// SPDX-License-Identifier: MIT
#include "dbc_decode_builder.h"
#include "dbc_decoder.h"
#include "signal_layout.h"
#include <QtTest>
#include <limits>
#include <stdexcept>
#include <utility>

namespace {
    DecodeFrame ValidFrame() {
        DecodeFrame frame;
        frame.canId = 0x123U;
        frame.dlc = 8U;
        DecodeSignal signal;
        signal.name = "Value";
        signal.length = 8U;
        frame.signals.push_back(signal);
        return frame;
    }

    DbcDatabase ParsedDefinitions(const std::vector<DecodeFrame> &frames) {
        DbcDatabase database;
        for (const DecodeFrame &frame: frames) {
            FrameInfo target;
            target.canId = frame.canId;
            target.isExtended = frame.isExtended;
            target.dlc = frame.dlc;
            for (const DecodeSignal &signal: frame.signals) {
                SignalInfo copy;
                copy.name = signal.name;
                copy.startBit = signal.startBit;
                copy.length = signal.length;
                copy.isLittleEndian = signal.byteOrder == ByteOrder::Intel;
                copy.isSigned = signal.valueType == ValueType::Signed;
                copy.factor = signal.factor;
                copy.offset = signal.offset;
                copy.minimum = signal.minimum;
                copy.maximum = signal.maximum;
                copy.multiplexing = signal.multiplexing;
                target.signals.push_back(copy);
            }
            database.frames.push_back(target);
        }
        return database;
    }
}// namespace

class DbcValidationTest : public QObject {
    Q_OBJECT
private Q_SLOTS:
    void invalidMetadata_data();
    void invalidMetadata();
    void numericParameters_data();
    void numericParameters();
    void validBoundaries();
    void layoutBoundaries();
    void builderSnapshot();
    void multiplexingBoundaries();
    void independentSnapshot();
    void failedReplacement();
};

void DbcValidationTest::invalidMetadata_data() {
    QTest::addColumn<int>("kind");
    QTest::newRow("standard-id") << 0;
    QTest::newRow("extended-id") << 1;
    QTest::newRow("encoded-id") << 2;
    QTest::newRow("duplicate-frame") << 3;
    QTest::newRow("duplicate-signal") << 4;
    QTest::newRow("zero-length") << 5;
    QTest::newRow("65-bits") << 6;
    QTest::newRow("length-overflow") << 7;
    QTest::newRow("intel-start-overflow") << 8;
    QTest::newRow("motorola-start-overflow") << 9;
    QTest::newRow("intel-outside-payload") << 10;
    QTest::newRow("motorola-outside-payload") << 11;
    QTest::newRow("zero-payload") << 12;
    QTest::newRow("inverted-range") << 13;
    QTest::newRow("byte-order") << 14;
    QTest::newRow("value-type") << 15;
    QTest::newRow("multiplex-role") << 16;
    QTest::newRow("missing-selector") << 17;
    QTest::newRow("signed-selector") << 18;
    QTest::newRow("two-selectors") << 19;
    QTest::newRow("branch-range") << 20;
    QTest::newRow("unconditional-overlap") << 21;
    QTest::newRow("mixed-order-overlap") << 22;
    QTest::newRow("same-branch-overlap") << 23;
    QTest::newRow("selector-branch-overlap") << 24;
    QTest::newRow("maximum-can-id") << 25;
}

