//
// Created by Alex Birch on 10/09/2017.
//

#include <iostream>
#include "FluidSynthModel.h"
#include "MidiConstants.h"

using namespace std;

FluidSynthModel::FluidSynthModel(SharesParams& p)
        : sharesParams(p),
          synth(nullptr),
          settings(nullptr),
          currentSoundFontAbsPath(),
          currentSampleRate(44100),
          initialised(false),
          sfont_id(0),
          channel(0)/*,
          mod(nullptr)*/

{}

FluidSynthModel::~FluidSynthModel() {
    if (initialised) {
//        delete_fluid_audio_driver(driver);
        delete_fluid_synth(synth);
        delete_fluid_settings(settings);
//        delete driver;
//        delete settings;
//        delete_fluid_mod(mod);
    }
}

void FluidSynthModel::initialise() {
//    if (initialised) {
//        delete_fluid_synth(synth);
//        delete_fluid_settings(settings);
//    }
    // deactivate all audio drivers in fluidsynth to avoid FL Studio deadlock when initialising CoreAudio
    // after all: we only use fluidsynth to render blocks of audio. it doesn't output to audio driver.
    const char *DRV[] = {NULL};
    fluid_audio_driver_register(DRV);

    settings = new_fluid_settings();
    // https://sourceforge.net/p/fluidsynth/wiki/FluidSettings/
    fluid_settings_setint(settings, "synth.verbose", 1);

    synth = new_fluid_synth(settings);
    fluid_synth_set_sample_rate(synth, currentSampleRate);

    if (sharesParams.getSoundFontPath().isNotEmpty()) {
        loadFont(sharesParams.getSoundFontPath());
        changePreset(sharesParams.getBank(), sharesParams.getPreset());
    }

    fluid_synth_set_gain(synth, 2.0);
    
    for(int i{SOUND_CTRL1}; i <= SOUND_CTRL10; i++)
    {
        fluid_midi_event_t *midi_event(new_fluid_midi_event());
        fluid_midi_event_set_type(midi_event, static_cast<int>(CONTROL_CHANGE));
        fluid_midi_event_set_channel(midi_event, channel);
        fluid_midi_event_set_control(midi_event, i);
        fluid_midi_event_set_value(midi_event, 0);
        fluid_synth_handle_midi_event(synth, midi_event);
        delete_fluid_midi_event(midi_event);
//        fluid_channel_set_cc(channel, i, 0);
    }

//    fluid_synth_bank_select(synth, 0, 3);

//    fluid_handle_inst

//    driver = new_fluid_audio_driver(settings, synth);

//    changePreset(128, 13);
    
//    float env_amount(12000.0f);
    
//     http://www.synthfont.com/SoundFont_NRPNs.PDF
    float env_amount(20000.0f);
//    float env_amount(24000.0f);
    
    // note: fluid_chan.c#fluid_channel_init_ctrl()
    // all SOUND_CTRL are inited with value of 64, not zero.
    // "Just like panning, a value of 64 indicates no change for sound ctrls"
    
    fluid_mod_t *mod(new_fluid_mod());
//
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL2), // MIDI CC 71 Timbre/Harmonic Intensity (filter resonance)
                          FLUID_MOD_CC
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_CONCAVE
                          | FLUID_MOD_POSITIVE);
    fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_FILTERQ);
    fluid_mod_set_amount(mod, FLUID_PEAK_ATTENUATION);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);
    
    mod = new_fluid_mod();
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL3), // MIDI CC 72 Release time
                          FLUID_MOD_CC
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_LINEAR
                          | FLUID_MOD_POSITIVE);
    fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_VOLENVRELEASE);
//    fluid_mod_set_amount(mod, 15200.0f);
    fluid_mod_set_amount(mod, env_amount);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);
    
    mod = new_fluid_mod();
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL4), // MIDI CC 73 Attack time
                          FLUID_MOD_CC
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_LINEAR
                          | FLUID_MOD_POSITIVE);
    fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_VOLENVATTACK);
    fluid_mod_set_amount(mod, env_amount);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);
    
    // soundfont spec says that if cutoff is >20kHz and resonance Q is 0, then no filtering occurs
    mod = new_fluid_mod();
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL5), // MIDI CC 74 Brightness (cutoff frequency, FILTERFC)
                          FLUID_MOD_CC
                          | FLUID_MOD_LINEAR
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_POSITIVE);
        fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_FILTERFC);
    fluid_mod_set_amount(mod, -2400.0f);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);
    
    mod = new_fluid_mod();
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL6), // MIDI CC 75 Decay Time
                          FLUID_MOD_CC
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_LINEAR
                          | FLUID_MOD_POSITIVE);
    fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_VOLENVDECAY);
    fluid_mod_set_amount(mod, env_amount);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);
    
    mod = new_fluid_mod();
    fluid_mod_set_source1(mod,
                          static_cast<int>(SOUND_CTRL10), // MIDI CC 79 undefined
                          FLUID_MOD_CC
                          | FLUID_MOD_UNIPOLAR
                          | FLUID_MOD_LINEAR
                          | FLUID_MOD_POSITIVE);
    fluid_mod_set_source2(mod, 0, 0);
    fluid_mod_set_dest(mod, GEN_VOLENVSUSTAIN);
    // fluice_voice.c#fluid_voice_update_param()
    // clamps the range to between 0 and 1000, so we'll copy that
    fluid_mod_set_amount(mod, 1000.0f);
    fluid_synth_add_default_mod(synth, mod, FLUID_SYNTH_ADD);
    delete_fluid_mod(mod);

