// Copyright 2022 The Dawn & Tint Authors
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#include "src/tint/utils/diagnostic/source.h"

#include <cstddef>
#include <memory>
#include <string_view>
#include <utility>

#include "gtest/gtest.h"

namespace tint {
namespace {

// Include a blank line to test that empty strings are handled correctly.
static constexpr std::string_view kSource = R"(line one
line two

line three)";

using SourceFileContentTest = testing::Test;

void CheckLineAndRangeConsistency(const Source::FileContent& fc) {
    EXPECT_EQ(fc.line_ranges.size(), fc.GetLineCount());

    for (size_t i = 0; i < fc.GetLineCount(); i++) {
        std::string_view line_view = fc.GetLine(i);
        std::string_view range_view =
            std::string_view(fc.data).substr(fc.line_ranges[i].start, fc.line_ranges[i].length);
        ASSERT_EQ(line_view.size(), range_view.size());
        ASSERT_EQ(line_view.data(), range_view.data());
    }
}

TEST_F(SourceFileContentTest, Init) {
    Source::FileContent fc(kSource);

    CheckLineAndRangeConsistency(fc);
    EXPECT_EQ(fc.data, kSource);
    ASSERT_EQ(fc.GetLineCount(), 4u);
    EXPECT_EQ(fc.GetLine(0), "line one");
    EXPECT_EQ(fc.GetLine(1), "line two");
    EXPECT_EQ(fc.GetLine(2), "");
    EXPECT_EQ(fc.GetLine(3), "line three");
}

TEST_F(SourceFileContentTest, CopyInit) {
    auto src = std::make_unique<Source::FileContent>(kSource);
    Source::FileContent fc{*src};
    src.reset();

    CheckLineAndRangeConsistency(fc);
    EXPECT_EQ(fc.data, kSource);
    ASSERT_EQ(fc.GetLineCount(), 4u);
    EXPECT_EQ(fc.GetLine(0), "line one");
    EXPECT_EQ(fc.GetLine(1), "line two");
    EXPECT_EQ(fc.GetLine(2), "");
    EXPECT_EQ(fc.GetLine(3), "line three");
}

TEST_F(SourceFileContentTest, MoveInit) {
    auto src = std::make_unique<Source::FileContent>(kSource);
    Source::FileContent fc{std::move(*src)};
    src.reset();

    CheckLineAndRangeConsistency(fc);
    EXPECT_EQ(fc.data, kSource);
    ASSERT_EQ(fc.GetLineCount(), 4u);
    EXPECT_EQ(fc.GetLine(0), "line one");
    EXPECT_EQ(fc.GetLine(1), "line two");
    EXPECT_EQ(fc.GetLine(2), "");
    EXPECT_EQ(fc.GetLine(3), "line three");
}

// Line break code points
#define kCR "\r"
#define kLF "\n"
#define kVTab "\x0B"
#define kFF "\x0C"
#define kNL "\xC2\x85"
#define kLS "\xE2\x80\xA8"
#define kPS "\xE2\x80\xA9"

using LineBreakTest = testing::TestWithParam<std::string_view>;
TEST_P(LineBreakTest, Single) {
    std::string src = "line one";
    src += GetParam();
    src += "line two";

    Source::FileContent fc(src);

    CheckLineAndRangeConsistency(fc);
    EXPECT_EQ(fc.GetLineCount(), 2u);
    EXPECT_EQ(fc.GetLine(0), "line one");
    EXPECT_EQ(fc.GetLine(1), "line two");
}
TEST_P(LineBreakTest, Double) {
    std::string src = "line one";
    src += GetParam();
    src += GetParam();
    src += "line two";

    Source::FileContent fc(src);

    CheckLineAndRangeConsistency(fc);
    EXPECT_EQ(fc.GetLineCount(), 3u);
    EXPECT_EQ(fc.GetLine(0), "line one");
    EXPECT_EQ(fc.GetLine(1), "");
    EXPECT_EQ(fc.GetLine(2), "line two");
}
INSTANTIATE_TEST_SUITE_P(SourceFileContentTest,
                         LineBreakTest,
                         testing::Values(kVTab, kFF, kNL, kLS, kPS, kLF, kCR, kCR kLF));

using RangeLengthTest = testing::TestWithParam<std::pair<Source::Range, size_t>>;
TEST_P(RangeLengthTest, Test) {
    Source::FileContent fc("X" kLF       // 1
                           "XX" kCR kLF  // 2
                           "X" kCR       // 3
                           kLS           // 4
                           "XX"          // 5
    );
    auto& range = GetParam().first;
    auto expected_length = GetParam().second;
    EXPECT_EQ(range.Length(fc), expected_length);
}

INSTANTIATE_TEST_SUITE_P(SingleLine,
                         RangeLengthTest,
                         testing::Values(  //

                             std::make_pair(Source::Range{{1, 1}, {1, 1}}, 0),
                             std::make_pair(Source::Range{{2, 1}, {2, 1}}, 0),
                             std::make_pair(Source::Range{{3, 1}, {3, 1}}, 0),
                             std::make_pair(Source::Range{{4, 1}, {4, 1}}, 0),
                             std::make_pair(Source::Range{{5, 1}, {5, 1}}, 0),

                             std::make_pair(Source::Range{{1, 1}, {1, 2}}, 1),
                             std::make_pair(Source::Range{{2, 1}, {2, 3}}, 2),
                             std::make_pair(Source::Range{{3, 1}, {3, 2}}, 1),
                             std::make_pair(Source::Range{{5, 1}, {5, 3}}, 2),

                             std::make_pair(Source::Range{{1, 2}, {1, 2}}, 0),
                             std::make_pair(Source::Range{{2, 2}, {2, 3}}, 1),
                             std::make_pair(Source::Range{{3, 2}, {3, 2}}, 0),
                             std::make_pair(Source::Range{{5, 2}, {5, 3}}, 1)));

INSTANTIATE_TEST_SUITE_P(MultiLine,
                         RangeLengthTest,
                         testing::Values(  //

                             std::make_pair(Source::Range{{1, 1}, {2, 1}}, 2),
                             std::make_pair(Source::Range{{2, 1}, {3, 1}}, 3),
                             std::make_pair(Source::Range{{3, 1}, {4, 1}}, 2),
                             std::make_pair(Source::Range{{4, 1}, {5, 1}}, 1),

                             std::make_pair(Source::Range{{1, 1}, {5, 3}}, 10),
                             std::make_pair(Source::Range{{2, 2}, {5, 2}}, 6)));

}  // namespace
}  // namespace tint