import type { Cloudly } from '../classes.cloudly.js';
import { logger } from '../logger.js';
import * as plugins from '../plugins.js';
import type { Service } from '../manager.service/classes.service.js';

type TAuthenticatedRegistryUser = {
  userId: string;
  username: string;
  canWrite: boolean;
};

export class CloudlyRegistryManager {
  private cloudlyRef: Cloudly;
  private smartRegistry!: plugins.smartregistry.SmartRegistry;
  private recordedTagDigests = new Map<string, string>();
  private started = false;

  constructor(cloudlyRefArg: Cloudly) {
    this.cloudlyRef = cloudlyRefArg;
  }

  public async start() {
    const publicRegistryUrl = this.getPublicRegistryUrl();
    const registryJwtSecret = JSON.stringify(this.cloudlyRef.authManager.smartjwtInstance.getKeyPairAsJson());
    const s3Descriptor = this.cloudlyRef.config.data.s3Descriptor;
    if (!s3Descriptor?.bucketName) {
      throw new Error('Cloudly registry requires an S3 bucketName');
    }

    this.smartRegistry = new plugins.smartregistry.SmartRegistry({
      storage: s3Descriptor as plugins.smartregistry.IStorageConfig,
      storageHooks: {
        afterPut: async (contextArg) => {
          await this.handleRegistryStorageAfterPut(contextArg);
        },
      },
      auth: {
        jwtSecret: registryJwtSecret,
        tokenStore: 'memory',
        npmTokens: { enabled: false },
        ociTokens: {
          enabled: true,
          realm: `${publicRegistryUrl}/v2/token`,
          service: this.cloudlyRef.config.data.publicUrl || 'cloudly',
        },
        pypiTokens: { enabled: false },
        rubygemsTokens: { enabled: false },
      },
      oci: {
        enabled: true,
        basePath: '/v2',
        registryUrl: publicRegistryUrl,
      },
    });

    await this.smartRegistry.init();
    this.started = true;
    logger.log('info', `Cloudly OCI registry available at ${publicRegistryUrl}/v2`);
  }

  public async stop() {
    if (this.smartRegistry) {
      this.smartRegistry.destroy();
    }
    this.started = false;
  }

  public async handleHttpRequest(
    req: plugins.typedserver.Request,
    res: plugins.typedserver.Response,
  ) {
    try {
      const requestUrl = new URL((req as any).originalUrl || req.url || '/', 'http://localhost');

      if (requestUrl.pathname === '/v2/token') {
        await this.handleTokenRequest(req, res, requestUrl);
        return;
      }

      if (!this.started) {
        res.status(503);
        res.end('registry is not ready');
        return;
      }

      const rawBody = await this.getRawBody(req);
      const response = await this.smartRegistry.handleRequest({
        method: req.method || 'GET',
        path: requestUrl.pathname,
        query: Object.fromEntries(requestUrl.searchParams),
        headers: this.headersToRecord(req.headers),
        rawBody: rawBody.length > 0 ? rawBody : undefined,
      });

      await this.sendRegistryResponse(res, response);
    } catch (error) {
      logger.log('error', `registry request failed: ${(error as Error).message}`);
      res.status(500);
      res.end('registry request failed');
    }
  }

  public getRegistryHost() {
    if (!this.cloudlyRef.config.data.publicUrl) {
      throw new Error('Cloudly registry requires publicUrl');
    }

    const publicPort = this.cloudlyRef.config.data.publicPort;
    const includePort =
      this.cloudlyRef.config.data.sslMode === 'none' && publicPort && !['80', '443'].includes(publicPort);
    return `${this.cloudlyRef.config.data.publicUrl}${includePort ? `:${publicPort}` : ''}`;
  }

  public getServiceRegistryTarget(
    serviceArg: Service,
    tagArg = 'latest',
  ): plugins.servezoneInterfaces.data.IRegistryTarget {
    const registryHost = this.getRegistryHost();
    const repository = this.getServiceRepository(serviceArg);
    return {
      protocol: 'oci',
      registryHost,
      repository,
      tag: tagArg,
      imageUrl: `${registryHost}/${repository}:${tagArg}`,
      serviceId: serviceArg.id,
      imageId: serviceArg.data?.imageId,
    };
  }