void DbcValidationTest::invalidMetadata() {
    QFETCH(int, kind);
    std::vector<DecodeFrame> frames = {ValidFrame()};
    DecodeFrame &frame = frames[0];
    DecodeSignal &signal = frame.signals[0];
    DecodeSignal other = signal;
    other.name = "Other";
    switch (kind) {
        case 0:
            frame.canId = 0x800U;
            break;
        case 1:
            frame.isExtended = true;
            frame.canId = 0x20000000U;
            break;
        case 2:
            frame.isExtended = true;
            frame.canId = 0x80000123U;
            break;
        case 3:
            frames.push_back(frame);
            break;
        case 4:
            frame.signals.push_back(signal);
            break;
        case 5:
            signal.length = 0U;
            break;
        case 6:
            signal.length = 65U;
            break;
        case 7:
            signal.length = std::numeric_limits<std::uint32_t>::max();
            break;
        case 8:
            signal.startBit = std::numeric_limits<std::uint32_t>::max();
            break;
        case 9:
            signal.byteOrder = ByteOrder::Motorola;
            signal.startBit = std::numeric_limits<std::uint32_t>::max();
            break;
        case 10:
            signal.startBit = 57U;
            break;
        case 11:
            signal.byteOrder = ByteOrder::Motorola;
            signal.startBit = 56U;
            break;
        case 12:
            frame.dlc = 0U;
            break;
        case 13:
            signal.minimum = 2.0;
            signal.maximum = 1.0;
            break;
        case 14:
            signal.byteOrder = static_cast<ByteOrder>(99);
            break;
        case 15:
            signal.valueType = static_cast<ValueType>(99);
            break;
        case 16:
            signal.multiplexing.role = static_cast<MultiplexRole>(99);
            break;
        case 17:
            signal.multiplexing.role = MultiplexRole::Branch;
            break;
        case 18:
            signal.multiplexing.role = MultiplexRole::Selector;
            signal.valueType = ValueType::Signed;
            break;
        case 19:
            signal.multiplexing.role = MultiplexRole::Selector;
            other.multiplexing.role = MultiplexRole::Selector;
            other.startBit = 8U;
            frame.signals.push_back(other);
            break;
        case 20:
        case 23:
        case 24:
            signal.multiplexing.role = MultiplexRole::Selector;
            other.multiplexing.role = MultiplexRole::Branch;
            other.startBit = kind == 24 ? 0U : 8U;
            other.multiplexing.value = kind == 20 ? 256U : 1U;
            frame.signals.push_back(other);
            if (kind == 23) {
                other.name = "Third";
                frame.signals.push_back(other);
            }
            break;
        case 21:
            frame.signals.push_back(other);
            break;
        case 22:
            other.byteOrder = ByteOrder::Motorola;
            other.startBit = 7U;
            frame.signals.push_back(other);
            break;
        case 25:
            frame.canId = std::numeric_limits<std::uint32_t>::max();
            break;
    }
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument, (void) DecodeDatabase(frames));
    // Parsed metadata uses bools for byte order and signedness, so invalid enum
    // values exist only in direct runtime definitions.
    if (kind != 14 && kind != 15)
        QVERIFY_THROWS_EXCEPTION(std::invalid_argument, (void) DbcDecodeBuilder().Build(ParsedDefinitions(frames)));
}

void DbcValidationTest::numericParameters_data() {
    QTest::addColumn<int>("field");
    QTest::addColumn<double>("value");
    const double values[] = {std::numeric_limits<double>::quiet_NaN(),
                             std::numeric_limits<double>::infinity(),
                             -std::numeric_limits<double>::infinity()};
    for (int field = 0; field < 4; ++field) {
        for (int index = 0; index < 3; ++index) {
            const QByteArray name = QByteArray::number(field) + "-" + QByteArray::number(index);
            QTest::newRow(name.constData()) << field << values[index];
        }
    }
}

void DbcValidationTest::numericParameters() {
    QFETCH(int, field);
    QFETCH(double, value);
    DecodeFrame frame = ValidFrame();
    DecodeSignal &signal = frame.signals[0];
    switch (field) {
        case 0:
            signal.factor = value;
            break;
        case 1:
            signal.offset = value;
            break;
        case 2:
            signal.minimum = value;
            break;
        case 3:
            signal.maximum = value;
            break;
    }
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument, (void) DecodeDatabase({frame}));
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument, (void) DbcDecodeBuilder().Build(ParsedDefinitions({frame})));
}

