(svn r28004) -Update from Eints:

[openttd.git] / src / script / script_instance.cpp

/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD 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.
 * OpenTTD 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 for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file script_instance.cpp Implementation of ScriptInstance. */

#include "../stdafx.h"
#include "../debug.h"
#include "../saveload/saveload.h"

#include "../script/squirrel_class.hpp"

#include "script_fatalerror.hpp"
#include "script_storage.hpp"
#include "script_info.hpp"
#include "script_instance.hpp"

#include "api/script_controller.hpp"
#include "api/script_error.hpp"
#include "api/script_event.hpp"
#include "api/script_log.hpp"

#include "../company_base.h"
#include "../company_func.h"
#include "../fileio_func.h"

#include "../safeguards.h"

ScriptStorage::~ScriptStorage()
{
        /* Free our pointers */
        if (event_data != NULL) ScriptEventController::FreeEventPointer();
        if (log_data != NULL) ScriptLog::FreeLogPointer();
}

/**
 * Callback called by squirrel when a script uses "print" and for error messages.
 * @param error_msg Is this an error message?
 * @param message The actual message text.
 */
static void PrintFunc(bool error_msg, const SQChar *message)
{
        /* Convert to OpenTTD internal capable string */
        ScriptController::Print(error_msg, message);
}

ScriptInstance::ScriptInstance(const char *APIName) :
        engine(NULL),
        versionAPI(NULL),
        controller(NULL),
        storage(NULL),
        instance(NULL),
        is_started(false),
        is_dead(false),
        is_save_data_on_stack(false),
        suspend(0),
        is_paused(false),
        callback(NULL)
{
        this->storage = new ScriptStorage();
        this->engine  = new Squirrel(APIName);
        this->engine->SetPrintFunction(&PrintFunc);
}

void ScriptInstance::Initialize(const char *main_script, const char *instance_name, CompanyID company)
{
        ScriptObject::ActiveInstance active(this);

        this->controller = new ScriptController(company);

        /* Register the API functions and classes */
        this->engine->SetGlobalPointer(this->engine);
        this->RegisterAPI();

        try {
                ScriptObject::SetAllowDoCommand(false);
                /* Load and execute the script for this script */
                if (strcmp(main_script, "%_dummy") == 0) {
                        this->LoadDummyScript();
                } else if (!this->engine->LoadScript(main_script) || this->engine->IsSuspended()) {
                        if (this->engine->IsSuspended()) ScriptLog::Error("This script took too long to load script. AI is not started.");
                        this->Died();
                        return;
                }

                /* Create the main-class */
                this->instance = MallocT<SQObject>(1);
                if (!this->engine->CreateClassInstance(instance_name, this->controller, this->instance)) {
                        this->Died();
                        return;
                }
                ScriptObject::SetAllowDoCommand(true);
        } catch (Script_FatalError e) {
                this->is_dead = true;
                this->engine->ThrowError(e.GetErrorMessage());
                this->engine->ResumeError();
                this->Died();
        }
}

void ScriptInstance::RegisterAPI()
{
        extern void squirrel_register_std(Squirrel *engine);
        squirrel_register_std(this->engine);
}

bool ScriptInstance::LoadCompatibilityScripts(const char *api_version, Subdirectory dir)
{
        char script_name[32];
        seprintf(script_name, lastof(script_name), "compat_%s.nut", api_version);
        char buf[MAX_PATH];
        Searchpath sp;
        FOR_ALL_SEARCHPATHS(sp) {
                FioAppendDirectory(buf, lastof(buf), sp, dir);
                strecat(buf, script_name, lastof(buf));
                if (!FileExists(buf)) continue;

                if (this->engine->LoadScript(buf)) return true;

                ScriptLog::Error("Failed to load API compatibility script");
                DEBUG(script, 0, "Error compiling / running API compatibility script: %s", buf);
                return false;
        }

