/**
 * Environment configuration for lt-auth-proxy.
 * All properties are lazily evaluated and cached on first access.
 */

export class Env {
    private static _proxyHost?: string;
    private static _proxyPort?: number;
    private static _apiKeys?: string[];
    private static _ltServerHost?: string;
    private static _ltServerPort?: number;

    private static getEnv(key: string, required = false): string | undefined {
        const value = Deno.env.get(key);
        if (required && (!value || value.trim() === '')) {
            throw new Error(`Missing required environment variable: ${key}`);
        }
        return value;
    }

    /** Hostname for the proxy (default: 0.0.0.0) */
    static get proxyHost(): string {
        if (this._proxyHost === undefined) {
            this._proxyHost = this.getEnv('PROXY_HOST') || '0.0.0.0';
        }
        return this._proxyHost;
    }

    /** Port for the proxy (default: 8011) */
    static get proxyPort(): number {
        if (this._proxyPort === undefined) {
            this._proxyPort = Number(this.getEnv('PROXY_PORT') || 8011);
        }
        return this._proxyPort;
    }

    /** List of allowed API keys (required) */
    static get apiKeys(): string[] {
        if (this._apiKeys === undefined) {
            const raw = this.getEnv('API_KEYS', true)!;
            this._apiKeys = raw.split(',').map((k) => k.trim()).filter((k) =>
                k.length > 0
            );
        }
        return this._apiKeys;
    }

    /** Hostname of the LanguageTool backend (default: localhost) */
    static get ltServerHost(): string {
        if (this._ltServerHost === undefined) {
            this._ltServerHost = this.getEnv('LT_SERVER_HOST') || 'localhost';
        }
        return this._ltServerHost;
    }

    /** Port of the LanguageTool backend (default: 8010) */
    static get ltServerPort(): number {
        if (this._ltServerPort === undefined) {
            this._ltServerPort = Number(this.getEnv('LT_SERVER_PORT') || 8010);
        }
        return this._ltServerPort;
    }

    /** VERBOSE */
    static get verbose(): boolean {
        return this.getEnv('VERBOSE') === 'true';
    }
}