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

   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
{

constexpr uint8 whiteNotes[] = { 0, 2, 4, 5, 7, 9, 11 };
constexpr uint8 blackNotes[] = { 1, 3, 6, 8, 10 };

//==============================================================================
struct KeyboardComponentBase::UpDownButton final : public Button
{
    UpDownButton (KeyboardComponentBase& c, int d)
        : Button ({}), owner (c), delta (d)
    {
    }

    void clicked() override
    {
        auto note = owner.getLowestVisibleKey();

        note = delta < 0 ? (note - 1) / 12 : note / 12 + 1;

        owner.setLowestVisibleKey (note * 12);
    }

    using Button::clicked;

    void paintButton (Graphics& g, bool shouldDrawButtonAsHighlighted, bool shouldDrawButtonAsDown) override
    {
        owner.drawUpDownButton (g, getWidth(), getHeight(),
                                shouldDrawButtonAsHighlighted, shouldDrawButtonAsDown,
                                delta > 0);
    }

private:
    KeyboardComponentBase& owner;
    int delta;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UpDownButton)
};

//==============================================================================
KeyboardComponentBase::KeyboardComponentBase (Orientation o)  : orientation (o)
{
    scrollDown = std::make_unique<UpDownButton> (*this, -1);
    scrollUp   = std::make_unique<UpDownButton> (*this, 1);

    addChildComponent (*scrollDown);
    addChildComponent (*scrollUp);

    colourChanged();
}

//==============================================================================
void KeyboardComponentBase::setKeyWidth (float widthInPixels)
{
    jassert (widthInPixels > 0);

    if (! approximatelyEqual (keyWidth, widthInPixels)) // Prevent infinite recursion if the width is being computed in a 'resized()' callback
    {
        keyWidth = widthInPixels;
        resized();
    }
}

void KeyboardComponentBase::setScrollButtonWidth (int widthInPixels)
{
    jassert (widthInPixels > 0);

    if (scrollButtonWidth != widthInPixels)
    {
        scrollButtonWidth = widthInPixels;
        resized();
    }
}

void KeyboardComponentBase::setOrientation (Orientation newOrientation)
{
    if (orientation != newOrientation)
    {
        orientation = newOrientation;
        resized();
    }
}

void KeyboardComponentBase::setAvailableRange (int lowestNote, int highestNote)
{
    jassert (lowestNote >= 0 && lowestNote <= 127);
    jassert (highestNote >= 0 && highestNote <= 127);
    jassert (lowestNote <= highestNote);

    if (rangeStart != lowestNote || rangeEnd != highestNote)
    {
        rangeStart = jlimit (0, 127, lowestNote);
        rangeEnd = jlimit (0, 127, highestNote);
        firstKey = jlimit ((float) rangeStart, (float) rangeEnd, firstKey);
        resized();
    }
}

void KeyboardComponentBase::setLowestVisibleKey (int noteNumber)
{
    setLowestVisibleKeyFloat ((float) noteNumber);
}

void KeyboardComponentBase::setLowestVisibleKeyFloat (float noteNumber)
{
    noteNumber = jlimit ((float) rangeStart, (float) rangeEnd, noteNumber);

    if (! approximatelyEqual (noteNumber, firstKey))
    {
        bool hasMoved = (((int) firstKey) != (int) noteNumber);
        firstKey = noteNumber;

        if (hasMoved)
            sendChangeMessage();

        resized();
    }
}

float KeyboardComponentBase::getWhiteNoteLength() const noexcept
{
    return (orientation == horizontalKeyboard) ? (float) getHeight() : (float) getWidth();
}

void KeyboardComponentBase::setBlackNoteLengthProportion (float ratio) noexcept
{
    jassert (ratio >= 0.0f && ratio <= 1.0f);

    if (! approximatelyEqual (blackNoteLengthRatio, ratio))
    {
        blackNoteLengthRatio = ratio;
        resized();
    }
}

float KeyboardComponentBase::getBlackNoteLength() const noexcept
{
    auto whiteNoteLength = orientation == horizontalKeyboard ? getHeight() : getWidth();
    return (float) whiteNoteLength * blackNoteLengthRatio;
}

void KeyboardComponentBase::setBlackNoteWidthProportion (float ratio) noexcept
{
    jassert (ratio >= 0.0f && ratio <= 1.0f);

    if (! approximatelyEqual (blackNoteWidthRatio, ratio))
    {
        blackNoteWidthRatio = ratio;
        resized();
    }
}

void KeyboardComponentBase::setScrollButtonsVisible (bool newCanScroll)
{
    if (canScroll != newCanScroll)
    {
        canScroll = newCanScroll;
        resized();
    }
}

