package com.ts3client.ui;

import javax.swing.JComponent;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

/**
 * Horizontal audio level meter (dBFS) with an optional VAD threshold marker.
 * The filled portion turns green once the level crosses the threshold, giving
 * immediate visual feedback while tuning voice activation.
 */
public final class LevelMeter extends JComponent {

    private static final double MIN_DB = -70.0;
    private static final double MAX_DB = 0.0;

    private volatile double levelDb = MIN_DB;
    private volatile double thresholdDb = -45.0;
    private volatile boolean showThreshold = true;

    public LevelMeter() {
        setPreferredSize(new Dimension(240, 18));
    }

    public void setLevel(double db) {
        this.levelDb = db;
        repaint();
    }

    public void setThreshold(double db) {
        this.thresholdDb = db;
        repaint();
    }

    public void setShowThreshold(boolean show) {
        this.showThreshold = show;
        repaint();
    }

    private int dbToX(double db, int w) {
        double clamped = Math.max(MIN_DB, Math.min(MAX_DB, db));
        return (int) ((clamped - MIN_DB) / (MAX_DB - MIN_DB) * w);
    }

    @Override
    protected void paintComponent(Graphics g0) {
        Graphics2D g = (Graphics2D) g0;
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        int w = getWidth();
        int h = getHeight();

        g.setColor(new Color(0x2B2B2B));
        g.fillRoundRect(0, 0, w - 1, h - 1, 6, 6);

        int level = dbToX(levelDb, w - 2);
        boolean over = levelDb >= thresholdDb;
        g.setColor(over ? Theme.TALKING : new Color(0x5A9BD4));
        g.fillRoundRect(1, 1, Math.max(0, level), h - 3, 5, 5);

        if (showThreshold) {
            int tx = dbToX(thresholdDb, w - 2);
            g.setColor(new Color(0xF0C419));
            g.fillRect(tx, 1, 2, h - 3);
        }
    }
}