import { join } from 'path';
import { createReadStream, stat } from 'fs';
import {
  CLOUD_API_MODEL_VERSION_PACKAGES_PATH,
  CloudApiUrl
} from '@alwaysai/cloud-api';
import { CliTerseError } from '@alwaysai/alwayscli';
import * as tar from 'tar';
import * as tempy from 'tempy';
import { promisify } from 'util';
import { ModelJsonFile } from './model-json-file';
import {
  JsSpawner,
  throwIfNotOk,
  copyFiles,
  stringifyError,
  logger
} from '../../util';
import {
  CliRpcClient,
  CliAuthenticationClient,
  getSystemId
} from '../../infrastructure';
import { ModelId } from './model-id';
import { fetchFilestream } from '../../util/fetch';
import { Readable } from 'stream';

async function getModelVersion(id: string, version: number) {
  try {
    return await CliRpcClient().getModelVersion({ id, version });
  } catch (exception) {
    logger.error(stringifyError(exception));
    throw new CliTerseError(`Model ${id} not found!`);
  }
}

export const modelPackageCloudClient = {
  async download(id: string, version: number) {
    const { uuid } = await getModelVersion(id, version);
    try {
      const modelPackageUrl = ModelPackageUrl(uuid);
      const authorizationHeader =
        await CliAuthenticationClient().getAuthorizationHeader();
      const filestream = await fetchFilestream(modelPackageUrl, {
        method: 'GET',
        headers: { ...authorizationHeader, 'Content-Length': '0' }
      });
      return filestream;
    } catch (exception) {
      logger.error(stringifyError(exception));
      throw new CliTerseError(`Failed to download model ${id}!`);
    }
  },

  async publish(dir = process.cwd()) {
    const modelJson = ModelJsonFile(dir).read();
    const rpcClient = CliRpcClient();
    const { uuid } = await rpcClient.createModelVersion(modelJson);

    const authorizationHeader =
      await CliAuthenticationClient().getAuthorizationHeader();

    // Ensure top level directory matches model name
    const { name } = ModelId.parse(modelJson.id);
    const tmpDir = tempy.directory({ prefix: 'alwaysai' });
    const tmpModelDir = join(tmpDir, name);
    await JsSpawner().mkdirp(tmpModelDir);
    await copyFiles(JsSpawner({ path: dir }), JsSpawner({ path: tmpModelDir }));

    const modelPackagePath = tempy.file();
    await tar.create({ cwd: tmpDir, gzip: true, file: modelPackagePath }, [
      name
    ]);

    await JsSpawner().rimraf(tmpDir);

    const stats = await promisify(stat)(modelPackagePath);

    const modelPackageStream = createReadStream(modelPackagePath);
    // Convert to web stream since Typescript maps to DOM types at compile time,
    // which don't include all supported runtime types.
    const webModelPackageStream = Readable.toWeb(modelPackageStream);

    // Again, typescript is mapping to DOM types which don't include the duplex
    // property. This change augments the type manually and avoids a more
    // in-depth change to the tsconfig.
    interface NodeRequestInit extends RequestInit {
      duplex?: 'half';
    }

    const response = await fetch(ModelPackageUrl(uuid), {
      method: 'PUT',
      headers: {
        'Content-Type': 'application/gzip',
        'Content-Length': stats.size.toString(),
        ...authorizationHeader
      },
      body: webModelPackageStream,
      duplex: 'half'
    } as NodeRequestInit);

    await throwIfNotOk(response);
    await rpcClient.finalizeModelVersion(uuid);
    return uuid;
  }
};

function ModelPackageUrl(uuid: string) {
  const cloudApiUrl = CloudApiUrl(getSystemId());
  return `${cloudApiUrl}${CLOUD_API_MODEL_VERSION_PACKAGES_PATH}/${uuid}`;
}