#include <QtTest>

#include <string>
#include <vector>

#include "fakeasr.h"
#include "streamingasr.h"

namespace {

std::vector<float> chunk(size_t samples, float value = 0.1f)
{
    return std::vector<float>(samples, value);
}

QString q(const std::string & s) { return QString::fromStdString(s); }

} // namespace

// 流式策略的回归测试（用 FakeAsr，不加载真模型）。
class TstStreamingAsr : public QObject {
    Q_OBJECT

private:
    static lc::StreamOptions baseOptions()
    {
        lc::StreamOptions o;
        o.chunkSec        = 1.0;   // 1s 一块，方便构造
        o.unfixedTokenNum = 1;     // 回滚 1 个 token，断言更直观
        o.unfixedChunkNum = 0;     // 默认就回喂前缀
        o.incremental     = true;
        return o;
    }

private slots:
    // 冷启动阶段（前 unfixedChunkNum 块）不回喂前缀
    void coldStartHasNoPrefix()
    {
        FakeAsr fake;
        fake.scripted = {"a b c d", "e f", "g h"};

        lc::StreamOptions o = baseOptions();
        o.unfixedChunkNum = 2;

        lc::StreamingAsr stream(fake, o);
        const auto cb = [](const lc::StreamingAsr::Step &) {};

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);
        stream.feed(c.data(), c.size(), cb);
        stream.feed(c.data(), c.size(), cb);

        QCOMPARE(fake.prefixesSeen.size(), size_t(3));
        QCOMPARE(q(fake.prefixesSeen[0]), QString(""));
        QCOMPARE(q(fake.prefixesSeen[1]), QString(""));
        QVERIFY(!fake.prefixesSeen[2].empty());
    }

    // 续写开头那个空格不能被吃掉。
    // 曾经用 trim 过的文本去拼接，导致 "potatoesand" 这种缺空格。
    void keepsJoiningSpace()
    {
        FakeAsr fake;
        fake.scripted = {"language English<asr_text>He hoped there",
                         " would be stew"};

        lc::StreamingAsr stream(fake, baseOptions());

        std::vector<lc::StreamingAsr::Step> steps;
        const auto cb = [&steps](const lc::StreamingAsr::Step & s) { steps.push_back(s); };

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);
        stream.feed(c.data(), c.size(), cb);

        QCOMPARE(steps.size(), size_t(2));
        QCOMPARE(q(steps[0].full), QString("He hoped there"));
        QVERIFY2(q(steps[1].full) == QString("He hoped would be stew"),
                 qPrintable(QString("实际为 \"%1\"").arg(q(steps[1].full))));
    }

    // 已提交文本 = 完整文本去掉最后 unfixedTokenNum 个 token；
    // 尾部单独作为不稳定部分给出。
    void committedDropsUnstableTail()
    {
        FakeAsr fake;
        fake.scripted = {"language English<asr_text>He hoped there",
                         " would be stew"};

        lc::StreamingAsr stream(fake, baseOptions());
        std::vector<lc::StreamingAsr::Step> steps;
        const auto cb = [&steps](const lc::StreamingAsr::Step & s) { steps.push_back(s); };

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);
        stream.feed(c.data(), c.size(), cb);

        QCOMPARE(q(steps[1].committed), QString("He hoped would be"));
        QCOMPARE(q(steps[1].tail), QString(" stew"));
        // 已提交 + 尾部 = 完整文本
        QCOMPARE(q(steps[1].committed + steps[1].tail), q(steps[1].full));
    }

    // 流结束时要全部提交，不能把尾部丢掉
    void flushCommitsEverything()
    {
        FakeAsr fake;
        fake.scripted = {"language English<asr_text>one two three"};

        lc::StreamOptions o = baseOptions();
        o.chunkSec = 100.0;   // 特意设大：让音频留在 pending 里，由 flush 处理
        lc::StreamingAsr stream(fake, o);

        std::vector<lc::StreamingAsr::Step> steps;
        const auto cb = [&steps](const lc::StreamingAsr::Step & s) { steps.push_back(s); };

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);
        QCOMPARE(steps.size(), size_t(0));   // 还没凑够一块

        stream.flush(cb);
        QCOMPARE(steps.size(), size_t(1));
        QCOMPARE(q(steps[0].committed), QString("one two three"));
        QVERIFY(steps[0].tail.empty());
    }

    // 多段：每段各自的 language 头都要剥掉，前面几段的正文不能丢。
    // 曾经用整段拼接后再解析，rfind 只保留最后一个头之后的内容，前面的正文全没了。
    void segmentsAccumulateWithoutLosingEarlierText()
    {
        FakeAsr fake;
        fake.scripted = {"language Chinese<asr_text>ni hao shi jie",
                         " language English<asr_text> hello there world"};

        lc::StreamOptions o = baseOptions();
        o.chunkSec = 1.0;

        lc::StreamingAsr stream(fake, o);
        const auto cb = [](const lc::StreamingAsr::Step &) {};

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);   // 第 1 段
        stream.flush(cb);                      // 收束第 1 段

        stream.feed(c.data(), c.size(), cb);   // 第 2 段
        stream.flush(cb);

        const QString all = q(stream.committedText());
        QVERIFY2(all.contains("ni hao"), qPrintable(all));
        QVERIFY2(all.contains("hello there world"), qPrintable(all));
    }

    // 追加式：每块音频作为新一轮追加，文本立即定稿，不回喂任何前缀
    void appendModeCommitsEachChunkImmediately()
    {
        FakeAsr fake;
        fake.scripted = {"language English<asr_text>one two",
                         " language English<asr_text> three four"};

        lc::StreamOptions o = baseOptions();
        o.appendOnly = true;

        lc::StreamingAsr stream(fake, o);
        std::vector<lc::StreamingAsr::Step> steps;
        const auto cb = [&steps](const lc::StreamingAsr::Step & s) { steps.push_back(s); };

        const auto c = chunk(16000);
        stream.feed(c.data(), c.size(), cb);
        stream.feed(c.data(), c.size(), cb);

        QCOMPARE(fake.turnsSeen.size(), size_t(2));
        QVERIFY2(fake.prefixesSeen.empty(), "追加式不应该回喂前缀");

        QCOMPARE(steps.size(), size_t(2));
        QCOMPARE(q(steps[0].committed), QString("one two"));
        QVERIFY(steps[0].tail.empty());                  // 追加式没有"不稳定尾部"
        QVERIFY(q(steps[1].committed).contains("three four"));
    }

    // 同一次 feed 里跨多块也要正确切分
    void splitsMultipleChunksInOneFeed()
    {
        FakeAsr fake;
        fake.scripted = {"a b c", "d e f", "g h i"};

        lc::StreamOptions o = baseOptions();
        lc::StreamingAsr stream(fake, o);
        int steps = 0;
        const auto cb = [&steps](const lc::StreamingAsr::Step &) { ++steps; };

        const auto c = chunk(16000 * 3);
        stream.feed(c.data(), c.size(), cb);

        QCOMPARE(steps, 3);
        QCOMPARE(fake.samplesSeen.size(), size_t(3));
        for (size_t n : fake.samplesSeen) QCOMPARE(n, size_t(16000));
    }
};

QTEST_MAIN(TstStreamingAsr)
#include "tst_streamingasr.moc"