export class MonacoEditorAdapter {
  constructor(hostElement) {
    this.hostElement = hostElement;
    this.editor = null;
    this.model = null;
    this.changeHandler = null;
    this.suppressChange = false;
    this.readOnly = true;
  }

  async init() {
    const monaco = await this.#loadMonaco();
    if (!monaco || !this.hostElement) return false;

    this.#defineTheme(monaco);
    this.model = monaco.editor.createModel("", "plaintext");
    this.editor = monaco.editor.create(this.hostElement, {
      model: this.model,
      theme: "app-dark-blue",
      automaticLayout: true,
      readOnly: this.readOnly,
      minimap: { enabled: false },
      scrollBeyondLastLine: false,
      fontSize: 14,
      fontFamily: "IBM Plex Mono, Consolas, monospace",
      tabSize: 2
    });

    this.model.onDidChangeContent(() => {
      if (this.suppressChange || !this.changeHandler) return;
      this.changeHandler(this.model.getValue());
    });

    return true;
  }

  onChange(handler) {
    this.changeHandler = handler;
  }

  setReadOnly(readOnly) {
    this.readOnly = Boolean(readOnly);
    if (!this.editor) return;
    this.editor.updateOptions({ readOnly: this.readOnly });
  }

  setValue(text) {
    if (!this.model) return;
    const next = text || "";
    if (this.model.getValue() === next) return;
    this.suppressChange = true;
    this.model.pushEditOperations(
      [],
      [{ range: this.model.getFullModelRange(), text: next }],
      () => null
    );
    this.model.pushStackElement();
    this.suppressChange = false;
  }

  setLanguageByPath(path) {
    if (!this.model || !window.monaco?.editor) return;
    window.monaco.editor.setModelLanguage(this.model, this.#detectLanguage(path));
  }

  focus() {
    if (this.editor) this.editor.focus();
  }

  layout() {
    if (this.editor) this.editor.layout();
  }

  async #loadMonaco() {
    if (window.monaco?.editor) return window.monaco;
    if (typeof window.require !== "function") return null;
    if (window.__monacoPromise) return window.__monacoPromise;

    window.__monacoPromise = new Promise((resolve, reject) => {
      window.require.config({
        paths: {
          vs: "https://cdnjs.cloudflare.com/ajax/libs/monaco-editor/0.52.2/min/vs"
        }
      });
      window.require(["vs/editor/editor.main"], () => resolve(window.monaco), reject);
    });

    return window.__monacoPromise;
  }

  #defineTheme(monaco) {
    monaco.editor.defineTheme("app-dark-blue", {
      base: "vs-dark",
      inherit: true,
      rules: [
        { token: "comment", foreground: "7f9bbf" },
        { token: "keyword", foreground: "8cc8ff" },
        { token: "string", foreground: "a7d98f" }
      ],
      colors: {
        "editor.background": "#0b1830",
        "editor.foreground": "#dce9ff",
        "editorLineNumber.foreground": "#5e79a2",
        "editorLineNumber.activeForeground": "#a7c3eb",
        "editor.selectionBackground": "#274f8677",
        "editor.inactiveSelectionBackground": "#274f8644",
        "editorCursor.foreground": "#4fa0ff"
      }
    });
  }

  #detectLanguage(path) {
    const ext = (path || "").split(".").pop()?.toLowerCase();
    switch (ext) {
      case "js":
      case "mjs":
      case "cjs":
        return "javascript";
      case "ts":
        return "typescript";
      case "json":
        return "json";
      case "md":
      case "markdown":
        return "markdown";
      case "yml":
      case "yaml":
        return "yaml";
      case "xml":
        return "xml";
      case "html":
        return "html";
      case "css":
        return "css";
      case "sh":
      case "bash":
        return "shell";
      case "py":
        return "python";
      case "toml":
        return "ini";
      default:
        return "plaintext";
    }
  }
}