#include "SequencerMatrix.h"

#include "../PluginProcessor.h"
#include "../Theme.h"

using namespace monostep;

SequencerMatrix::SequencerMatrix (MonostepAudioProcessor& processorRef)
    : processor (processorRef)
{
}

int SequencerMatrix::rowForSemitone (int semitone) const
{
    return maxSemitone - semitone;
}

int SequencerMatrix::semitoneForRow (int row) const
{
    return maxSemitone - row;
}

juce::Rectangle<int> SequencerMatrix::matrixBounds() const
{
    const int w = getWidth();
    const int h = getHeight();

    if (w > labelW && h > headerH)
    {
        cellW = (float) (w - labelW) / (float) numSteps;
        cellH = (float) (h - headerH) / (float) (numRows + 2);
    }

    const int gridW = juce::roundToInt (cellW * numSteps);
    const int gridH = juce::roundToInt (cellH * (numRows + 2));

    return { juce::roundToInt (labelW), juce::roundToInt (headerH), gridW, gridH };
}

void SequencerMatrix::setSelectedStep (int stepIdx)
{
    if (stepIdx < 0 || stepIdx >= numSteps)
        return;

    selectedStep = stepIdx;
    repaint();
}

void SequencerMatrix::setPlayPosition (int stepIdx)
{
    if (stepIdx < -1 || stepIdx >= numSteps)
        return;

    if (stepIdx == playPos)
        return;

    playPos = stepIdx;
    repaint();
}

void SequencerMatrix::paint (juce::Graphics& g)
{
    g.fillAll (colours::panel);

    const auto bounds = matrixBounds();
    const float ox = (float) bounds.getX();
    const float oy = (float) bounds.getY();

    // Slightly-3D header band above the grid.
    juce::ColourGradient headerGrad (colours::gridLight,
                                     0.0f, 0.0f,
                                     colours::panel.darker (0.10f),
                                     0.0f, headerH, false);
    g.setGradientFill (headerGrad);
    g.fillRect (0.0f, 0.0f, (float) getWidth(), headerH);

    g.setColour (colours::gridLight.brighter (0.3f).withAlpha (0.4f));
    g.fillRect (0.0f, 0.0f, (float) getWidth(), 1.0f);

    g.setColour (colours::grid);
    g.drawHorizontalLine (juce::roundToInt (headerH) - 1, 0, (float) getWidth());
    g.setColour (colours::bg);
    g.drawHorizontalLine (juce::roundToInt (headerH), 0, (float) getWidth());

    // grid background
    g.setColour (colours::bg);
    g.fillRect (bounds.toFloat());

    // selected column highlight
    g.setColour (colours::selected.withAlpha (0.02f));
    g.fillRect (ox + selectedStep * cellW, oy, cellW, (float) bounds.getHeight());

    // play position column highlight (drawn before cells so notes stay vivid)
    if (playPos >= 0)
    {
        g.setColour (colours::accent.withAlpha (0.04f));
        g.fillRect (ox + playPos * cellW, oy, cellW, (float) bounds.getHeight());
    }

    // grid lines
    g.setColour (colours::grid);

    for (int i = 0; i <= numSteps; ++i)
    {
        const float x = ox + i * cellW;
        g.drawVerticalLine (juce::roundToInt (x), oy, oy + (float) bounds.getHeight());
    }

    for (int i = 0; i <= numRows + 2; ++i)
    {
        const float y = oy + i * cellH;
        g.drawHorizontalLine (juce::roundToInt (y), ox, ox + (float) bounds.getWidth());
    }

    // accent C rows (semitone multiple of 12)
    for (int r = 0; r < numRows; ++r)
    {
        const int st = semitoneForRow (r);

        if (st % 12 == 0)
        {
            g.setColour (colours::gridLight);
            const float y = oy + r * cellH;
            g.drawHorizontalLine (juce::roundToInt (y), ox, ox + (float) bounds.getWidth());
        }
    }

    // step header numbers + selected marker
    const int seqLen = processor.getPatternLength();

    for (int i = 0; i < numSteps; ++i)
    {
        const float cx = ox + i * cellW + cellW * 0.5f;
        const float cy = oy - headerH * 0.5f;

        g.setColour ((i % 4 == 0 && i < seqLen) ? colours::text : colours::textDim);
        g.setFont (font (10.0f));
        g.drawText (juce::String (i + 1), juce::roundToInt (cx - 8.0f), juce::roundToInt (cy - 6.0f), 16, 12, juce::Justification::centred);
    }

    // pitch labels
    for (int r = 0; r < numRows; ++r)
    {
        const int st = semitoneForRow (r);
        const float ly = oy + r * cellH + cellH * 0.5f;

        g.setFont (font (8.5f));
        g.setColour (colours::textDim);
        g.drawText (juce::String (st > 0 ? "+" : "") + juce::String (st),
                    juce::roundToInt (labelW * 0.1f), juce::roundToInt (ly - 5.0f), juce::roundToInt (labelW * 0.6f), 10,
                    juce::Justification::centredRight);

        g.setColour (st % 12 == 0 ? colours::accent : colours::text);
        g.drawText (noteNameForOffset (st),
                    juce::roundToInt (labelW * 0.62f), juce::roundToInt (ly - 5.0f), juce::roundToInt (labelW * 0.4f), 10,
                    juce::Justification::centredRight);
    }

