &default_val)
    {
        unsigned int number = (unsigned int)x.size();
        Do(number);
        switch (mode) {
        case MODE_READ:
            {
                x.clear();
                while (number > 0)
                {
                    K first = K();
                    Do(first);
                    T second = default_val;
                    Do(second);
                    x[first] = second;
                    --number;
                }
            }
            break;
        case MODE_WRITE:
        case MODE_MEASURE:
        case MODE_VERIFY:
            {
                typename std::map<K, T>::iterator itr = x.begin();
                while (number > 0)
                {
                    K first = itr->first;
                    Do(first);
                    Do(itr->second);
                    --number;
                    ++itr;
                }
            }
            break;
        }
    }

    template<class K, class T>
    void Do(std::multimap<K, T *> &x)
    {
        if (mode == MODE_READ)
        {
            for (auto it = x.begin(), end = x.end(); it != end; ++it)
            {
                if (it->second != NULL)
                    delete it->second;
            }
        }
        T *dv = NULL;
        DoMultimap(x, dv);
    }

    template<class K, class T>
    void Do(std::multimap<K, T> &x)
    {
        T dv = T();
        DoMultimap(x, dv);
    }

    template<class K, class T>
    void DoMultimap(std::multimap<K, T> &x, T &default_val)
    {
        unsigned int number = (unsigned int)x.size();
        Do(number);
        switch (mode) {
        case MODE_READ:
            {
                x.clear();
                while (number > 0)
                {
                    K first = K();
                    Do(first);
                    T second = default_val;
                    Do(second);
                    x.insert(std::make_pair(first, second));
                    --number;
                }
            }
            break;
        case MODE_WRITE:
        case MODE_MEASURE:
        case MODE_VERIFY:
            {
                typename std::multimap<K, T>::iterator itr = x.begin();
                while (number > 0)
                {
                    Do(itr->first);
                    Do(itr->second);
                    --number;
                    ++itr;
                }
            }
            break;
        }
    }

    // Store vectors.
    template<class T>
    void Do(std::vector<T *> &x)
    {
        T *dv = NULL;
        DoVector(x, dv);
    }

    template<class T>
    void Do(std::vector<T> &x)
    {
        T dv = T();
        DoVector(x, dv);
    }


    template<class T>
    void DoPOD(std::vector<T> &x)
    {
        T dv = T();
        DoVectorPOD(x, dv);
    }

    template<class T>
    void Do(std::vector<T> &x, T &default_val)
    {
        DoVector(x, default_val);
    }

    template<class T>
    void DoVector(std::vector<T> &x, T &default_val)
    {
        u32 vec_size = (u32)x.size();
        Do(vec_size);
        x.resize(vec_size, default_val);
        if (vec_size > 0)
            DoArray(&x[0], vec_size);
    }

    template<class T>
    void DoVectorPOD(std::vector<T> &x, T &default_val)
    {
        u32 vec_size = (u32)x.size();
        Do(vec_size);
        x.resize(vec_size, default_val);
        if (vec_size > 0)
            DoArray(&x[0], vec_size);
    }
    
    // Store deques.
    template<class T>
    void Do(std::deque<T *> &x)
    {
        T *dv = NULL;
        DoDeque(x, dv);
    }

    template<class T>
    void Do(std::deque<T> &x)
    {
        T dv = T();
        DoDeque(x, dv);
    }

    template<class T>
    void DoDeque(std::deque<T> &x, T &default_val)
    {
        u32 deq_size = (u32)x.size();
        Do(deq_size);
        x.resize(deq_size, default_val);
        u32 i;
        for(i = 0; i < deq_size; i++)
            Do(x[i]);
    }

    // Store STL lists.
    template<class T>
    void Do(std::list<T *> &x)
    {
        T *dv = NULL;
        Do(x, dv);
    }

    template<class T>
    void Do(std::list<T> &x)
    {
        T dv = T();
        DoList(x, dv);
    }

    template<class T>
    void Do(std::list<T> &x, T &default_val)
    {
        DoList(x, default_val);
    }

    template<class T>
    void DoList(std::list<T> &x, T &default_val)
    {
        u32 list_size = (u32)x.size();
        Do(list_size);
        x.resize(list_size, default_val);

        typename std::list<T>::iterator itr, end;
        for (itr = x.begin(), end = x.end(); itr != end; ++itr)
            Do(*itr);
    }