//==============================================================================
Range<float> KeyboardComponentBase::getKeyPos (int midiNoteNumber) const
{
    return getKeyPosition (midiNoteNumber, keyWidth)
             - xOffset
             - getKeyPosition (rangeStart, keyWidth).getStart();
}

float KeyboardComponentBase::getKeyStartPosition (int midiNoteNumber) const
{
    return getKeyPos (midiNoteNumber).getStart();
}

float KeyboardComponentBase::getTotalKeyboardWidth() const noexcept
{
    return getKeyPos (rangeEnd).getEnd();
}

KeyboardComponentBase::NoteAndVelocity KeyboardComponentBase::getNoteAndVelocityAtPosition (Point<float> pos, bool children)
{
    if (! reallyContains (pos, children))
        return { -1, 0.0f };

    auto p = pos;

    if (orientation != horizontalKeyboard)
    {
        p = { p.y, p.x };

        if (orientation == verticalKeyboardFacingLeft)
            p = { p.x, (float) getWidth() - p.y };
        else
            p = { (float) getHeight() - p.x, p.y };
    }

    return remappedXYToNote (p + Point<float> (xOffset, 0));
}

KeyboardComponentBase::NoteAndVelocity KeyboardComponentBase::remappedXYToNote (Point<float> pos) const
{
    auto blackNoteLength = getBlackNoteLength();

    if (pos.getY() < blackNoteLength)
    {
        for (int octaveStart = 12 * (rangeStart / 12); octaveStart <= rangeEnd; octaveStart += 12)
        {
            for (int i = 0; i < 5; ++i)
            {
                auto note = octaveStart + blackNotes[i];

                if (rangeStart <= note && note <= rangeEnd)
                {
                    if (getKeyPos (note).contains (pos.x - xOffset))
                    {
                        return { note, jmax (0.0f, pos.y / blackNoteLength) };
                    }
                }
            }
        }
    }

    for (int octaveStart = 12 * (rangeStart / 12); octaveStart <= rangeEnd; octaveStart += 12)
    {
        for (int i = 0; i < 7; ++i)
        {
            auto note = octaveStart + whiteNotes[i];

            if (note >= rangeStart && note <= rangeEnd)
            {
                if (getKeyPos (note).contains (pos.x - xOffset))
                {
                    auto whiteNoteLength = (orientation == horizontalKeyboard) ? getHeight() : getWidth();
                    return { note, jmax (0.0f, pos.y / (float) whiteNoteLength) };
                }
            }
        }
    }

    return { -1, 0 };
}

Rectangle<float> KeyboardComponentBase::getRectangleForKey (int note) const
{
    jassert (note >= rangeStart && note <= rangeEnd);

    auto pos = getKeyPos (note);
    auto x = pos.getStart();
    auto w = pos.getLength();

    if (MidiMessage::isMidiNoteBlack (note))
    {
        auto blackNoteLength = getBlackNoteLength();

        switch (orientation)
        {
            case horizontalKeyboard:            return { x, 0, w, blackNoteLength };
            case verticalKeyboardFacingLeft:    return { (float) getWidth() - blackNoteLength, x, blackNoteLength, w };
            case verticalKeyboardFacingRight:   return { 0, (float) getHeight() - x - w, blackNoteLength, w };
            default:                            jassertfalse; break;
        }
    }
    else
    {
        switch (orientation)
        {
            case horizontalKeyboard:            return { x, 0, w, (float) getHeight() };
            case verticalKeyboardFacingLeft:    return { 0, x, (float) getWidth(), w };
            case verticalKeyboardFacingRight:   return { 0, (float) getHeight() - x - w, (float) getWidth(), w };
            default:                            jassertfalse; break;
        }
    }

    return {};
}

//==============================================================================
void KeyboardComponentBase::setOctaveForMiddleC (int octaveNum)
{
    octaveNumForMiddleC = octaveNum;
    repaint();
}

//==============================================================================
void KeyboardComponentBase::drawUpDownButton (Graphics& g, int w, int h, bool mouseOver, bool buttonDown, bool movesOctavesUp)
{
    g.fillAll (findColour (upDownButtonBackgroundColourId));

    float angle = 0;

    switch (getOrientation())
    {
        case horizontalKeyboard:            angle = movesOctavesUp ? 0.0f  : 0.5f;  break;
        case verticalKeyboardFacingLeft:    angle = movesOctavesUp ? 0.25f : 0.75f; break;
        case verticalKeyboardFacingRight:   angle = movesOctavesUp ? 0.75f : 0.25f; break;
        default:                            jassertfalse; break;
    }