        ScriptLog::Warning("API compatibility script not found");
        return true;
}

ScriptInstance::~ScriptInstance()
{
        ScriptObject::ActiveInstance active(this);

        if (instance != NULL) this->engine->ReleaseObject(this->instance);
        if (engine != NULL) delete this->engine;
        delete this->storage;
        delete this->controller;
        free(this->instance);
}

void ScriptInstance::Continue()
{
        assert(this->suspend < 0);
        this->suspend = -this->suspend - 1;
}

void ScriptInstance::Died()
{
        DEBUG(script, 0, "The script died unexpectedly.");
        this->is_dead = true;

        if (this->instance != NULL) this->engine->ReleaseObject(this->instance);
        delete this->engine;
        this->instance = NULL;
        this->engine = NULL;
}

void ScriptInstance::GameLoop()
{
        ScriptObject::ActiveInstance active(this);

        if (this->IsDead()) return;
        if (this->engine->HasScriptCrashed()) {
                /* The script crashed during saving, kill it here. */
                this->Died();
                return;
        }
        if (this->is_paused) return;
        this->controller->ticks++;

        if (this->suspend   < -1) this->suspend++; // Multiplayer suspend, increase up to -1.
        if (this->suspend   < 0)  return;          // Multiplayer suspend, wait for Continue().
        if (--this->suspend > 0)  return;          // Singleplayer suspend, decrease to 0.

        _current_company = ScriptObject::GetCompany();

        /* If there is a callback to call, call that first */
        if (this->callback != NULL) {
                if (this->is_save_data_on_stack) {
                        sq_poptop(this->engine->GetVM());
                        this->is_save_data_on_stack = false;
                }
                try {
                        this->callback(this);
                } catch (Script_Suspend e) {
                        this->suspend  = e.GetSuspendTime();
                        this->callback = e.GetSuspendCallback();

                        return;
                }
        }

        this->suspend  = 0;
        this->callback = NULL;

        if (!this->is_started) {
                try {
                        ScriptObject::SetAllowDoCommand(false);
                        /* Run the constructor if it exists. Don't allow any DoCommands in it. */
                        if (this->engine->MethodExists(*this->instance, "constructor")) {
                                if (!this->engine->CallMethod(*this->instance, "constructor", MAX_CONSTRUCTOR_OPS) || this->engine->IsSuspended()) {
                                        if (this->engine->IsSuspended()) ScriptLog::Error("This script took too long to initialize. Script is not started.");
                                        this->Died();
                                        return;
                                }
                        }
                        if (!this->CallLoad() || this->engine->IsSuspended()) {
                                if (this->engine->IsSuspended()) ScriptLog::Error("This script took too long in the Load function. Script is not started.");
                                this->Died();
                                return;
                        }
                        ScriptObject::SetAllowDoCommand(true);
                        /* Start the script by calling Start() */
                        if (!this->engine->CallMethod(*this->instance, "Start",  _settings_game.script.script_max_opcode_till_suspend) || !this->engine->IsSuspended()) this->Died();
                } catch (Script_Suspend e) {
                        this->suspend  = e.GetSuspendTime();
                        this->callback = e.GetSuspendCallback();
                } catch (Script_FatalError e) {
                        this->is_dead = true;
                        this->engine->ThrowError(e.GetErrorMessage());
                        this->engine->ResumeError();
                        this->Died();
                }

                this->is_started = true;
                return;
        }
        if (this->is_save_data_on_stack) {
                sq_poptop(this->engine->GetVM());
                this->is_save_data_on_stack = false;
        }

        /* Continue the VM */
        try {
                if (!this->engine->Resume(_settings_game.script.script_max_opcode_till_suspend)) this->Died();
        } catch (Script_Suspend e) {
                this->suspend  = e.GetSuspendTime();
                this->callback = e.GetSuspendCallback();
        } catch (Script_FatalError e) {
                this->is_dead = true;
                this->engine->ThrowError(e.GetErrorMessage());
                this->engine->ResumeError();
                this->Died();
        }
}

void ScriptInstance::CollectGarbage() const
{
        if (this->is_started && !this->IsDead()) this->engine->CollectGarbage();
}

/* static */ void ScriptInstance::DoCommandReturn(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetLastCommandRes());
}

/* static */ void ScriptInstance::DoCommandReturnVehicleID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewVehicleID());
}

/* static */ void ScriptInstance::DoCommandReturnSignID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewSignID());
}

/* static */ void ScriptInstance::DoCommandReturnGroupID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewGroupID());
}

/* static */ void ScriptInstance::DoCommandReturnGoalID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewGoalID());
}

/* static */ void ScriptInstance::DoCommandReturnStoryPageID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewStoryPageID());
}

/* static */ void ScriptInstance::DoCommandReturnStoryPageElementID(ScriptInstance *instance)
{
        instance->engine->InsertResult(ScriptObject::GetNewStoryPageElementID());
}