    // active cells
    for (int i = 0; i < numSteps; ++i)
    {
        const auto& s = processor.getSequencer().step (i);

        if (! s.gate)
            continue;

        const int r = rowForSemitone (s.semitone);

        const auto cell = juce::Rectangle<float> (ox + i * cellW + 1.5f, oy + r * cellH + 1.5f,
                                                  cellW - 3.0f, cellH - 3.0f);

        const bool isSelected = (i == selectedStep);
        const float radius = 3.0f;

        // cell body: keep a visible top->bottom gradient in both states. The selected
        // note is brighter overall, but still holds its gradient (a flat bright fill
        // would read as "no gradient").
        const juce::Colour noteTop    = isSelected ? colours::accent.brighter (0.2f) : colours::accent;
        const juce::Colour noteBottom = colours::accent.darker (0.3f);

        juce::ColourGradient grad (noteTop,
                                   cell.getTopLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                   noteBottom,
                                   cell.getBottomLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                   false);

        g.setGradientFill (grad);
        g.fillRoundedRectangle (cell, radius);

        // fine-tune indicator
        if (std::fabs (s.cents) > 0.5f)
        {
            g.setColour (colours::bg.withAlpha (0.85f));
            g.setFont (font (7.5f));
            g.drawText (formatCents (s.cents), cell.toNearestInt().reduced (1, 1), juce::Justification::topLeft);
        }
    }

    // --- slide row (bottom row) ----------------------------------------------
    const float slideY = oy + numRows * cellH;

    g.setColour (colours::accentDim);
    g.drawHorizontalLine (juce::roundToInt (slideY - 1.0f), ox, ox + (float) bounds.getWidth());

    g.setFont (font (9.0f));
    g.setColour (colours::textDim);
    g.drawText ("SLIDE",
                juce::roundToInt (labelW * 0.1f), juce::roundToInt (slideY + cellH * 0.5f - 6.0f),
                juce::roundToInt (labelW * 0.8f), 12,
                juce::Justification::centredRight);

    for (int i = 0; i < numSteps; ++i)
    {
        if (! processor.getSequencer().step (i).slide)
            continue;

        const auto cell = juce::Rectangle<float> (ox + i * cellW + 1.5f, slideY + 1.5f,
                                                   cellW - 3.0f, cellH - 3.0f);

        // match the gradient style of the note cells
        juce::ColourGradient grad (colours::accent,
                                   cell.getTopLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                   colours::accent.darker (0.3f),
                                   cell.getBottomLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                   false);
        g.setGradientFill (grad);
        g.fillRoundedRectangle (cell, 3.0f);

        const float ax = cell.getX() + cell.getWidth() * 0.5f;
        const float ay = cell.getY() + cell.getHeight() * 0.5f;

        g.setColour (colours::bg);
        juce::Path tri;
        tri.addTriangle (ax - 3.0f, ay - 2.0f, ax - 3.0f, ay + 2.0f, ax + 3.5f, ay);
        g.fillPath (tri);
    }

    // --- accent row (bottom row) ----------------------------------------------
    const float accentY = oy + (numRows + 1) * cellH;

    g.setColour (colours::accentDim);
    g.drawHorizontalLine (juce::roundToInt (accentY - 1.0f), ox, ox + (float) bounds.getWidth());

    g.setFont (font (9.0f));
    g.setColour (colours::textDim);
    g.drawText ("ACCENT",
                juce::roundToInt (labelW * 0.1f), juce::roundToInt (accentY + cellH * 0.5f - 6.0f),
                juce::roundToInt (labelW * 0.8f), 12,
                juce::Justification::centredRight);

    for (int i = 0; i < numSteps; ++i)
    {
        if (! processor.getSequencer().step (i).accent)
            continue;

        const auto cell = juce::Rectangle<float> (ox + i * cellW + 1.5f, accentY + 1.5f,
                                                  cellW - 3.0f, cellH - 3.0f);

        const bool isSelected = (i == selectedStep);

        juce::ColourGradient agrad (isSelected ? colours::accent2.brighter (0.2f) : colours::accent2,
                                    cell.getTopLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                    colours::accent2.darker (0.3f),
                                    cell.getBottomLeft().translated (cell.getWidth() * 0.5f, 0.0f),
                                    false);

        g.setGradientFill (agrad);
        g.fillRoundedRectangle (cell, 3.0f);

        const float ax = cell.getX() + cell.getWidth() * 0.5f;
        const float ay = cell.getY() + cell.getHeight() * 0.5f;

        g.setColour (colours::bg);
        juce::Path tri;
        tri.addTriangle (ax - 2.0f, ay - 2.5f, ax + 2.0f, ay - 2.5f, ax, ay + 2.5f);
        g.fillPath (tri);
    }