    Path path;
    path.addTriangle (0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.5f);
    path.applyTransform (AffineTransform::rotation (MathConstants<float>::twoPi * angle, 0.5f, 0.5f));

    g.setColour (findColour (upDownButtonArrowColourId)
                  .withAlpha (buttonDown ? 1.0f : (mouseOver ? 0.6f : 0.4f)));

    g.fillPath (path, path.getTransformToScaleToFit (1.0f, 1.0f, (float) w - 2.0f, (float) h - 2.0f, true));
}

Range<float> KeyboardComponentBase::getKeyPosition (int midiNoteNumber, float targetKeyWidth) const
{
    auto ratio = getBlackNoteWidthProportion();

    static const float notePos[] = { 0.0f, 1 - ratio * 0.6f,
                                     1.0f, 2 - ratio * 0.4f,
                                     2.0f,
                                     3.0f, 4 - ratio * 0.7f,
                                     4.0f, 5 - ratio * 0.5f,
                                     5.0f, 6 - ratio * 0.3f,
                                     6.0f };

    auto octave = midiNoteNumber / 12;
    auto note   = midiNoteNumber % 12;

    auto start = (float) octave * 7.0f * targetKeyWidth + notePos[note] * targetKeyWidth;
    auto width = MidiMessage::isMidiNoteBlack (note) ? blackNoteWidthRatio * targetKeyWidth : targetKeyWidth;

    return { start, start + width };
}

//==============================================================================
void KeyboardComponentBase::paint (Graphics& g)
{
    drawKeyboardBackground (g, getLocalBounds().toFloat());

    for (int octaveBase = 0; octaveBase < 128; octaveBase += 12)
    {
        for (auto noteNum : whiteNotes)
        {
            const auto key = octaveBase + noteNum;

            if (rangeStart <= key && key <= rangeEnd)
                drawWhiteKey (key, g, getRectangleForKey (key));
        }

        for (auto noteNum : blackNotes)
        {
            const auto key = octaveBase + noteNum;

            if (rangeStart <= key && key <= rangeEnd)
                drawBlackKey (key, g, getRectangleForKey (key));
        }
    }
}

void KeyboardComponentBase::resized()
{
    auto w = getWidth();
    auto h = getHeight();

    if (w > 0 && h > 0)
    {
        if (orientation != horizontalKeyboard)
            std::swap (w, h);

        auto kx2 = getKeyPos (rangeEnd).getEnd();

        if ((int) firstKey != rangeStart)
        {
            auto kx1 = getKeyPos (rangeStart).getStart();

            if (kx2 - kx1 <= (float) w)
            {
                firstKey = (float) rangeStart;
                sendChangeMessage();
                repaint();
            }
        }

        scrollDown->setVisible (canScroll && firstKey > (float) rangeStart);

        xOffset = 0;

        if (canScroll)
        {
            auto scrollButtonW = jmin (scrollButtonWidth, w / 2);
            auto r = getLocalBounds();

            if (orientation == horizontalKeyboard)
            {
                scrollDown->setBounds (r.removeFromLeft  (scrollButtonW));
                scrollUp  ->setBounds (r.removeFromRight (scrollButtonW));
            }
            else if (orientation == verticalKeyboardFacingLeft)
            {
                scrollDown->setBounds (r.removeFromTop    (scrollButtonW));
                scrollUp  ->setBounds (r.removeFromBottom (scrollButtonW));
            }
            else
            {
                scrollDown->setBounds (r.removeFromBottom (scrollButtonW));
                scrollUp  ->setBounds (r.removeFromTop    (scrollButtonW));
            }

            auto endOfLastKey = getKeyPos (rangeEnd).getEnd();

            auto spaceAvailable = w;
            auto lastStartKey = remappedXYToNote ({ endOfLastKey - (float) spaceAvailable, 0 }).note + 1;

            if (lastStartKey >= 0 && ((int) firstKey) > lastStartKey)
            {
                firstKey = (float) jlimit (rangeStart, rangeEnd, lastStartKey);
                sendChangeMessage();
            }

            xOffset = getKeyPos ((int) firstKey).getStart();
        }
        else
        {
            firstKey = (float) rangeStart;
        }

        scrollUp->setVisible (canScroll && getKeyPos (rangeEnd).getStart() > (float) w);
        repaint();
    }
}

//==============================================================================
void KeyboardComponentBase::mouseWheelMove (const MouseEvent&, const MouseWheelDetails& wheel)
{
    auto amount = (orientation == horizontalKeyboard && ! approximatelyEqual (wheel.deltaX, 0.0f))
                       ? wheel.deltaX : (orientation == verticalKeyboardFacingLeft ? wheel.deltaY
                                                                                   : -wheel.deltaY);

    setLowestVisibleKeyFloat (firstKey - amount * keyWidth);
}

} // namespace juce