    // Store STL sets.
    template <class T>
    void Do(std::set<T *> &x)
    {
        if (mode == MODE_READ)
        {
            for (auto it = x.begin(), end = x.end(); it != end; ++it)
            {
                if (*it != NULL)
                    delete *it;
            }
        }
        DoSet(x);
    }

    template <class T>
    void Do(std::set<T> &x)
    {
        DoSet(x);
    }

    template <class T>
    void DoSet(std::set<T> &x)
    {
        unsigned int number = (unsigned int)x.size();
        Do(number);

        switch (mode)
        {
        case MODE_READ:
            {
                x.clear();
                while (number-- > 0)
                {
                    T it = T();
                    Do(it);
                    x.insert(it);
                }
            }
            break;
        case MODE_WRITE:
        case MODE_MEASURE:
        case MODE_VERIFY:
            {
                typename std::set<T>::iterator itr = x.begin();
                while (number-- > 0)
                    Do(*itr++);
            }
            break;

        default:
            ERROR_LOG(COMMON, "Savestate error: invalid mode %d.", mode);
        }
    }

    // Store strings.
    void Do(std::string &x) 
    {
        int stringLen = (int)x.length() + 1;
        Do(stringLen);
        
        switch (mode) {
        case MODE_READ:        x = (char*)*ptr; break;
        case MODE_WRITE:    memcpy(*ptr, x.c_str(), stringLen); break;
        case MODE_MEASURE: break;
        case MODE_VERIFY: _dbg_assert_msg_(COMMON, !strcmp(x.c_str(), (char*)*ptr), "Savestate verification failure: \"%s\" != \"%s\" (at %p).\n", x.c_str(), (char*)*ptr, ptr); break;
        }
        (*ptr) += stringLen;
    }

    void Do(std::wstring &x) 
    {
        int stringLen = sizeof(wchar_t)*((int)x.length() + 1);
        Do(stringLen);

        switch (mode) {
        case MODE_READ:        x = (wchar_t*)*ptr; break;
        case MODE_WRITE:    memcpy(*ptr, x.c_str(), stringLen); break;
        case MODE_MEASURE: break;
        case MODE_VERIFY: _dbg_assert_msg_(COMMON, x == (wchar_t*)*ptr, "Savestate verification failure: \"%ls\" != \"%ls\" (at %p).\n", x.c_str(), (wchar_t*)*ptr, ptr); break;
        }
        (*ptr) += stringLen;
    }

    template<class T>
    void DoClass(T &x) {
        x.DoState(*this);
    }

    template<class T>
    void DoClass(T *&x) {
        if (mode == MODE_READ)
        {
            if (x != NULL)
                delete x;
            x = new T();
        }
        x->DoState(*this);
    }

    template<class T>
    void DoArray(T *x, int count) {
        DoHelper<T>::DoArray(this, x, count);
    }

    template<class T>
    void Do(T &x) {
        DoHelper<T>::Do(this, x);
    }
    
    template<class T>
    void DoPOD(T &x) {
        DoHelper<T>::Do(this, x);
    }

    template<class T>
    void DoPointer(T* &x, T*const base) {
        // pointers can be more than 2^31 apart, but you're using this function wrong if you need that much range
        s32 offset = x - base;
        Do(offset);
        if (mode == MODE_READ)
            x = base + offset;
    }

    template<class T, LinkedListItem<T>* (*TNew)(), void (*TFree)(LinkedListItem<T>*), void (*TDo)(PointerWrap&, T*)>
    void DoLinkedList(LinkedListItem<T>*& list_start, LinkedListItem<T>** list_end=0)
    {
        LinkedListItem<T>* list_cur = list_start;
        LinkedListItem<T>* prev = 0;

