import type { IgdbGame } from "@/lib/game/game-profile-types";
import { normalizeGameTitle } from "@/lib/game/game-format";
import { warnDev } from "@/lib/log";

const IGDB_GAME_FIELDS =
    "name,slug,genres.name,summary,storyline,cover.url,artworks.url,screenshots.url," +
    "websites.url,websites.category,involved_companies.developer," +
    "involved_companies.publisher,involved_companies.company.name," +
    "platforms.abbreviation,platforms.name,first_release_date;";

const TWITCH_TOKEN_URL = "https://id.twitch.tv/oauth2/token";
const TOKEN_FALLBACK_EXPIRY_S = 3600;
const MS_PER_SECOND = 1000;
const TOKEN_EXPIRY_SKEW_MS = 60_000;

let igdbTokenCache: { token: string; expires: number } | null = null;

let igdbKeyWarned = false;

export function _resetIgdbState(): void {
    igdbTokenCache = null;
    igdbKeyWarned = false;
}

async function getIgdbToken(): Promise<string | null> {
    const clientId = process.env.TWITCH_CLIENT_ID;
    const clientSecret = process.env.TWITCH_CLIENT_SECRET;
    if (!clientId || !clientSecret) {
        if (!igdbKeyWarned) {
            igdbKeyWarned = true;
            warnDev("igdb not configured");
        }
        return null;
    }
    if (igdbTokenCache && Date.now() < igdbTokenCache.expires) {
        return igdbTokenCache.token;
    }
    try {
        const response = await fetch(TWITCH_TOKEN_URL, {
            method: "POST",
            headers: { "Content-Type": "application/x-www-form-urlencoded" },
            body: new URLSearchParams({
                client_id: clientId,
                client_secret: clientSecret,
                grant_type: "client_credentials",
            }),
        });
        if (!response.ok) {
            warnDev(`igdb token failed: ${response.status}`);
            return null;
        }
        const json = (await response.json()) as { access_token?: string; expires_in?: number };
        if (!json.access_token) {
            return null;
        }
        igdbTokenCache = {
            token: json.access_token,
            expires:
                Date.now() +
                (json.expires_in ?? TOKEN_FALLBACK_EXPIRY_S) * MS_PER_SECOND -
                TOKEN_EXPIRY_SKEW_MS,
        };
        return json.access_token;
    } catch (error) {
        warnDev(`igdb token request failed: ${error instanceof Error ? error.message : error}`);
        return null;
    }
}

async function igdbQuery<T>(token: string, endpoint: string, body: string): Promise<T | null> {
    try {
        const response = await fetch(`https://api.igdb.com/v4/${endpoint}`, {
            method: "POST",
            headers: {
                "Client-ID": process.env.TWITCH_CLIENT_ID ?? "",
                Authorization: `Bearer ${token}`,
                "Content-Type": "text/plain",
            },
            body,
            next: { revalidate: 86_400 },
        });
        if (!response.ok) {
            warnDev(`igdb query failed: ${response.status}`);
            return null;
        }
        return (await response.json()) as T;
    } catch (error) {
        warnDev(`igdb query request failed: ${error instanceof Error ? error.message : error}`);
        return null;
    }
}

export function igdbImage(url: string | undefined, size: string): string | null {
    if (!url) {
        return null;
    }
    const full = url.startsWith("//") ? `https:${url}` : url;
    return full.replace(/t_thumb|t_cover_small|t_logo_med/, size);
}

export async function getIgdbGame(name: string, steamId: string | null): Promise<IgdbGame | null> {
    const token = await getIgdbToken();
    if (!token) {
        return null;
    }
    if (steamId) {
        const external = await igdbQuery<Array<{ game?: number }>>(
            token,
            "external_games",
            `fields game; where uid = "${steamId}"; limit 1;`,
        );
        const gameId = external?.[0]?.game;
        if (gameId) {
            const games = await igdbQuery<IgdbGame[]>(
                token,
                "games",
                `fields ${IGDB_GAME_FIELDS} where id = ${gameId}; limit 1;`,
            );
            if (games?.[0]) {
                return games[0];
            }
        }
    }
    const cleaned = name
        .replace(/[®™©]/g, "")
        .replace(/\s{2,}/g, " ")
        .trim();
    const escaped = cleaned.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
    const games = await igdbQuery<IgdbGame[]>(
        token,
        "games",
        `fields ${IGDB_GAME_FIELDS} search "${escaped}"; limit 5;`,
    );
    if (!games || games.length === 0) {
        return null;
    }
    const wanted = normalizeGameTitle(name);
    return games.find((g) => g.name && normalizeGameTitle(g.name) === wanted) ?? games[0] ?? null;
}