/*
 * Copyright 2022 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 assert = require('assert');
import { validateServiceConfig } from '../src/service-config';

function createRetryServiceConfig(retryConfig: object): object {
  return {
    loadBalancingConfig: [],
    methodConfig: [
      {
        name: [
          {
            service: 'A',
            method: 'B',
          },
        ],

        retryPolicy: retryConfig,
      },
    ],
  };
}

function createHedgingServiceConfig(hedgingConfig: object): object {
  return {
    loadBalancingConfig: [],
    methodConfig: [
      {
        name: [
          {
            service: 'A',
            method: 'B',
          },
        ],

        hedgingPolicy: hedgingConfig,
      },
    ],
  };
}

function createThrottlingServiceConfig(retryThrottling: object): object {
  return {
    loadBalancingConfig: [],
    methodConfig: [],
    retryThrottling: retryThrottling,
  };
}

interface TestCase {
  description: string;
  config: object;
  error: RegExp;
}

const validRetryConfig = {
  maxAttempts: 2,
  initialBackoff: '1s',
  maxBackoff: '1s',
  backoffMultiplier: 1,
  retryableStatusCodes: [14, 'RESOURCE_EXHAUSTED'],
};

const RETRY_TEST_CASES: TestCase[] = [
  {
    description: 'omitted maxAttempts',
    config: {
      initialBackoff: '1s',
      maxBackoff: '1s',
      backoffMultiplier: 1,
      retryableStatusCodes: [14],
    },
    error: /retry policy: maxAttempts must be an integer at least 2/,
  },
  {
    description: 'a low maxAttempts',
    config: { ...validRetryConfig, maxAttempts: 1 },
    error: /retry policy: maxAttempts must be an integer at least 2/,
  },
  {
    description: 'omitted initialBackoff',
    config: {
      maxAttempts: 2,
      maxBackoff: '1s',
      backoffMultiplier: 1,
      retryableStatusCodes: [14],
    },
    error:
      /retry policy: initialBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'a non-numeric initialBackoff',
    config: { ...validRetryConfig, initialBackoff: 'abcs' },
    error:
      /retry policy: initialBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'an initialBackoff without an s',
    config: { ...validRetryConfig, initialBackoff: '123' },
    error:
      /retry policy: initialBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'omitted maxBackoff',
    config: {
      maxAttempts: 2,
      initialBackoff: '1s',
      backoffMultiplier: 1,
      retryableStatusCodes: [14],
    },
    error:
      /retry policy: maxBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'a non-numeric maxBackoff',
    config: { ...validRetryConfig, maxBackoff: 'abcs' },
    error:
      /retry policy: maxBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'an maxBackoff without an s',
    config: { ...validRetryConfig, maxBackoff: '123' },
    error:
      /retry policy: maxBackoff must be a string consisting of a positive integer or decimal followed by s/,
  },
  {
    description: 'omitted backoffMultiplier',
    config: {
      maxAttempts: 2,
      initialBackoff: '1s',
      maxBackoff: '1s',
      retryableStatusCodes: [14],
    },
    error: /retry policy: backoffMultiplier must be a number greater than 0/,
  },
  {
    description: 'a negative backoffMultiplier',
    config: { ...validRetryConfig, backoffMultiplier: -1 },
    error: /retry policy: backoffMultiplier must be a number greater than 0/,
  },
  {
    description: 'omitted retryableStatusCodes',
    config: {
      maxAttempts: 2,
      initialBackoff: '1s',
      maxBackoff: '1s',
      backoffMultiplier: 1,
    },
    error: /retry policy: retryableStatusCodes is required/,
  },
  {
    description: 'empty retryableStatusCodes',
    config: { ...validRetryConfig, retryableStatusCodes: [] },
    error: /retry policy: retryableStatusCodes must be non-empty/,
  },
  {
    description: 'unknown status code name',
    config: { ...validRetryConfig, retryableStatusCodes: ['abcd'] },
    error: /retry policy: retryableStatusCodes value not a status code name/,
  },
  {
    description: 'out of range status code number',
    config: { ...validRetryConfig, retryableStatusCodes: [12345] },
    error: /retry policy: retryableStatusCodes value not in status code range/,
  },
];

const validHedgingConfig = {
  maxAttempts: 2,
};

