import * as plugins from './smartacme.plugins.js';
import type { ICertManager } from './interfaces/certmanager.js';
import { SmartacmeCertMatcher } from './smartacme.classes.certmatcher.js';
import { commitinfo } from './00_commitinfo_data.js';
import { SmartacmeCert } from './smartacme.classes.cert.js';

/**
 * the options for the class @see SmartAcme
 */
export interface ISmartAcmeOptions {
  accountPrivateKey?: string;
  accountEmail: string;
  /**
   * Certificate storage manager (e.g., Mongo or in-memory).
   */
  certManager: ICertManager;
  // Removed legacy setChallenge/removeChallenge in favor of `challengeHandlers`
  environment: 'production' | 'integration';
  /**
   * Optional retry/backoff configuration for transient failures
   */
  retryOptions?: {
    /** number of retry attempts */
    retries?: number;
    /** backoff multiplier */
    factor?: number;
    /** initial delay in milliseconds */
    minTimeoutMs?: number;
    /** maximum delay cap in milliseconds */
    maxTimeoutMs?: number;
  };
  /**
   * Pluggable ACME challenge handlers (DNS-01, HTTP-01, TLS-ALPN-01, etc.)
   */
  challengeHandlers?: plugins.handlers.IChallengeHandler<any>[];
  /**
   * Order of challenge types to try (e.g. ['http-01','dns-01']).
   * Defaults to ['dns-01'] or first supported type from handlers.
   */
  challengePriority?: string[];
}

/**
 * class SmartAcme
 * can be used for setting up communication with an ACME authority
 *
 * ```ts
 * const mySmartAcmeInstance = new SmartAcme({
 *  // see ISmartAcmeOptions for options
 * })
 * ```
 */
export class SmartAcme {
  private options: ISmartAcmeOptions;

  // the acme client
  private client: plugins.acme.Client;
  private smartdns = new plugins.smartdnsClient.Smartdns({});
  public logger: plugins.smartlog.Smartlog;

  // the account private key
  private privateKey: string;


  // certificate manager for persistence (implements ICertManager)
  private certmanager: ICertManager;
  private certmatcher: SmartacmeCertMatcher;
  // retry/backoff configuration (resolved with defaults)
  private retryOptions: { retries: number; factor: number; minTimeoutMs: number; maxTimeoutMs: number };
  // track pending DNS challenges for graceful shutdown
  private pendingChallenges: plugins.tsclass.network.IDnsChallenge[] = [];
  // configured pluggable ACME challenge handlers
  private challengeHandlers: plugins.handlers.IChallengeHandler<any>[];
  // priority order of challenge types
  private challengePriority: string[];

  constructor(optionsArg: ISmartAcmeOptions) {
    this.options = optionsArg;
    this.logger = plugins.smartlog.Smartlog.createForCommitinfo(commitinfo);
    // enable console output for structured logging
    this.logger.enableConsole();
    // initialize retry/backoff options
    this.retryOptions = {
      retries: optionsArg.retryOptions?.retries ?? 10,
      factor: optionsArg.retryOptions?.factor ?? 4,
      minTimeoutMs: optionsArg.retryOptions?.minTimeoutMs ?? 1000,
      maxTimeoutMs: optionsArg.retryOptions?.maxTimeoutMs ?? 60000,
    };
    // initialize challenge handlers (must provide at least one)
    if (!optionsArg.challengeHandlers || optionsArg.challengeHandlers.length === 0) {
      throw new Error(
        'You must provide at least one ACME challenge handler via options.challengeHandlers',
      );
    }
    this.challengeHandlers = optionsArg.challengeHandlers;
    // initialize challenge priority
    this.challengePriority =
      optionsArg.challengePriority && optionsArg.challengePriority.length > 0
        ? optionsArg.challengePriority
        : this.challengeHandlers.map((h) => h.getSupportedTypes()[0]);
  }

  /**
   * starts the instance
   * ```ts
   * await myCloudlyInstance.start() // does not support options
   * ```
   */
  public async start() {
    this.privateKey =
      this.options.accountPrivateKey || (await plugins.acme.forge.createPrivateKey()).toString();

    // Initialize certificate manager
    if (!this.options.certManager) {
      throw new Error('You must provide a certManager via options.certManager');
    }
    this.certmanager = this.options.certManager;
    await this.certmanager.init();
    // For integration environment, clear any existing certificates to avoid stale entries
    if (this.options.environment === 'integration' && typeof (this.certmanager as any).wipe === 'function') {
      // this.logger.log('warn', 'Wiping existing certificates for integration environment');
      // await (this.certmanager as any).wipe();
    }

