// The hub's file editor (hub spec §6.9): CodeMirror 6 mounted over a
// textarea, which stays the form field, so the page works without script.
import { EditorView, basicSetup } from "codemirror";
import { EditorState } from "@codemirror/state";
import { keymap } from "@codemirror/view";
import { indentWithTab } from "@codemirror/commands";
import { javascript } from "@codemirror/lang-javascript";
import { rust } from "@codemirror/lang-rust";
import { cpp } from "@codemirror/lang-cpp";
import { python } from "@codemirror/lang-python";
import { markdown } from "@codemirror/lang-markdown";
import { html } from "@codemirror/lang-html";
import { css } from "@codemirror/lang-css";
import { json } from "@codemirror/lang-json";
import { yaml } from "@codemirror/lang-yaml";
import { oneDark } from "@codemirror/theme-one-dark";

function language(path) {
  const ext = (path.split(".").pop() || "").toLowerCase();
  switch (ext) {
    case "js": case "mjs": case "cjs": return javascript();
    case "ts": case "mts": return javascript({ typescript: true });
    case "jsx": return javascript({ jsx: true });
    case "tsx": return javascript({ jsx: true, typescript: true });
    case "rs": return rust();
    case "c": case "h": case "cc": case "cpp": case "hpp": case "cxx": return cpp();
    case "py": return python();
    case "md": case "markdown": return markdown();
    case "html": case "htm": return html();
    case "css": return css();
    case "json": return json();
    case "yml": case "yaml": return yaml();
    default: return [];
  }
}

function dark() {
  const t = document.documentElement.dataset.theme;
  if (t === "light") return false;
  if (t === "dark") return true;
  return !window.matchMedia || !window.matchMedia("(prefers-color-scheme: light)").matches;
}

function mount(textarea) {
  const view = new EditorView({
    state: EditorState.create({
      doc: textarea.value,
      extensions: [basicSetup, keymap.of([indentWithTab]), language(textarea.dataset.path || ""), dark() ? oneDark : [], EditorView.lineWrapping],
    }),
  });
  textarea.style.display = "none";
  textarea.parentNode.insertBefore(view.dom, textarea);
  view.dom.classList.add("cm-host");
  const form = textarea.form;
  if (form) {
    form.addEventListener("submit", () => {
      textarea.value = view.state.doc.toString();
    });
  }
  return view;
}

document.querySelectorAll("textarea.code").forEach(mount);
window.OxyEditor = { mount };