import type { MapProjection } from "../geometry/mapProjection";
import type { MapPolygon } from "../model/mapTypes";

const SURVEY_COLORS: Record<string, string> = {
  OPTICS: "#FFA040",
  RSA: "#40AFFF",
  COMBINED: "#C080FF"
};
const DEFAULT_COLOR = "#FFA040";

type Pt = { x: number; y: number };

function unwrapX(points: Pt[], worldSize: number): Pt[] {
  if (points.length === 0) return [];
  const out: Pt[] = [points[0]];
  let prevX = points[0].x;
  for (let i = 1; i < points.length; i++) {
    let x = points[i].x;
    while (x - prevX > worldSize / 2) x -= worldSize;
    while (prevX - x > worldSize / 2) x += worldSize;
    out.push({ x, y: points[i].y });
    prevX = x;
  }
  return out;
}

export function drawRequests(
  ctx: CanvasRenderingContext2D,
  polygons: MapPolygon[],
  projection: MapProjection,
  viewport: { width: number; height: number }
) {
  ctx.save();
  for (const polygon of polygons) {
    if (polygon.points.length < 3) continue;
    const raw = polygon.points.map((p) => projection.project(p));
    const pts = unwrapX(raw, projection.worldSize);
    const color = SURVEY_COLORS[polygon.surveyType ?? ""] ?? DEFAULT_COLOR;
    ctx.fillStyle = hexToRgba(color, 0.18);
    ctx.strokeStyle = hexToRgba(color, 0.85);
    ctx.lineWidth = 1.5;
    ctx.setLineDash([4, 3]);
    for (const dx of [0, projection.worldSize, -projection.worldSize]) {
      const visible = pts.some((p) => {
        const x = p.x + dx;
        return x >= -64 && x <= viewport.width + 64 && p.y >= -64 && p.y <= viewport.height + 64;
      });
      if (!visible) continue;
      ctx.beginPath();
      for (let i = 0; i < pts.length; i++) {
        if (i === 0) ctx.moveTo(pts[i].x + dx, pts[i].y);
        else ctx.lineTo(pts[i].x + dx, pts[i].y);
      }
      ctx.closePath();
      ctx.fill();
      ctx.stroke();
    }
    ctx.setLineDash([]);
  }
  ctx.restore();
}

function hexToRgba(hex: string, alpha: number): string {
  const value = hex.replace("#", "");
  const red = Number.parseInt(value.slice(0, 2), 16);
  const green = Number.parseInt(value.slice(2, 4), 16);
  const blue = Number.parseInt(value.slice(4, 6), 16);
  return `rgba(${red}, ${green}, ${blue}, ${alpha})`;
}