// Copyright 2020 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 "src/ast/if_statement.h"

#include "src/ast/discard_statement.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/test_helper.h"

namespace tint {
namespace ast {
namespace {

using IfStatementTest = TestHelper;

TEST_F(IfStatementTest, Creation) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(Source{Source::Location{20, 2}}, cond, body,
                                   ElseStatementList{});
  auto src = stmt->source();
  EXPECT_EQ(src.range.begin.line, 20u);
  EXPECT_EQ(src.range.begin.column, 2u);
}

TEST_F(IfStatementTest, IsIf) {
  auto* stmt = create<IfStatement>(
      nullptr, create<BlockStatement>(StatementList{}), ElseStatementList{});
  EXPECT_TRUE(stmt->Is<IfStatement>());
}

TEST_F(IfStatementTest, IsValid) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(cond, body, ElseStatementList{});
  EXPECT_TRUE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_WithElseStatements) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(create<IdentifierExpression>(
                                    mod->RegisterSymbol("Ident"), "Ident"),
                                create<BlockStatement>(StatementList{})),
          create<ElseStatement>(nullptr,
                                create<BlockStatement>(StatementList{})),
      });
  EXPECT_TRUE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_MissingCondition) {
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(nullptr, body, ElseStatementList{});
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_InvalidCondition) {
  auto* cond = Expr("");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(cond, body, ElseStatementList{});
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_NullBodyStatement) {
  auto* cond = Expr("cond");
  auto* body = create<BlockStatement>(StatementList{
      create<DiscardStatement>(),
      nullptr,
  });
  auto* stmt = create<IfStatement>(cond, body, ElseStatementList{});
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_InvalidBodyStatement) {
  auto* cond = Expr("cond");
  auto* body = create<BlockStatement>(

      StatementList{
          create<DiscardStatement>(),
          create<IfStatement>(nullptr, create<BlockStatement>(StatementList{}),
                              ast::ElseStatementList{}),
      });
  auto* stmt = create<IfStatement>(cond, body, ElseStatementList{});
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_NullElseStatement) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(create<IdentifierExpression>(
                                    mod->RegisterSymbol("Ident"), "Ident"),
                                create<BlockStatement>(StatementList{})),
          create<ElseStatement>(nullptr,
                                create<BlockStatement>(StatementList{})),
          nullptr,
      });
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_InvalidElseStatement) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(Expr(""),
                                create<BlockStatement>(StatementList{})),
      });
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_MultipleElseWiththoutCondition) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(nullptr,
                                create<BlockStatement>(StatementList{})),
          create<ElseStatement>(nullptr,
                                create<BlockStatement>(StatementList{})),
      });
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, IsValid_ElseNotLast) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(nullptr,
                                create<BlockStatement>(StatementList{})),
          create<ElseStatement>(create<IdentifierExpression>(
                                    mod->RegisterSymbol("Ident"), "Ident"),
                                create<BlockStatement>(StatementList{})),
      });
  EXPECT_FALSE(stmt->IsValid());
}

TEST_F(IfStatementTest, ToStr) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(cond, body, ElseStatementList{});

  std::ostringstream out;
  stmt->to_str(out, 2);
  EXPECT_EQ(demangle(out.str()), R"(  If{
    (
      Identifier[not set]{cond}
    )
    {
      Discard{}
    }
  }
)");
}

TEST_F(IfStatementTest, ToStr_WithElseStatements) {
  auto* cond = Expr("cond");
  auto* body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* else_if_body =
      create<BlockStatement>(StatementList{create<DiscardStatement>()});
  auto* else_body = create<BlockStatement>(
      StatementList{create<DiscardStatement>(), create<DiscardStatement>()});
  auto* stmt = create<IfStatement>(
      cond, body,
      ElseStatementList{
          create<ElseStatement>(create<IdentifierExpression>(
                                    mod->RegisterSymbol("ident"), "ident"),
                                else_if_body),
          create<ElseStatement>(nullptr, else_body),
      });

  std::ostringstream out;
  stmt->to_str(out, 2);
  EXPECT_EQ(demangle(out.str()), R"(  If{
    (
      Identifier[not set]{cond}
    )
    {
      Discard{}
    }
  }
  Else{
    (
      Identifier[not set]{ident}
    )
    {
      Discard{}
    }
  }
  Else{
    {
      Discard{}
      Discard{}
    }
  }
)");
}

}  // namespace
}  // namespace ast
}  // namespace tint