  private async handleRegistryStorageAfterPut(
    contextArg: plugins.smartregistry.IStorageHookContext,
  ) {
    try {
      if (contextArg.protocol !== 'oci') {
        return;
      }
      if (!contextArg.key.startsWith('oci/tags/') || !contextArg.key.endsWith('/tags.json')) {
        return;
      }

      const repository = contextArg.key.slice('oci/tags/'.length, -'/tags.json'.length);
      const tagsBuffer = await this.smartRegistry.getStorage().getObject(contextArg.key);
      if (!tagsBuffer) {
        return;
      }

      const tags = JSON.parse(tagsBuffer.toString('utf8')) as Record<string, string>;
      for (const [tag, digest] of Object.entries(tags)) {
        const tagKey = `${repository}:${tag}`;
        if (this.recordedTagDigests.get(tagKey) === digest) {
          continue;
        }
        this.recordedTagDigests.set(tagKey, digest);
        await this.recordRegistryPushEvent(repository, tag, digest, contextArg.actor?.userId);
      }
    } catch (error) {
      logger.log('error', `registry push event handling failed: ${(error as Error).message}`);
    }
  }

  private async recordRegistryPushEvent(
    repositoryArg: string,
    tagArg: string,
    digestArg: string,
    actorUserIdArg?: string,
  ) {
    const service = await this.getServiceByRegistryRepository(repositoryArg);
    if (!service) {
      logger.log('info', `registry push for unmapped repository ${repositoryArg}:${tagArg}`);
      return;
    }

    const registryTarget = this.getServiceRegistryTarget(service, tagArg);
    const pushEvent: plugins.servezoneInterfaces.data.IRegistryPushEvent = {
      protocol: 'oci',
      registryHost: registryTarget.registryHost,
      repository: repositoryArg,
      tag: tagArg,
      digest: digestArg,
      imageUrl: registryTarget.imageUrl,
      pushedAt: Date.now(),
      serviceId: service.id,
      imageId: service.data.imageId,
      actorUserId: actorUserIdArg,
    };

    service.data = {
      ...service.data,
      ...(service.data.deployOnPush === false ? {} : { imageVersion: tagArg }),
      registryTarget,
    };
    await service.save();

    await this.recordImagePushEvent(service, pushEvent);
    logger.log('info', `recorded registry push ${repositoryArg}:${tagArg} -> ${digestArg}`);
  }

  private async recordImagePushEvent(
    serviceArg: Service,
    pushEventArg: plugins.servezoneInterfaces.data.IRegistryPushEvent,
  ) {
    if (!serviceArg.data.imageId) {
      return;
    }

    const image = await this.cloudlyRef.imageManager.CImage.getInstance({
      id: serviceArg.data.imageId,
    }).catch(() => null);
    if (!image) {
      return;
    }

    image.data.versions = image.data.versions || [];
    const existingVersion = image.data.versions.find((versionArg) => {
      return versionArg.versionString === pushEventArg.tag;
    });
    const versionData = {
      versionString: pushEventArg.tag,
      digest: pushEventArg.digest,
      registryRepository: pushEventArg.repository,
      registryTag: pushEventArg.tag,
      source: 'registry' as const,
      size: existingVersion?.size || 0,
      createdAt: existingVersion?.createdAt || pushEventArg.pushedAt,
    };
    if (existingVersion) {
      Object.assign(existingVersion, versionData);
    } else {
      image.data.versions.push(versionData);
    }
    image.data.lastPushEvent = pushEventArg;
    await image.save();
  }

  private async getServiceByRegistryRepository(repositoryArg: string) {
    const services = await this.cloudlyRef.serviceManager.CService.getInstances({});
    return services.find((serviceArg) => {
      return this.getServiceRepository(serviceArg) === repositoryArg;
    });
  }

  private getServiceRepository(serviceArg: Service) {
    const serviceName = this.slugify(serviceArg.data?.name || serviceArg.id);
    const serviceId = this.slugify(serviceArg.id).slice(0, 12) || serviceArg.id;
    return `workloads/${serviceName}-${serviceId}`;
  }

  private slugify(valueArg: string) {
    return valueArg
      .toLowerCase()
      .replace(/[^a-z0-9._-]+/g, '-')
      .replace(/^-+|-+$/g, '')
      || 'service';
  }

  private async handleTokenRequest(
    req: plugins.typedserver.Request,
    res: plugins.typedserver.Response,
    requestUrl: URL,
  ) {
    const user = await this.authenticateRequest(req);
    if (!user) {
      res.status(401);
      res.setHeader('WWW-Authenticate', 'Basic realm="Cloudly Registry"');
      res.end('authentication required');
      return;
    }