    initialised = true;
}

int FluidSynthModel::getChannel() {
    return channel;
}

void FluidSynthModel::changePreset(int bank, int preset) {
    if (bank == -1 || preset == -1) {
        unique_ptr<BankAndPreset> bankAndPreset = getFirstBankAndPreset();
        bank = bankAndPreset->getBank();
        preset = bankAndPreset->getPreset();
    }
    changePresetImpl(bank, preset);
    sharesParams.setPreset(preset);
    sharesParams.setBank(bank);
}

void FluidSynthModel::changePresetImpl(int bank, int preset) {
    fluid_synth_program_select(synth, channel, sfont_id, static_cast<unsigned int>(bank), static_cast<unsigned int>(preset));
}

fluid_preset_t* FluidSynthModel::getFirstPreset() {
    fluid_sfont_t* sfont = fluid_synth_get_sfont_by_id(synth, sfont_id);

    jassert(sfont != nullptr);
    fluid_sfont_iteration_start(sfont);

    return fluid_sfont_iteration_next(sfont);
}

unique_ptr<BankAndPreset> FluidSynthModel::getFirstBankAndPreset() {
    fluid_preset_t* preset = getFirstPreset();

    int offset = fluid_synth_get_bank_offset(synth, sfont_id);

    return make_unique<BankAndPreset>(fluid_preset_get_banknum(preset) + offset, fluid_preset_get_num(preset));
};

void FluidSynthModel::selectFirstPreset() {
    fluid_preset_t* preset = getFirstPreset();

    int offset = fluid_synth_get_bank_offset(synth, sfont_id);

    changePreset(fluid_preset_get_banknum(preset) + offset, fluid_preset_get_num(preset));
}

BanksToPresets FluidSynthModel::getBanks() {
    BanksToPresets banksToPresets;

    int soundfontCount = fluid_synth_sfcount(synth);

    if (soundfontCount == 0) {
        // no soundfont selected
        return banksToPresets;
    }

    fluid_sfont_t* sfont = fluid_synth_get_sfont_by_id(synth, sfont_id);
    if(sfont == nullptr) {
        // no soundfont found by that ID
        // the above guard (soundfontCount) protects us for the
        // main case we're expecting. this guard is just defensive programming.
        return banksToPresets;
    }

    int offset = fluid_synth_get_bank_offset(synth, sfont_id);

    fluid_sfont_iteration_start(sfont);

    for(fluid_preset_t* preset = fluid_sfont_iteration_next(sfont);
    preset != nullptr;
    preset = fluid_sfont_iteration_next(sfont)) {
        banksToPresets.insert(BanksToPresets::value_type(
                fluid_preset_get_banknum(preset) + offset,
                *new Preset(
                        fluid_preset_get_num(preset),
                        fluid_preset_get_name(preset)
                )
        ));
    }

    return banksToPresets;
}

fluid_synth_t* FluidSynthModel::getSynth() {
    // https://msdn.microsoft.com/en-us/library/hh279669.aspx
    // You can pass a shared_ptr to another function in the following ways:
    // Pass the shared_ptr by value. This invokes the copy constructor, increments the reference count, and makes the callee an owner.
    return synth;
}

void FluidSynthModel::onFileNameChanged(const String &absPath, int bank, int preset) {
    if (!shouldLoadFont(absPath)) {
        return;
    }
    unloadAndLoadFont(absPath);
    changePreset(bank, preset);
    sharesParams.setSoundFontPath(absPath);
    eventListeners.call(&FluidSynthModel::Listener::fontChanged, this, absPath);
}

void FluidSynthModel::unloadAndLoadFont(const String &absPath) {
    // in the base case, there is no font loaded
    if (fluid_synth_sfcount(synth) > 0) {
        fluid_synth_sfunload(synth, sfont_id, 1);
    }
    loadFont(absPath);
}

void FluidSynthModel::loadFont(const String &absPath) {
    currentSoundFontAbsPath = absPath;
    sfont_id++;
    fluid_synth_sfload(synth, absPath.toStdString().c_str(), 1);
}

FluidSynthModel::Listener::~Listener() {
}

bool FluidSynthModel::shouldLoadFont(const String &absPath) {
    if (absPath.isEmpty()) {
        return false;
    }
    if (absPath == currentSoundFontAbsPath) {
        return false;
    }
    return true;
}

void FluidSynthModel::Listener::fontChanged(FluidSynthModel * model, const String &absPath) {
}

const String& FluidSynthModel::getCurrentSoundFontAbsPath() {
    return currentSoundFontAbsPath;
}

//==============================================================================
void FluidSynthModel::addListener (FluidSynthModel::Listener* const newListener)
{
    eventListeners.add(newListener);
}

void FluidSynthModel::removeListener (FluidSynthModel::Listener* const listener)
{
    eventListeners.remove(listener);
}

void FluidSynthModel::setSampleRate(float sampleRate) {
    currentSampleRate = sampleRate;
    if (!initialised) {
        // don't worry; we'll do this in initialise phase regardless
        return;
    }
    fluid_synth_set_sample_rate(synth, sampleRate);
}