        while (true)
        {
            u8 shouldExist = (list_cur ? 1 : 0);
            Do(shouldExist);
            if (shouldExist == 1)
            {
                LinkedListItem<T>* cur = list_cur ? list_cur : TNew();
                TDo(*this, (T*)cur);
                if (!list_cur)
                {
                    if (mode == MODE_READ)
                    {
                        cur->next = 0;
                        list_cur = cur;
                        if (prev)
                            prev->next = cur;
                        else
                            list_start = cur;
                    }
                    else
                    {
                        TFree(cur);
                        continue;
                    }
                }
            }
            else
            {
                if (mode == MODE_READ)
                {
                    if (prev)
                        prev->next = 0;
                    if (list_end)
                        *list_end = prev;
                    if (list_cur)
                    {
                        if (list_start == list_cur)
                            list_start = 0;
                        do
                        {
                            LinkedListItem<T>* next = list_cur->next;
                            TFree(list_cur);
                            list_cur = next;
                        }
                        while (list_cur);
                    }
                }
                break;
            }
            prev = list_cur;
            list_cur = list_cur->next;
        }
    }

    void DoMarker(const char* prevName, u32 arbitraryNumber=0x42)
    {
        u32 cookie = arbitraryNumber;
        Do(cookie);
        if(mode == PointerWrap::MODE_READ && cookie != arbitraryNumber)
        {
            PanicAlertT("Error: After \"%s\", found %d (0x%X) instead of save marker %d (0x%X). Aborting savestate load...", prevName, cookie, cookie, arbitraryNumber, arbitraryNumber);
            SetError(ERROR_FAILURE);
        }
    }
};

inline PointerWrapSection::~PointerWrapSection() {
    if (ver_ > 0) {
        p_.DoMarker(title_);
    }
}


class CChunkFileReader
{
public:
    enum Error {
        ERROR_NONE,
        ERROR_BAD_FILE,
        ERROR_BROKEN_STATE,
    };

    // Load file template
    template<class T>
    static Error Load(const std::string& _rFilename, int _Revision, const char *_VersionString, T& _class, std::string* _failureReason) 
    {
        INFO_LOG(COMMON, "ChunkReader: Loading %s" , _rFilename.c_str());
        _failureReason->clear();
        _failureReason->append("LoadStateWrongVersion");

        if (!File::Exists(_rFilename)) {
            _failureReason->clear();
            _failureReason->append("LoadStateDoesntExist");
            ERROR_LOG(COMMON, "ChunkReader: File doesn't exist");
            return ERROR_BAD_FILE;
        }
                
        // Check file size
        const u64 fileSize = File::GetSize(_rFilename);
        static const u64 headerSize = sizeof(SChunkHeader);
        if (fileSize < headerSize)
        {
            ERROR_LOG(COMMON,"ChunkReader: File too small");
            return ERROR_BAD_FILE;
        }

        File::IOFile pFile(_rFilename, "rb");
        if (!pFile)
        {
            ERROR_LOG(COMMON,"ChunkReader: Can't open file for reading");
            return ERROR_BAD_FILE;
        }

        // read the header
        SChunkHeader header;
        if (!pFile.ReadArray(&header, 1))
        {
            ERROR_LOG(COMMON,"ChunkReader: Bad header size");
            return ERROR_BAD_FILE;
        }
        
        // Check revision
        if (header.Revision != _Revision)
        {
            ERROR_LOG(COMMON,"ChunkReader: Wrong file revision, got %d expected %d",
                header.Revision, _Revision);
            return ERROR_BAD_FILE;
        }
        
        if (strcmp(header.GitVersion, _VersionString) != 0)
        {
            WARN_LOG(COMMON, "This savestate was generated by a different version of PPSSPP, %s. It may not load properly.",
                header.GitVersion);
        }

        // get size
        const int sz = (int)(fileSize - headerSize);
        if (header.ExpectedSize != sz)
        {
            ERROR_LOG(COMMON,"ChunkReader: Bad file size, got %d expected %d",
                sz, header.ExpectedSize);
            return ERROR_BAD_FILE;
        }
        
        // read the state
        u8* buffer = new u8[sz];
        if (!pFile.ReadBytes(buffer, sz))
        {
            ERROR_LOG(COMMON,"ChunkReader: Error reading file");
            return ERROR_BAD_FILE;
        }

        u8 *ptr = buffer;
        u8 *buf = buffer;
        if (header.Compress) {
            u8 *uncomp_buffer = new u8[header.UncompressedSize];
            size_t uncomp_size = header.UncompressedSize;
            snappy_uncompress((const char *)buffer, sz, (char *)uncomp_buffer, &uncomp_size);
            if ((int)uncomp_size != header.UncompressedSize) {
                ERROR_LOG(COMMON,"Size mismatch: file: %i  calc: %i", (int)header.UncompressedSize, (int)uncomp_size);
            }
            ptr = uncomp_buffer;
            buf = uncomp_buffer;
            delete [] buffer;
        }