const HEDGING_TEST_CASES: TestCase[] = [
  {
    description: 'omitted maxAttempts',
    config: {},
    error: /hedging policy: maxAttempts must be an integer at least 2/,
  },
  {
    description: 'a low maxAttempts',
    config: { ...validHedgingConfig, maxAttempts: 1 },
    error: /hedging policy: maxAttempts must be an integer at least 2/,
  },
  {
    description: 'a non-numeric hedgingDelay',
    config: { ...validHedgingConfig, hedgingDelay: 'abcs' },
    error:
      /hedging policy: hedgingDelay must be a string consisting of a positive integer followed by s/,
  },
  {
    description: 'a hedgingDelay without an s',
    config: { ...validHedgingConfig, hedgingDelay: '123' },
    error:
      /hedging policy: hedgingDelay must be a string consisting of a positive integer followed by s/,
  },
  {
    description: 'unknown status code name',
    config: { ...validHedgingConfig, nonFatalStatusCodes: ['abcd'] },
    error: /hedging policy: nonFatalStatusCodes value not a status code name/,
  },
  {
    description: 'out of range status code number',
    config: { ...validHedgingConfig, nonFatalStatusCodes: [12345] },
    error: /hedging policy: nonFatalStatusCodes value not in status code range/,
  },
];

const validThrottlingConfig = {
  maxTokens: 100,
  tokenRatio: 0.1,
};

const THROTTLING_TEST_CASES: TestCase[] = [
  {
    description: 'omitted maxTokens',
    config: { tokenRatio: 0.1 },
    error: /retryThrottling: maxTokens must be a number in \(0, 1000\]/,
  },
  {
    description: 'a large maxTokens',
    config: { ...validThrottlingConfig, maxTokens: 1001 },
    error: /retryThrottling: maxTokens must be a number in \(0, 1000\]/,
  },
  {
    description: 'zero maxTokens',
    config: { ...validThrottlingConfig, maxTokens: 0 },
    error: /retryThrottling: maxTokens must be a number in \(0, 1000\]/,
  },
  {
    description: 'omitted tokenRatio',
    config: { maxTokens: 100 },
    error: /retryThrottling: tokenRatio must be a number greater than 0/,
  },
  {
    description: 'zero tokenRatio',
    config: { ...validThrottlingConfig, tokenRatio: 0 },
    error: /retryThrottling: tokenRatio must be a number greater than 0/,
  },
];

describe('Retry configs', () => {
  describe('Retry', () => {
    it('Should accept a valid config', () => {
      assert.doesNotThrow(() => {
        validateServiceConfig(createRetryServiceConfig(validRetryConfig));
      });
    });
    for (const testCase of RETRY_TEST_CASES) {
      it(`Should reject ${testCase.description}`, () => {
        assert.throws(() => {
          validateServiceConfig(createRetryServiceConfig(testCase.config));
        }, testCase.error);
      });
    }
  });
  describe('Hedging', () => {
    it('Should accept valid configs', () => {
      assert.doesNotThrow(() => {
        validateServiceConfig(createHedgingServiceConfig(validHedgingConfig));
      });
      assert.doesNotThrow(() => {
        validateServiceConfig(
          createHedgingServiceConfig({
            ...validHedgingConfig,
            hedgingDelay: '1s',
          })
        );
      });
      assert.doesNotThrow(() => {
        validateServiceConfig(
          createHedgingServiceConfig({
            ...validHedgingConfig,
            nonFatalStatusCodes: [14, 'RESOURCE_EXHAUSTED'],
          })
        );
      });
    });
    for (const testCase of HEDGING_TEST_CASES) {
      it(`Should reject ${testCase.description}`, () => {
        assert.throws(() => {
          validateServiceConfig(createHedgingServiceConfig(testCase.config));
        }, testCase.error);
      });
    }
  });
  describe('Throttling', () => {
    it('Should accept a valid config', () => {
      assert.doesNotThrow(() => {
        validateServiceConfig(
          createThrottlingServiceConfig(validThrottlingConfig)
        );
      });
    });
    for (const testCase of THROTTLING_TEST_CASES) {
      it(`Should reject ${testCase.description}`, () => {
        assert.throws(() => {
          validateServiceConfig(createThrottlingServiceConfig(testCase.config));
        }, testCase.error);
      });
    }
  });
});