"use strict";
(() => {
  const nodes = new Map([[0, document.getElementById("keluna-root")]]);
  let inputRevision = 0;
  const revisions = new Map();
  const resetInput = new Map();
  const composingInputs = new Set();
  let keys = new Set();
  let forwardBlur = false;
  window.addEventListener("keydown", event => {
    const key = event.key.length === 1 ? event.key.toLowerCase() : event.key;
    if (!keys.has(key) || event.ctrlKey || event.altKey || event.metaKey || event.isComposing) return;
    event.preventDefault();
    if (!event.repeat) window.webkit.messageHandlers.keluna.postMessage(`key:${key}`);
  });
  window.addEventListener("blur", () => {
    if (forwardBlur) window.webkit.messageHandlers.keluna.postMessage("blur");
  });
  window.keluna = {
    apply(patches) {
      for (const patch of patches) {
        if (patch.op === "keyboard") { keys = new Set(patch.keys); continue; }
        if (patch.op === "blur") { forwardBlur = true; continue; }
        if (patch.op === "create") {
          const element = document.createElement(patch.tag);
          element.dataset.kelunaId = String(patch.node);
          nodes.set(patch.node, element);
          nodes.get(patch.parent).appendChild(element);
          continue;
        }
        const node = nodes.get(patch.node);
        if (!node) throw new Error(`Unknown Keluna node ${patch.node}`);
        switch (patch.op) {
          case "property": {
            if (patch.name === "value" && composingInputs.has(patch.node)) break;
            if ((patch.name === "value" || patch.name === "checked") && patch.revision < (revisions.get(patch.node) || 0)) break;
            // Assigning even identical values can move the caret in some controls.
            if (node[patch.name] !== patch.value || (patch.name === "value" && node.validity?.badInput)) node[patch.name] = patch.value;
            if (patch.name === "value" || patch.name === "checked") resetInput.get(patch.node)?.();
            break;
          }
          case "listenValue": {
            let composing = false;
            let lastSent;
            const send = event => {
              if (composing || event.isComposing || node.disabled || node.readOnly) return;
              const value = String(node[patch.property]);
              const bad = node.validity?.badInput ? 1 : 0;
              const signature = `${bad}:${value}`;
              if (signature === lastSent) return;
              lastSent = signature;
              const revision = ++inputRevision;
              revisions.set(patch.node, revision);
              if (node.type === "radio") {
                for (const [id, peer] of nodes) {
                  if (peer.type === "radio" && peer.name === node.name) revisions.set(id, revision);
                }
              }
              window.webkit.messageHandlers.keluna.postMessage(`value:${patch.node}:${revision}:${bad}:${value}`);
            };
            resetInput.set(patch.node, () => { lastSent = undefined; });
            node.addEventListener(patch.event, send);
            node.addEventListener("compositionstart", () => { composing = true; composingInputs.add(patch.node); });
            node.addEventListener("compositionend", () => { composing = false; composingInputs.delete(patch.node); send({}); });
            break;
          }
          case "text": node.textContent = patch.value; break;
          case "attribute": node.setAttribute(patch.name, patch.value); break;
          case "style": node.style.setProperty(patch.name, patch.value); break;
          case "listen": node.addEventListener("click", () => {
            window.webkit.messageHandlers.keluna.postMessage(`click:${patch.node}`);
          }); break;
          default: throw new Error(`Unknown Keluna operation ${patch.op}`);
        }
      }
    }
  };
})();