ScriptStorage *ScriptInstance::GetStorage()
{
        return this->storage;
}

void *ScriptInstance::GetLogPointer()
{
        ScriptObject::ActiveInstance active(this);

        return ScriptObject::GetLogPointer();
}

/*
 * All data is stored in the following format:
 * First 1 byte indicating if there is a data blob at all.
 * 1 byte indicating the type of data.
 * The data itself, this differs per type:
 *  - integer: a binary representation of the integer (int32).
 *  - string:  First one byte with the string length, then a 0-terminated char
 *             array. The string can't be longer than 255 bytes (including
 *             terminating '\0').
 *  - array:   All data-elements of the array are saved recursive in this
 *             format, and ended with an element of the type
 *             SQSL_ARRAY_TABLE_END.
 *  - table:   All key/value pairs are saved in this format (first key 1, then
 *             value 1, then key 2, etc.). All keys and values can have an
 *             arbitrary type (as long as it is supported by the save function
 *             of course). The table is ended with an element of the type
 *             SQSL_ARRAY_TABLE_END.
 *  - bool:    A single byte with value 1 representing true and 0 false.
 *  - null:    No data.
 */

/** The type of the data that follows in the savegame. */
enum SQSaveLoadType {
        SQSL_INT             = 0x00, ///< The following data is an integer.
        SQSL_STRING          = 0x01, ///< The following data is an string.
        SQSL_ARRAY           = 0x02, ///< The following data is an array.
        SQSL_TABLE           = 0x03, ///< The following data is an table.
        SQSL_BOOL            = 0x04, ///< The following data is a boolean.
        SQSL_NULL            = 0x05, ///< A null variable.
        SQSL_ARRAY_TABLE_END = 0xFF, ///< Marks the end of an array or table, no data follows.
};

static byte _script_sl_byte; ///< Used as source/target by the script saveload code to store/load a single byte.

/** SaveLoad array that saves/loads exactly one byte. */
static const SaveLoad _script_byte[] = {
        SLEG_VAR(_script_sl_byte, SLE_UINT8),
        SLE_END()
};

/* static */ bool ScriptInstance::SaveObject(HSQUIRRELVM vm, SQInteger index, int max_depth, bool test)
{
        if (max_depth == 0) {
                ScriptLog::Error("Savedata can only be nested to 25 deep. No data saved."); // SQUIRREL_MAX_DEPTH = 25
                return false;
        }

        switch (sq_gettype(vm, index)) {
                case OT_INTEGER: {
                        if (!test) {
                                _script_sl_byte = SQSL_INT;
                                SlObject(NULL, _script_byte);
                        }
                        SQInteger res;
                        sq_getinteger(vm, index, &res);
                        if (!test) {
                                int value = (int)res;
                                SlArray(&value, 1, SLE_INT32);
                        }
                        return true;
                }

                case OT_STRING: {
                        if (!test) {
                                _script_sl_byte = SQSL_STRING;
                                SlObject(NULL, _script_byte);
                        }
                        const SQChar *buf;
                        sq_getstring(vm, index, &buf);
                        size_t len = strlen(buf) + 1;
                        if (len >= 255) {
                                ScriptLog::Error("Maximum string length is 254 chars. No data saved.");
                                return false;
                        }
                        if (!test) {
                                _script_sl_byte = (byte)len;
                                SlObject(NULL, _script_byte);
                                SlArray(const_cast<char *>(buf), len, SLE_CHAR);
                        }
                        return true;
                }

                case OT_ARRAY: {
                        if (!test) {
                                _script_sl_byte = SQSL_ARRAY;
                                SlObject(NULL, _script_byte);
                        }
                        sq_pushnull(vm);
                        while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
                                /* Store the value */
                                bool res = SaveObject(vm, -1, max_depth - 1, test);
                                sq_pop(vm, 2);
                                if (!res) {
                                        sq_pop(vm, 1);
                                        return false;
                                }
                        }
                        sq_pop(vm, 1);
                        if (!test) {
                                _script_sl_byte = SQSL_ARRAY_TABLE_END;
                                SlObject(NULL, _script_byte);
                        }
                        return true;
                }

                case OT_TABLE: {
                        if (!test) {
                                _script_sl_byte = SQSL_TABLE;
                                SlObject(NULL, _script_byte);
                        }
                        sq_pushnull(vm);
                        while (SQ_SUCCEEDED(sq_next(vm, index - 1))) {
                                /* Store the key + value */
                                bool res = SaveObject(vm, -2, max_depth - 1, test) && SaveObject(vm, -1, max_depth - 1, test);
                                sq_pop(vm, 2);
                                if (!res) {
                                        sq_pop(vm, 1);
                                        return false;
                                }
                        }
                        sq_pop(vm, 1);
                        if (!test) {
                                _script_sl_byte = SQSL_ARRAY_TABLE_END;
                                SlObject(NULL, _script_byte);
                        }
                        return true;
                }

