/*
 * MIT License
 *
 * Copyright (c) Robin E.R. Davies
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "pch.h"
#include "catch.hpp"
#include <cmath>
#include <mutex>
#include <iostream>
#include <algorithm>

#include "AlsaDriver.hpp"
#include "ChannelRouterSettings.hpp"

using namespace pipedal;
using namespace std;

class AlsaTester : private AudioDriverHost
{
public:
    enum class TestType
    {
        Oscillator,
        LatencyMonitor,
        NullTest
    };

private:
    AudioDriver *audioDriver = nullptr;
    TestType testType;

public:
    AlsaTester(TestType testType)
        : testType(testType)
    {
        // audioDriver = CreateAlsaDriver(this);
        // audioDriver = CreateJackDriver(this);
    }
    ~AlsaTester()
    {
        delete audioDriver;
        delete[] inputBuffers;
        delete[] outputBuffers;
    }

    bool OnRealtimeUpdateDeviceVus(size_t nFrames) override { return false; }

    void initializeChannelSelection(JackConfiguration &jackConfiguration, ChannelSelection &channelSelection)
    {
        size_t nInputs = std::max(jackConfiguration.inputAudioPorts().size(),size_t(2));
        size_t nOutputs = std::max(jackConfiguration.outputAudioPorts().size(),size_t(2));
        auto &inputSelections = channelSelection.mainInputChannels();
        auto &outputSelections = channelSelection.mainOutputChannels();
        inputSelections.resize(nInputs);
        for (size_t i = 0; i < nInputs; ++i)
        {
            inputSelections[i] = i;
        }
        outputSelections.resize(nOutputs);
        for (size_t i = 0; i < nOutputs; ++i)
        {
            outputSelections[i] = i;
        }

    }

    void Test()
    {

        test::AlsaFormatEncodeDecodeTest(this);

        JackServerSettings serverSettings("hw:M2","hw:M2", 48000, 32, 3);

        JackConfiguration jackConfiguration;
        jackConfiguration.AlsaInitialize(serverSettings);

        ChannelSelection channelSelection;

        audioDriver = CreateAlsaDriver(this);

        initializeChannelSelection(jackConfiguration, channelSelection);

        oscillator.Init(440, jackConfiguration.sampleRate());
        latencyMonitor.Init(jackConfiguration.sampleRate());
        audioDriver->Open(serverSettings, channelSelection);

        inputBuffers = new float *[channelSelection.mainInputChannels().size()];
        outputBuffers = new float *[channelSelection.mainOutputChannels().size()];

        audioDriver->Activate();

        for (int i = 0; i < 10; ++i)
        {
            sleep(1);
            if (testType == TestType::LatencyMonitor)
            {
                auto latency = this->latencyMonitor.GetLatency();
                double ms = 1000.0 * latency / jackConfiguration.sampleRate();

                cout << "Latency: " << latency << " samples " << ms << "ms" << " xruns: " << GetXruns() << " Cpu: " << audioDriver->CpuUse() << "%" << endl;
            }
        }

        audioDriver->Deactivate();
        audioDriver->Close();
    }

    float **inputBuffers = nullptr;
    float **outputBuffers = nullptr;

    class Oscillator
    {
    private:
        double dx = 0;
        double x = 0;
        double dx2 = 0;
        double x2 = 0;

    public:
        void Init(float frequency, size_t sampleRate)
        {
            dx = frequency * 3.141592736 * 2 / sampleRate;
            dx2 = 0.5 * 3.141592736 * 2 / sampleRate;
        }

        float Next()
        {
            float result = (float)std::cos(x);
            float env = (float)std::cos(x2);
            x += dx;
            x2 += dx2;
            return result * env;
        }
    };

    class LatencyMonitor
    {
        enum class State
        {
            Idle,
            Waiting,
        };
        State state = State::Idle;
        uint64_t t;
        uint64_t idle_samples;
        uint64_t waiting_samples;
        size_t current_latency = 0;
        size_t latency = 0;
        std::mutex sync;

    public:
        void Init(uint64_t sampleRate)
        {
            idle_samples = (uint64_t)sampleRate * 2;
            waiting_samples = (uint64_t)sampleRate * 2;

            state = State::Idle;
            t = idle_samples;
            latency = 0;
        }

        size_t GetLatency()
        {
            std::lock_guard lock{sync};
            return latency;
        }
        float Next(float input)
        {
            switch (state)
            {
            default:
            case State::Idle:
            {
                if (t-- == 0)
                {
                    state = State::Waiting;
                    current_latency = 0;
                }
                return 0.01;
            }
            break;
            case State::Waiting:
            {
                if (std::abs(input) > 0.1 || current_latency > 500)
                {
                    {
                        std::lock_guard lock{sync};
                        latency = current_latency;
                    }
                    state = State::Idle;
                    t = idle_samples;
                }
                else
                {
                    ++current_latency;
                }
                return current_latency < 100 ? 0.25 : 0.0;
            }
            break;
            }
        }
    };

    Oscillator oscillator;
    LatencyMonitor latencyMonitor;

    virtual void OnAudioTerminated()
    {
    }

    virtual void OnAlsaDriverStopped()
    {
    }
    virtual void OnProcess(size_t nFrames)
    {
        if (testType == TestType::NullTest)
            return;

        size_t inputs = audioDriver->MainInputBufferCount();
        size_t outputs = audioDriver->MainOutputBufferCount();

        for (size_t i = 0; i < inputs; ++i)
        {
            inputBuffers[i] = audioDriver->GetMainInputBuffer(i);
        }
        for (size_t i = 0; i < outputs; ++i)
        {
            outputBuffers[i] = audioDriver->GetMainOutputBuffer(i);
        }
        if (this->testType == TestType::Oscillator)
        {
            for (size_t i = 0; i < nFrames; ++i)
            {
                float v = oscillator.Next() * 0.25f;
                for (size_t c = 0; c < outputs; ++c)
                {
                    outputBuffers[c][i] = v;
                }
            }
        }
        else
        {
            for (size_t i = 0; i < nFrames; ++i)
            {
                float v = latencyMonitor.Next(inputBuffers[0][i]);
                for (size_t c = 0; c < outputs; ++c)
                {
                    outputBuffers[c][i] = v;
                }
            }
        }
    }
    std::mutex sync;
    uint64_t xruns;

    uint64_t GetXruns()
    {
        lock_guard lock{sync};
        return xruns;
    }
    virtual void OnUnderrun()
    {
        lock_guard lock{sync};
        ++xruns;
    }
};

TEST_CASE("alsa_test", "[alsa_test]")
{

    AlsaTester alsaDriver(AlsaTester::TestType::Oscillator);

    alsaDriver.Test();
}

TEST_CASE("alsa_midi_test", "[alsa_midi_test]")
{
    AlsaTester alsaDriver(AlsaTester::TestType::Oscillator);

    test::MidiDecoderTest();
}