void DbcValidationTest::validBoundaries() {
    for (ByteOrder order: {ByteOrder::Intel, ByteOrder::Motorola}) {
        for (std::uint8_t dlc: {std::uint8_t(8U), std::uint8_t(64U), std::uint8_t(255U)}) {
            DecodeFrame standard = ValidFrame();
            standard.canId = 0x7FFU;
            standard.dlc = dlc;
            DecodeSignal &signal = standard.signals[0];
            signal.byteOrder = order;
            signal.startBit = (std::uint32_t(dlc) - 8U) * 8U + (order == ByteOrder::Intel ? 0U : 7U);
            signal.length = 64U;
            signal.factor = -2.0;
            signal.offset = std::numeric_limits<double>::max();
            signal.minimum = -std::numeric_limits<double>::max();
            signal.maximum = std::numeric_limits<double>::max();
            DecodeFrame extended = standard;
            extended.isExtended = true;
            DecodeFrame maximum = extended;
            maximum.canId = 0x1FFFFFFFU;
            const std::vector<DecodeFrame> frames = {standard, extended, maximum};
            const DecodeDatabase direct(frames);
            const DecodeDatabase built = DbcDecodeBuilder().Build(ParsedDefinitions(frames));
            for (const DecodeFrame &frame: frames) {
                QVERIFY(direct.FindFrame(frame.GetKey()));
                QVERIFY(built.FindSignal(SignalKey(frame.GetKey(), "Value")));
            }
        }
    }
    DecodeFrame empty;
    empty.canId = 0U;
    QVERIFY(DecodeDatabase({empty}).FindFrame(empty.GetKey()));
    QVERIFY(DbcDecodeBuilder().Build(DbcDatabase()).GetFrames().empty());
}

void DbcValidationTest::layoutBoundaries() {
    // Compare the shared coordinate calculation with independent DBC bit traversal.
    for (const std::uint8_t dlc: {std::uint8_t(0U), std::uint8_t(1U), std::uint8_t(8U),
                                  std::uint8_t(64U), std::uint8_t(255U)}) {
        const std::uint64_t payloadBits = std::uint64_t(dlc) * 8U;
        for (const bool littleEndian: {true, false}) {
            for (std::uint32_t start = 0U; start < payloadBits + 8U; ++start) {
                std::uint64_t bit = start;
                bool fits = true;
                QVERIFY(!IsValidSignalLayout(start, 0U, littleEndian, dlc));
                for (std::uint32_t length = 1U; length <= 64U; ++length) {
                    fits = fits && bit < payloadBits;
                    QCOMPARE(IsValidSignalLayout(start, length, littleEndian, dlc), fits);
                    if (littleEndian)
                        ++bit;
                    else
                        bit = bit % 8U == 0U ? bit + 15U : bit - 1U;
                }
                QVERIFY(!IsValidSignalLayout(start, 65U, littleEndian, dlc));
            }
            const std::uint32_t maximum = std::numeric_limits<std::uint32_t>::max();
            QVERIFY(!IsValidSignalLayout(maximum, 1U, littleEndian, dlc));
            QVERIFY(!IsValidSignalLayout(maximum, maximum, littleEndian, dlc));
            QVERIFY(!IsValidSignalLayout(0U, maximum, littleEndian, dlc));
        }
    }
}

void DbcValidationTest::builderSnapshot() {
    DbcDatabase source = ParsedDefinitions({ValidFrame()});
    source.frames[0].signals[0].valueDescriptions.emplace(std::uint64_t(1U), "One");
    const FrameKey key(source.frames[0].canId, source.frames[0].isExtended);
    const DecodeDatabase database = DbcDecodeBuilder().Build(source);
    source.frames[0].canId = 0x800U;
    source.frames[0].signals[0].name = "Changed";
    source.frames[0].signals[0].valueDescriptions.begin()->second = "Changed";
    source.frames.clear();
    const std::shared_ptr<const DecodeSignal> signal = database.FindSignal(SignalKey(key, "Value"));
    QVERIFY(signal);
    QCOMPARE(signal->valueDescriptions.begin()->second, std::string("One"));
    QVERIFY(database.FindFrame(key));
    QVERIFY(!database.FindFrame(FrameKey(0x800U, false)));
}

