// Blazor bridge for Monaco editor.
// Exposes window.MonacoBlazor with createEditor / setValue / getValue / dispose / setMarkers.
// Lazy-loads Monaco's AMD bundle the first time createEditor is called.

(function () {
    const VS_BASE = "/_content/ScadaLink.CentralUI/lib/monaco/vs";

    const editors = {};
    let readyPromise = null;

    function ensureLoaded() {
        if (readyPromise) return readyPromise;
        readyPromise = new Promise(function (resolve, reject) {
            const loader = document.createElement("script");
            loader.src = VS_BASE + "/loader.js";
            loader.onload = function () {
                // eslint-disable-next-line no-undef
                require.config({ paths: { vs: VS_BASE } });
                // eslint-disable-next-line no-undef
                require(["vs/editor/editor.main"], function () {
                    registerCSharpProviders();
                    resolve();
                });
            };
            loader.onerror = function (e) { reject(e); };
            document.head.appendChild(loader);
        });
        return readyPromise;
    }

    // ---- Roslyn-backed C# language providers --------------------------------

    const KIND_MAP = {
        Method: 0, Field: 4, Property: 9, Event: 10, Class: 6,
        Module: 8, Variable: 4, Text: 18
    };

    function registerCSharpProviders() {
        // Completion: triggered on ".", "(", "\"" and on demand (Ctrl-Space).
        monaco.languages.registerCompletionItemProvider("csharp", {
            triggerCharacters: [".", "(", "\""],
            provideCompletionItems: async function (model, position) {
                try {
                    const resp = await fetch("/api/script-analysis/completions", {
                        method: "POST",
                        credentials: "same-origin",
                        headers: { "Content-Type": "application/json" },
                        body: JSON.stringify({
                            codeText: model.getValue(),
                            line: position.lineNumber,
                            column: position.column
                        })
                    });
                    if (!resp.ok) return { suggestions: [] };
                    const data = await resp.json();
                    const word = model.getWordUntilPosition(position);
                    const range = {
                        startLineNumber: position.lineNumber,
                        endLineNumber: position.lineNumber,
                        startColumn: word.startColumn,
                        endColumn: word.endColumn
                    };
                    return {
                        suggestions: (data.items || []).map(function (it) {
                            return {
                                label: it.label,
                                insertText: it.insertText,
                                detail: it.detail,
                                kind: KIND_MAP[it.kind] != null ? KIND_MAP[it.kind] : 18,
                                range: range
                            };
                        })
                    };
                } catch (e) {
                    return { suggestions: [] };
                }
            }
        });
    }

    async function fetchDiagnostics(code) {
        try {
            const resp = await fetch("/api/script-analysis/diagnostics", {
                method: "POST",
                credentials: "same-origin",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify({ code: code })
            });
            if (!resp.ok) return [];
            const data = await resp.json();
            return data.markers || [];
        } catch (e) {
            return [];
        }
    }

    async function createEditor(id, host, options, dotNetRef) {
        await ensureLoaded();
        if (!host) return;
        const editor = monaco.editor.create(host, {
            value: options.value || "",
            language: options.language || "csharp",
            theme: "vs",
            minimap: { enabled: false },
            scrollBeyondLastLine: false,
            automaticLayout: true,
            fontSize: 13,
            lineNumbers: "on",
            renderLineHighlight: "line",
            readOnly: !!options.readOnly,
            tabSize: 4,
            insertSpaces: true,
            wordWrap: "off",
            fixedOverflowWidgets: true
        });
        let diagTimer = null;
        const scheduleDiagnostics = function () {
            if (diagTimer) clearTimeout(diagTimer);
            diagTimer = setTimeout(async function () {
                const markers = await fetchDiagnostics(editor.getValue());
                const model = editor.getModel();
                if (model) monaco.editor.setModelMarkers(model, "scadalink", markers);
            }, 500);
        };

        editor.onDidChangeModelContent(function () {
            const value = editor.getValue();
            dotNetRef.invokeMethodAsync("OnValueChanged", value).catch(function () {});
            if (options.language === "csharp") scheduleDiagnostics();
        });
        editors[id] = { editor: editor, dotNetRef: dotNetRef };

        // Run an initial diagnostic pass so existing scripts show their markers.
        if (options.language === "csharp") scheduleDiagnostics();
    }

    function setValue(id, value) {
        const entry = editors[id];
        if (!entry) return;
        if (entry.editor.getValue() !== value) {
            entry.editor.setValue(value || "");
        }
    }

    function getValue(id) {
        const entry = editors[id];
        return entry ? entry.editor.getValue() : null;
    }

    function setMarkers(id, markers) {
        const entry = editors[id];
        if (!entry) return;
        const model = entry.editor.getModel();
        if (!model) return;
        monaco.editor.setModelMarkers(model, "scadalink", markers || []);
    }

    function dispose(id) {
        const entry = editors[id];
        if (!entry) return;
        try { entry.editor.dispose(); } catch (e) {}
        delete editors[id];
    }

    window.MonacoBlazor = {
        createEditor: createEditor,
        setValue: setValue,
        getValue: getValue,
        setMarkers: setMarkers,
        dispose: dispose
    };
})();