/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
MidiKeyboardComponent::MidiKeyboardComponent (MidiKeyboardState& stateToUse, Orientation orientationToUse)
    : KeyboardComponentBase (orientationToUse), state (stateToUse)
{
    state.addListener (this);

    // initialise with a default set of qwerty key-mappings.
    const std::string_view keys { "awsedftgyhujkolp;" };

    for (const char& c : keys)
        setKeyPressForNote ({c, 0, 0}, (int) std::distance (keys.data(), &c));

    mouseOverNotes.insertMultiple (0, -1, 32);
    mouseDownNotes.insertMultiple (0, -1, 32);

    colourChanged();
    setWantsKeyboardFocus (true);

    startTimerHz (20);
}

MidiKeyboardComponent::~MidiKeyboardComponent()
{
    state.removeListener (this);
}

//==============================================================================
void MidiKeyboardComponent::setVelocity (float v, bool useMousePosition)
{
    velocity = v;
    useMousePositionForVelocity = useMousePosition;
}

//==============================================================================
void MidiKeyboardComponent::setMidiChannel (int midiChannelNumber)
{
    jassert (midiChannelNumber > 0 && midiChannelNumber <= 16);

    if (midiChannel != midiChannelNumber)
    {
        resetAnyKeysInUse();
        midiChannel = jlimit (1, 16, midiChannelNumber);
    }
}

void MidiKeyboardComponent::setMidiChannelsToDisplay (int midiChannelMask)
{
    midiInChannelMask = midiChannelMask;
    noPendingUpdates.store (false);
}

//==============================================================================
void MidiKeyboardComponent::clearKeyMappings()
{
    resetAnyKeysInUse();
    keyPressNotes.clear();
    keyPresses.clear();
}

void MidiKeyboardComponent::setKeyPressForNote (const KeyPress& key, int midiNoteOffsetFromC)
{
    removeKeyPressForNote (midiNoteOffsetFromC);

    keyPressNotes.add (midiNoteOffsetFromC);
    keyPresses.add (key);
}

void MidiKeyboardComponent::removeKeyPressForNote (int midiNoteOffsetFromC)
{
    for (int i = keyPressNotes.size(); --i >= 0;)
    {
        if (keyPressNotes.getUnchecked (i) == midiNoteOffsetFromC)
        {
            keyPressNotes.remove (i);
            keyPresses.remove (i);
        }
    }
}

void MidiKeyboardComponent::setKeyPressBaseOctave (int newOctaveNumber)
{
    jassert (newOctaveNumber >= 0 && newOctaveNumber <= 10);

    keyMappingOctave = newOctaveNumber;
}

//==============================================================================
void MidiKeyboardComponent::resetAnyKeysInUse()
{
    if (! keysPressed.isZero())
    {
        for (int i = 128; --i >= 0;)
            if (keysPressed[i])
                state.noteOff (midiChannel, i, 0.0f);

        keysPressed.clear();
    }

    for (int i = mouseDownNotes.size(); --i >= 0;)
    {
        auto noteDown = mouseDownNotes.getUnchecked (i);

        if (noteDown >= 0)
        {
            state.noteOff (midiChannel, noteDown, 0.0f);
            mouseDownNotes.set (i, -1);
        }

        mouseOverNotes.set (i, -1);
    }
}

void MidiKeyboardComponent::updateNoteUnderMouse (const MouseEvent& e, bool isDown)
{
    updateNoteUnderMouse (e.getEventRelativeTo (this).position, isDown, e.source.getIndex());
}

void MidiKeyboardComponent::updateNoteUnderMouse (Point<float> pos, bool isDown, int fingerNum)
{
    const auto noteInfo = getNoteAndVelocityAtPosition (pos);
    const auto newNote = noteInfo.note;
    const auto oldNote = mouseOverNotes.getUnchecked (fingerNum);
    const auto oldNoteDown = mouseDownNotes.getUnchecked (fingerNum);
    const auto eventVelocity = useMousePositionForVelocity ? noteInfo.velocity * velocity : velocity;

