package com.grigowashere.aismap.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;
import androidx.core.content.ContextCompat;

import com.grigowashere.aismap.R;

import java.util.Locale;

/**
 * Простой аналоговый спидометр (узлы) в стиле картплоттера.
 */
public class PlotterSpeedometerView extends View {

    private static final float MAX_SPEED_KNOTS = 30f;

    private final Paint bgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint arcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint tickPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint needlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint labelPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint valuePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final RectF arcRect = new RectF();

    private float speedKnots = 0f;
    private String title;

    public PlotterSpeedometerView(Context context) {
        super(context);
        init();
    }

    public PlotterSpeedometerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        title = getContext().getString(R.string.radar_plotter_sog_label);
        int labelColor = ContextCompat.getColor(getContext(), R.color.plotter_text_label);
        int textColor = ContextCompat.getColor(getContext(), R.color.plotter_text_primary);
        int accent = ContextCompat.getColor(getContext(), R.color.plotter_text_accent);

        bgPaint.setStyle(Paint.Style.STROKE);
        bgPaint.setStrokeWidth(dp(2));
        bgPaint.setColor(0x44FFFFFF);

        arcPaint.setStyle(Paint.Style.STROKE);
        arcPaint.setStrokeWidth(dp(6));
        arcPaint.setColor(accent);
        arcPaint.setStrokeCap(Paint.Cap.ROUND);

        tickPaint.setStyle(Paint.Style.STROKE);
        tickPaint.setStrokeWidth(dp(1));
        tickPaint.setColor(labelColor);

        needlePaint.setStyle(Paint.Style.STROKE);
        needlePaint.setStrokeWidth(dp(2.5f));
        needlePaint.setColor(accent);
        needlePaint.setStrokeCap(Paint.Cap.ROUND);

        labelPaint.setColor(labelColor);
        labelPaint.setTextSize(dp(10));
        labelPaint.setLetterSpacing(0.08f);

        valuePaint.setColor(textColor);
        valuePaint.setTextSize(dp(18));
        valuePaint.setFakeBoldText(true);
    }

    public void setSpeedKnots(double knots) {
        float v = (float) Math.max(0.0, Math.min(MAX_SPEED_KNOTS, knots));
        if (Math.abs(v - speedKnots) > 0.05f) {
            speedKnots = v;
            invalidate();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int w = getWidth();
        int h = getHeight();
        if (w <= 0 || h <= 0) return;

        float pad = dp(8);
        float titleY = dp(14);
        canvas.drawText(title, w * 0.5f - labelPaint.measureText(title) / 2f, titleY, labelPaint);

        float cx = w * 0.5f;
        float bottom = h - pad;
        float maxRadius = Math.min((w - 2f * pad) * 0.5f, bottom - titleY - pad);
        float radius = Math.max(dp(12), maxRadius * 0.88f);
        float cy = bottom;
        arcRect.set(cx - radius, cy - radius, cx + radius, cy + radius);

        canvas.drawArc(arcRect, 180f, 180f, false, bgPaint);

        float sweep = 180f * (speedKnots / MAX_SPEED_KNOTS);
        canvas.drawArc(arcRect, 180f, sweep, false, arcPaint);

        for (int k = 0; k <= 30; k += 5) {
            float frac = k / MAX_SPEED_KNOTS;
            double ang = Math.toRadians(180 + 180 * frac);
            float x1 = cx + (float) (Math.cos(ang) * (radius - dp(4)));
            float y1 = cy + (float) (Math.sin(ang) * (radius - dp(4)));
            float x2 = cx + (float) (Math.cos(ang) * radius);
            float y2 = cy + (float) (Math.sin(ang) * radius);
            canvas.drawLine(x1, y1, x2, y2, tickPaint);
            if (k % 10 == 0) {
                String t = String.valueOf(k);
                float tw = labelPaint.measureText(t);
                canvas.drawText(t,
                        cx + (float) (Math.cos(ang) * (radius - dp(16))) - tw / 2f,
                        cy + (float) (Math.sin(ang) * (radius - dp(16))) + dp(4),
                        labelPaint);
            }
        }

        double needleAng = Math.toRadians(180 + 180 * (speedKnots / MAX_SPEED_KNOTS));
        float nx = cx + (float) (Math.cos(needleAng) * (radius - dp(10)));
        float ny = cy + (float) (Math.sin(needleAng) * (radius - dp(10)));
        canvas.drawLine(cx, cy, nx, ny, needlePaint);
        canvas.drawCircle(cx, cy, dp(4), needlePaint);

        String val = String.format(Locale.US, "%.1f", speedKnots);
        canvas.drawText(val, cx - valuePaint.measureText(val) / 2f, cy - dp(6), valuePaint);
        String unit = "kn";
        canvas.drawText(unit, cx - labelPaint.measureText(unit) / 2f, cy + dp(12), labelPaint);
    }

    private float dp(float v) {
        return v * getResources().getDisplayMetrics().density;
    }
}