    // CertMatcher
    this.certmatcher = new SmartacmeCertMatcher();

    // ACME Client
    this.client = new plugins.acme.Client({
      directoryUrl: (() => {
        if (this.options.environment === 'production') {
          return plugins.acme.directory.letsencrypt.production;
        } else {
          return plugins.acme.directory.letsencrypt.staging;
        }
      })(),
      accountKey: this.privateKey,
    });

    /* Register account */
    await this.client.createAccount({
      termsOfServiceAgreed: true,
      contact: [`mailto:${this.options.accountEmail}`],
    });
    // Setup graceful shutdown handlers
    process.on('SIGINT', () => this.handleSignal('SIGINT'));
    process.on('SIGTERM', () => this.handleSignal('SIGTERM'));
  }

  /**
   * Stops the SmartAcme instance and closes certificate store connections.
   */
  public async stop() {
    if (this.certmanager && typeof (this.certmanager as any).close === 'function') {
      await (this.certmanager as any).close();
    }
  }
    /** Retry helper with exponential backoff */
    private async retry<T>(operation: () => Promise<T>, operationName: string = 'operation'): Promise<T> {
      let attempt = 0;
      let delay = this.retryOptions.minTimeoutMs;
      while (true) {
        try {
          return await operation();
        } catch (err) {
          attempt++;
          if (attempt > this.retryOptions.retries) {
            await this.logger.log('error', `Operation ${operationName} failed after ${attempt} attempts`, err);
            throw err;
          }
          await this.logger.log('warn', `Operation ${operationName} failed on attempt ${attempt}, retrying in ${delay}ms`, err);
          await plugins.smartdelay.delayFor(delay);
          delay = Math.min(delay * this.retryOptions.factor, this.retryOptions.maxTimeoutMs);
        }
      }
    }
    /** Clean up pending challenges and shut down */
    private async handleShutdown(): Promise<void> {
      for (const input of [...this.pendingChallenges]) {
        const type: string = (input as any).type;
        const handler = this.challengeHandlers.find((h) => h.getSupportedTypes().includes(type));
        if (handler) {
          try {
            await handler.cleanup(input);
            await this.logger.log('info', `Removed pending ${type} challenge during shutdown`, input);
          } catch (err) {
            await this.logger.log('error', `Failed to remove pending ${type} challenge during shutdown`, err);
          }
        } else {
          await this.logger.log(
            'warn',
            `No handler for pending challenge type '${type}' during shutdown; skipping cleanup`,
            input,
          );
        }
      }
      this.pendingChallenges = [];
      await this.stop();
    }
    /** Handle process signals for graceful shutdown */
    private handleSignal(sig: string): void {
      this.logger.log('info', `Received signal ${sig}, shutting down gracefully`);
      this.handleShutdown()
        .then(() => process.exit(0))
        .catch((err) => {
          this.logger.log('error', 'Error during shutdown', err).then(() => process.exit(1));
        });
    }

  /**
   * gets a certificate
   * it runs through the following steps
   *
   * * look in the database
   * * if in the database and still valid return it
   * * if not in the database announce it
   * * then get it from letsencrypt
   * * store it
   * * remove it from the pending map (which it go onto by announcing it)
   * * retrieve it from the databse and return it
   *
   * @param domainArg
   */
  public async getCertificateForDomain(domainArg: string): Promise<SmartacmeCert> {
    const certDomainName = this.certmatcher.getCertificateDomainNameByDomainName(domainArg);
    const retrievedCertificate = await this.certmanager.retrieveCertificate(certDomainName);

    if (
      !retrievedCertificate &&
      (await this.certmanager.interestMap.checkInterest(certDomainName))
    ) {
      const existingCertificateInterest = this.certmanager.interestMap.findInterest(certDomainName);
      const certificate = existingCertificateInterest.interestFullfilled;
      return certificate;
    } else if (retrievedCertificate && !retrievedCertificate.shouldBeRenewed()) {
      return retrievedCertificate;
    } else if (retrievedCertificate && retrievedCertificate.shouldBeRenewed()) {
      // Remove old certificate via certManager
      await this.certmanager.deleteCertificate(certDomainName);
    }

    // lets make sure others get the same interest
    const currentDomainInterst = await this.certmanager.interestMap.addInterest(certDomainName);

    /* Place new order with retry */
    const order = await this.retry(() => this.client.createOrder({
      identifiers: [
        { type: 'dns', value: certDomainName },
        { type: 'dns', value: `*.${certDomainName}` },
      ],
    }), 'createOrder');