    if (oldNote != newNote)
    {
        repaintNote (oldNote);
        repaintNote (newNote);
        mouseOverNotes.set (fingerNum, newNote);
    }

    if (isDown)
    {
        if (newNote != oldNoteDown)
        {
            if (oldNoteDown >= 0)
            {
                mouseDownNotes.set (fingerNum, -1);

                if (! mouseDownNotes.contains (oldNoteDown))
                    state.noteOff (midiChannel, oldNoteDown, eventVelocity);
            }

            if (newNote >= 0 && ! mouseDownNotes.contains (newNote))
            {
                state.noteOn (midiChannel, newNote, eventVelocity);
                mouseDownNotes.set (fingerNum, newNote);
            }
        }
    }
    else if (oldNoteDown >= 0)
    {
        mouseDownNotes.set (fingerNum, -1);

        if (! mouseDownNotes.contains (oldNoteDown))
            state.noteOff (midiChannel, oldNoteDown, eventVelocity);
    }
}

void MidiKeyboardComponent::repaintNote (int noteNum)
{
    if (getRangeStart() <= noteNum && noteNum <= getRangeEnd())
        repaint (getRectangleForKey (noteNum).getSmallestIntegerContainer());
}


void MidiKeyboardComponent::mouseMove (const MouseEvent& e)
{
    updateNoteUnderMouse (e, false);
}

void MidiKeyboardComponent::mouseDrag (const MouseEvent& e)
{
    auto newNote = getNoteAndVelocityAtPosition (e.position).note;

    if (newNote >= 0 && mouseDraggedToKey (newNote, e))
        updateNoteUnderMouse (e, true);
}

void MidiKeyboardComponent::mouseDown (const MouseEvent& e)
{
    auto newNote = getNoteAndVelocityAtPosition (e.position).note;

    if (newNote >= 0 && mouseDownOnKey (newNote, e))
        updateNoteUnderMouse (e, true);
}

void MidiKeyboardComponent::mouseUp (const MouseEvent& e)
{
    updateNoteUnderMouse (e, false);

    auto note = getNoteAndVelocityAtPosition (e.position).note;

    if (note >= 0)
        mouseUpOnKey (note, e);
}

void MidiKeyboardComponent::mouseEnter (const MouseEvent& e)
{
    updateNoteUnderMouse (e, false);
}

void MidiKeyboardComponent::mouseExit (const MouseEvent& e)
{
    updateNoteUnderMouse (e, false);
}

void MidiKeyboardComponent::timerCallback()
{
    if (noPendingUpdates.exchange (true))
        return;

    for (auto i = getRangeStart(); i <= getRangeEnd(); ++i)
    {
        const auto isOn = state.isNoteOnForChannels (midiInChannelMask, i);

        if (keysCurrentlyDrawnDown[i] != isOn)
        {
            keysCurrentlyDrawnDown.setBit (i, isOn);
            repaintNote (i);
        }
    }
}

bool MidiKeyboardComponent::keyStateChanged (bool /*isKeyDown*/)
{
    bool keyPressUsed = false;

    for (int i = keyPresses.size(); --i >= 0;)
    {
        auto note = 12 * keyMappingOctave + keyPressNotes.getUnchecked (i);

        if (keyPresses.getReference (i).isCurrentlyDown())
        {
            if (! keysPressed[note])
            {
                keysPressed.setBit (note);
                state.noteOn (midiChannel, note, velocity);
                keyPressUsed = true;
            }
        }
        else
        {
            if (keysPressed[note])
            {
                keysPressed.clearBit (note);
                state.noteOff (midiChannel, note, 0.0f);
                keyPressUsed = true;
            }
        }
    }

    return keyPressUsed;
}

bool MidiKeyboardComponent::keyPressed (const KeyPress& key)
{
    return keyPresses.contains (key);
}

void MidiKeyboardComponent::focusLost (FocusChangeType)
{
    resetAnyKeysInUse();
}

