#include "TestHarness.h"

#include "src/ai/ConversationStore.h"

#include <QByteArray>
#include <QDate>
#include <QDateTime>
#include <QDir>
#include <QFile>
#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QTemporaryDir>
#include <QTime>

namespace
{
ChatMessage message(const QString &role, const QString &content, int minute)
{
    return {
        role,
        content,
        QDateTime(QDate(2026, 7, 17), QTime(10, minute)),
        QStringLiteral("openai"),
        QStringLiteral("test-model"),
    };
}

bool writeBytes(const QString &filePath, const QByteArray &bytes)
{
    QFile file(filePath);
    return file.open(QIODevice::WriteOnly | QIODevice::Truncate)
        && file.write(bytes) == bytes.size();
}
}

QA_TEST(ConversationStore, SavesLoadsAndLimitsEvenHistory)
{
    QTemporaryDir directory;
    QA_EXPECT(directory.isValid());
    const QString filePath = directory.filePath(QStringLiteral("conversation_history.json"));
    const ConversationStore store(filePath);
    const QVector<ChatMessage> messages = {
        message(QStringLiteral("user"), QStringLiteral("one"), 0),
        message(QStringLiteral("assistant"), QStringLiteral("two"), 1),
        message(QStringLiteral("user"), QStringLiteral("three"), 2),
        message(QStringLiteral("assistant"), QStringLiteral("four"), 3),
    };

    QA_EXPECT(store.save(messages, 4));
    const QVector<ChatMessage> loaded = store.load(3);
    QA_EXPECT_EQ(loaded.size(), 2);
    QA_EXPECT_EQ(loaded.first().content, QStringLiteral("three"));
    QA_EXPECT_EQ(loaded.last().model, QStringLiteral("test-model"));
}

QA_TEST(ConversationStore, AvoidsDuplicatingOverlappingMessages)
{
    QTemporaryDir directory;
    QA_EXPECT(directory.isValid());
    const ConversationStore store(directory.filePath(QStringLiteral("history.json")));
    const QVector<ChatMessage> firstPair = {
        message(QStringLiteral("user"), QStringLiteral("hello"), 0),
        message(QStringLiteral("assistant"), QStringLiteral("world"), 1),
    };

    QA_EXPECT(store.save(firstPair, 10));
    QA_EXPECT(store.save(firstPair, 10));
    QA_EXPECT_EQ(store.load(10).size(), 2);
}

QA_TEST(ConversationStore, LoadsLegacyCreatedAtField)
{
    QTemporaryDir directory;
    QA_EXPECT(directory.isValid());
    const QString filePath = directory.filePath(QStringLiteral("legacy.json"));
    QJsonArray messages;
    messages.append(QJsonObject{
        {QStringLiteral("role"), QStringLiteral("user")},
        {QStringLiteral("content"), QStringLiteral("legacy-user")},
        {QStringLiteral("createdAt"), QStringLiteral("2026-07-17T10:00:00")},
    });
    messages.append(QJsonObject{
        {QStringLiteral("role"), QStringLiteral("assistant")},
        {QStringLiteral("content"), QStringLiteral("legacy-assistant")},
        {QStringLiteral("createdAt"), QStringLiteral("2026-07-17T10:00:01")},
    });
    QA_EXPECT(writeBytes(filePath, QJsonDocument(QJsonObject{{QStringLiteral("messages"), messages}}).toJson()));

    const QVector<ChatMessage> loaded = ConversationStore(filePath).load(10);
    QA_EXPECT_EQ(loaded.size(), 2);
    QA_EXPECT(loaded.first().timestamp.isValid());
    QA_EXPECT(loaded.first().provider.isEmpty());
}

QA_TEST(ConversationStore, BacksUpBrokenJsonAndClearsHistory)
{
    QTemporaryDir directory;
    QA_EXPECT(directory.isValid());
    const QString filePath = directory.filePath(QStringLiteral("conversation_history.json"));
    QA_EXPECT(writeBytes(filePath, QByteArrayLiteral("{broken")));

    QString errorMessage;
    const ConversationStore store(filePath);
    QA_EXPECT(store.load(10, &errorMessage).isEmpty());
    QA_EXPECT(!errorMessage.isEmpty());
    QA_EXPECT(!QFile::exists(filePath));
    QA_EXPECT_EQ(
        QDir(directory.path()).entryList({QStringLiteral("conversation_history.broken.*.json")}, QDir::Files).size(),
        1);

    QA_EXPECT(store.save({
        message(QStringLiteral("user"), QStringLiteral("hello"), 0),
        message(QStringLiteral("assistant"), QStringLiteral("world"), 1),
    }, 10));
    QA_EXPECT(store.clear());
    QA_EXPECT(!QFile::exists(filePath));
}