/* Copyright (C) 2019 Mr Goldberg
   This file is part of the Goldberg Emulator

   The Goldberg Emulator is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   The Goldberg Emulator 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the Goldberg Emulator; if not, see
   <http://www.gnu.org/licenses/>.  */

#include "dll/steam_apps.h"
#include "sha/sha1.hpp"

Steam_Apps::Steam_Apps(Settings *settings, class SteamCallResults *callback_results, class SteamCallBacks *callbacks)
{
    this->settings = settings;
    this->callback_results = callback_results;
    this->callbacks = callbacks;
}

// returns 0 if the key does not exist
// this may be true on first call, since the app data may not be cached locally yet
// If you expect it to exists wait for the AppDataChanged_t after the first failure and ask again
int Steam_Apps::GetAppData( AppId_t nAppID, const char *pchKey, char *pchValue, int cchValueMax )
{
    //TODO
    PRINT_DEBUG_TODO();
    return 0;
}

bool Steam_Apps::BIsSubscribed()
{
    PRINT_DEBUG_ENTRY();
    return true;
}

bool Steam_Apps::BIsLowViolence()
{
    PRINT_DEBUG_ENTRY();
    return false;
}

bool Steam_Apps::BIsCybercafe()
{
    PRINT_DEBUG_ENTRY();
    return false;
}

bool Steam_Apps::BIsVACBanned()
{
    PRINT_DEBUG_ENTRY();
    return false;
}

// valid list: https://partner.steamgames.com/doc/store/localization/languages
const char *Steam_Apps::GetCurrentGameLanguage()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return settings->get_language();
}

// Gets a comma separated list of the languages the current app supports.
// valid list: https://partner.steamgames.com/doc/store/localization/languages
const char *Steam_Apps::GetAvailableGameLanguages()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return settings->get_supported_languages().c_str();
}


// only use this member if you need to check ownership of another game related to yours, a demo for example
bool Steam_Apps::BIsSubscribedApp( AppId_t appID )
{
    PRINT_DEBUG("%u", appID);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    if (appID == 0) return false; // steam returns false
    if (appID == UINT32_MAX) return true; // steam returns true
    if (appID == settings->get_local_game_id().AppID()) return true; // steam returns true
    return settings->hasDLC(appID);
}


// Takes AppID of DLC and checks if the user owns the DLC & if the DLC is installed
bool Steam_Apps::BIsDlcInstalled( AppId_t appID )
{
    PRINT_DEBUG("%u", appID);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    if (appID == 0) return false; // steam returns false (also appid 1958220 expects false otherwise it hangs in loading screen)
    if (appID == UINT32_MAX) return false; // steam returns false
    
    // Age of Empires 2: Definitive Edition expects the app itself to be an owned DLC.
    // otherwise it will only load the "Return of Rome" game mode, also most options are disabled
    if (appID == settings->get_local_game_id().AppID()) return true; // steam returns true

    return settings->hasDLC(appID);
}


// returns the Unix time of the purchase of the app
uint32 Steam_Apps::GetEarliestPurchaseUnixTime( AppId_t nAppID )
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    if (nAppID == 0) return 0; // steam returns 0
    if (nAppID == UINT32_MAX) return 0; // steam returns 0
    if (nAppID == settings->get_local_game_id().AppID() || settings->hasDLC(nAppID)) {
        auto t =
            // 4 days ago
            startup_time
            - std::chrono::hours(24 * 4);
        auto duration = std::chrono::duration_cast<std::chrono::seconds>(t.time_since_epoch());
        return (uint32)duration.count();
    }

    //TODO ?
    return 0;
}


// Checks if the user is subscribed to the current app through a free weekend
// This function will return false for users who have a retail or other type of license
// Before using, please ask your Valve technical contact how to package and secure your free weekened
bool Steam_Apps::BIsSubscribedFromFreeWeekend()
{
    PRINT_DEBUG_ENTRY();
    return false;
}


// Returns the number of DLC pieces for the running app
int Steam_Apps::GetDLCCount()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return settings->DLCCount();
}


