"use strict";

// Shared item rendering helpers.  Field rendering stays in item_render_runtime.js.

function segmentPathCacheKey(item, segments, extra = "") {
  const version = Number(item?._mechanicalShapeVersion || 0) || 0;
  const len = Array.isArray(segments) ? segments.length : 0;
  let h = len * 2654435761;
  if (Array.isArray(segments)) {
    const step = Math.max(1, Math.floor(len / 24));
    for (let i = 0; i < len; i += step) {
      const seg = segments[i];
      if (!Array.isArray(seg)) continue;
      for (let j = 0; j < 4; j += 1) {
        h ^= Math.round((Number(seg[j]) || 0) * 10) & 0xffff;
        h = Math.imul(h, 16777619);
      }
    }
  }
  return `${item?.type || ""}|${version}|${len}|${h >>> 0}|${extra}`;
}

function getSegmentPath(item, segments, extra = "") {
  if (typeof Path2D === "undefined" || !Array.isArray(segments)) return null;
  const key = segmentPathCacheKey(item, segments, extra);
  const cache = item._segmentRenderPathCache || (item._segmentRenderPathCache = Object.create(null));
  if (cache.key === key && cache.path) return cache.path;
  const path = new Path2D();
  for (const seg of segments) {
    if (!Array.isArray(seg) || seg.length < 4) continue;
    path.moveTo(Number(seg[0]) || 0, Number(seg[1]) || 0);
    path.lineTo(Number(seg[2]) || 0, Number(seg[3]) || 0);
  }
  cache.key = key;
  cache.path = path;
  return path;
}

function strokeSegments(ctx, item, segments, extra = "") {
  const path = getSegmentPath(item, segments, extra);
  if (path) {
    ctx.stroke(path);
    return;
  }
  ctx.beginPath();
  for (const seg of segments || []) {
    if (!Array.isArray(seg) || seg.length < 4) continue;
    ctx.moveTo(Number(seg[0]) || 0, Number(seg[1]) || 0);
    ctx.lineTo(Number(seg[2]) || 0, Number(seg[3]) || 0);
  }
  ctx.stroke();
}

function mechanicalRenderTier() {
  return window.TarinaiPerf.renderQualityTier();
}

function itemShadowQualityTier() {
  return window.TarinaiPerf?.shadowQualityTier?.() || "high";
}

function itemShadowsEnabled() {
  return itemShadowQualityTier() !== "off";
}

function drawRopeParticlePath(ctx, particles, ox, oy) {
  if (!Array.isArray(particles) || particles.length < 2) return false;
  const tier = mechanicalRenderTier();
  const stride = tier === "low" && particles.length > 10 ? 2 : 1;
  ctx.moveTo((Number(particles[0].x) || 0) - ox, (Number(particles[0].y) || 0) - oy);
  for (let i = stride; i < particles.length - 1; i += stride) {
    ctx.lineTo((Number(particles[i].x) || 0) - ox, (Number(particles[i].y) || 0) - oy);
  }
  const last = particles[particles.length - 1];
  ctx.lineTo((Number(last.x) || 0) - ox, (Number(last.y) || 0) - oy);
  return true;
}
function drawRopeRuntimePath(ctx, particles, item, pb, ax, ay, bx, by) {
  if (particles && drawRopeParticlePath(ctx, particles, item.x, item.y)) return true;
  const midX = Number(pb?.linkScalar?.(item, "midX", NaN));
  const midY = Number(pb?.linkScalar?.(item, "midY", NaN));
  const mx = Number.isFinite(midX) ? midX - item.x : (ax + bx) * 0.5;
  const my = Number.isFinite(midY) ? midY - item.y : (ay + by) * 0.5;
  ctx.moveTo(ax, ay);
  ctx.quadraticCurveTo(mx, my, bx, by);
  return true;
}