//==============================================================================
void MidiKeyboardComponent::drawKeyboardBackground (Graphics& g, Rectangle<float> area)
{
    g.fillAll (findColour (whiteNoteColourId));

    auto width = area.getWidth();
    auto height = area.getHeight();
    auto currentOrientation = getOrientation();
    Point<float> shadowGradientStart, shadowGradientEnd;

    if (currentOrientation == verticalKeyboardFacingLeft)
    {
        shadowGradientStart.x = width - 1.0f;
        shadowGradientEnd.x   = width - 5.0f;
    }
    else if (currentOrientation == verticalKeyboardFacingRight)
    {
        shadowGradientEnd.x = 5.0f;
    }
    else
    {
        shadowGradientEnd.y = 5.0f;
    }

    auto keyboardWidth = getRectangleForKey (getRangeEnd()).getRight();
    auto shadowColour = findColour (shadowColourId);

    if (! shadowColour.isTransparent())
    {
        g.setGradientFill ({ shadowColour, shadowGradientStart,
                             shadowColour.withAlpha (0.0f), shadowGradientEnd,
                             false });

        switch (currentOrientation)
        {
            case horizontalKeyboard:            g.fillRect (0.0f, 0.0f, keyboardWidth, 5.0f); break;
            case verticalKeyboardFacingLeft:    g.fillRect (width - 5.0f, 0.0f, 5.0f, keyboardWidth); break;
            case verticalKeyboardFacingRight:   g.fillRect (0.0f, 0.0f, 5.0f, keyboardWidth); break;
            default: break;
        }
    }

    auto lineColour = findColour (keySeparatorLineColourId);

    if (! lineColour.isTransparent())
    {
        g.setColour (lineColour);

        switch (currentOrientation)
        {
            case horizontalKeyboard:            g.fillRect (0.0f, height - 1.0f, keyboardWidth, 1.0f); break;
            case verticalKeyboardFacingLeft:    g.fillRect (0.0f, 0.0f, 1.0f, keyboardWidth); break;
            case verticalKeyboardFacingRight:   g.fillRect (width - 1.0f, 0.0f, 1.0f, keyboardWidth); break;
            default: break;
        }
    }
}

void MidiKeyboardComponent::drawWhiteNote (int midiNoteNumber, Graphics& g, Rectangle<float> area,
                                           bool isDown, bool isOver, Colour lineColour, Colour textColour)
{
    auto c = Colours::transparentWhite;

    if (isDown)  c = findColour (keyDownOverlayColourId);
    if (isOver)  c = c.overlaidWith (findColour (mouseOverKeyOverlayColourId));

    g.setColour (c);
    g.fillRect (area);

    const auto currentOrientation = getOrientation();

    auto text = getWhiteNoteText (midiNoteNumber);

    if (text.isNotEmpty())
    {
        auto fontHeight = jmin (12.0f, getKeyWidth() * 0.9f);

        g.setColour (textColour);
        g.setFont (withDefaultMetrics (FontOptions { fontHeight }).withHorizontalScale (0.8f));

        switch (currentOrientation)
        {
            case horizontalKeyboard:            g.drawText (text, area.withTrimmedLeft (1.0f).withTrimmedBottom (2.0f), Justification::centredBottom, false); break;
            case verticalKeyboardFacingLeft:    g.drawText (text, area.reduced (2.0f), Justification::centredLeft,   false); break;
            case verticalKeyboardFacingRight:   g.drawText (text, area.reduced (2.0f), Justification::centredRight,  false); break;
            default: break;
        }
    }

    if (! lineColour.isTransparent())
    {
        g.setColour (lineColour);

        switch (currentOrientation)
        {
            case horizontalKeyboard:            g.fillRect (area.withWidth (1.0f)); break;
            case verticalKeyboardFacingLeft:    g.fillRect (area.withHeight (1.0f)); break;
            case verticalKeyboardFacingRight:   g.fillRect (area.removeFromBottom (1.0f)); break;
            default: break;
        }

