/*
 * Copyright 2019 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

import * as assert from 'assert';
import * as fs from 'fs';
import { promisify } from 'util';

import { CallCredentials } from '../src/call-credentials';
import { ChannelCredentials } from '../src/channel-credentials';

import { assert2, mockFunction } from './common';

class CallCredentialsMock implements CallCredentials {
  child: CallCredentialsMock | null = null;
  constructor(child?: CallCredentialsMock) {
    if (child) {
      this.child = child;
    }
  }

  generateMetadata = mockFunction;

  compose(callCredentials: CallCredentialsMock): CallCredentialsMock {
    return new CallCredentialsMock(callCredentials);
  }

  _equals(other: CallCredentialsMock): boolean {
    if (!this.child) {
      return this === other;
    } else if (!other || !other.child) {
      return false;
    } else {
      return this.child._equals(other.child);
    }
  }
}

// tslint:disable-next-line:no-any
const readFile: (...args: any[]) => Promise<Buffer> = promisify(fs.readFile);
// A promise which resolves to loaded files in the form { ca, key, cert }
const pFixtures = Promise.all(
  ['ca.pem', 'server1.key', 'server1.pem'].map(file =>
    readFile(`${__dirname}/fixtures/${file}`)
  )
).then(result => {
  return { ca: result[0], key: result[1], cert: result[2] };
});

describe('ChannelCredentials Implementation', () => {
  describe('createInsecure', () => {
    it('should return a ChannelCredentials object with no associated secure context', () => {
      const creds = assert2.noThrowAndReturn(() =>
        ChannelCredentials.createInsecure()
      );
      assert.ok(!creds._getConnectionOptions());
    });
  });

  describe('createSsl', () => {
    it('should work when given no arguments', () => {
      const creds: ChannelCredentials = assert2.noThrowAndReturn(() =>
        ChannelCredentials.createSsl()
      );
      assert.ok(!!creds._getConnectionOptions());
    });

    it('should work with just a CA override', async () => {
      const { ca } = await pFixtures;
      const creds = assert2.noThrowAndReturn(() =>
        ChannelCredentials.createSsl(ca)
      );
      assert.ok(!!creds._getConnectionOptions());
    });

    it('should work with just a private key and cert chain', async () => {
      const { key, cert } = await pFixtures;
      const creds = assert2.noThrowAndReturn(() =>
        ChannelCredentials.createSsl(null, key, cert)
      );
      assert.ok(!!creds._getConnectionOptions());
    });

    it('should work with three parameters specified', async () => {
      const { ca, key, cert } = await pFixtures;
      const creds = assert2.noThrowAndReturn(() =>
        ChannelCredentials.createSsl(ca, key, cert)
      );
      assert.ok(!!creds._getConnectionOptions());
    });

    it('should throw if just one of private key and cert chain are missing', async () => {
      const { ca, key, cert } = await pFixtures;
      assert.throws(() => ChannelCredentials.createSsl(ca, key));
      assert.throws(() => ChannelCredentials.createSsl(ca, key, null));
      assert.throws(() => ChannelCredentials.createSsl(ca, null, cert));
      assert.throws(() => ChannelCredentials.createSsl(null, key));
      assert.throws(() => ChannelCredentials.createSsl(null, key, null));
      assert.throws(() => ChannelCredentials.createSsl(null, null, cert));
    });
  });

  describe('compose', () => {
    it('should return a ChannelCredentials object', () => {
      const channelCreds = ChannelCredentials.createSsl();
      const callCreds = new CallCredentialsMock();
      const composedChannelCreds = channelCreds.compose(callCreds);
      assert.strictEqual(composedChannelCreds._getCallCredentials(), callCreds);
    });

    it('should be chainable', () => {
      const callCreds1 = new CallCredentialsMock();
      const callCreds2 = new CallCredentialsMock();
      // Associate both call credentials with channelCreds
      const composedChannelCreds = ChannelCredentials.createSsl()
        .compose(callCreds1)
        .compose(callCreds2);
      // Build a mock object that should be an identical copy
      const composedCallCreds = callCreds1.compose(callCreds2);
      assert.ok(
        composedCallCreds._equals(
          composedChannelCreds._getCallCredentials() as CallCredentialsMock
        )
      );
    });
  });
});