/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * 
 */
import inspect from '../../jsutils/inspect';
import { GraphQLError } from '../../error/GraphQLError';
import { Kind } from '../../language/kinds';
import { isNonNullType } from '../../type/definition';
import { isTypeSubTypeOf } from '../../utilities/typeComparators';
import { typeFromAST } from '../../utilities/typeFromAST';
export function badVarPosMessage(varName, varType, expectedType) {
  return "Variable \"$".concat(varName, "\" of type \"").concat(varType, "\" used in ") + "position expecting type \"".concat(expectedType, "\".");
}
/**
 * Variables passed to field arguments conform to type
 */

export function VariablesInAllowedPosition(context) {
  var varDefMap = Object.create(null);
  return {
    OperationDefinition: {
      enter: function enter() {
        varDefMap = Object.create(null);
      },
      leave: function leave(operation) {
        var usages = context.getRecursiveVariableUsages(operation);
        var _iteratorNormalCompletion = true;
        var _didIteratorError = false;
        var _iteratorError = undefined;

        try {
          for (var _iterator = usages[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
            var _ref2 = _step.value;
            var node = _ref2.node;
            var type = _ref2.type;
            var defaultValue = _ref2.defaultValue;
            var varName = node.name.value;
            var varDef = varDefMap[varName];

            if (varDef && type) {
              // A var type is allowed if it is the same or more strict (e.g. is
              // a subtype of) than the expected type. It can be more strict if
              // the variable type is non-null when the expected type is nullable.
              // If both are list types, the variable item type can be more strict
              // than the expected item type (contravariant).
              var schema = context.getSchema();
              var varType = typeFromAST(schema, varDef.type);

              if (varType && !allowedVariableUsage(schema, varType, varDef.defaultValue, type, defaultValue)) {
                context.reportError(new GraphQLError(badVarPosMessage(varName, inspect(varType), inspect(type)), [varDef, node]));
              }
            }
          }
        } catch (err) {
          _didIteratorError = true;
          _iteratorError = err;
        } finally {
          try {
            if (!_iteratorNormalCompletion && _iterator.return != null) {
              _iterator.return();
            }
          } finally {
            if (_didIteratorError) {
              throw _iteratorError;
            }
          }
        }
      }
    },
    VariableDefinition: function VariableDefinition(node) {
      varDefMap[node.variable.name.value] = node;
    }
  };
}
/**
 * Returns true if the variable is allowed in the location it was found,
 * which includes considering if default values exist for either the variable
 * or the location at which it is located.
 */

function allowedVariableUsage(schema, varType, varDefaultValue, locationType, locationDefaultValue) {
  if (isNonNullType(locationType) && !isNonNullType(varType)) {
    var hasNonNullVariableDefaultValue = varDefaultValue != null && varDefaultValue.kind !== Kind.NULL;
    var hasLocationDefaultValue = locationDefaultValue !== undefined;

    if (!hasNonNullVariableDefaultValue && !hasLocationDefaultValue) {
      return false;
    }

    var nullableLocationType = locationType.ofType;
    return isTypeSubTypeOf(schema, varType, nullableLocationType);
  }

  return isTypeSubTypeOf(schema, varType, locationType);
}