// Copyright 2022 The Tint Authors.
//
// 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 <utility>

#include "gtest/gtest-spi.h"
#include "src/tint/debug.h"
#include "src/tint/program_builder.h"
#include "src/tint/transform/test_helper.h"
#include "src/tint/transform/utils/get_insertion_point.h"

namespace tint::transform {
namespace {

using GetInsertionPointTest = ::testing::Test;

TEST_F(GetInsertionPointTest, Block) {
  // fn f() {
  //     var a = 1;
  // }
  ProgramBuilder b;
  auto* expr = b.Expr(1);
  auto* var = b.Decl(b.Var("a", nullptr, expr));
  auto* block = b.Block(var);
  b.Func("f", {}, b.ty.void_(), {block});

  Program original(std::move(b));
  ProgramBuilder cloned_b;
  CloneContext ctx(&cloned_b, &original);

  // Can insert in block containing the variable, above or below the input
  // statement.
  auto ip = utils::GetInsertionPoint(ctx, var);
  ASSERT_EQ(ip.first->Declaration(), block);
  ASSERT_EQ(ip.second, var);
}

TEST_F(GetInsertionPointTest, ForLoopInit) {
  // fn f() {
  //     for(var a = 1; true; ) {
  //     }
  // }
  ProgramBuilder b;
  auto* expr = b.Expr(1);
  auto* var = b.Decl(b.Var("a", nullptr, expr));
  auto* fl = b.For(var, b.Expr(true), {}, b.Block());
  auto* func_block = b.Block(fl);
  b.Func("f", {}, b.ty.void_(), {func_block});

  Program original(std::move(b));
  ProgramBuilder cloned_b;
  CloneContext ctx(&cloned_b, &original);

  // Can insert in block containing for-loop above the for-loop itself.
  auto ip = utils::GetInsertionPoint(ctx, var);
  ASSERT_EQ(ip.first->Declaration(), func_block);
  ASSERT_EQ(ip.second, fl);
}

TEST_F(GetInsertionPointTest, ForLoopCont_Invalid) {
  // fn f() {
  //     for(; true; var a = 1) {
  //     }
  // }
  ProgramBuilder b;
  auto* expr = b.Expr(1);
  auto* var = b.Decl(b.Var("a", nullptr, expr));
  auto* s = b.For({}, b.Expr(true), var, b.Block());
  b.Func("f", {}, b.ty.void_(), {s});

  Program original(std::move(b));
  ProgramBuilder cloned_b;
  CloneContext ctx(&cloned_b, &original);

  // Can't insert before/after for loop continue statement (would ned to be
  // converted to loop).
  auto ip = utils::GetInsertionPoint(ctx, var);
  ASSERT_EQ(ip.first, nullptr);
  ASSERT_EQ(ip.second, nullptr);
}

}  // namespace
}  // namespace tint::transform