import { CONFIG } from "./config.js";
import { loadSession, saveSession, clearSession } from "./storage.js";

function urlJoin(base, path) {
    if (!base) return path;
    return base.replace(/\/+$/, "") + "/" + path.replace(/^\/+/, "");
}

async function parseResponse(res) {
    const ct = (res.headers.get("content-type") || "").toLowerCase();
    if (ct.includes("application/json")) return await res.json();

    const text = await res.text();
    try { return JSON.parse(text); } catch { return text; }
}

function applyAuthHeaders(reqHeaders, session) {
    const t = String(session.short_token);
    reqHeaders["short_token"] = t;               // контракт твоего API
    reqHeaders["Authorization"] = `Bearer ${t}`; // дубль (не мешает, пригодится)
}

function filenameFromDisposition(cd) {
    if (!cd) return null;

    let m = cd.match(/filename\*\s*=\s*UTF-8''([^;]+)/i);
    if (m?.[1]) return decodeURIComponent(m[1].replace(/"/g, "").trim());

    m = cd.match(/filename\s*=\s*"?([^";]+)"?/i);
    if (m?.[1]) return m[1].trim();

    return null;
}

export async function renewTokens() {
    const s = loadSession();
    if (!s?.user_id || !s?.live_token) {
        clearSession();
        throw new Error("NO_SESSION");
    }

    const res = await fetch(urlJoin(CONFIG.API_BASE_URL, CONFIG.ENDPOINTS.renew), {
        method: "GET",
        headers: {
            "user_id": String(s.user_id),
                            "live_token": String(s.live_token),
                            // дубли (на случай фильтрации) — сервер может игнорировать
                            "user-id": String(s.user_id),
                            "live-token": String(s.live_token),
                            "X-User-Id": String(s.user_id),
                            "X-Live-Token": String(s.live_token),
        }
    });

    if (res.status === CONFIG.AUTH_ERROR_STATUS) {
        clearSession();
        throw new Error("RENEW_DENIED");
    }

    if (!res.ok) {
        const body = await parseResponse(res);
        const err = new Error("RENEW_FAILED");
        err.status = res.status;
        err.payload = body;
        throw err;
    }

    const data = await parseResponse(res);
    if (!data?.short_token || !data?.live_token) {
        const err = new Error("BAD_RENEW_RESPONSE");
        err.payload = data;
        throw err;
    }

    const next = { ...s, short_token: data.short_token, live_token: data.live_token };
    saveSession(next);
    return next;
}

export async function apiFetch(path, {
    method = "GET",
    headers = {},
    body = null,
    auth = true
} = {}) {
    const s = loadSession();
    const reqHeaders = { ...headers };

    if (auth) {
        if (!s?.short_token) throw new Error("NO_AUTH");
        applyAuthHeaders(reqHeaders, s);
    }

    const doRequest = async () => {
        const finalHeaders = {
            ...reqHeaders,
            ...(body ? { "content-type": "application/json" } : {})
        };

        return await fetch(urlJoin(CONFIG.API_BASE_URL, path), {
            method,
            headers: finalHeaders,
            body: body ? JSON.stringify(body) : null
        });
    };

    let res = await doRequest();

    if (auth && res.status === CONFIG.AUTH_ERROR_STATUS) {
        await renewTokens();
        const s2 = loadSession();
        applyAuthHeaders(reqHeaders, s2);
        res = await doRequest();
    }

    const payload = await parseResponse(res);
    if (!res.ok) {
        const err = new Error("API_ERROR");
        err.status = res.status;
        err.payload = payload;
        throw err;
    }

    return payload;
}

export async function apiFetchBlob(path, {
    method = "GET",
    headers = {},
    auth = true
} = {}) {
    const s = loadSession();
    const reqHeaders = { ...headers };

    if (auth) {
        if (!s?.short_token) throw new Error("NO_AUTH");
        applyAuthHeaders(reqHeaders, s);
    }

    const doRequest = async () => {
        return await fetch(urlJoin(CONFIG.API_BASE_URL, path), {
            method,
            headers: reqHeaders
        });
    };

    let res = await doRequest();

    if (auth && res.status === CONFIG.AUTH_ERROR_STATUS) {
        await renewTokens();
        const s2 = loadSession();
        applyAuthHeaders(reqHeaders, s2);
        res = await doRequest();
    }

    if (!res.ok) {
        const text = await res.text().catch(() => "");
        const err = new Error("API_BLOB_ERROR");
        err.status = res.status;
        err.payload = text;
        throw err;
    }

    const blob = await res.blob();
    const filename = filenameFromDisposition(res.headers.get("content-disposition"));
    return { blob, filename };
}