/**
 * Copyright (c) 2021-2026 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "scriptFunction.h"

#include <ir/astDump.h>
#include <ir/base/methodDefinition.h>
#include <ir/expressions/assignmentExpression.h>
#include <ir/expressions/memberExpression.h>
#include <ir/statements/blockStatement.h>
#include <ir/statements/expressionStatement.h>
#include <ir/ts/tsTypeParameterDeclaration.h>

namespace panda::es2panda::ir {

size_t ScriptFunction::FormalParamsLength() const
{
    size_t length = 0;

    for (const auto *param : params_) {
        if (param->IsRestElement() || param->IsAssignmentPattern()) {
            break;
        }

        length++;
    }

    return length;
}

util::StringView ScriptFunction::GetName() const
{
    if (id_) {
        return id_->Name();
    }

    if (exportDefault_) {
        return parser::SourceTextModuleRecord::DEFAULT_LOCAL_NAME;
    }

    return "";
}

void ScriptFunction::Iterate(const NodeTraverser &cb) const
{
    if (id_) {
        cb(id_);
    }

    if (typeParams_) {
        cb(typeParams_);
    }

    if (thisParam_) {
        cb(thisParam_);
    }

    for (auto *it : params_) {
        cb(it);
    }

    if (returnTypeAnnotation_) {
        cb(returnTypeAnnotation_);
    }

    if (body_) {
        cb(body_);
    }
}

void ScriptFunction::Dump(ir::AstDumper *dumper) const
{
    dumper->Add({{"type", "ScriptFunction"},
                 {"id", AstDumper::Nullable(id_)},
                 {"generator", IsGenerator()},
                 {"async", IsAsync()},
                 {"expression", ((flags_ & ir::ScriptFunctionFlags::EXPRESSION) != 0)},
                 {"thisParam", AstDumper::Optional(thisParam_)},
                 {"params", params_},
                 {"returnType", AstDumper::Optional(returnTypeAnnotation_)},
                 {"typeParameters", AstDumper::Optional(typeParams_)},
                 {"declare", AstDumper::Optional(declare_)},
                 {"body", AstDumper::Optional(body_)}});
}

void ScriptFunction::Compile([[maybe_unused]] compiler::PandaGen *pg) const {}

void ScriptFunction::UpdateSelf(const NodeUpdater &cb, binder::Binder *binder)
{
    if (id_) {
        id_ = std::get<ir::AstNode *>(cb(id_))->AsIdentifier();
    }

    auto paramScopeCtx = binder::LexicalScope<binder::FunctionParamScope>::Enter(binder, scope_->ParamScope());

    if (typeParams_) {
        typeParams_ = std::get<ir::AstNode *>(cb(typeParams_))->AsTSTypeParameterDeclaration();
    }

    if (thisParam_) {
        thisParam_ = std::get<ir::AstNode *>(cb(thisParam_))->AsExpression();
    }

    for (auto iter = params_.begin(); iter != params_.end(); iter++) {
        *iter = std::get<ir::AstNode *>(cb(*iter))->AsExpression();
    }

    if (returnTypeAnnotation_) {
        returnTypeAnnotation_ = std::get<ir::AstNode *>(cb(returnTypeAnnotation_))->AsExpression();
    }

    auto scopeCtx = binder::LexicalScope<binder::FunctionScope>::Enter(binder, scope_);

    if (body_) {
        body_ = std::get<ir::AstNode *>(cb(body_));
    }
}

util::StringView ScriptFunction::SourceCode(binder::Binder *binder) const
{
    auto *funcNode = this->Parent();
    if (funcNode->IsFunctionExpression() &&
        funcNode->Parent()->IsMethodDefinition() &&
        funcNode->Parent()->AsMethodDefinition()->Value() == funcNode->AsFunctionExpression()) {
        funcNode = funcNode->Parent();
    }

    auto startIndex = funcNode->Start().index;
    auto endIndex = funcNode->End().index;
    return binder->Program()->SourceCode().Substr(startIndex, endIndex);
}

void ScriptFunction::CalculateFunctionExpectedPropertyCount()
{
    // Counting more or less than the actual number does not affect execution.
    if (Body() == nullptr) {
        return;
    }

    std::unordered_set<util::StringView> propertyNames;
    auto addPropertyName = [this, &propertyNames](const util::StringView &name) {
        if (propertyNames.find(name) == propertyNames.end()) {
            propertyNames.insert(name);
            IncreasePropertyCount();
        }
    };

    const ir::BlockStatement *blockStat = Body()->AsBlockStatement();
    for (const auto &stmt : blockStat->Statements()) {
        ExtractThisPropertyFromStatement(stmt, addPropertyName);
    }
}

void ScriptFunction::ExtractThisPropertyFromStatement(
    const ir::Statement *stmt,
    const std::function<void(const util::StringView&)>& addPropertyName)
{
    if (!stmt->IsExpressionStatement()) {
        return;
    }

    const auto *expr = stmt->AsExpressionStatement()->GetExpression();
    if (!expr || !expr->IsAssignmentExpression()) {
        return;
    }

    const auto *left = expr->AsAssignmentExpression()->Left();
    if (!left || !left->IsMemberExpression()) {
        return;
    }

    const auto *memberExpr = left->AsMemberExpression();
    if (memberExpr->Object()->IsThisExpression() && memberExpr->Property()->IsIdentifier()) {
        addPropertyName(memberExpr->Property()->AsIdentifier()->Name());
    }
}
}  // namespace panda::es2panda::ir