/**
 * Copyright (c) 2021-2024 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 "lexenv.h"

#include "varbinder/variable.h"
#include "compiler/core/envScope.h"
#include "compiler/core/pandagen.h"
#include "compiler/core/moduleContext.h"
#include "ir/expressions/identifier.h"

namespace ark::es2panda::compiler {
// Helpers

static bool CheckTdz(const ir::AstNode *node)
{
    return node->IsIdentifier() && node->AsIdentifier()->IsTdz();
}

static void CheckConstAssignment(PandaGen *pg, const ir::AstNode *node, varbinder::Variable *variable)
{
    if (!variable->Declaration()->IsConstDecl()) {
        return;
    }

    pg->ThrowConstAssignment(node, variable->Name());
}

// VirtualLoadVar

static void ExpandLoadLexVar(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result)
{
    if (result.variable->Declaration()->IsVarDecl()) {
        pg->LoadLexicalVar(node, result.lexLevel, result.variable->AsLocalVariable()->LexIdx());
    } else {
        pg->LoadLexical(node, result.name, result.lexLevel, result.variable->AsLocalVariable()->LexIdx());
    }
}

static void ExpandLoadNormalVar(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result)
{
    auto *local = result.variable->AsLocalVariable();

    if (CheckTdz(node)) {
        pg->ThrowTdz(node, local->Name());
    } else {
        pg->LoadAccumulator(node, local->Vreg());
    }
}

void VirtualLoadVar::Expand(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result)
{
    if (result.variable->LexicalBound()) {
        ExpandLoadLexVar(pg, node, result);
    } else {
        ExpandLoadNormalVar(pg, node, result);
    }
}

// VirtualStoreVar

static void StoreLocalExport(PandaGen *pg, const ir::AstNode *node, varbinder::Variable *variable)
{
    if (!variable->HasFlag(varbinder::VariableFlags::LOCAL_EXPORT) || !pg->Scope()->IsModuleScope()) {
        return;
    }

    auto range = pg->Scope()->AsModuleScope()->LocalExports().equal_range(variable);

    for (auto it = range.first; it != range.second; ++it) {
        if (it->second != "default") {
            pg->StoreModuleVar(node, it->second);
        }
    }
}

static void ExpandStoreLexVar(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result,
                              bool isDecl)
{
    varbinder::LocalVariable *local = result.variable->AsLocalVariable();

    const auto *decl = result.variable->Declaration();

    if (decl->IsLetOrConstDecl() && !isDecl) {
        if (decl->IsConstDecl()) {
            pg->ThrowConstAssignment(node, local->Name());
        }

        pg->StoreLexical(node, result.name, result.lexLevel, local->LexIdx());
    } else {
        pg->StoreLexicalVar(node, result.lexLevel, local->LexIdx());
    }

    StoreLocalExport(pg, node, local);
}

static void ExpandStoreNormalVar(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result,
                                 bool isDecl)
{
    auto *local = result.variable->AsLocalVariable();
    VReg localReg = local->Vreg();

    if (!isDecl) {
        if (CheckTdz(node)) {
            pg->ThrowTdz(node, local->Name());
        }

        CheckConstAssignment(pg, node, local);
    }

    pg->StoreAccumulator(node, localReg);
    StoreLocalExport(pg, node, local);
}

void VirtualStoreVar::Expand(PandaGen *pg, const ir::AstNode *node, const varbinder::ConstScopeFindResult &result,
                             bool isDecl)
{
    if (result.variable->LexicalBound()) {
        ExpandStoreLexVar(pg, node, result, isDecl);
    } else {
        ExpandStoreNormalVar(pg, node, result, isDecl);
    }
}
}  // namespace ark::es2panda::compiler