/*
 * Copyright (c) 2016-present Samsung Electronics Co., Ltd
 *
 *  This library 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 2 of the License, or (at your option) any later version.
 *
 *  This library 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 this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
 *  USA
 */

#include "Escargot.h"
#include "ScriptParser.h"
#include "runtime/Context.h"
#include "runtime/VMInstance.h"
#include "interpreter/ByteCode.h"
#include "parser/esprima_cpp/esprima.h"
#include "parser/ScriptParser.h"
#include "parser/ast/AST.h"
#include "parser/CodeBlock.h"

namespace Escargot {

ScriptParser::ScriptParser(Context* c)
    : m_context(c)
{
}

InterpretedCodeBlock* ScriptParser::generateCodeBlockTreeFromASTWalker(Context* ctx, StringView source, Script* script, ASTScopeContext* scopeCtx, InterpretedCodeBlock* parentCodeBlock)
{
    InterpretedCodeBlock* codeBlock;
    if (parentCodeBlock == nullptr) {
        // globalBlock
        codeBlock = new InterpretedCodeBlock(ctx, script, source, scopeCtx, ExtendedNodeLOC(1, 1, 0));
    } else {
        codeBlock = new InterpretedCodeBlock(ctx, script, source, scopeCtx, scopeCtx->m_locStart, parentCodeBlock);
    }

#ifndef NDEBUG
    codeBlock->m_locStart = scopeCtx->m_locStart;
    codeBlock->m_locEnd = scopeCtx->m_locEnd;
    codeBlock->m_scopeContext = scopeCtx;
#endif

    if (parentCodeBlock) {
        if (scopeCtx->m_hasEvaluateBindingId) {
            InterpretedCodeBlock* c = codeBlock;
            while (c) {
                c->m_canAllocateEnvironmentOnStack = false;
                c = c->parentCodeBlock();
            }
        }

        if (codeBlock->hasEvalWithYield() || codeBlock->isFunctionDeclarationWithSpecialBinding()) {
            InterpretedCodeBlock* c = codeBlock;
            while (c) {
                c->notifySelfOrChildHasEvalWithYield();
                c = c->parentCodeBlock();
            }
        }

        bool hasCapturedIdentifier = false;
        AtomicString arguments = ctx->staticStrings().arguments;
        AtomicString stringThis = ctx->staticStrings().stringThis;
        for (size_t i = 0; i < scopeCtx->m_usingNames.size(); i++) {
            AtomicString uname = scopeCtx->m_usingNames[i];
            if (uname == arguments) {
                if (UNLIKELY(codeBlock->hasParameter(arguments))) {
                    continue;
                } else {
                    if (LIKELY(!codeBlock->isArrowFunctionExpression())) {
                        codeBlock->captureArguments();
                        continue;
                    } else {
                        InterpretedCodeBlock* c = codeBlock->parentCodeBlock();
                        while (c && !c->isGlobalScopeCodeBlock()) {
                            if (c->hasParameter(arguments)) {
                                break;
                            } else if (!c->isArrowFunctionExpression()) {
                                c->captureArguments();
                                break;
                            }
                            c = c->parentCodeBlock();
                        }
                    }
                }
            } else if (uname == stringThis) {
                ASSERT(codeBlock->isArrowFunctionExpression());
                if (!codeBlock->parentCodeBlock()->isGlobalScopeCodeBlock()) {
                    codeBlock->parentCodeBlock()->captureThis();
                    codeBlock->setNeedToLoadThisValue();
                    hasCapturedIdentifier = true;
                }
                continue;
            }

            if (!codeBlock->hasName(uname)) {
                InterpretedCodeBlock* c = codeBlock->parentCodeBlock();
                while (c) {
                    if (c->tryCaptureIdentifiersFromChildCodeBlock(uname)) {
                        hasCapturedIdentifier = true;
                        break;
                    }
                    c = c->parentCodeBlock();
                }
            }
        }

        if (hasCapturedIdentifier) {
            InterpretedCodeBlock* c = codeBlock->parentCodeBlock();
            while (c && c->m_canAllocateEnvironmentOnStack) {
                c->m_canAllocateEnvironmentOnStack = false;
                c = c->parentCodeBlock();
            }
        }
    }

    codeBlock->m_childBlocks.resizeWithUninitializedValues(scopeCtx->m_childScopes.size());
    for (size_t i = 0; i < scopeCtx->m_childScopes.size(); i++) {
        codeBlock->m_childBlocks[i] = generateCodeBlockTreeFromASTWalker(ctx, source, script, scopeCtx->m_childScopes[i], codeBlock);
    }

    return codeBlock;
}

// generate code blocks from AST
InterpretedCodeBlock* ScriptParser::generateCodeBlockTreeFromAST(Context* ctx, StringView source, Script* script, ProgramNode* program)
{
    return generateCodeBlockTreeFromASTWalker(ctx, source, script, program->scopeContext(), nullptr);
}

void ScriptParser::generateCodeBlockTreeFromASTWalkerPostProcess(InterpretedCodeBlock* cb)
{
    for (size_t i = 0; i < cb->m_childBlocks.size(); i++) {
        generateCodeBlockTreeFromASTWalkerPostProcess(cb->m_childBlocks[i]);
    }
    cb->computeVariables();
    if (cb->m_identifierOnStackCount > VARIABLE_LIMIT || cb->m_identifierOnHeapCount > VARIABLE_LIMIT) {
        auto err = new esprima::Error(new ASCIIString("variable limit exceeded"));
        err->errorCode = ErrorObject::SyntaxError;
        err->lineNumber = cb->m_sourceElementStart.line;
        err->column = cb->m_sourceElementStart.column;
        err->index = cb->m_sourceElementStart.index;
        throw * err;
    }
}

