import { env } from '$env/dynamic/private';
import { redirect, type Cookies } from '@sveltejs/kit';

const DEFAULT_WORKSPACE_BASE_URL = 'https://workspace.aduanasoft.com';
const RETURN_PATH_COOKIE = 'workspace_return_path';

/**
 * Returns true only when the public-facing URL uses HTTPS.
 * Use this for cookie `secure` flag instead of NODE_ENV so that
 * cookies work on HTTP LAN dev environments (e.g. 192.168.x.x).
 */
export function isSecureContext(): boolean {
	const origin = (env.ORIGIN || process.env.ORIGIN || '').trim();
	if (origin) return origin.startsWith('https://');
	return process.env.NODE_ENV === 'production';
}

function stripTrailingSlashes(value: string): string {
	return value.replace(/\/+$/, '');
}

function isInternalOnlyHost(rawUrl: string): boolean {
	try {
		const parsed = new URL(rawUrl);
		const host = parsed.hostname.toLowerCase();
		return host === 'host.docker.internal' || host === 'backend' || host === 'hub-keycloak';
	} catch {
		return false;
	}
}

export function getWorkspaceBaseUrl(): string {
	const candidates = [
		(env.VITE_HUB_URL || '').trim(),
		(env.HUB_URL || '').trim(),
		DEFAULT_WORKSPACE_BASE_URL
	].filter(Boolean);

	for (const candidate of candidates) {
		if (!isInternalOnlyHost(candidate)) {
			return stripTrailingSlashes(candidate);
		}
	}

	return DEFAULT_WORKSPACE_BASE_URL;
}

export type WorkspaceLoginUrlOptions = {
	/**
	 * URL del login del Hub sin `return_to`. Usar en `post_logout_redirect_uri` para que,
	 * tras logout en KC, el Hub aplique myApps() (launcher si el usuario tiene varias apps).
	 * Con `return_to` a Anexo76, el re-login siempre rebotaba a esa app aunque hubiera más.
	 */
	forPostLogout?: boolean;
};

export function getWorkspaceLoginUrl(
	systemBaseUrl: string,
	options?: WorkspaceLoginUrlOptions
): string {
	const workspaceBaseUrl = getWorkspaceBaseUrl();
	if (options?.forPostLogout) {
		return `${workspaceBaseUrl}/login`;
	}
	// return_to includes sso_verified=1 so the workspace preserves it when redirecting
	// back, regardless of what additional params the workspace appends.
	const loginUrl = `${systemBaseUrl}/login?sso_verified=1`;
	return `${workspaceBaseUrl}/login?return_to=${encodeURIComponent(loginUrl)}`;
}

export function storeReturnPath(cookies: Cookies, path: string): void {
	if (!path || !path.startsWith('/')) return;
	cookies.set(RETURN_PATH_COOKIE, path, {
		path: '/',
		httpOnly: true,
		sameSite: 'lax',
		secure: isSecureContext(),
		maxAge: 60 * 10
	});
}

export function getPublicKeycloakBaseUrl(): string {
	const configuredKeycloakUrl = (env.VITE_KEYCLOAK_URL || '').trim();
	if (configuredKeycloakUrl) {
		return stripTrailingSlashes(configuredKeycloakUrl);
	}

	return `${getWorkspaceBaseUrl()}/kcauth`;
}

export function getKeycloakRealm(): string {
	return (env.KEYCLOAK_REALM || env.VITE_KEYCLOAK_REALM || 'master').trim();
}

export function getKeycloakClientId(): string {
	return (env.KEYCLOAK_CLIENT_ID || env.VITE_KEYCLOAK_CLIENT_ID || 'hub-frontend').trim();
}

export function getCleanReturnPath(url: URL): string {
	const cleanParams = new URLSearchParams(url.searchParams);
	cleanParams.delete('sso_verified');

