interface SavedSearch {
    query: string;
    type: "text" | "title" | "tag";
    sort: "hot" | "new";
}

export default () => {
    // deno-lint-ignore ban-types
    const oldOnloadHandler: Function = window.onload ?? (() => {});

    window.onload = () => {
        oldOnloadHandler();
        const button = document.getElementById("favorite");

        if (!button) throw "how did your button not init what";

        let savedSearches: SavedSearch[] = JSON.parse(
            localStorage.getItem("savedSearches") ?? "[]",
        );

        function handler() {
            if (button?.textContent === "Favorite") {
                savedSearches.push({
                    query: (new URL(document.URL)).searchParams.get(
                        "query",
                    ) as string,
                    type: (new URL(document.URL)).searchParams.get(
                        "type",
                    ) as "text" | "title" | "tag",
                    sort: (new URL(document.URL)).searchParams.get(
                        "sort",
                    ) as "hot" | "new",
                });
                button.textContent = "Unfavorite";
            } else if (button?.textContent === "Unfavorite") {
                savedSearches = savedSearches.filter((search) =>
                    search.query !==
                        (new URL(document.URL)).searchParams.get("query") &&
                    search.type !==
                        (new URL(document.URL)).searchParams.get("type") &&
                    search.type !==
                        (new URL(document.URL)).searchParams.get("sort")
                );
                button.textContent = "Favorite";
            }
            localStorage.setItem(
                "savedSearches",
                JSON.stringify(savedSearches),
            );
        }

        if (
            savedSearches.filter((search) =>
                search.query ===
                    (new URL(document.URL)).searchParams.get("query") &&
                search.type ===
                    (new URL(document.URL)).searchParams.get("type") &&
                search.sort ===
                    (new URL(document.URL)).searchParams.get("sort")
            ).length > 0
        ) {
            button.textContent = "Unfavorite";
        }

        button.onclick = handler;
    };
};