import maplibregl from 'maplibre-gl';
import 'maplibre-gl/dist/maplibre-gl.css';
import { FogCanvas, metersToPixels } from './fog.js';
import { MapSync } from './sync.js';

const BOTTOM_STYLE = 'https://tiles.openfreemap.org/styles/bright';
const TOP_STYLE = 'https://tiles.openfreemap.org/styles/liberty';

let mode = 'explore'; // 'explore' | 'navigate'
let brushRadius = 8000;

// ── Maps ──
const mapBottom = new maplibregl.Map({
  container: 'map-bottom',
  style: BOTTOM_STYLE,
  center: [0, 30],
  zoom: 3,
  attributionControl: false,
});

const mapTop = new maplibregl.Map({
  container: 'map-top',
  style: TOP_STYLE,
  center: [0, 30],
  zoom: 3,
  attributionControl: false,
  interactive: false,       // will be toggled
});

// Make top map transparent background and mute layers
mapTop.on('load', () => {
  const layers = mapTop.getStyle().layers;
  for (const layer of layers) {
    const id = layer.id.toLowerCase();
    const src = (layer['source-layer'] || '').toLowerCase();

    const isWater = id.includes('ocean') || id.includes('sea') || id.includes('water') ||
                    src.includes('water') || src.includes('ocean');
    const isAdmin = id.includes('admin') || id.includes('boundar') || src.includes('admin') || src.includes('boundar');
    const isPlace = id.includes('place') || id.includes('label') || id.includes('capital') ||
                    id.includes('city') || id.includes('country') || id.includes('continent') ||
                    src.includes('place');

    if (!isWater && !isAdmin && !isPlace) {
      mapTop.setLayoutProperty(layer.id, 'visibility', 'none');
    } else if (isPlace && layer.type === 'symbol') {
      // Only keep country labels and major/capital cities, hide small places
      const isCountryOrCapital = id.includes('country') || id.includes('capital') ||
                                  id.includes('continent') || id.includes('state');
      if (!isCountryOrCapital) {
        // Filter to only show cities with high rank (major cities)
        try {
          mapTop.setFilter(layer.id, ['<=', ['get', 'rank'], 3]);
        } catch {}
      }
      try { mapTop.setPaintProperty(layer.id, 'text-color', 'rgba(200,215,255,0.45)'); } catch {}
      try { mapTop.setPaintProperty(layer.id, 'text-halo-color', 'rgba(6,10,24,0.7)'); } catch {}
    } else if (isAdmin && layer.type === 'line') {
      try { mapTop.setPaintProperty(layer.id, 'line-color', 'rgba(200,215,255,0.25)'); } catch {}
      try { mapTop.setPaintProperty(layer.id, 'line-opacity', 0.4); } catch {}
    } else if (isWater) {
      // Mute water to a subtle blue-grey
      if (layer.type === 'fill') {
        try { mapTop.setPaintProperty(layer.id, 'fill-color', 'rgba(140,160,185,0.3)'); } catch {}
      }
    }
  }
});

// Sync maps
const sync = new MapSync(mapTop, mapBottom);
mapTop.on('load', () => { mapBottom.on('load', () => sync.enable()); });

// ── Fog ──
const fogCanvas = new FogCanvas(document.getElementById('fog'), mapTop);

// Re-render fog on map move
mapTop.on('move', () => fogCanvas.markDirty());
mapBottom.on('load', () => {
  // initial render once both ready
  fogCanvas.render();
});

// Resize
const ro = new ResizeObserver(() => fogCanvas.resize());
ro.observe(document.getElementById('container'));

// ── Brush cursor ──
const cursor = document.getElementById('brush-cursor');

function updateCursorSize(e) {
  const r = metersToPixels(mapTop, [e.lngLat.lng, e.lngLat.lat], brushRadius);
  const d = r * 2;
  cursor.style.width = d + 'px';
  cursor.style.height = d + 'px';
  cursor.style.left = e.point.x + 'px';
  cursor.style.top = e.point.y + 'px';
}

// ── Interaction ──
let dragging = false;
let lastPt = null;

function setMode(m) {
  mode = m;
  document.getElementById('btn-explore').classList.toggle('active', m === 'explore');
  document.getElementById('btn-navigate').classList.toggle('active', m === 'navigate');

  if (m === 'explore') {
    mapTop.dragPan.disable();
    mapTop.scrollZoom.enable();
    mapTop.doubleClickZoom.enable();
    document.getElementById('map-top').style.cursor = 'none';
    cursor.style.display = 'block';
  } else {
    mapTop.dragPan.enable();
    mapTop.scrollZoom.enable();
    mapTop.doubleClickZoom.enable();
    document.getElementById('map-top').style.cursor = '';
    cursor.style.display = 'none';
  }
}

mapTop.on('load', () => setMode('explore'));

mapTop.on('mousedown', (e) => {
  if (mode !== 'explore') return;
  dragging = true;
  lastPt = e.point;
  addPoint(e);
});

mapTop.on('mousemove', (e) => {
  if (mode === 'explore') updateCursorSize(e);
  if (!dragging || mode !== 'explore') return;

  // Interpolate between last and current to avoid gaps
  const dx = e.point.x - lastPt.x;
  const dy = e.point.y - lastPt.y;
  const dist = Math.sqrt(dx * dx + dy * dy);
  const step = 10;
  if (dist > step) {
    const steps = Math.ceil(dist / step);
    for (let i = 1; i <= steps; i++) {
      const t = i / steps;
      const px = lastPt.x + dx * t;
      const py = lastPt.y + dy * t;
      const ll = mapTop.unproject([px, py]);
      fogCanvas.addErasePoint([ll.lng, ll.lat], brushRadius);
    }
  } else {
    addPoint(e);
  }
  lastPt = e.point;
});

mapTop.on('mouseup', () => { dragging = false; lastPt = null; });
mapTop.on('mouseleave', () => { dragging = false; lastPt = null; cursor.style.display = 'none'; });
mapTop.on('mouseenter', () => { if (mode === 'explore') cursor.style.display = 'block'; });

function addPoint(e) {
  fogCanvas.addErasePoint([e.lngLat.lng, e.lngLat.lat], brushRadius);
}

// ── Toolbar ──
document.getElementById('btn-explore').addEventListener('click', () => setMode('explore'));
document.getElementById('btn-navigate').addEventListener('click', () => setMode('navigate'));
document.getElementById('btn-reset').addEventListener('click', () => fogCanvas.reset());
document.getElementById('btn-zoom-in').addEventListener('click', () => mapTop.zoomIn());
document.getElementById('btn-zoom-out').addEventListener('click', () => mapTop.zoomOut());
document.getElementById('brush-slider').addEventListener('input', (e) => {
  brushRadius = Number(e.target.value);
});

// Keyboard shortcuts
document.addEventListener('keydown', (e) => {
  if (e.key === 'e' || e.key === 'E') setMode('explore');
  if (e.key === 'n' || e.key === 'N') setMode('navigate');
});