	const queryString = cleanParams.toString();
	return queryString ? `${url.pathname}?${queryString}` : url.pathname;
}

export function storeWorkspaceReturnPath(cookies: Cookies, url: URL): string {
	const returnPath = getCleanReturnPath(url);

	cookies.set(RETURN_PATH_COOKIE, returnPath, {
		path: '/',
		httpOnly: true,
		sameSite: 'lax',
		secure: isSecureContext(),
		maxAge: 60 * 10
	});

	return returnPath;
}

export function readWorkspaceReturnPath(cookies: Cookies, fallbackPath: string): string {
	const storedReturnPath = cookies.get(RETURN_PATH_COOKIE);
	if (storedReturnPath && storedReturnPath.startsWith('/')) {
		return storedReturnPath;
	}

	return fallbackPath;
}

export function clearWorkspaceReturnPath(cookies: Cookies): void {
	cookies.delete(RETURN_PATH_COOKIE, { path: '/' });
}

export function buildKeycloakAuthorizationUrl(systemBaseUrl: string, redirectPath: string): string {
	const keycloakBaseUrl = getPublicKeycloakBaseUrl();
	const redirectUri = `${systemBaseUrl}/auth/callback`;
	const state = JSON.stringify({ redirect_url: redirectPath });
	const params = new URLSearchParams({
		client_id: getKeycloakClientId(),
		redirect_uri: redirectUri,
		response_type: 'code',
		scope: 'openid',
		prompt: 'none',
		state
	});

	return `${keycloakBaseUrl}/realms/${getKeycloakRealm()}/protocol/openid-connect/auth?${params.toString()}`;
}

/**
 * Construye URL de login directo en KC sin prompt=none.
 * Usa la sesión KC existente si la hay; si no, muestra el form de login.
 * Usar cuando se recibe ?redirect= del Hub (rompe el loop Hub↔login).
 */
export function buildKeycloakLoginUrl(systemBaseUrl: string, redirectPath: string): string {
	const keycloakBaseUrl = getPublicKeycloakBaseUrl();
	const redirectUri = `${systemBaseUrl}/auth/callback`;
	const state = JSON.stringify({ redirect_url: redirectPath });
	const params = new URLSearchParams({
		client_id: getKeycloakClientId(),
		redirect_uri: redirectUri,
		response_type: 'code',
		scope: 'openid',
		state
	});

	return `${keycloakBaseUrl}/realms/${getKeycloakRealm()}/protocol/openid-connect/auth?${params.toString()}`;
}

export function redirectToWorkspaceLogin(cookies: Cookies, url: URL): never {
	storeWorkspaceReturnPath(cookies, url);
	throw redirect(303, getWorkspaceLoginUrl(url.origin));
}

export function redirectToKeycloakAuthorization(systemBaseUrl: string, redirectPath: string): never {
	throw redirect(303, buildKeycloakAuthorizationUrl(systemBaseUrl, redirectPath));
}

export function redirectToKeycloakLogin(systemBaseUrl: string, redirectPath: string): never {
	throw redirect(303, buildKeycloakLoginUrl(systemBaseUrl, redirectPath));
}

export function buildKeycloakLogoutUrl(systemBaseUrl: string, idTokenHint?: string): string {
	const keycloakBaseUrl = getPublicKeycloakBaseUrl();
	const postLogoutRedirectUri = `${systemBaseUrl}/auth/post-logout`;
	const params = new URLSearchParams({
		client_id: getKeycloakClientId(),
		post_logout_redirect_uri: postLogoutRedirectUri
	});

	// Con id_token_hint KC acepta cualquier post_logout_redirect_uri sin necesidad
	// de que esté registrado explícitamente en el cliente.
	if (idTokenHint) {
		params.set('id_token_hint', idTokenHint);
	}

	return `${keycloakBaseUrl}/realms/${getKeycloakRealm()}/protocol/openid-connect/logout?${params.toString()}`;
}