import { warnDev } from "@/lib/log";

export function discordAppIconUrl(
    applicationId: string,
    iconHash: string | null,
    size = 128,
): string | null {
    if (!iconHash) {
        return null;
    }
    const extension = iconHash.startsWith("a_") ? "gif" : "png";
    return `https://cdn.discordapp.com/app-icons/${applicationId}/${iconHash}.${extension}?size=${size}`;
}

export function discordGameUrl(gameId: string): string {
    return `https://discord.com/games/${gameId}`;
}

export function discordAppCoverUrl(
    applicationId: string,
    coverHash: string | null,
    size = 512,
): string | null {
    if (!coverHash) {
        return null;
    }
    return `https://cdn.discordapp.com/app-icons/${applicationId}/${coverHash}.png?size=${size}`;
}

export function steamdbAppUrl(steamId: string): string {
    return `https://steamdb.info/app/${steamId}/`;
}

export interface DiscordAppInfo {
    id: string;
    name: string;
    icon: string | null;
    iconUrl: string | null;
    coverImage: string | null;
    coverUrl: string | null;
    gameId: string;
    gameUrl: string;
}

interface DiscordRpcResponse {
    id?: string;
    name?: string;
    icon?: string | null;
    cover_image?: string | null;
    linked_games?: Array<{ id: string }> | null;
}

export async function getDiscordAppInfo(applicationId: string): Promise<DiscordAppInfo | null> {
    if (!/^\d+$/.test(applicationId)) {
        return null;
    }
    let response: Response;
    try {
        response = await fetch(`https://discord.com/api/v10/applications/${applicationId}/rpc`, {
            headers: { "User-Agent": "fristy.net (personal site)" },
            next: { revalidate: 86_400 },
        });
    } catch (error) {
        throw new Error(`discord rpc unreachable: ${applicationId}`, { cause: error });
    }
    if (!response.ok) {
        if (response.status === 404) {
            return null;
        }
        if (response.status >= 500 || response.status === 429) {
            throw new Error(`discord rpc upstream failed: ${applicationId} -> ${response.status}`, {
                cause: new Error(`HTTP ${response.status}`),
            });
        }
        warnDev(`discord app failed: ${response.status}`);
        return null;
    }
    let json: DiscordRpcResponse;
    try {
        json = (await response.json()) as DiscordRpcResponse;
    } catch (error) {
        throw new Error(`discord rpc malformed response: ${applicationId}`, { cause: error });
    }
    const gameId = json.linked_games?.[0]?.id ?? json.id ?? applicationId;
    return {
        id: json.id ?? applicationId,
        name: json.name ?? "",
        icon: json.icon ?? null,
        iconUrl: discordAppIconUrl(applicationId, json.icon ?? null),
        coverImage: json.cover_image ?? null,
        coverUrl: discordAppCoverUrl(applicationId, json.cover_image ?? null),
        gameId,
        gameUrl: discordGameUrl(gameId),
    };
}