/**
 * @fileoverview The instance of Ajv validator.
 * @author Evgeny Poberezkin
 */

//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------

import Ajv from 'ajv';

//-----------------------------------------------------------------------------
// Helpers
//-----------------------------------------------------------------------------

/*
 * Copied from ajv/lib/refs/json-schema-draft-04.json
 * The MIT License (MIT)
 * Copyright (c) 2015-2017 Evgeny Poberezkin
 */
const metaSchema = {
  id: 'http://json-schema.org/draft-04/schema#',
  $schema: 'http://json-schema.org/draft-04/schema#',
  description: 'Core schema meta-schema',
  definitions: {
    schemaArray: {
      type: 'array',
      minItems: 1,
      items: { $ref: '#' },
    },
    positiveInteger: {
      type: 'integer',
      minimum: 0,
    },
    positiveIntegerDefault0: {
      allOf: [{ $ref: '#/definitions/positiveInteger' }, { default: 0 }],
    },
    simpleTypes: {
      enum: [
        'array',
        'boolean',
        'integer',
        'null',
        'number',
        'object',
        'string',
      ],
    },
    stringArray: {
      type: 'array',
      items: { type: 'string' },
      minItems: 1,
      uniqueItems: true,
    },
  },
  type: 'object',
  properties: {
    id: {
      type: 'string',
    },
    $schema: {
      type: 'string',
    },
    title: {
      type: 'string',
    },
    description: {
      type: 'string',
    },
    default: {},
    multipleOf: {
      type: 'number',
      minimum: 0,
      exclusiveMinimum: true,
    },
    maximum: {
      type: 'number',
    },
    exclusiveMaximum: {
      type: 'boolean',
      default: false,
    },
    minimum: {
      type: 'number',
    },
    exclusiveMinimum: {
      type: 'boolean',
      default: false,
    },
    maxLength: { $ref: '#/definitions/positiveInteger' },
    minLength: { $ref: '#/definitions/positiveIntegerDefault0' },
    pattern: {
      type: 'string',
      format: 'regex',
    },
    additionalItems: {
      anyOf: [{ type: 'boolean' }, { $ref: '#' }],
      default: {},
    },
    items: {
      anyOf: [{ $ref: '#' }, { $ref: '#/definitions/schemaArray' }],
      default: {},
    },
    maxItems: { $ref: '#/definitions/positiveInteger' },
    minItems: { $ref: '#/definitions/positiveIntegerDefault0' },
    uniqueItems: {
      type: 'boolean',
      default: false,
    },
    maxProperties: { $ref: '#/definitions/positiveInteger' },
    minProperties: { $ref: '#/definitions/positiveIntegerDefault0' },
    required: { $ref: '#/definitions/stringArray' },
    additionalProperties: {
      anyOf: [{ type: 'boolean' }, { $ref: '#' }],
      default: {},
    },
    definitions: {
      type: 'object',
      additionalProperties: { $ref: '#' },
      default: {},
    },
    properties: {
      type: 'object',
      additionalProperties: { $ref: '#' },
      default: {},
    },
    patternProperties: {
      type: 'object',
      additionalProperties: { $ref: '#' },
      default: {},
    },
    dependencies: {
      type: 'object',
      additionalProperties: {
        anyOf: [{ $ref: '#' }, { $ref: '#/definitions/stringArray' }],
      },
    },
    enum: {
      type: 'array',
      minItems: 1,
      uniqueItems: true,
    },
    type: {
      anyOf: [
        { $ref: '#/definitions/simpleTypes' },
        {
          type: 'array',
          items: { $ref: '#/definitions/simpleTypes' },
          minItems: 1,
          uniqueItems: true,
        },
      ],
    },
    format: { type: 'string' },
    allOf: { $ref: '#/definitions/schemaArray' },
    anyOf: { $ref: '#/definitions/schemaArray' },
    oneOf: { $ref: '#/definitions/schemaArray' },
    not: { $ref: '#' },
  },
  dependencies: {
    exclusiveMaximum: ['maximum'],
    exclusiveMinimum: ['minimum'],
  },
  default: {},
};

//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------

export default (additionalOptions = {}) => {
  const ajv = new Ajv({
    meta: false,
    useDefaults: true,
    validateSchema: false,
    missingRefs: 'ignore',
    verbose: true,
    schemaId: 'auto',
    ...additionalOptions,
  });

  ajv.addMetaSchema(metaSchema);
  // eslint-disable-next-line no-underscore-dangle -- part of the API
  ajv._opts.defaultMeta = metaSchema.id;

  return ajv;
};