        if (midiNoteNumber == getRangeEnd())
        {
            switch (currentOrientation)
            {
                case horizontalKeyboard:            g.fillRect (area.expanded (1.0f, 0).removeFromRight (1.0f)); break;
                case verticalKeyboardFacingLeft:    g.fillRect (area.expanded (0, 1.0f).removeFromBottom (1.0f)); break;
                case verticalKeyboardFacingRight:   g.fillRect (area.expanded (0, 1.0f).removeFromTop (1.0f)); break;
                default: break;
            }
        }
    }
}

void MidiKeyboardComponent::drawBlackNote (int /*midiNoteNumber*/, Graphics& g, Rectangle<float> area,
                                           bool isDown, bool isOver, Colour noteFillColour)
{
    auto c = noteFillColour;

    if (isDown)  c = c.overlaidWith (findColour (keyDownOverlayColourId));
    if (isOver)  c = c.overlaidWith (findColour (mouseOverKeyOverlayColourId));

    g.setColour (c);
    g.fillRect (area);

    if (isDown)
    {
        g.setColour (noteFillColour);
        g.drawRect (area);
    }
    else
    {
        g.setColour (c.brighter());
        auto sideIndent = 1.0f / 8.0f;
        auto topIndent = 7.0f / 8.0f;
        auto w = area.getWidth();
        auto h = area.getHeight();

        switch (getOrientation())
        {
            case horizontalKeyboard:            g.fillRect (area.reduced (w * sideIndent, 0).removeFromTop   (h * topIndent)); break;
            case verticalKeyboardFacingLeft:    g.fillRect (area.reduced (0, h * sideIndent).removeFromRight (w * topIndent)); break;
            case verticalKeyboardFacingRight:   g.fillRect (area.reduced (0, h * sideIndent).removeFromLeft  (w * topIndent)); break;
            default: break;
        }
    }
}

String MidiKeyboardComponent::getWhiteNoteText (int midiNoteNumber)
{
    if (midiNoteNumber % 12 == 0)
        return MidiMessage::getMidiNoteName (midiNoteNumber, true, true, getOctaveForMiddleC());

    return {};
}

void MidiKeyboardComponent::colourChanged()
{
    setOpaque (findColour (whiteNoteColourId).isOpaque());
    repaint();
}

//==============================================================================
void MidiKeyboardComponent::drawWhiteKey (int midiNoteNumber, Graphics& g, Rectangle<float> area)
{
    drawWhiteNote (midiNoteNumber, g, area, state.isNoteOnForChannels (midiInChannelMask, midiNoteNumber),
                   mouseOverNotes.contains (midiNoteNumber), findColour (keySeparatorLineColourId), findColour (textLabelColourId));
}

void MidiKeyboardComponent::drawBlackKey (int midiNoteNumber, Graphics& g, Rectangle<float> area)
{
    drawBlackNote (midiNoteNumber, g, area, state.isNoteOnForChannels (midiInChannelMask, midiNoteNumber),
                   mouseOverNotes.contains (midiNoteNumber), findColour (blackNoteColourId));
}

//==============================================================================
void MidiKeyboardComponent::handleNoteOn (MidiKeyboardState*, int /*midiChannel*/, int /*midiNoteNumber*/, float /*velocity*/)
{
    noPendingUpdates.store (false);
}

void MidiKeyboardComponent::handleNoteOff (MidiKeyboardState*, int /*midiChannel*/, int /*midiNoteNumber*/, float /*velocity*/)
{
    noPendingUpdates.store (false);
}

//==============================================================================
bool MidiKeyboardComponent::mouseDownOnKey    ([[maybe_unused]] int midiNoteNumber, [[maybe_unused]] const MouseEvent& e)  { return true; }
bool MidiKeyboardComponent::mouseDraggedToKey ([[maybe_unused]] int midiNoteNumber, [[maybe_unused]] const MouseEvent& e)  { return true; }
void MidiKeyboardComponent::mouseUpOnKey      ([[maybe_unused]] int midiNoteNumber, [[maybe_unused]] const MouseEvent& e)  {}

} // namespace juce
