import { LunaUnload, Tracer } from "@luna/core";

// Import CSS directly using Luna's file:// syntax
import unlockSelection from "file://styles.css?minify";

export const { trace } = Tracer("[Copy Lyrics]");

// clean up resources
export const unloads = new Set<LunaUnload>();

function ApplyCSS(style: string): HTMLStyleElement {
    const styleElement = document.createElement("style");
    styleElement.type = "text/css";
    styleElement.textContent = style;
    document.head.appendChild(styleElement);
    return styleElement;
}

function SetClipboard(text: string): void {
    const textarea = document.createElement("textarea");
    textarea.value = text;
    textarea.style.position = "fixed"; // Avoid scrolling to bottom
    document.body.appendChild(textarea);
    textarea.select();

    try {
        const success = document.execCommand("copy");
        if (!success) throw new Error("Failed to copy text.");
    } catch (err) {
        trace.msg.err(err instanceof Error ? err.message : String(err));
    } finally {
        document.body.removeChild(textarea);
    }
}

const styleElement = ApplyCSS(unlockSelection);

let isSelecting = false;

const onMouseDown = function (): void {
    isSelecting = true;
};

const onMouseUp = function (event: MouseEvent): void {
    if (isSelecting) {
        const selection = window.getSelection();
        if (selection && selection.toString().length > 0) {
            const selectedSpans: HTMLSpanElement[] = [];
            const range = selection.getRangeAt(0);
            let container = range.commonAncestorContainer;
            
            // If the container is NOT an element and a document, adjust it.
            if (
                container.nodeType !== Node.ELEMENT_NODE &&
                container.nodeType !== Node.DOCUMENT_NODE
            ) {
                // Get the parent element if it's a text node
                const parentElement = container.parentElement;
                if (parentElement && parentElement.hasAttribute("data-current")) {
                    let text_ = selection.toString().trim();
                    SetClipboard(text_);
                    trace.msg.log("Copied to clipboard!");
                    return;
                }
            }

            // Get all the spans inside the container.
            const spans = (container as Element).getElementsByTagName("span");
            for (let span of spans) {
                if (selection.containsNode(span, true)) {
                    selectedSpans.push(span as HTMLSpanElement);
                }
            }

            // Concat the text of the selected spans.
            let hasCorrectAttribute = false;
            let text = "";
            selectedSpans.forEach((span) => {
                if (span.hasAttribute("data-current")) {
                    hasCorrectAttribute = true;
                    text += span.textContent + "\n";
                    if ([...span.classList].some((className) => className.startsWith("endOfStanza--"))) {
                        text += "\n";
                    }
                }
            });

            text = text.trim();

            if (hasCorrectAttribute) {
                SetClipboard(text);
                trace.msg.log("Copied to clipboard!");
                selection.removeAllRanges();
            }
        }
        isSelecting = false;
    }
};

const onClickHooked = function (event: MouseEvent): boolean | void {
    if (!isSelecting) return;

    const target = event.target as HTMLElement;
    if (target.tagName.toLowerCase() === "span" && target.hasAttribute("data-current")) {
        // Prevent default behavior and stop event propagation
        event.preventDefault();
        event.stopPropagation();
        event.stopImmediatePropagation();
        return false;
    }
};

// Add event listener with capture phase to intercept events before they reach other handlers
document.addEventListener("click", onClickHooked, true);
document.addEventListener("mousedown", onMouseDown);
document.addEventListener("mouseup", onMouseUp);

// Add cleanup to unloads
unloads.add(() => {
    if (styleElement.parentNode) {
        styleElement.parentNode.removeChild(styleElement);
    }

    // Remove event listeners
    document.removeEventListener("click", onClickHooked, true);
    document.removeEventListener("mousedown", onMouseDown);
    document.removeEventListener("mouseup", onMouseUp);
});