// Returns metadata for DLC by index, of range [0, GetDLCCount()]
bool Steam_Apps::BGetDLCDataByIndex( int iDLC, AppId_t *pAppID, bool *pbAvailable, char *pchName, int cchNameBufferSize )
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    AppId_t appid = k_uAppIdInvalid;
    bool available = false;
    std::string name{};
    if (!settings->getDLC(iDLC, appid, available, name)) return false;

    if (pAppID) *pAppID = appid;
    if (pbAvailable) *pbAvailable = available;
    if (pchName && cchNameBufferSize > 0) {
        memset(pchName, 0, cchNameBufferSize);
        name.copy(pchName, cchNameBufferSize - 1);
    }

    return true;
}


// Install/Uninstall control for optional DLC
void Steam_Apps::InstallDLC( AppId_t nAppID )
{
    PRINT_DEBUG_TODO();
    // we lock here because the API is supposed to modify the DLC list
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    if (settings->hasDLC(nAppID)) {
        DlcInstalled_t data{};
        data.m_nAppID = nAppID;
        callbacks->addCBResult(data.k_iCallback, &data, sizeof(data), 0.01);
    }
}

void Steam_Apps::UninstallDLC( AppId_t nAppID )
{
    PRINT_DEBUG_ENTRY();
    // we lock here because the API is supposed to modify the DLC list
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
}


static void FillProofOfPurchaseKey( AppProofOfPurchaseKeyResponse_t& data, AppId_t nAppID, bool ok_result, std::string key = "cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd" )
{
    data.m_nAppID = nAppID;
    if (ok_result) {
        // TODO maybe read this from a config file "purchased_keys.txt":
        // 480=AAAAA-BBBBB-CCCCC-DDDDD
        // 218620=XYZFJ-13370-98765
        size_t min_len = key.size() < k_cubAppProofOfPurchaseKeyMax
            ? key.size() < k_cubAppProofOfPurchaseKeyMax
            : k_cubAppProofOfPurchaseKeyMax - 1; // -1 because we need space for null
        data.m_eResult = EResult::k_EResultOK;
        data.m_cchKeyLength = static_cast<uint32>(min_len);
        memcpy(data.m_rgchKey, key.c_str(), min_len);
        data.m_rgchKey[min_len] = 0;
    } else {
        data.m_eResult = EResult::k_EResultFail;
        data.m_cchKeyLength = 0;
        data.m_rgchKey[0] = 0;
        data.m_rgchKey[1] = 0;
    }
}

// Request legacy cd-key for yourself or owned DLC. If you are interested in this
// data then make sure you provide us with a list of valid keys to be distributed
// to users when they purchase the game, before the game ships.
// You'll receive an AppProofOfPurchaseKeyResponse_t callback when
// the key is available (which may be immediately).
void Steam_Apps::RequestAppProofOfPurchaseKey( AppId_t nAppID )
{
    PRINT_DEBUG_TODO();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    AppProofOfPurchaseKeyResponse_t data{};
    data.m_nAppID = nAppID;
    
    // check Steam_Apps::BIsAppInstalled()
    if (nAppID == 0 || nAppID == UINT32_MAX) {
        FillProofOfPurchaseKey(data, nAppID, false);
    } else if (nAppID == settings->get_local_game_id().AppID() || settings->hasDLC(nAppID)) {
        FillProofOfPurchaseKey(data, nAppID, true);
    } else {
        //TODO what to do here?
        FillProofOfPurchaseKey(data, nAppID, false);
    }

    callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
}

// returns current beta branch name, 'public' is the default branch
// "true if the user is on a beta branch; otherwise, false"
// https://partner.steamgames.com/doc/api/ISteamApps
bool Steam_Apps::GetCurrentBetaName( char *pchName, int cchNameBufferSize )
{
    PRINT_DEBUG("%p [%i]", pchName, cchNameBufferSize);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    const auto &current_branch_name = settings->branches[settings->selected_branch_idx].name;
    if (pchName && cchNameBufferSize > 0 && static_cast<size_t>(cchNameBufferSize) > current_branch_name.size()) {
        memset(pchName, 0, cchNameBufferSize);
        memcpy(pchName, current_branch_name.c_str(), current_branch_name.size());
    }

    PRINT_DEBUG("returned '%s'", pchName);
    return settings->is_beta_branch;
}

// signal Steam that game files seems corrupt or missing
bool Steam_Apps::MarkContentCorrupt( bool bMissingFilesOnly )
{
    PRINT_DEBUG_TODO();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    //TODO: warn user
    return true;
}