    // --- dim columns beyond the pattern length ---------------------------------
    if (seqLen < numSteps)
    {
        g.setColour (colours::bg.withAlpha (0.55f));
        g.fillRect (ox + seqLen * cellW, oy,
                    (numSteps - seqLen) * cellW, (float) bounds.getHeight());
    }
}

SequencerMatrix::CellRect SequencerMatrix::cellAt (const juce::MouseEvent& e) const
{
    const auto bounds = matrixBounds();

    const int col = (int) std::floor ((e.getPosition().getX() - bounds.getX()) / cellW);
    const int row = (int) std::floor ((e.getPosition().getY() - bounds.getY()) / cellH);

    const bool hit = bounds.contains (e.getPosition())
                     && col >= 0 && col < numSteps
                     && row >= -1 && row < numRows + 2;

    return { juce::jlimit (0, numSteps - 1, col), juce::jlimit (0, numRows + 1, row), hit };
}

void SequencerMatrix::mouseDown (const juce::MouseEvent& e)
{
    const auto cell = cellAt (e);

    if (! cell.hit)
        return;

    if (cell.row == -1)
    {
        selectedStep = cell.step;
        if (onStepSelected)
            onStepSelected (cell.step);
        return;
    }

    selectedStep = cell.step;

    if (onStepSelected)
        onStepSelected (cell.step);

    if (cell.row == numRows + 1)
    {
        accentDragging = true;
        accentLastStep = cell.step;
        startedAccentActive = processor.getSequencer().step (cell.step).accent;

        if (onAccentChanged)
            onAccentChanged (cell.step, ! startedAccentActive);

        repaint();
        return;
    }

    if (cell.row == numRows)
    {
        slideDragging = true;
        slideLastStep = cell.step;
        startedSlideActive = processor.getSequencer().step (cell.step).slide;

        if (onSlideChanged)
            onSlideChanged (cell.step, ! startedSlideActive);

        repaint();
        return;
    }

    if (e.mods.isAltDown())
    {
        fineDragging = true;
        fineRefRow = cell.row;
        fineStartCents = processor.getSequencer().step (cell.step).cents;
        fineLastCents = -1000.0f;
        repaint();
        return;
    }

    dragging = true;
    moved = false;
    dragStep = cell.step;
    lastRow = cell.row;

    const auto& s = processor.getSequencer().step (cell.step);
    startedActive = (s.gate && s.semitone == semitoneForRow (cell.row));
}

void SequencerMatrix::mouseDrag (const juce::MouseEvent& e)
{
    const auto cell = cellAt (e);
    if (! cell.hit || cell.row == -1)
        return;

    if (fineDragging)
    {
        // one matrix row (one semitone) maps to 4 cents of fine tuning
        const float cents = juce::jlimit (-50.0f, 50.0f,
                                          fineStartCents + (fineRefRow - cell.row) * 4.0f);

        if (std::fabs (cents - fineLastCents) >= 0.5f)
        {
            fineLastCents = cents;

            if (onFineChanged)
                onFineChanged (selectedStep, cents);

            repaint();
        }

        return;
    }

    if (slideDragging)
    {
        if (cell.hit && cell.row == numRows && cell.step != slideLastStep)
        {
            slideLastStep = cell.step;

            if (onSlideChanged)
                onSlideChanged (cell.step, ! startedSlideActive);

            repaint();
        }

        return;
    }

    if (accentDragging)
    {
        if (cell.hit && cell.row == numRows + 1 && cell.step != accentLastStep)
        {
            accentLastStep = cell.step;

            if (onAccentChanged)
                onAccentChanged (cell.step, ! startedAccentActive);

            repaint();
        }

        return;
    }

    if (! dragging)
        return;

    if (cell.row >= numRows)
        return;

    if (cell.hit && cell.row < numRows && cell.row != lastRow)
    {
        lastRow = cell.row;
        moved = true;

        const int pitch = semitoneForRow (cell.row);

        const auto& s = processor.getSequencer().step (cell.step);

        if (startedActive)
        {
            if (onNoteChanged)
                onNoteChanged (dragStep, pitch);
        }
        else
        {
            if (onGateChanged)
                onGateChanged (dragStep, true);

            if (onNoteChanged)
                onNoteChanged (dragStep, pitch);
        }

        repaint();
    }
}

void SequencerMatrix::mouseUp (const juce::MouseEvent& e)
{
    if (fineDragging)
    {
        fineDragging = false;
        return;
    }

    if (slideDragging)
    {
        slideDragging = false;
        return;
    }

    if (accentDragging)
    {
        accentDragging = false;
        return;
    }

    if (! dragging)
        return;

    dragging = false;

    const auto cell = cellAt (e);

    if (! cell.hit || cell.step != dragStep || cell.row >= numRows || cell.row == -1)
        return;

    const int pitch = semitoneForRow (cell.row);

    if (startedActive && ! moved)
    {
        if (onGateChanged)
            onGateChanged (cell.step, false);
    }
    else if (! startedActive && ! moved)
    {
        if (onGateChanged)
            onGateChanged (cell.step, true);

        if (onNoteChanged)
            onNoteChanged (cell.step, pitch);
    }
}