import { window, OverviewRulerLane, DecorationOptions, Uri, MarkdownString, Range, workspace, ExtensionContext } from "vscode";
import { findReferences } from "./reference";

let timeout: NodeJS.Timer | undefined = undefined;

// create a decorator type that we use to decorate small numbers
const referenceDecorationType = window.createTextEditorDecorationType({
    borderWidth: '2px',
    borderStyle: 'none none solid none',
    overviewRulerColor: 'blue',
    overviewRulerLane: OverviewRulerLane.Right,
    light: {
        // this color will be used in light color themes
        borderColor: 'darkblue'
    },
    dark: {
        // this color will be used in dark color themes
        borderColor: 'lightblue'
    }
});


let activeEditor = window.activeTextEditor;

function updateDecorations() {
    if (!activeEditor) {
        return;
    }
    const regEx = /\d+/g;
    const text = activeEditor.document.getText();
    const decorations: DecorationOptions[] = [];

    const references = findReferences(activeEditor.document);

    for(let reference of references) {
        const uriArguments = `?${encodeURIComponent(JSON.stringify([reference]))}`;
        const pdfCommandUri = Uri.parse(`command:zoterolens.openZoteroPDF`+uriArguments);
        const viewCommandUri = Uri.parse(`command:zoterolens.showInZotero`+uriArguments);
        const pageNr = reference.pagenr === null ? "" : `(${reference.pagenr})`;
        const contents = new MarkdownString(`${reference.citekey} ${pageNr}\n\n[View in Zotero](${viewCommandUri}) | [Open PDF](${pdfCommandUri})`);

        // To enable command URIs in Markdown content, you must set the `isTrusted` flag.
        // When creating trusted Markdown string, make sure to properly sanitize all the
        // input content so that only expected command URIs can be executed
        contents.isTrusted = true;

        const decoration = { range: reference.range, hoverMessage: contents };
        decorations.push(decoration);
    }

    activeEditor.setDecorations(referenceDecorationType, decorations);
}

function triggerUpdateDecorations(throttle = false) {
    if (timeout) {
        clearTimeout(timeout);
        timeout = undefined;
    }
    if (throttle) {
        timeout = setTimeout(updateDecorations, 500);
    } else {
        updateDecorations();
    }
}

export function activateDecorations(context: ExtensionContext) {

    if (activeEditor) {
        triggerUpdateDecorations();
    }

    window.onDidChangeActiveTextEditor(editor => {
        activeEditor = editor;
        if (editor) {
            triggerUpdateDecorations();
        }
    }, null, context.subscriptions);

    workspace.onDidChangeTextDocument(event => {
        console.log(event.contentChanges);
        if (activeEditor && event.document === activeEditor.document) {
            triggerUpdateDecorations(true);
        }
    }, null, context.subscriptions);

}