// return installed depots in mount order
uint32 Steam_Apps::GetInstalledDepots( AppId_t appID, DepotId_t *pvecDepots, uint32 cMaxDepots )
{
    PRINT_DEBUG("%u, %u", appID, cMaxDepots);
    //TODO not sure about the behavior of this function, I didn't actually test this.
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    unsigned int count = (unsigned int)settings->depots.size();
    if (!pvecDepots || !cMaxDepots || !count) return 0;

    if (cMaxDepots < count) count = cMaxDepots;
    std::copy(settings->depots.begin(), settings->depots.begin() + count, pvecDepots);
    return count;
}

uint32 Steam_Apps::GetInstalledDepots( DepotId_t *pvecDepots, uint32 cMaxDepots )
{
    PRINT_DEBUG("old");
    return GetInstalledDepots( settings->get_local_game_id().AppID(), pvecDepots, cMaxDepots );
}

// returns current app install folder for AppID, returns folder name length
uint32 Steam_Apps::GetAppInstallDir( AppId_t appID, char *pchFolder, uint32 cchFolderBufferSize )
{
    PRINT_DEBUG("%u %p %u", appID, pchFolder, cchFolderBufferSize);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    //TODO return real path instead of dll path
    std::string installed_path = settings->getAppInstallPath(appID);

    if (installed_path.empty()) {
        std::string dll_path = get_full_program_path();
        std::string current_path = get_current_path();
        PRINT_DEBUG("  dll: '%s', current: '%s'", dll_path.c_str(), current_path.c_str());

        //Just pick the smallest path, it has the most chances of being the good one
        if (dll_path.size() > current_path.size() && current_path.size()) {
            installed_path = current_path;
        } else {
            installed_path = dll_path;
        }
    }

    PRINT_DEBUG("  final path '%s'", installed_path.c_str());
    if (pchFolder && cchFolderBufferSize) {
        memset(pchFolder, 0, cchFolderBufferSize);
        installed_path.copy(pchFolder, cchFolderBufferSize - 1);
    }

    return static_cast<uint32>(installed_path.length()); //Real steam always returns the actual path length, not the copied one.
}

// returns true if that app is installed (not necessarily owned)
// "This only works for base applications, not Downloadable Content (DLC). Use BIsDlcInstalled for DLC instead"
// https://partner.steamgames.com/doc/api/ISteamApps
bool Steam_Apps::BIsAppInstalled( AppId_t appID )
{
    PRINT_DEBUG("%u", appID);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    
    if (appID == 0) return false; // steam returns false
    // game LEGO 2K Drive (app id 1451810) checks for a proper steam behavior by sending uint32_max and expects false in return
    if (appID == UINT32_MAX) return false; // steam returns false
    if (appID == settings->get_local_game_id().AppID()) return true; // steam returns true

    // TODO is this correct?
    // the docs say that this function won't work on DLCs, but HITMAN 3 uses it on every DLC
    if (settings->hasDLC(appID)) return true;

    return settings->isAppInstalled(appID);
}

// returns the SteamID of the original owner. If different from current user, it's borrowed
CSteamID Steam_Apps::GetAppOwner()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return settings->get_local_steam_id();
}

// Returns the associated launch param if the game is run via steam://run/<appid>//?param1=value1;param2=value2;param3=value3 etc.
// Parameter names starting with the character '@' are reserved for internal use and will always return and empty string.
// Parameter names starting with an underscore '_' are reserved for steam features -- they can be queried by the game,
// but it is advised that you not param names beginning with an underscore for your own features.
const char *Steam_Apps::GetLaunchQueryParam( const char *pchKey )
{
    PRINT_DEBUG_TODO();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return "";
}


// get download progress for optional DLC
bool Steam_Apps::GetDlcDownloadProgress( AppId_t nAppID, uint64 *punBytesDownloaded, uint64 *punBytesTotal )
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return false;
}
 

// return the buildid of this app, may change at any time based on backend updates to the game
int Steam_Apps::GetAppBuildId()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return static_cast<int>(this->settings->branches[settings->selected_branch_idx].build_id);
}