                case OT_BOOL: {
                        if (!test) {
                                _script_sl_byte = SQSL_BOOL;
                                SlObject(NULL, _script_byte);
                        }
                        SQBool res;
                        sq_getbool(vm, index, &res);
                        if (!test) {
                                _script_sl_byte = res ? 1 : 0;
                                SlObject(NULL, _script_byte);
                        }
                        return true;
                }

                case OT_NULL: {
                        if (!test) {
                                _script_sl_byte = SQSL_NULL;
                                SlObject(NULL, _script_byte);
                        }
                        return true;
                }

                default:
                        ScriptLog::Error("You tried to save an unsupported type. No data saved.");
                        return false;
        }
}

/* static */ void ScriptInstance::SaveEmpty()
{
        _script_sl_byte = 0;
        SlObject(NULL, _script_byte);
}

void ScriptInstance::Save()
{
        ScriptObject::ActiveInstance active(this);

        /* Don't save data if the script didn't start yet or if it crashed. */
        if (this->engine == NULL || this->engine->HasScriptCrashed()) {
                SaveEmpty();
                return;
        }

        HSQUIRRELVM vm = this->engine->GetVM();
        if (this->is_save_data_on_stack) {
                _script_sl_byte = 1;
                SlObject(NULL, _script_byte);
                /* Save the data that was just loaded. */
                SaveObject(vm, -1, SQUIRREL_MAX_DEPTH, false);
        } else if (!this->is_started) {
                SaveEmpty();
                return;
        } else if (this->engine->MethodExists(*this->instance, "Save")) {
                HSQOBJECT savedata;
                /* We don't want to be interrupted during the save function. */
                bool backup_allow = ScriptObject::GetAllowDoCommand();
                ScriptObject::SetAllowDoCommand(false);
                try {
                        if (!this->engine->CallMethod(*this->instance, "Save", &savedata, MAX_SL_OPS)) {
                                /* The script crashed in the Save function. We can't kill
                                 * it here, but do so in the next script tick. */
                                SaveEmpty();
                                this->engine->CrashOccurred();
                                return;
                        }
                } catch (Script_FatalError e) {
                        /* If we don't mark the script as dead here cleaning up the squirrel
                         * stack could throw Script_FatalError again. */
                        this->is_dead = true;
                        this->engine->ThrowError(e.GetErrorMessage());
                        this->engine->ResumeError();
                        SaveEmpty();
                        /* We can't kill the script here, so mark it as crashed (not dead) and
                         * kill it in the next script tick. */
                        this->is_dead = false;
                        this->engine->CrashOccurred();
                        return;
                }
                ScriptObject::SetAllowDoCommand(backup_allow);

                if (!sq_istable(savedata)) {
                        ScriptLog::Error(this->engine->IsSuspended() ? "This script took too long to Save." : "Save function should return a table.");
                        SaveEmpty();
                        this->engine->CrashOccurred();
                        return;
                }
                sq_pushobject(vm, savedata);
                if (SaveObject(vm, -1, SQUIRREL_MAX_DEPTH, true)) {
                        _script_sl_byte = 1;
                        SlObject(NULL, _script_byte);
                        SaveObject(vm, -1, SQUIRREL_MAX_DEPTH, false);
                        this->is_save_data_on_stack = true;
                } else {
                        SaveEmpty();
                        this->engine->CrashOccurred();
                }
        } else {
                ScriptLog::Warning("Save function is not implemented");
                _script_sl_byte = 0;
                SlObject(NULL, _script_byte);
        }
}

void ScriptInstance::Pause()
{
        /* Suspend script. */
        HSQUIRRELVM vm = this->engine->GetVM();
        Squirrel::DecreaseOps(vm, _settings_game.script.script_max_opcode_till_suspend);

        this->is_paused = true;
}

void ScriptInstance::Unpause()
{
        this->is_paused = false;
}

bool ScriptInstance::IsPaused()
{
        return this->is_paused;
}

/* static */ bool ScriptInstance::LoadObjects(HSQUIRRELVM vm)
{
        SlObject(NULL, _script_byte);
        switch (_script_sl_byte) {
                case SQSL_INT: {
                        int value;
                        SlArray(&value, 1, SLE_INT32);
                        if (vm != NULL) sq_pushinteger(vm, (SQInteger)value);
                        return true;
                }

