// 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/lang/wgsl/ast/helper_test.h"
#include "src/tint/lang/wgsl/ast/workgroup_attribute.h"
#include "src/tint/lang/wgsl/reader/parser/helper_test.h"
#include "src/tint/utils/text/string.h"

namespace tint::wgsl::reader {
namespace {

TEST_F(WGSLParserTest, FunctionDecl) {
    auto p = parser("fn main(a : i32, b : f32) { return; }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get("main"));
    EXPECT_EQ(f->return_type, nullptr);

    ASSERT_EQ(f->params.Length(), 2u);
    EXPECT_EQ(f->params[0]->name->symbol, p->builder().Symbols().Get("a"));
    EXPECT_EQ(f->params[1]->name->symbol, p->builder().Symbols().Get("b"));

    EXPECT_EQ(f->return_type, nullptr);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_Unicode) {
    const std::string function_ident =  // "𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻"
        "\xf0\x9d\x97\xb3\xf0\x9d\x98\x82\xf0\x9d\x97\xbb\xf0\x9d\x97\xb0\xf0\x9d"
        "\x98\x81\xf0\x9d\x97\xb6\xf0\x9d\x97\xbc\xf0\x9d\x97\xbb";

    const std::string param_a_ident =  // "𝓹𝓪𝓻𝓪𝓶_𝓪"
        "\xf0\x9d\x93\xb9\xf0\x9d\x93\xaa\xf0\x9d\x93\xbb\xf0\x9d\x93\xaa\xf0\x9d"
        "\x93\xb6\x5f\xf0\x9d\x93\xaa";

    const std::string param_b_ident =  // "𝕡𝕒𝕣𝕒𝕞_𝕓"
        "\xf0\x9d\x95\xa1\xf0\x9d\x95\x92\xf0\x9d\x95\xa3\xf0\x9d\x95\x92\xf0\x9d"
        "\x95\x9e\x5f\xf0\x9d\x95\x93";

    std::string src = "fn $function($param_a : i32, $param_b : f32) { return; }";
    src = tint::ReplaceAll(src, "$function", function_ident);
    src = tint::ReplaceAll(src, "$param_a", param_a_ident);
    src = tint::ReplaceAll(src, "$param_b", param_b_ident);

    auto p = parser(src);
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get(function_ident));
    EXPECT_EQ(f->return_type, nullptr);

    ASSERT_EQ(f->params.Length(), 2u);
    EXPECT_EQ(f->params[0]->name->symbol, p->builder().Symbols().Get(param_a_ident));
    EXPECT_EQ(f->params[1]->name->symbol, p->builder().Symbols().Get(param_b_ident));

    EXPECT_EQ(f->return_type, nullptr);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_AttributeList) {
    auto p = parser("@workgroup_size(2, 3, 4) fn main() { return; }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    ASSERT_TRUE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get("main"));
    EXPECT_EQ(f->return_type, nullptr);
    ASSERT_EQ(f->params.Length(), 0u);

    auto& attributes = f->attributes;
    ASSERT_EQ(attributes.Length(), 1u);
    ASSERT_TRUE(attributes[0]->Is<ast::WorkgroupAttribute>());

    auto values = attributes[0]->As<ast::WorkgroupAttribute>()->Values();

    ASSERT_TRUE(values[0]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->value, 2);
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[1]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->value, 3);
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[2]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->value, 4);
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_AttributeList_MultipleEntries) {
    auto p = parser(R"(
@workgroup_size(2, 3, 4) @compute
fn main() { return; })");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    ASSERT_TRUE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get("main"));
    EXPECT_EQ(f->return_type, nullptr);
    ASSERT_EQ(f->params.Length(), 0u);

    auto& attributes = f->attributes;
    ASSERT_EQ(attributes.Length(), 2u);

    ASSERT_TRUE(attributes[0]->Is<ast::WorkgroupAttribute>());
    auto values = attributes[0]->As<ast::WorkgroupAttribute>()->Values();

