// 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 "gtest/gtest.h"
#include "src/reader/wgsl/parser_impl.h"
#include "src/reader/wgsl/parser_impl_test_helper.h"

namespace tint {
namespace reader {
namespace wgsl {
namespace {

class ParserImplErrorResyncTest : public ParserImplTest {};

#define EXPECT(SOURCE, EXPECTED)                                     \
  do {                                                               \
    std::string source = SOURCE;                                     \
    std::string expected = EXPECTED;                                 \
    auto p = parser(source);                                         \
    EXPECT_EQ(false, p->Parse());                                    \
    EXPECT_EQ(true, p->diagnostics().contains_errors());             \
    EXPECT_EQ(expected, diag::Formatter().format(p->diagnostics())); \
  } while (false)

TEST_F(ParserImplErrorResyncTest, BadFunctionDecls) {
  EXPECT(R"(
fn .() -> . {}
fn x(.) . {}
[[.,.]] fn -> {}
fn good() -> void {}
)",
         "test.wgsl:2:4 error: expected identifier for function declaration\n"
         "fn .() -> . {}\n"
         "   ^\n"
         "\n"
         "test.wgsl:2:11 error: unable to determine function return type\n"
         "fn .() -> . {}\n"
         "          ^\n"
         "\n"
         "test.wgsl:3:6 error: expected ')' for function declaration\n"
         "fn x(.) . {}\n"
         "     ^\n"
         "\n"
         "test.wgsl:3:9 error: expected '->' for function declaration\n"
         "fn x(.) . {}\n"
         "        ^\n"
         "\n"
         "test.wgsl:4:3 error: expected decoration\n"
         "[[.,.]] fn -> {}\n"
         "  ^\n"
         "\n"
         "test.wgsl:4:5 error: expected decoration\n"
         "[[.,.]] fn -> {}\n"
         "    ^\n"
         "\n"
         "test.wgsl:4:12 error: expected identifier for function declaration\n"
         "[[.,.]] fn -> {}\n"
         "           ^^\n");
}

TEST_F(ParserImplErrorResyncTest, AssignmentStatement) {
  EXPECT(R"(
fn f() -> void {
  blah blah blah blah;
  good = 1;
  blah blah blah blah;
  x = .;
  good = 1;
}
)",
         "test.wgsl:3:8 error: expected '=' for assignment\n"
         "  blah blah blah blah;\n"
         "       ^^^^\n"
         "\n"
         "test.wgsl:5:8 error: expected '=' for assignment\n"
         "  blah blah blah blah;\n"
         "       ^^^^\n"
         "\n"
         "test.wgsl:6:7 error: unable to parse right side of assignment\n"
         "  x = .;\n"
         "      ^\n");
}

TEST_F(ParserImplErrorResyncTest, DiscardStatement) {
  EXPECT(R"(
fn f() -> void {
  discard blah blah blah;
  a = 1;
  discard blah blah blah;
}
)",
         "test.wgsl:3:11 error: expected ';' for discard statement\n"
         "  discard blah blah blah;\n"
         "          ^^^^\n"
         "\n"
         "test.wgsl:5:11 error: expected ';' for discard statement\n"
         "  discard blah blah blah;\n"
         "          ^^^^\n");
}

TEST_F(ParserImplErrorResyncTest, StructMembers) {
  EXPECT(R"(
struct S {
    blah blah blah;
    a : i32;
    blah blah blah;
    b : i32;
    [[block]] x : i32;
    c : i32;
}
)",
         "test.wgsl:3:10 error: expected ':' for struct member\n"
         "    blah blah blah;\n"
         "         ^^^^\n"
         "\n"
         "test.wgsl:5:10 error: expected ':' for struct member\n"
         "    blah blah blah;\n"
         "         ^^^^\n"
         "\n"
         "test.wgsl:7:7 error: struct decoration type cannot be used for "
         "struct member\n"
         "    [[block]] x : i32;\n"
         "      ^^^^^\n");
}

// Check that the forward scan in resynchronize() stop at nested sync points.
// In this test the inner resynchronize() is looking for a terminating ';', and
// the outer resynchronize() is looking for a terminating '}' for the function
// scope.
TEST_F(ParserImplErrorResyncTest, NestedSyncPoints) {
  EXPECT(R"(
fn f() -> void {
  x = 1;
  discard
}
struct S { blah };
)",
         "test.wgsl:5:1 error: expected ';' for discard statement\n"
         "}\n"
         "^\n"
         "\n"
         "test.wgsl:6:17 error: expected ':' for struct member\n"
         "struct S { blah };\n"
         "                ^\n");
}

TEST_F(ParserImplErrorResyncTest, BracketCounting) {
  EXPECT(R"(
[[woof[[[[]]]]]]
fn f(x(((())))) -> void {
  meow = {{{}}}
}
struct S { blah };
)",
         "test.wgsl:2:3 error: expected decoration\n"
         "[[woof[[[[]]]]]]\n"
         "  ^^^^\n"
         "\n"
         "test.wgsl:3:7 error: expected ':' for parameter\n"
         "fn f(x(((())))) -> void {\n"
         "      ^\n"
         "\n"
         "test.wgsl:4:10 error: unable to parse right side of assignment\n"
         "  meow = {{{}}}\n"
         "         ^\n"
         "\n"
         "test.wgsl:6:17 error: expected ':' for struct member\n"
         "struct S { blah };\n"
         "                ^\n");
}

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