    const requestedScopes = this.getRequestedOciScopes(requestUrl.searchParams);
    const requestedWriteAccess = requestedScopes.some((scopeArg) => {
      const action = scopeArg.split(':').at(-1);
      return action === 'push' || action === 'delete';
    });
    if (requestedWriteAccess && !user.canWrite) {
      res.status(403);
      res.end('registry write access denied');
      return;
    }

    const token = await this.smartRegistry.getAuthManager().createOciToken(
      user.userId,
      requestedScopes,
      3600,
    );
    res.status(200);
    res.setHeader('Content-Type', 'application/json');
    res.end(
      JSON.stringify({
        token,
        access_token: token,
        expires_in: 3600,
        issued_at: new Date().toISOString(),
      }),
    );
  }

  private async authenticateRequest(
    req: plugins.typedserver.Request,
  ): Promise<TAuthenticatedRegistryUser | null> {
    const credentials = this.getBasicCredentials(req);
    if (!credentials) {
      return null;
    }

    const users = await this.cloudlyRef.authManager.CUser.getInstances({});
    for (const user of users) {
      if (user.data?.username !== credentials.username) {
        continue;
      }

      const passwordMatches = user.data.password === credentials.password;
      const matchingToken = user.data.tokens?.find((tokenArg) => {
        return tokenArg.token === credentials.password && tokenArg.expiresAt > Date.now();
      });
      if (!passwordMatches && !matchingToken) {
        continue;
      }

      const assignedRoles = matchingToken?.assignedRoles || [];
      return {
        userId: user.id,
        username: user.data.username,
        canWrite: user.data.role === 'admin' || assignedRoles.includes('admin'),
      };
    }

    return null;
  }

  private getBasicCredentials(req: plugins.typedserver.Request) {
    const authHeader = req.headers.authorization;
    if (!authHeader?.startsWith('Basic ')) {
      return null;
    }

    const decoded = Buffer.from(authHeader.slice('Basic '.length), 'base64').toString('utf8');
    const separatorIndex = decoded.indexOf(':');
    if (separatorIndex <= 0) {
      return null;
    }

    return {
      username: decoded.slice(0, separatorIndex),
      password: decoded.slice(separatorIndex + 1),
    };
  }

  private getRequestedOciScopes(searchParamsArg: URLSearchParams) {
    const scopes: string[] = [];
    for (const scope of searchParamsArg.getAll('scope')) {
      const [scopeType, scopeName, actionsString] = scope.split(':');
      if (scopeType !== 'repository' || !scopeName || !actionsString) {
        continue;
      }
      for (const action of actionsString.split(',')) {
        if (action) {
          scopes.push(`oci:${scopeType}:${scopeName}:${action}`);
        }
      }
    }
    return scopes;
  }

  private getPublicRegistryUrl() {
    return `${this.cloudlyRef.config.data.sslMode === 'none' ? 'http' : 'https'}://${this.getRegistryHost()}`;
  }

  private headersToRecord(headersArg: plugins.typedserver.Request['headers']) {
    return Object.fromEntries(
      Object.entries(headersArg).map(([key, value]) => [
        key.toLowerCase(),
        Array.isArray(value) ? value.join(', ') : value || '',
      ]),
    );
  }

  private async getRawBody(req: plugins.typedserver.Request) {
    const chunks: Buffer[] = [];
    for await (const chunk of req as any) {
      chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
    }
    return Buffer.concat(chunks);
  }

  private async sendRegistryResponse(
    res: plugins.typedserver.Response,
    responseArg: plugins.smartregistry.IResponse,
  ) {
    res.status(responseArg.status);
    for (const [key, value] of Object.entries(responseArg.headers)) {
      res.setHeader(key, value);
    }

    if (!responseArg.body) {
      res.end();
      return;
    }

    if (responseArg.body instanceof ReadableStream) {
      plugins.stream.Readable.fromWeb(responseArg.body as any).pipe(res);
      return;
    }

    if (Buffer.isBuffer(responseArg.body) || typeof responseArg.body === 'string') {
      res.end(responseArg.body);
      return;
    }

    res.setHeader('Content-Type', responseArg.headers['Content-Type'] || 'application/json');
    res.end(JSON.stringify(responseArg.body));
  }
}