    /* Get authorizations and select challenges */
    const authorizations = await this.retry(() => this.client.getAuthorizations(order), 'getAuthorizations');

    for (const authz of authorizations) {
      await this.logger.log('debug', 'Authorization received', authz);
      // select a handler based on configured priority
      let selectedHandler: { type: string; handler: plugins.handlers.IChallengeHandler<any> } | null = null;
      let selectedChallengeArg: any = null;
      for (const type of this.challengePriority) {
        const candidate = authz.challenges.find((c: any) => c.type === type);
        if (!candidate) continue;
        const handler = this.challengeHandlers.find((h) => h.getSupportedTypes().includes(type));
        if (handler) {
          selectedHandler = { type, handler };
          selectedChallengeArg = candidate;
          break;
        }
      }
      if (!selectedHandler) {
        throw new Error(`No challenge handler for domain ${authz.identifier.value}: supported types [${this.challengePriority.join(',')}]`);
      }
      const { type, handler } = selectedHandler;
      // build handler input with keyAuthorization
      let input: any;
      // retrieve keyAuthorization for challenge
      const keyAuth = await this.client.getChallengeKeyAuthorization(selectedChallengeArg);
      if (type === 'dns-01') {
        input = { type, hostName: `_acme-challenge.${authz.identifier.value}`, challenge: keyAuth };
      } else if (type === 'http-01') {
        // HTTP-01 requires serving token at webPath
        input = {
          type,
          token: (selectedChallengeArg as any).token,
          keyAuthorization: keyAuth,
          webPath: `/.well-known/acme-challenge/${(selectedChallengeArg as any).token}`,
        };
      } else {
        // generic challenge input: include raw challenge properties
        input = { type, keyAuthorization: keyAuth, ...selectedChallengeArg };
      }
      this.pendingChallenges.push(input);
      try {
        // Prepare the challenge (set DNS record, write file, etc.)
        await this.retry(() => handler.prepare(input), `${type}.prepare`);
        // For DNS-01, wait for propagation before verification
        if (type === 'dns-01') {
          const dnsInput = input as { hostName: string; challenge: string };
          // Wait for authoritative DNS propagation before ACME verify
          await this.retry(
            () => this.smartdns.checkUntilAvailable(dnsInput.hostName, 'TXT', dnsInput.challenge, 100, 5000),
            `${type}.propagation`,
          );
          // Extra cool-down to ensure ACME server sees the new TXT record
          this.logger.log('info', 'Cooling down for 1 minute before ACME verification');
          await plugins.smartdelay.delayFor(60000);
        }
        // Official ACME verification (ensures challenge is publicly reachable)
        await this.retry(
          () => this.client.verifyChallenge(authz, selectedChallengeArg),
          `${type}.verifyChallenge`,
        );
        // Notify ACME server to complete the challenge
        await this.retry(
          () => this.client.completeChallenge(selectedChallengeArg),
          `${type}.completeChallenge`,
        );
        // Wait for valid status (warnings on staging timeouts)
        try {
          await this.retry(
            () => this.client.waitForValidStatus(selectedChallengeArg),
            `${type}.waitForValidStatus`,
          );
        } catch (err) {
          await this.logger.log(
            'warn',
            `Challenge ${type} did not reach valid status in time, proceeding to finalize`,
            err,
          );
        }
      } finally {
        // Always cleanup resource
        try {
          await this.retry(() => handler.cleanup(input), `${type}.cleanup`);
        } catch (err) {
          await this.logger.log('error', `Error during ${type}.cleanup`, err);
        } finally {
          this.pendingChallenges = this.pendingChallenges.filter((c) => c !== input);
        }
      }
    }

    /* Finalize order */
    const [key, csr] = await plugins.acme.forge.createCsr({
      commonName: `*.${certDomainName}`,
      altNames: [certDomainName],
    });

    await this.retry(() => this.client.finalizeOrder(order, csr), 'finalizeOrder');
    const cert = await this.retry(() => this.client.getCertificate(order), 'getCertificate');

    /* Done */

    // Store the new certificate record
    const certRecord = new SmartacmeCert({
      id: plugins.smartunique.shortId(),
      domainName: certDomainName,
      privateKey: key.toString(),
      publicKey: cert.toString(),
      csr: csr.toString(),
      created: Date.now(),
      validUntil: Date.now() + plugins.smarttime.getMilliSecondsFromUnits({ days: 90 }),
    });
    await this.certmanager.storeCertificate(certRecord);

    const newCertificate = await this.certmanager.retrieveCertificate(certDomainName);
    currentDomainInterst.fullfillInterest(newCertificate);
    currentDomainInterst.destroy();
    return newCertificate;
  }

}