import { awaitEvent, emitEvent } from "./events.js";
import { clearPlanner, loadPlanner } from "./planner.js";
import { getAtlasIndexFromMetadata } from "./atlas.js";

export function showOpenFileDialog() {
  const input = document.createElement("input");
  input.type = "file";
  input.accept = ".ncpf.json";
  input.addEventListener("change", async () => {
    const data = await new Promise(resolve => {
      const reader = new FileReader();
      reader.addEventListener("load", () => {
        resolve(JSON.parse(reader.result));
      });
      reader.readAsText(input.files[0]);
    });
    void loadFile(data);
  });
  input.click();
}

export async function loadExampleFile(filename) {
  const data = await fetch(`./examples/${filename}.ncpf.json`)
      .then(data => data.json());
  return loadFile(data);
}

export async function loadFile(data) {
  if (!data.designs) throw new Error("invalid file");
  if (data.designs.length === 0) throw new Error("no designs");

  let design = data.designs[0];
  if (data.designs.length > 1) {
    const prepChoice = awaitEvent("fileLoad:chooseDesign:choice");
    emitEvent("fileLoad:chooseDesign", data);
    const res = await prepChoice;
    design = data.designs[res.detail];
  }

  if (!design) throw new Error("no design");

  const blocks = data.configuration[design.type].blocks
      .map(block => getAtlasIndexFromMetadata(block, design.type, "blocks"));

  const designWithAtlas = design.design.map(a => a.map(b => b.map(c => c === -1 ? -1 : blocks[c])));

  loadPlanner(design.dimensions, design.type, designWithAtlas);
}