// Request all proof of purchase keys for the calling appid and asociated DLC.
// A series of AppProofOfPurchaseKeyResponse_t callbacks will be sent with
// appropriate appid values, ending with a final callback where the m_nAppId
// member is k_uAppIdInvalid (zero).
void Steam_Apps::RequestAllProofOfPurchaseKeys()
{
    PRINT_DEBUG_TODO();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    // current app
    {
        AppProofOfPurchaseKeyResponse_t data{};
        FillProofOfPurchaseKey(data, settings->get_local_game_id().AppID(), true);
        callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
    }

    // DLCs
    const auto count = settings->DLCCount();
    for (unsigned int i = 0; i < settings->DLCCount(); i++) {
        AppId_t app_id;
        bool available;
        std::string name;
        settings->getDLC(i, app_id, available, name);

        AppProofOfPurchaseKeyResponse_t data{};
        FillProofOfPurchaseKey(data, app_id, true);
        callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
    }
    
    // termination entry
    {
        AppProofOfPurchaseKeyResponse_t data{};
        FillProofOfPurchaseKey(data, k_uAppIdInvalid, true, "");
        callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
    }

}


STEAM_CALL_RESULT( FileDetailsResult_t )
SteamAPICall_t Steam_Apps::GetFileDetails( const char* pszFileName )
{
    PRINT_DEBUG("%s", pszFileName);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    FileDetailsResult_t data = {};
    //TODO? this function should only return found if file is actually part of the steam depots
    if (file_exists_(pszFileName)) {
        data.m_eResult = k_EResultOK; //
        std::ifstream stream(std::filesystem::u8path(pszFileName), std::ios::binary);
        SHA1 checksum;
        checksum.update(stream);
        checksum.final().copy((char *)data.m_FileSHA, sizeof(data.m_FileSHA));
        data.m_ulFileSize = file_size_(pszFileName);
        //TODO data.m_unFlags; 0 is file //TODO: check if 64 is folder
    } else {
        data.m_eResult = k_EResultFileNotFound;
    }

    auto ret = callback_results->addCallResult(data.k_iCallback, &data, sizeof(data));
    callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
    return ret;
}

// Get command line if game was launched via Steam URL, e.g. steam://run/<appid>//<command line>/.
// This method of passing a connect string (used when joining via rich presence, accepting an
// invite, etc) is preferable to passing the connect string on the operating system command
// line, which is a security risk.  In order for rich presence joins to go through this
// path and not be placed on the OS command line, you must set a value in your app's
// configuration on Steam.  Ask Valve for help with this.
//
// If game was already running and launched again, the NewUrlLaunchParameters_t will be fired.
int Steam_Apps::GetLaunchCommandLine( char *pszCommandLine, int cubCommandLine )
{
    PRINT_DEBUG_TODO();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return 0;
}

// Check if user borrowed this game via Family Sharing, If true, call GetAppOwner() to get the lender SteamID
bool Steam_Apps::BIsSubscribedFromFamilySharing()
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return false;
}

// check if game is a timed trial with limited playtime
bool Steam_Apps::BIsTimedTrial( uint32* punSecondsAllowed, uint32* punSecondsPlayed )
{
    PRINT_DEBUG_ENTRY();
    std::lock_guard<std::recursive_mutex> lock(global_mutex);
    return false;
}

// TODO no public docs
// set current DLC AppID being played (or 0 if none). Allows Steam to track usage of major DLC extensions
bool Steam_Apps::SetDlcContext( AppId_t nAppID )
{
    PRINT_DEBUG("%u // TODO", nAppID);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    // TODO this one is very odd, in all other functions of this interface they were returning false
    // tested by `universal963` on real steam
    if (nAppID == 0) return true;

    if (nAppID == UINT32_MAX) return false; // TODO is this correct? (see Steam_Apps::BIsDlcInstalled)

    if (nAppID == settings->get_local_game_id().AppID()) return true; // TODO is this correct?