                case SQSL_STRING: {
                        SlObject(NULL, _script_byte);
                        static char buf[256];
                        SlArray(buf, _script_sl_byte, SLE_CHAR);
                        if (vm != NULL) sq_pushstring(vm, buf, -1);
                        return true;
                }

                case SQSL_ARRAY: {
                        if (vm != NULL) sq_newarray(vm, 0);
                        while (LoadObjects(vm)) {
                                if (vm != NULL) sq_arrayappend(vm, -2);
                                /* The value is popped from the stack by squirrel. */
                        }
                        return true;
                }

                case SQSL_TABLE: {
                        if (vm != NULL) sq_newtable(vm);
                        while (LoadObjects(vm)) {
                                LoadObjects(vm);
                                if (vm != NULL) sq_rawset(vm, -3);
                                /* The key (-2) and value (-1) are popped from the stack by squirrel. */
                        }
                        return true;
                }

                case SQSL_BOOL: {
                        SlObject(NULL, _script_byte);
                        if (vm != NULL) sq_pushbool(vm, (SQBool)(_script_sl_byte != 0));
                        return true;
                }

                case SQSL_NULL: {
                        if (vm != NULL) sq_pushnull(vm);
                        return true;
                }

                case SQSL_ARRAY_TABLE_END: {
                        return false;
                }

                default: NOT_REACHED();
        }
}

/* static */ void ScriptInstance::LoadEmpty()
{
        SlObject(NULL, _script_byte);
        /* Check if there was anything saved at all. */
        if (_script_sl_byte == 0) return;

        LoadObjects(NULL);
}

void ScriptInstance::Load(int version)
{
        ScriptObject::ActiveInstance active(this);

        if (this->engine == NULL || version == -1) {
                LoadEmpty();
                return;
        }
        HSQUIRRELVM vm = this->engine->GetVM();

        SlObject(NULL, _script_byte);
        /* Check if there was anything saved at all. */
        if (_script_sl_byte == 0) return;

        sq_pushinteger(vm, version);
        LoadObjects(vm);
        this->is_save_data_on_stack = true;
}

bool ScriptInstance::CallLoad()
{
        HSQUIRRELVM vm = this->engine->GetVM();
        /* Is there save data that we should load? */
        if (!this->is_save_data_on_stack) return true;
        /* Whatever happens, after CallLoad the savegame data is removed from the stack. */
        this->is_save_data_on_stack = false;

        if (!this->engine->MethodExists(*this->instance, "Load")) {
                ScriptLog::Warning("Loading failed: there was data for the script to load, but the script does not have a Load() function.");

                /* Pop the savegame data and version. */
                sq_pop(vm, 2);
                return true;
        }

        /* Go to the instance-root */
        sq_pushobject(vm, *this->instance);
        /* Find the function-name inside the script */
        sq_pushstring(vm, "Load", -1);
        /* Change the "Load" string in a function pointer */
        sq_get(vm, -2);
        /* Push the main instance as "this" object */
        sq_pushobject(vm, *this->instance);
        /* Push the version data and savegame data as arguments */
        sq_push(vm, -5);
        sq_push(vm, -5);

        /* Call the script load function. sq_call removes the arguments (but not the
         * function pointer) from the stack. */
        if (SQ_FAILED(sq_call(vm, 3, SQFalse, SQFalse, MAX_SL_OPS))) return false;

        /* Pop 1) The version, 2) the savegame data, 3) the object instance, 4) the function pointer. */
        sq_pop(vm, 4);
        return true;
}

SQInteger ScriptInstance::GetOpsTillSuspend()
{
        return this->engine->GetOpsTillSuspend();
}

void ScriptInstance::DoCommandCallback(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
{
        ScriptObject::ActiveInstance active(this);

        ScriptObject::SetLastCommandRes(result.Succeeded());

        if (result.Failed()) {
                ScriptObject::SetLastError(ScriptError::StringToError(result.GetErrorMessage()));
        } else {
                ScriptObject::IncreaseDoCommandCosts(result.GetCost());
                ScriptObject::SetLastCost(result.GetCost());
        }
}

void ScriptInstance::InsertEvent(class ScriptEvent *event)
{
        ScriptObject::ActiveInstance active(this);

        ScriptEventController::InsertEvent(event);
}