import { EditorState } from '@codemirror/state';
import { openSearchPanel, highlightSelectionMatches, searchKeymap } from '@codemirror/search';
import { openLintPanel, lintGutter, lintKeymap, linter, setDiagnostics, } from "@codemirror/lint"
import { indentWithTab, history, defaultKeymap, historyKeymap } from '@codemirror/commands';
import { foldGutter, indentOnInput, indentUnit, bracketMatching, foldKeymap, syntaxHighlighting, defaultHighlightStyle } from '@codemirror/language';
import { closeBrackets, autocompletion, closeBracketsKeymap, completionKeymap } from '@codemirror/autocomplete';
import { lineNumbers, highlightActiveLineGutter, highlightSpecialChars, drawSelection, dropCursor, rectangularSelection, crosshairCursor, highlightActiveLine, keymap, EditorView } from '@codemirror/view';

// Theme
import { oneDark } from "@codemirror/theme-one-dark";
import { LSPClient, LSPPlugin, languageServerSupport } from "@codemirror/lsp-client";
// Language
import { xml } from "@codemirror/lang-xml";

// return promise with socket map or reject if no connect
function simpleWebSocketTransport(uri) {
    let handlers = [];
    return new Promise(function (resolve, reject) {
        let sock = new WebSocket(uri);
        sock.onmessage = e => { for (let h of handlers) h(e.data.toString()); };
        sock.onerror = e => reject(e);
        sock.onopen = () => resolve({
            socket: sock,
            send: (message) => sock.send(message),
            subscribe: (handler) => handlers.push(handler),
            unsubscribe: (handler) => handlers = handlers.filter(h => h != handler)
        });
    }
    );
};

const baseExts = [
    lineNumbers(),
    highlightActiveLineGutter(),
    highlightSpecialChars(),
    history(),
    foldGutter(),
    lintGutter(),
    drawSelection(),
    indentUnit.of("    "),
    EditorState.allowMultipleSelections.of(true),
    EditorView.lineWrapping,
    indentOnInput(),
    bracketMatching(),
    closeBrackets(),
    autocompletion(),
    rectangularSelection(),
    crosshairCursor(),
    highlightActiveLine(),
    highlightSelectionMatches(),
    keymap.of([
        indentWithTab,
        ...closeBracketsKeymap,
        ...defaultKeymap,
        ...historyKeymap,
        ...foldKeymap,
        ...completionKeymap,
        ...searchKeymap,
        ...lintKeymap
    ]),
    xml(),
    syntaxHighlighting(defaultHighlightStyle, { fallback: true })
];

function createEditorState(initialContents, extensions, options = {}) {

    if (options.oneDark)
        extensions.push(oneDark);

    return EditorState.create({
        doc: initialContents,
        extensions
    });
}

function createEditorView(state, parent) {
    return new EditorView({ state, parent });
}

class xqLinter {
    constructor(parameters) {
        this.fred = parameters;
    }
}
function debouncedChangeListener({ delay = 750, onChange }) {
    let timeoutId = null;
    let lastContent = '';
    
    return EditorView.updateListener.of(update => {
      if (update.docChanged) {
        const currentContent = update.state.doc.toString();
        
        if (timeoutId) {
          clearTimeout(timeoutId);
        }
        
        timeoutId = setTimeout(() => {
          if (currentContent !== lastContent) {
            lastContent = currentContent;
            onChange(currentContent, update.state);
          }
        }, delay);
      }
    });
  }
  
export { createEditorState, createEditorView, openSearchPanel, openLintPanel, languageServerSupport, baseExts, simpleWebSocketTransport, linter, LSPPlugin, setDiagnostics, xqLinter, LSPClient,debouncedChangeListener };