/**
 * Copyright (c) 2021 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 "checker.h"

#include <ir/expression.h>
#include <ir/statements/blockStatement.h>
#include <parser/program/program.h>
#include <util/helpers.h>
#include <binder/binder.h>
#include <binder/scope.h>
#include <binder/variable.h>
#include <es2panda.h>

#include <cstdint>
#include <initializer_list>
#include <memory>

namespace panda::es2panda::checker {

Checker::Checker(ArenaAllocator *allocator, binder::Binder *binder)
    : allocator_(allocator),
      binder_(binder),
      rootNode_(binder->TopScope()->Node()->AsBlockStatement()),
      scope_(binder->TopScope()),
      context_(CheckerStatus::NO_OPTS)
{
    scopeStack_.push_back(scope_);
    globalTypes_ = allocator_->New<GlobalTypesHolder>(allocator_);
    relation_ = allocator_->New<TypeRelation>(this);
}

void Checker::StartChecker()
{
    ASSERT(rootNode_->IsProgram());
    rootNode_->Check(this);
}

void Checker::ThrowTypeError(std::initializer_list<TypeErrorMessageElement> list, const lexer::SourcePosition &pos)
{
    std::stringstream ss;

    for (const auto &it : list) {
        if (std::holds_alternative<char *>(it)) {
            ss << std::get<char *>(it);
        } else if (std::holds_alternative<util::StringView>(it)) {
            ss << std::get<util::StringView>(it);
        } else if (std::holds_alternative<lexer::TokenType>(it)) {
            ss << TokenToString(std::get<lexer::TokenType>(it));
        } else if (std::holds_alternative<const Type *>(it)) {
            std::get<const Type *>(it)->ToString(ss);
        } else if (std::holds_alternative<AsSrc>(it)) {
            std::get<AsSrc>(it).GetType()->ToStringAsSrc(ss);
        } else if (std::holds_alternative<size_t>(it)) {
            ss << std::to_string(std::get<size_t>(it));
        } else {
            UNREACHABLE();
        }
    }

    std::string err = ss.str();
    ThrowTypeError(err, pos);
}

void Checker::ThrowTypeError(std::string_view message, const lexer::SourcePosition &pos)
{
    lexer::LineIndex index(binder_->Program()->SourceCode());
    lexer::SourceLocation loc = index.GetLocation(pos);

    throw Error {ErrorType::TYPE, message, loc.line, loc.col};
}

Type *Checker::CheckTypeCached(const ir::Expression *expr)
{
    auto res = nodeCache_.find(expr);
    if (res != nodeCache_.end()) {
        return res->second;
    }

    Type *returnType = expr->Check(this);
    nodeCache_.insert({expr, returnType});

    return returnType;
}

}  // namespace panda::es2panda::checker