ScriptParser::ScriptParserResult ScriptParser::parse(StringView scriptSource, String* fileName, InterpretedCodeBlock* parentCodeBlock, bool strictFromOutside, bool isEvalCodeInFunction, size_t stackSizeRemain)
{
    Script* script = nullptr;
    ScriptParseError* error = nullptr;

    GC_disable();

    try {
        m_context->vmInstance()->m_parsedSourceCodes.push_back(scriptSource.string());
        RefPtr<ProgramNode> program = esprima::parseProgram(m_context, scriptSource, strictFromOutside, stackSizeRemain);

        script = new Script(fileName, new StringView(scriptSource));
        InterpretedCodeBlock* topCodeBlock;
        if (parentCodeBlock) {
            program->scopeContext()->m_hasEval = parentCodeBlock->hasEval();
            program->scopeContext()->m_hasWith = parentCodeBlock->hasWith();
            program->scopeContext()->m_hasCatch = parentCodeBlock->hasCatch();
            program->scopeContext()->m_hasYield = parentCodeBlock->hasYield();
            program->scopeContext()->m_isClassConstructor = parentCodeBlock->isClassConstructor();
            topCodeBlock = generateCodeBlockTreeFromASTWalker(m_context, scriptSource, script, program->scopeContext(), parentCodeBlock);
            topCodeBlock->m_isEvalCodeInFunction = true;
            topCodeBlock->m_isInWithScope = parentCodeBlock->m_isInWithScope;
        } else {
            topCodeBlock = generateCodeBlockTreeFromAST(m_context, scriptSource, script, program.get());
        }

        topCodeBlock->m_isEvalCodeInFunction = isEvalCodeInFunction;

        generateCodeBlockTreeFromASTWalkerPostProcess(topCodeBlock);

        program->ref();
        topCodeBlock->m_cachedASTNode = program.get();
        script->m_topCodeBlock = topCodeBlock;

// dump Code Block
#ifndef NDEBUG
        if (getenv("DUMP_CODEBLOCK_TREE") && strlen(getenv("DUMP_CODEBLOCK_TREE"))) {
            std::function<void(InterpretedCodeBlock*, size_t depth)> fn = [&fn](InterpretedCodeBlock* cb, size_t depth) {

#define PRINT_TAB()                      \
    for (size_t i = 0; i < depth; i++) { \
        printf("  ");                    \
    }

                PRINT_TAB()
                printf("CodeBlock %s %s (%d:%d -> %d:%d)(%s, %s) (E:%d, W:%d, C:%d, Y:%d, A:%d)\n", cb->m_functionName.string()->toUTF8StringData().data(),
                       cb->m_isStrict ? "Strict" : "",
                       (int)cb->m_locStart.line,
                       (int)cb->m_locStart.column,
                       (int)cb->m_locEnd.line,
                       (int)cb->m_locEnd.column,
                       cb->m_canAllocateEnvironmentOnStack ? "Stack" : "Heap",
                       cb->m_canUseIndexedVariableStorage ? "Indexed" : "Named",
                       (int)cb->m_hasEval, (int)cb->m_hasWith, (int)cb->m_hasCatch, (int)cb->m_hasYield, (int)cb->m_usesArgumentsObject);

                PRINT_TAB()
                printf("Names: ");
                for (size_t i = 0; i < cb->m_identifierInfos.size(); i++) {
                    printf("%s(%s, %s, %d), ", cb->m_identifierInfos[i].m_name.string()->toUTF8StringData().data(),
                           cb->m_identifierInfos[i].m_needToAllocateOnStack ? "Stack" : "Heap",
                           cb->m_identifierInfos[i].m_isMutable ? "Mutable" : "Inmmutable",
                           (int)cb->m_identifierInfos[i].m_indexForIndexedStorage);
                }
                puts("");

                PRINT_TAB()
                printf("Using Names: ");
                for (size_t i = 0; i < cb->m_scopeContext->m_usingNames.size(); i++) {
                    printf("%s, ", cb->m_scopeContext->m_usingNames[i].string()->toUTF8StringData().data());
                }
                puts("");

                for (size_t i = 0; i < cb->m_childBlocks.size(); i++) {
                    fn(cb->m_childBlocks[i], depth + 1);
                }

            };
            fn(topCodeBlock, 0);
        }
#endif

    } catch (esprima::Error& orgError) {
        script = nullptr;
        error = new ScriptParseError();
        error->column = orgError.column;
        error->description = orgError.description;
        error->index = orgError.index;
        error->lineNumber = orgError.lineNumber;
        error->message = orgError.message;
        error->name = orgError.name;
        error->errorCode = orgError.errorCode;
    }

    GC_enable();

    ScriptParser::ScriptParserResult result(script, error);
    return result;
}

std::tuple<RefPtr<Node>, ASTScopeContext*> ScriptParser::parseFunction(InterpretedCodeBlock* codeBlock, size_t stackSizeRemain, ExecutionState* state)
{
    try {
        std::tuple<RefPtr<Node>, ASTScopeContext*> body = esprima::parseSingleFunction(m_context, codeBlock, stackSizeRemain);
        return body;
    } catch (esprima::Error& orgError) {
        ErrorObject::throwBuiltinError(*state, ErrorObject::SyntaxError, orgError.message->toUTF8StringData().data());
        RELEASE_ASSERT_NOT_REACHED();
    }
}
}