// 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/tint/reader/wgsl/parser_impl_test_helper.h"

namespace tint::reader::wgsl {
namespace {

TEST_F(ParserImplTest, Empty) {
  auto p = parser("");
  ASSERT_TRUE(p->Parse()) << p->error();
}

TEST_F(ParserImplTest, Parses) {
  auto p = parser(R"(
@stage(fragment)
fn main() -> @location(0) vec4<f32> {
  return vec4<f32>(.4, .2, .3, 1);
}
)");
  ASSERT_TRUE(p->Parse()) << p->error();

  Program program = p->program();
  ASSERT_EQ(1u, program.AST().Functions().size());
}

TEST_F(ParserImplTest, Parses_ExtraSemicolons) {
  auto p = parser(R"(
;
struct S {
  a : f32,
};;
;
fn foo() -> S {
  ;
  return S();;;
  ;
};;
;
)");
  ASSERT_TRUE(p->Parse()) << p->error();

  Program program = p->program();
  ASSERT_EQ(1u, program.AST().Functions().size());
  ASSERT_EQ(1u, program.AST().TypeDecls().size());
}

TEST_F(ParserImplTest, HandlesError) {
  auto p = parser(R"(
fn main() ->  {  // missing return type
  return;
})");

  ASSERT_FALSE(p->Parse());
  ASSERT_TRUE(p->has_error());
  EXPECT_EQ(p->error(), "2:15: unable to determine function return type");
}

TEST_F(ParserImplTest, HandlesUnexpectedToken) {
  auto p = parser(R"(
fn main() {
}
foobar
)");

  ASSERT_FALSE(p->Parse());
  ASSERT_TRUE(p->has_error());
  EXPECT_EQ(p->error(), "4:1: unexpected token");
}

TEST_F(ParserImplTest, HandlesBadToken_InMiddle) {
  auto p = parser(R"(
fn main() {
  let f = 0x1p500000000000; // Exponent too big for hex float
  return;
})");

  ASSERT_FALSE(p->Parse());
  ASSERT_TRUE(p->has_error());
  EXPECT_EQ(p->error(), "3:11: exponent is too large for hex float");
}

TEST_F(ParserImplTest, HandlesBadToken_AtModuleScope) {
  auto p = parser(R"(
fn main() {
  return;
}
0x1p5000000000000
)");

  ASSERT_FALSE(p->Parse());
  ASSERT_TRUE(p->has_error());
  EXPECT_EQ(p->error(), "5:1: exponent is too large for hex float");
}

TEST_F(ParserImplTest, Comments_TerminatedBlockComment) {
  auto p = parser(R"(
/**
 * Here is my shader.
 *
 * /* I can nest /**/ comments. */
 * // I can nest line comments too.
 **/
@stage(fragment) // This is the stage
fn main(/*
no
parameters
*/) -> @location(0) vec4<f32> {
  return/*block_comments_delimit_tokens*/vec4<f32>(.4, .2, .3, 1);
}/* block comments are OK at EOF...*/)");

  ASSERT_TRUE(p->Parse()) << p->error();
  ASSERT_EQ(1u, p->program().AST().Functions().size());
}

TEST_F(ParserImplTest, Comments_UnterminatedBlockComment) {
  auto p = parser(R"(
@stage(fragment)
fn main() -> @location(0) vec4<f32> {
  return vec4<f32>(.4, .2, .3, 1);
} /* unterminated block comments are invalid ...)");

  ASSERT_FALSE(p->Parse());
  ASSERT_TRUE(p->has_error());
  EXPECT_EQ(p->error(), "5:3: unterminated block comment") << p->error();
}

}  // namespace
}  // namespace tint::reader::wgsl