void DbcValidationTest::multiplexingBoundaries() {
    DecodeFrame frame = ValidFrame();
    frame.dlc = 9U;
    DecodeSignal &selector = frame.signals[0];
    selector.length = 64U;
    selector.multiplexing.role = MultiplexRole::Selector;
    DecodeSignal first;
    first.name = "First";
    first.startBit = 64U;
    first.length = 8U;
    first.multiplexing.role = MultiplexRole::Branch;
    first.multiplexing.value = std::numeric_limits<std::uint64_t>::max();
    DecodeSignal second = first;
    second.name = "Second";
    second.byteOrder = ByteOrder::Motorola;
    second.startBit = 71U;
    second.multiplexing.value = 0U;
    frame.signals.push_back(first);
    frame.signals.push_back(second);
    const DecodeDatabase direct({frame});
    const DecodeDatabase built = DbcDecodeBuilder().Build(ParsedDefinitions({frame}));
    RawCanFrame raw;
    raw.canId = frame.canId;
    raw.data.assign(9U, 255U);
    for (const DecodeDatabase &database: {direct, built}) {
        const DecodedFrameValue result = DbcDecoder().Decode(database, raw);
        QCOMPARE(result.signals[1].status, SignalDecodeStatus::Valid);
        QCOMPARE(result.signals[2].status, SignalDecodeStatus::Inactive);
    }
}

void DbcValidationTest::independentSnapshot() {
    std::vector<DecodeFrame> frames = {ValidFrame()};
    DecodeFrame &alias = frames[0];
    DecodeSignal &signalAlias = alias.signals[0];
    signalAlias.valueDescriptions.emplace(std::uint64_t(1U), "One");
    std::string &descriptionAlias = signalAlias.valueDescriptions.begin()->second;
    const FrameKey key = alias.GetKey();
    const DecodeDatabase database(std::move(frames));
    alias.canId = 456U;
    signalAlias.name = "Changed";
    signalAlias.startBit = std::numeric_limits<std::uint32_t>::max();
    descriptionAlias = "Changed";
    const std::shared_ptr<const DecodeFrame> saved = database.FindFrame(key);
    QVERIFY(saved);
    QCOMPARE(saved->canId, key.canId);
    QVERIFY(!database.FindFrame(FrameKey(456U, false)));
    const std::shared_ptr<const DecodeSignal> signal = database.FindSignal(SignalKey(key, "Value"));
    QVERIFY(signal);
    QCOMPARE(signal->startBit, 0U);
    QCOMPARE(signal->valueDescriptions.begin()->second, std::string("One"));
}

void DbcValidationTest::failedReplacement() {
    const DecodeFrame valid = ValidFrame();
    DecodeDatabase database({valid});
    const std::shared_ptr<const DecodeFrame> original = database.FindFrame(valid.GetKey());
    DecodeFrame invalid = valid;
    invalid.canId = 0x800U;
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument, database = DecodeDatabase({invalid}));
    QCOMPARE(database.FindFrame(valid.GetKey()).get(), original.get());
    invalid = valid;
    invalid.signals[0].factor = std::numeric_limits<double>::infinity();
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument,
                             database = DbcDecodeBuilder().Build(ParsedDefinitions({invalid})));
    QCOMPARE(database.FindFrame(valid.GetKey()).get(), original.get());
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument, database = DecodeDatabase({valid, valid}));
    QCOMPARE(database.FindFrame(valid.GetKey()).get(), original.get());
    invalid = valid;
    invalid.signals.push_back(invalid.signals[0]);
    QVERIFY_THROWS_EXCEPTION(std::invalid_argument,
                             database = DbcDecodeBuilder().Build(ParsedDefinitions({invalid})));
    QCOMPARE(database.FindFrame(valid.GetKey()).get(), original.get());
    QVERIFY(database.FindSignal(SignalKey(valid.GetKey(), "Value")));
    QCOMPARE(database.GetFrames().size(), std::size_t(1U));
    database = DecodeDatabase();
    QVERIFY(database.GetFrames().empty());
    QVERIFY(!database.FindFrame(valid.GetKey()));
    QVERIFY(original);
}

int RunValidationTests(int argc, char **argv) {
    DbcValidationTest tests;
    return QTest::qExec(&tests, argc, argv);
}

#include "dbc_validation_test.moc"