package com.evsuite.abrp;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.os.SystemClock;

import java.util.Locale;

/**
 * The Terminal Overview style: text only, green phosphor on black, faint scan lines, as if a
 * shell printed the car's state — each value on a row with an ASCII bar, the gear as [D], and
 * a prompt with a blinking cursor (it blinks because readings redraw the view; it does not
 * animate on its own). A low battery turns its row amber. Unread values show "—" and an empty
 * bar.
 *
 * Two palettes: green phosphor, or the chosen accent colour ({@link #setAccentPalette}) — the
 * text in its light shade, the command line in the accent itself, on plain black. The low
 * battery stays amber in both.
 */
final class TerminalView extends ClusterCanvasView {

    private static final int BAR = 24;

    private final Paint text = new Paint(Paint.ANTI_ALIAS_FLAG);
    private final Paint scan = new Paint();
    private final int accentText, accentDim;
    private final int amber = 0xFFFFB000;
    private int green, dim, background;

    TerminalView(Context context) {
        super(context);
        accentText = AccentColor.resolve(context, R.attr.evAccentLight);
        accentDim = AccentColor.resolve(context, R.attr.evAccent);
        setAccentPalette(false);
        text.setTypeface(Typeface.MONOSPACE);
        scan.setColor(0x0CFFFFFF);
    }

    /** The chosen accent colour instead of green phosphor. */
    void setAccentPalette(boolean accent) {
        green = accent ? accentText : 0xFF33FF66;
        dim = accent ? accentDim : 0xFF1C8A3A;
        background = accent ? 0xFF050505 : 0xFF020A04;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas c) {
        super.onDraw(c);
        float w = getWidth(), h = getHeight();
        if (w <= 0 || h <= 0) return;
        c.drawColor(background);

        // About 14 rows at 1.32 em each plus margins; monospace is about 0.6 em wide and the
        // longest row about 58 characters.
        float x = 16f * dp;
        float size = Math.min(h / 19.5f, (w - x) / 38f);
        text.setTextSize(size);
        float line = size * 1.32f, y = 12f * dp + line;
        String gear = gearRow();

        print(c, "nils@mg4:~$ watch -n 0.2 vehicle-status", x, y, dim);
        y += line * 1.4f;
        print(c, row("SPEED", fmt(v.speedKmh, "%.0f km/h", "—")) + bar(v.speedKmh, 0f, 180f), x, y, green);
        y += line;
        print(c, row("POWER", fmt(v.powerKw, "%.1f kW", "—")) + powerBar(), x, y, green);
        y += line;
        boolean low = v.socPercent != null && v.socPercent < 20f;
        print(c, row("BATTERY", fmt(v.socPercent, "%.0f %%", "—")) + bar(v.socPercent, 0f, 100f)
                + (low ? "  ! LOW" : ""), x, y, low ? amber : green);
        y += line;
        print(c, row("RANGE", fmt(v.rangeKm, "%.0f km", "—")), x, y, green);
        y += line;
        print(c, row("GEAR", gear), x, y, green);
        y += line * 1.4f;
        print(c, row("USAGE", fmt(v.usage5Min, "%.1f kWh/100km", "—")) + "  # last 5 min", x, y, green);
        y += line;
        print(c, row("SINCE", fmt(v.usageTrip, "%.1f kWh/100km", "—")) + "  # trip "
                + fmt(v.tripKm, "%.1f km", "—"), x, y, green);
        y += line;
        print(c, row("CLIMATE", fmt(v.climateCelsius, "%.0f C", "—")) + "  ODO " + fmt(v.odometerKm, "%06.0f km", "—"), x, y, green);
        y += line;
        print(c, row("TYRES", "FL " + v.tyreFl + "  FR " + v.tyreFr + "  RL " + v.tyreRl + "  RR " + v.tyreRr), x, y, green);
        y += line * 1.4f;
        if (v.songTitle != null) {
            // What plays, cut to the row's width.
            String label = String.format(Locale.US, "%-9s", "PLAYING");
            String s = v.songTitle + (v.songArtist == null ? "" : " — " + v.songArtist);
            int fits = text.breakText(s, true, Math.max(0f, getWidth() - x - text.measureText(label)), null);
            print(c, label + (fits < s.length() ? s.substring(0, Math.max(0, fits - 1)).trim() + "…" : s), x, y, green);
            y += line;
        }
        boolean cursor = (SystemClock.uptimeMillis() / 500) % 2 == 0;
        print(c, "[" + (v.clock.isEmpty() ? "--:--" : v.clock) + "] nils@mg4:~$ " + (cursor ? "█" : ""), x, y, green);

        // Scan lines over everything.
        for (float sy = 0; sy < h; sy += 3f * dp) c.drawLine(0, sy, w, sy, scan);
    }

    private void print(Canvas c, String s, float x, float y, int colour) {
        text.setColor(colour);
        c.drawText(s, x, y, text);
    }

    private static String row(String label, String value) {
        return String.format(Locale.US, "%-9s%-16s", label, value);
    }

    /** [#####.......] from min to max; empty when unread. */
    private static String bar(Float value, float min, float max) {
        int n = value == null ? 0 : Math.round(BAR * (Math.max(min, Math.min(max, value)) - min) / (max - min));
        StringBuilder sb = new StringBuilder("[");
        for (int i = 0; i < BAR; i++) sb.append(i < n ? '#' : '.');
        return sb.append(']').toString();
    }

    /** −50…150 kW with a | at zero: < for regeneration to its left, # for drawing to its right. */
    private String powerBar() {
        int zero = BAR / 4;
        int to = v.powerKw == null ? zero : zero + Math.round(BAR * Math.max(-50f, Math.min(150f, v.powerKw)) / 200f);
        StringBuilder sb = new StringBuilder("[");
        for (int i = 0; i < BAR; i++) {
            if (i == zero) sb.append('|');
            else if (v.powerKw != null && i < zero && i >= to) sb.append('<');
            else if (v.powerKw != null && i > zero && i <= to) sb.append('#');
            else sb.append('.');
        }
        return sb.append(']').toString();
    }

    private String gearRow() {
        String[] letters = { "P", "R", "N", "D" };
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 4; i++) {
            boolean on = v.gear != null && v.gear == i + 1;
            sb.append(on ? "[" + letters[i] + "]" : " " + letters[i] + " ");
        }
        return sb.toString();
    }
}