    return settings->hasDLC(nAppID);
}

// TODO no public docs
// returns total number of known app beta branches (including default "public" branch )
int Steam_Apps::GetNumBetas( int *pnAvailable, int *pnPrivate )
{
    PRINT_DEBUG("%p, %p", pnAvailable, pnPrivate);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    // I assume 'available' means installed on the user's disk and could be used
    // in that case only 1 should be *available* since the user can only have 1 active and usable branch with the emu, unlike real steam
    // the user can switch the active (available) branch from configs.app.ini
    // right??
    if (pnAvailable) { // TODO what is this?
        *pnAvailable = 0;
        for (const auto &item : settings->branches) {
            if (item.flags & EBetaBranchFlags::k_EBetaBranch_Available) {
                *pnAvailable += 1;
            }
        }
        PRINT_DEBUG("available branches = %i", *pnAvailable);
    }

    if (pnPrivate) {
        *pnPrivate = 0;
        for (const auto &item : settings->branches) {
            if (item.flags & EBetaBranchFlags::k_EBetaBranch_Private) {
                *pnPrivate += 1;
            }
        }
        PRINT_DEBUG("private branches = %i", *pnPrivate);
    }

    return static_cast<int>(settings->branches.size()); // we always return at least 1 since "public" branch
}

// TODO no public docs
// return beta branch details, name, description, current BuildID and state flags (EBetaBranchFlags)
bool Steam_Apps::GetBetaInfo( int iBetaIndex, uint32 *punFlags, uint32 *punBuildID, char *pchBetaName, int cchBetaName, char *pchDescription, int cchDescription ) // iterate through
{
    // I assume this API is like "Steam_User_Stats::GetNextMostAchievedAchievementInfo()", it returns 'ok' until index is out of range
    PRINT_DEBUG("[%i] %p %p --- %p %i --- %p %i", iBetaIndex, punFlags, punBuildID, pchBetaName, cchBetaName, pchDescription, cchDescription);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    if (iBetaIndex < 0) return false;
    if (static_cast<size_t>(iBetaIndex) >= settings->branches.size()) return false;
    
    const auto &branch = settings->branches[iBetaIndex];

    if (punFlags) *punFlags = branch.flags;
    if (punBuildID) *punBuildID = branch.build_id;
    
    if (pchBetaName && cchBetaName > 0 && static_cast<size_t>(cchBetaName) > branch.name.size()) {
        memset(pchBetaName, 0, cchBetaName);
        memcpy(pchBetaName, branch.name.c_str(), branch.name.size());
    }

    if (pchDescription && cchDescription > 0 && static_cast<size_t>(cchDescription) > branch.description.size()) {
        memset(pchDescription, 0, cchDescription);
        memcpy(pchDescription, branch.description.c_str(), branch.description.size());
    }

    return true;
}

// TODO no public docs
// select this beta branch for this app as active, might need the game to restart so Steam can update to that branch
bool Steam_Apps::SetActiveBeta( const char *pchBetaName )
{
    PRINT_DEBUG("'%s'", pchBetaName);
    std::lock_guard<std::recursive_mutex> lock(global_mutex);

    // (sdk 1.60) apparently steam always returns true if the string is null or empty, tested by 'universal963' on appid 480
    if (!pchBetaName || !pchBetaName[0]) return true;

    std::string beta_name = pchBetaName;
    auto branch_it = std::find_if(settings->branches.begin(), settings->branches.end(), [&beta_name](const Branch_Info &item){
        return common_helpers::str_cmp_insensitive(beta_name, item.name);
    });

    if (settings->branches.end() != branch_it) {
        // reset the 'active' flag for all branches
        for (auto &item : settings->branches) {
            item.active = false;
        }
        // then set the flag for this branch
        branch_it->active = true;
        PRINT_DEBUG("game changed active beta branch!");
        return true;
    }

    return false;
}


#ifdef _PS3
	// Result returned in a RegisterActivationCodeResponse_t callresult
	SteamAPICall_t Steam_Apps::RegisterActivationCode( const char *pchActivationCode )
    {
        PRINT_DEBUG("%s", pchActivationCode);
        std::lock_guard<std::recursive_mutex> lock(global_mutex);

        if (!pchActivationCode) return 
        RegisterActivationCodeResponse_t data{};
        data.m_eResult = ERegisterActivationCodeResult::k_ERegisterActivationCodeResultOK;
        // data.m_unPackageRegistered = 0; // TODO set this

        auto ret = callback_results->addCallResult(data.k_iCallback, &data, sizeof(data));
        callbacks->addCBResult(data.k_iCallback, &data, sizeof(data));
        return ret;
    }
#endif