// Copyright 2020 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
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#include "src/tint/lang/wgsl/ast/unary_op_expression.h"
#include "src/tint/lang/wgsl/reader/parser/helper_test.h"

namespace tint::wgsl::reader {
namespace {

TEST_F(WGSLParserTest, UnaryExpression_Postix) {
    auto p = parser("a[2]");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);

    ASSERT_TRUE(e->Is<ast::IndexAccessorExpression>());
    auto* idx = e->As<ast::IndexAccessorExpression>();
    ASSERT_TRUE(idx->object->Is<ast::IdentifierExpression>());
    auto* ident_expr = idx->object->As<ast::IdentifierExpression>();
    EXPECT_EQ(ident_expr->identifier->symbol, p->builder().Symbols().Get("a"));

    ASSERT_TRUE(idx->index->Is<ast::IntLiteralExpression>());
    ASSERT_EQ(idx->index->As<ast::IntLiteralExpression>()->value, 2);
    ASSERT_EQ(idx->index->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);
}

TEST_F(WGSLParserTest, UnaryExpression_Minus) {
    auto p = parser("- 1");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    ASSERT_EQ(u->op, core::UnaryOp::kNegation);

    ASSERT_TRUE(u->expr->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(u->expr->As<ast::IntLiteralExpression>()->value, 1);
    ASSERT_EQ(u->expr->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);
}

TEST_F(WGSLParserTest, UnaryExpression_AddressOf) {
    auto p = parser("&x");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    EXPECT_EQ(u->op, core::UnaryOp::kAddressOf);
    EXPECT_TRUE(u->expr->Is<ast::IdentifierExpression>());
}

TEST_F(WGSLParserTest, UnaryExpression_Dereference) {
    auto p = parser("*x");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    EXPECT_EQ(u->op, core::UnaryOp::kIndirection);
    EXPECT_TRUE(u->expr->Is<ast::IdentifierExpression>());
}

TEST_F(WGSLParserTest, UnaryExpression_AddressOf_Precedence) {
    auto p = parser("&x.y");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    EXPECT_EQ(u->op, core::UnaryOp::kAddressOf);
    EXPECT_TRUE(u->expr->Is<ast::MemberAccessorExpression>());
}

TEST_F(WGSLParserTest, UnaryExpression_Dereference_Precedence) {
    auto p = parser("*x.y");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    EXPECT_EQ(u->op, core::UnaryOp::kIndirection);
    EXPECT_TRUE(u->expr->Is<ast::MemberAccessorExpression>());
}

TEST_F(WGSLParserTest, UnaryExpression_Minus_InvalidRHS) {
    auto p = parser("-if(a) {}");
    auto e = p->unary_expression();
    EXPECT_FALSE(e.matched);
    EXPECT_TRUE(e.errored);
    EXPECT_EQ(e.value, nullptr);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(p->error(), "1:2: unable to parse right side of - expression");
}

TEST_F(WGSLParserTest, UnaryExpression_Bang) {
    auto p = parser("!1");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    ASSERT_EQ(u->op, core::UnaryOp::kNot);

    ASSERT_TRUE(u->expr->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(u->expr->As<ast::IntLiteralExpression>()->value, 1);
    ASSERT_EQ(u->expr->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);
}

TEST_F(WGSLParserTest, UnaryExpression_Bang_InvalidRHS) {
    auto p = parser("!if (a) {}");
    auto e = p->unary_expression();
    EXPECT_FALSE(e.matched);
    EXPECT_TRUE(e.errored);
    EXPECT_EQ(e.value, nullptr);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(p->error(), "1:2: unable to parse right side of ! expression");
}

TEST_F(WGSLParserTest, UnaryExpression_Tilde) {
    auto p = parser("~1");
    auto e = p->unary_expression();
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    auto* u = e->As<ast::UnaryOpExpression>();
    ASSERT_EQ(u->op, core::UnaryOp::kComplement);

    ASSERT_TRUE(u->expr->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(u->expr->As<ast::IntLiteralExpression>()->value, 1);
    ASSERT_EQ(u->expr->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);
}

// (++a) is not a valid unary expression.
TEST_F(WGSLParserTest, _PrefixPlusPlus) {
    auto p = parser("++a");
    auto e = p->unary_expression();
    EXPECT_FALSE(e.matched);
    EXPECT_TRUE(e.errored);
    EXPECT_EQ(e.value, nullptr);
    EXPECT_TRUE(p->has_error());
    EXPECT_EQ(p->error(), "1:1: prefix increment and decrement operators are not supported");
}

// A unary expression of form (--a) should be parsed as nested Negation unary expression (-(-a)).
TEST_F(WGSLParserTest, UnaryExpression_PrefixMinusMinus) {
    auto p = parser("-- 1");
    auto e = p->unary_expression();

    // The expression should be parsed as a MINUS unary expression.
    EXPECT_TRUE(e.matched);
    EXPECT_FALSE(e.errored);
    EXPECT_FALSE(p->has_error()) << p->error();
    ASSERT_NE(e.value, nullptr);
    ASSERT_TRUE(e->Is<ast::UnaryOpExpression>());

    // The outer unary expression should be Negation of the inner unary expression.
    auto* outer = e->As<ast::UnaryOpExpression>();
    ASSERT_EQ(outer->op, core::UnaryOp::kNegation);
    ASSERT_TRUE(outer->expr->Is<ast::UnaryOpExpression>());

    // The inner unary expression should be Negation of integer literal.
    auto* inner = outer->expr->As<ast::UnaryOpExpression>();
    ASSERT_EQ(inner->op, core::UnaryOp::kNegation);

    ASSERT_TRUE(inner->expr->Is<ast::IntLiteralExpression>());
    EXPECT_EQ(inner->expr->As<ast::IntLiteralExpression>()->value, 1);
    ASSERT_EQ(inner->expr->As<ast::IntLiteralExpression>()->suffix,
              ast::IntLiteralExpression::Suffix::kNone);
}

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