function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * 
 */

import invariant from '../jsutils/invariant';

import { GraphQLError } from '../error';
import { visit, visitInParallel, visitWithTypeInfo } from '../language/visitor';
import * as Kind from '../language/kinds';

import { GraphQLSchema } from '../type/schema';

import { assertValidSchema } from '../type/validate';
import { TypeInfo } from '../utilities/TypeInfo';
import { specifiedRules } from './specifiedRules';

/**
 * Implements the "Validation" section of the spec.
 *
 * Validation runs synchronously, returning an array of encountered errors, or
 * an empty array if no errors were encountered and the document is valid.
 *
 * A list of specific validation rules may be provided. If not provided, the
 * default list of rules defined by the GraphQL specification will be used.
 *
 * Each validation rules is a function which returns a visitor
 * (see the language/visitor API). Visitor methods are expected to return
 * GraphQLErrors, or Arrays of GraphQLErrors when invalid.
 *
 * Optionally a custom TypeInfo instance may be provided. If not provided, one
 * will be created from the provided schema.
 */
export function validate(schema, ast, rules, typeInfo) {
  !ast ? invariant(0, 'Must provide document') : void 0;
  // If the schema used for validation is invalid, throw an error.
  assertValidSchema(schema);
  return visitUsingRules(schema, typeInfo || new TypeInfo(schema), ast, rules || specifiedRules);
}

/**
 * This uses a specialized visitor which runs multiple visitors in parallel,
 * while maintaining the visitor skip and break API.
 *
 * @internal
 */
function visitUsingRules(schema, typeInfo, documentAST, rules) {
  var context = new ValidationContext(schema, documentAST, typeInfo);
  var visitors = rules.map(function (rule) {
    return rule(context);
  });
  // Visit the whole document with each instance of all provided rules.
  visit(documentAST, visitWithTypeInfo(typeInfo, visitInParallel(visitors)));
  return context.getErrors();
}

/**
 * An instance of this class is passed as the "this" context to all validators,
 * allowing access to commonly useful contextual information from within a
 * validation rule.
 */
export var ValidationContext = function () {
  function ValidationContext(schema, ast, typeInfo) {
    _classCallCheck(this, ValidationContext);

    this._schema = schema;
    this._ast = ast;
    this._typeInfo = typeInfo;
    this._errors = [];
    this._fragmentSpreads = new Map();
    this._recursivelyReferencedFragments = new Map();
    this._variableUsages = new Map();
    this._recursiveVariableUsages = new Map();
  }

  ValidationContext.prototype.reportError = function reportError(error) {
    this._errors.push(error);
  };

  ValidationContext.prototype.getErrors = function getErrors() {
    return this._errors;
  };

  ValidationContext.prototype.getSchema = function getSchema() {
    return this._schema;
  };

  ValidationContext.prototype.getDocument = function getDocument() {
    return this._ast;
  };

  ValidationContext.prototype.getFragment = function getFragment(name) {
    var fragments = this._fragments;
    if (!fragments) {
      this._fragments = fragments = this.getDocument().definitions.reduce(function (frags, statement) {
        if (statement.kind === Kind.FRAGMENT_DEFINITION) {
          frags[statement.name.value] = statement;
        }
        return frags;
      }, Object.create(null));
    }
    return fragments[name];
  };

  ValidationContext.prototype.getFragmentSpreads = function getFragmentSpreads(node) {
    var spreads = this._fragmentSpreads.get(node);
    if (!spreads) {
      spreads = [];
      var setsToVisit = [node];
      while (setsToVisit.length !== 0) {
        var set = setsToVisit.pop();
        for (var i = 0; i < set.selections.length; i++) {
          var selection = set.selections[i];
          if (selection.kind === Kind.FRAGMENT_SPREAD) {
            spreads.push(selection);
          } else if (selection.selectionSet) {
            setsToVisit.push(selection.selectionSet);
          }
        }
      }
      this._fragmentSpreads.set(node, spreads);
    }
    return spreads;
  };

  ValidationContext.prototype.getRecursivelyReferencedFragments = function getRecursivelyReferencedFragments(operation) {
    var fragments = this._recursivelyReferencedFragments.get(operation);
    if (!fragments) {
      fragments = [];
      var collectedNames = Object.create(null);
      var nodesToVisit = [operation.selectionSet];
      while (nodesToVisit.length !== 0) {
        var _node = nodesToVisit.pop();
        var spreads = this.getFragmentSpreads(_node);
        for (var i = 0; i < spreads.length; i++) {
          var fragName = spreads[i].name.value;
          if (collectedNames[fragName] !== true) {
            collectedNames[fragName] = true;
            var fragment = this.getFragment(fragName);
            if (fragment) {
              fragments.push(fragment);
              nodesToVisit.push(fragment.selectionSet);
            }
          }
        }
      }
      this._recursivelyReferencedFragments.set(operation, fragments);
    }
    return fragments;
  };

  ValidationContext.prototype.getVariableUsages = function getVariableUsages(node) {
    var usages = this._variableUsages.get(node);
    if (!usages) {
      var newUsages = [];
      var typeInfo = new TypeInfo(this._schema);
      visit(node, visitWithTypeInfo(typeInfo, {
        VariableDefinition: function VariableDefinition() {
          return false;
        },
        Variable: function Variable(variable) {
          newUsages.push({ node: variable, type: typeInfo.getInputType() });
        }
      }));
      usages = newUsages;
      this._variableUsages.set(node, usages);
    }
    return usages;
  };

  ValidationContext.prototype.getRecursiveVariableUsages = function getRecursiveVariableUsages(operation) {
    var usages = this._recursiveVariableUsages.get(operation);
    if (!usages) {
      usages = this.getVariableUsages(operation);
      var fragments = this.getRecursivelyReferencedFragments(operation);
      for (var i = 0; i < fragments.length; i++) {
        Array.prototype.push.apply(usages, this.getVariableUsages(fragments[i]));
      }
      this._recursiveVariableUsages.set(operation, usages);
    }
    return usages;
  };

  ValidationContext.prototype.getType = function getType() {
    return this._typeInfo.getType();
  };

  ValidationContext.prototype.getParentType = function getParentType() {
    return this._typeInfo.getParentType();
  };

  ValidationContext.prototype.getInputType = function getInputType() {
    return this._typeInfo.getInputType();
  };

  ValidationContext.prototype.getParentInputType = function getParentInputType() {
    return this._typeInfo.getParentInputType();
  };

  ValidationContext.prototype.getFieldDef = function getFieldDef() {
    return this._typeInfo.getFieldDef();
  };

  ValidationContext.prototype.getDirective = function getDirective() {
    return this._typeInfo.getDirective();
  };

  ValidationContext.prototype.getArgument = function getArgument() {
    return this._typeInfo.getArgument();
  };

  return ValidationContext;
}();