import axios from "axios";

import { withPrefix } from "@/utils/redirect";
import { rethrowSimple } from "@/utils/simple-error";

export type OIDCConfigEntry = {
    icon?: string;
    label?: string;
    custom_button_text?: string;
    end_user_registration_endpoint?: string;
    profile_url?: string;
};

/** Shape of the OIDC config object coming from Galaxy’s `/api/config`. */
export type OIDCConfig = Record<string, OIDCConfigEntry>;

export type OIDCConfigWithRegistration = Record<string, OIDCConfigEntry & { end_user_registration_endpoint: string }>;

/** Return the per-IDP config, minus anything the caller wants to hide. */
export function getFilteredOIDCIdps(oidcConfig: OIDCConfig, exclude: string[] = []): OIDCConfig {
    const blacklist = new Set(["cilogon", ...exclude]);
    const filtered: OIDCConfig = {};
    Object.entries(oidcConfig).forEach(([idp, cfg]) => {
        if (!blacklist.has(idp)) {
            filtered[idp] = cfg;
        }
    });
    return filtered;
}

export function getOIDCIdpsWithRegistration(oidcConfig: OIDCConfig): OIDCConfigWithRegistration {
    const filtered: OIDCConfigWithRegistration = {};
    Object.entries(oidcConfig).forEach(([idp, cfg]) => {
        if (cfg.end_user_registration_endpoint && typeof cfg.end_user_registration_endpoint === "string") {
            filtered[idp] = {
                ...cfg,
                end_user_registration_endpoint: cfg.end_user_registration_endpoint,
            };
        }
    });
    return filtered;
}

/** Do we need to show the institution picker at all? */
export const getNeedShowCilogonInstitutionList = (cfg: OIDCConfig): boolean => {
    return Boolean(cfg.cilogon);
};

/**
 * Generic OIDC login (all providers *except* CILogon).
 * Returns the redirect URI Galaxy gives back, or throws.
 */
export async function submitOIDCLogon(idp: string, redirectParam: string | null = null): Promise<string | null> {
    const formData = new FormData();
    formData.append("next", redirectParam ?? "");

    try {
        const { data } = await axios.post<{ redirect_uri?: string }>(withPrefix(`/authnz/${idp}/login`), formData, {
            withCredentials: true,
        });
        return data.redirect_uri ?? null;
    } catch (error) {
        rethrowSimple(error);
    }
}

/**
 * CILogon login.
 * @param useIDPHint If true, append ?idphint=
 * @param idpHint    The entityID to hint with (ignored when useIDPHint = false)
 */
export async function submitCILogon(useIDPHint = false, idpHint?: string): Promise<string | null> {
    let url = withPrefix("/authnz/cilogon/login/");
    if (useIDPHint && idpHint) {
        url += `?idphint=${encodeURIComponent(idpHint)}`;
    }

    try {
        const { data } = await axios.post<{ redirect_uri?: string }>(url);
        return data.redirect_uri ?? null;
    } catch (error) {
        rethrowSimple(error);
    }
}

export function isOnlyOneOIDCProviderConfigured(config: OIDCConfig): boolean {
    return Object.keys(config).length === 1;
}

export function getSingleOidcConfig(config: OIDCConfig): OIDCConfigEntry | null {
    const providers = Object.keys(config);
    if (providers.length !== 1) {
        return null;
    }
    const idp = providers[0];
    if (idp === undefined) {
        throw new Error("OIDC provider key is undefined.");
    }
    return config[idp] || null;
}

export function hasSingleOidcProfile(config: OIDCConfig): boolean {
    if (!isOnlyOneOIDCProviderConfigured(config)) {
        return false;
    }
    const idp_config = getSingleOidcConfig(config);
    return !!idp_config?.profile_url;
}

export async function redirectToSingleProvider(config: OIDCConfig): Promise<string | null> {
    const providers = Object.keys(config);

    if (providers.length !== 1) {
        return null;
    }

    const idp = providers[0];
    if (!idp) {
        throw new Error("OIDC provider key is undefined.");
    }

    if (idp === "cilogon") {
        const redirectUri = await submitCILogon(false);
        return redirectUri;
    } else {
        const redirectUri = await submitOIDCLogon(idp, "");
        return redirectUri;
    }
}