        PointerWrap p(&ptr, PointerWrap::MODE_READ);
        _class.DoState(p);
        delete[] buf;
        
        INFO_LOG(COMMON, "ChunkReader: Done loading %s" , _rFilename.c_str());
        if (p.error != p.ERROR_FAILURE) {
            return ERROR_NONE;
        } else {
            return ERROR_BROKEN_STATE;
        }
    }
    
    // Save file template
    template<class T>
    static Error Save(const std::string& _rFilename, int _Revision, const char *_VersionString, T& _class)
    {
        INFO_LOG(COMMON, "ChunkReader: Writing %s" , _rFilename.c_str());

        File::IOFile pFile(_rFilename, "wb");
        if (!pFile)
        {
            ERROR_LOG(COMMON,"ChunkReader: Error opening file for write");
            return ERROR_BAD_FILE;
        }

        bool compress = true;

        // Get data
        u8 *ptr = 0;
        PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
        _class.DoState(p);
        size_t const sz = (size_t)ptr;
        
        u8 * buffer = new u8[sz];
        ptr = &buffer[0];
        p.SetMode(PointerWrap::MODE_WRITE);
        _class.DoState(p);

        // Create header
        SChunkHeader header;
        header.Compress = compress ? 1 : 0;
        header.Revision = _Revision;
        header.ExpectedSize = (int)sz;
        header.UncompressedSize = (int)sz;
        strncpy(header.GitVersion, _VersionString, 32);
        header.GitVersion[31] = '\0';

        // Write to file
        if (compress) {
            size_t comp_len = snappy_max_compressed_length(sz);
            u8 *compressed_buffer = new u8[comp_len];
            snappy_compress((const char *)buffer, sz, (char *)compressed_buffer, &comp_len);
            delete [] buffer;
            header.ExpectedSize = (int)comp_len;
            if (!pFile.WriteArray(&header, 1))
            {
                ERROR_LOG(COMMON,"ChunkReader: Failed writing header");
                return ERROR_BAD_FILE;
            }
            if (!pFile.WriteBytes(&compressed_buffer[0], comp_len)) {
                ERROR_LOG(COMMON,"ChunkReader: Failed writing compressed data");
                return ERROR_BAD_FILE;
            }    else {
                INFO_LOG(COMMON, "Savestate: Compressed %i bytes into %i", (int)sz, (int)comp_len);
            }
            delete [] compressed_buffer;
        } else {
            if (!pFile.WriteArray(&header, 1))
            {
                ERROR_LOG(COMMON,"ChunkReader: Failed writing header");
                return ERROR_BAD_FILE;
            }
            if (!pFile.WriteBytes(&buffer[0], sz))
            {
                ERROR_LOG(COMMON,"ChunkReader: Failed writing data");
                return ERROR_BAD_FILE;
            }
            delete [] buffer;
        }
        
        INFO_LOG(COMMON,"ChunkReader: Done writing %s", 
                 _rFilename.c_str());
        if (p.error != p.ERROR_FAILURE) {
            return ERROR_NONE;
        } else {
            return ERROR_BROKEN_STATE;
        }
    }
    
    template <class T>
    static Error Verify(T& _class)
    {
        u8 *ptr = 0;

        // Step 1: Measure the space required.
        PointerWrap p(&ptr, PointerWrap::MODE_MEASURE);
        _class.DoState(p);
        size_t const sz = (size_t)ptr;
        std::vector<u8> buffer(sz);

        // Step 2: Dump the state.
        ptr = &buffer[0];
        p.SetMode(PointerWrap::MODE_WRITE);
        _class.DoState(p);

        // Step 3: Verify the state.
        ptr = &buffer[0];
        p.SetMode(PointerWrap::MODE_VERIFY);
        _class.DoState(p);

        return ERROR_NONE;
    }

private:
    struct SChunkHeader
    {
        int Revision;
        int Compress;
        int ExpectedSize;
        int UncompressedSize;
        char GitVersion[32];
    };
};

#endif  // _POINTERWRAP_H_