import { readFabric } from "/mirror_record.js";

const TRUST_SCHEMA = "elementfold.mirror.trust.v1";
const TRUST_ROOT_SHA256 = "d8cfc19f687d8de16a202fd15608ae81b04efaa91f8ca870009360a3e625f870";

async function trustRead() {
  const response = await fetch("/trust_root.json", { cache: "no-store" });
  if (!response.ok) {
    throw new Error("the trust root cannot be read");
  }
  const bytes = await response.arrayBuffer();
  const digest = [...new Uint8Array(await crypto.subtle.digest("SHA-256", bytes))]
    .map(byte => byte.toString(16).padStart(2, "0")).join("");
  if (digest !== TRUST_ROOT_SHA256) {
    throw new Error("the trust root is not anchored by this release");
  }
  const trust = JSON.parse(new TextDecoder().decode(bytes));
  if (trust.schema !== TRUST_SCHEMA || typeof trust.issuers !== "object" || !Array.isArray(trust.nodes)) {
    throw new Error("the trust root has the wrong shape");
  }
  return trust;
}

function drawn(record) {
  const panel = document.querySelector(`[data-panel="${record.type}"]`);
  if (!panel) {
    return;
  }
  const line = document.createElement("p");
  line.className = "record";
  line.textContent = new TextDecoder("utf-8", { fatal: true }).decode(
    Uint8Array.from(atob(record.payload), character => character.charCodeAt(0)),
  );
  panel.append(line);
}

async function draw() {
  const standing = document.querySelector("#standing");
  document.querySelectorAll(".record").forEach(record => record.remove());
  try {
    const trust = await trustRead();
    const { records, refusals } = await readFabric(trust);
    records.forEach(drawn);
    standing.textContent = refusals.length ? `${refusals.length} record or path problem(s): ${refusals.join(" · ")}` : "";
  } catch (failure) {
    standing.textContent = failure instanceof Error ? failure.message : String(failure);
  }
}

void draw();