    ASSERT_TRUE(values[0]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->value, 2);
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[1]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->value, 3);
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[2]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->value, 4);
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(attributes[1]->Is<ast::StageAttribute>());
    EXPECT_EQ(attributes[1]->As<ast::StageAttribute>()->stage, ast::PipelineStage::kCompute);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_AttributeList_MultipleLists) {
    auto p = parser(R"(
@workgroup_size(2, 3, 4)
@compute
fn main() { return; })");
    auto attributes = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attributes.errored);
    ASSERT_TRUE(attributes.matched);
    auto f = p->function_decl(attributes.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get("main"));
    EXPECT_EQ(f->return_type, nullptr);
    ASSERT_EQ(f->params.Length(), 0u);

    auto& attrs = f->attributes;
    ASSERT_EQ(attrs.Length(), 2u);

    ASSERT_TRUE(attrs[0]->Is<ast::WorkgroupAttribute>());
    auto values = attrs[0]->As<ast::WorkgroupAttribute>()->Values();

    ASSERT_TRUE(values[0]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->value, 2);
    EXPECT_EQ(values[0]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[1]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->value, 3);
    EXPECT_EQ(values[1]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(values[2]->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->value, 4);
    EXPECT_EQ(values[2]->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);

    ASSERT_TRUE(attrs[1]->Is<ast::StageAttribute>());
    EXPECT_EQ(attrs[1]->As<ast::StageAttribute>()->stage, ast::PipelineStage::kCompute);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_ReturnTypeAttributeList) {
    auto p = parser("fn main() -> @location(1) f32 { return 1.0; }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    EXPECT_EQ(f->name->symbol, p->builder().Symbols().Get("main"));
    ASSERT_NE(f->return_type, nullptr);

    ast::CheckIdentifier(f->return_type, "f32");

    ASSERT_EQ(f->params.Length(), 0u);

    auto& attributes = f->attributes;
    EXPECT_EQ(attributes.Length(), 0u);

    auto& ret_type_attributes = f->return_type_attributes;
    ASSERT_EQ(ret_type_attributes.Length(), 1u);
    auto* loc = ret_type_attributes[0]->As<ast::LocationAttribute>();
    ASSERT_TRUE(loc != nullptr);
    EXPECT_TRUE(loc->expr->Is<ast::IntLiteralExpression>());

    auto* exp = loc->expr->As<ast::IntLiteralExpression>();
    EXPECT_EQ(1u, exp->value);

    auto* body = f->body;
    ASSERT_EQ(body->statements.Length(), 1u);
    EXPECT_TRUE(body->statements[0]->Is<ast::ReturnStatement>());
}

TEST_F(WGSLParserTest, FunctionDecl_MustUse) {
    auto p = parser("@must_use fn main() { return; }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    ASSERT_TRUE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_FALSE(p->has_error()) << p->error();
    EXPECT_FALSE(f.errored);
    EXPECT_TRUE(f.matched);
    ASSERT_NE(f.value, nullptr);

    auto& attributes = f->attributes;
    ASSERT_EQ(attributes.Length(), 1u);
    ASSERT_TRUE(attributes[0]->Is<ast::MustUseAttribute>());
}

TEST_F(WGSLParserTest, FunctionDecl_InvalidHeader) {
    auto p = parser("fn main() -> { }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_TRUE(f.errored);
    EXPECT_FALSE(f.matched);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(f.value, nullptr);
    EXPECT_EQ(p->error(), "1:14: unable to determine function return type");
}

TEST_F(WGSLParserTest, FunctionDecl_InvalidBody) {
    auto p = parser("fn main() { return }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_TRUE(f.errored);
    EXPECT_FALSE(f.matched);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(f.value, nullptr);
    EXPECT_EQ(p->error(), "1:20: expected ';' for return statement");
}

TEST_F(WGSLParserTest, FunctionDecl_MissingLeftBrace) {
    auto p = parser("fn main() return; }");
    auto attrs = p->attribute_list();
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_FALSE(attrs.errored);
    EXPECT_FALSE(attrs.matched);
    auto f = p->function_decl(attrs.value);
    EXPECT_TRUE(f.errored);
    EXPECT_FALSE(f.matched);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(f.value, nullptr);
    EXPECT_EQ(p->error(), "1:11: expected '{' for function body");
}

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