<?php

declare(strict_types=1);

namespace GraphQL\Tests;

use GraphQL\Language\Parser;
use GraphQL\Validator\DocumentValidator;
use PHPUnit\Framework\TestCase;

class StarWarsValidationTest extends TestCase
{
    // Star Wars Validation Tests
    // Basic Queries

    /**
     * @see it('Validates a complex but valid query')
     */
    public function testValidatesAComplexButValidQuery() : void
    {
        $query  = '
        query NestedQueryWithFragment {
          hero {
            ...NameAndAppearances
            friends {
              ...NameAndAppearances
              friends {
                ...NameAndAppearances
              }
            }
          }
        }

        fragment NameAndAppearances on Character {
          name
          appearsIn
        }
      ';
        $errors = $this->validationErrors($query);
        self::assertEquals(true, empty($errors));
    }

    /**
     * Helper function to test a query and the expected response.
     */
    private function validationErrors($query)
    {
        $ast = Parser::parse($query);

        return DocumentValidator::validate(StarWarsSchema::build(), $ast);
    }

    /**
     * @see it('Notes that non-existent fields are invalid')
     */
    public function testThatNonExistentFieldsAreInvalid() : void
    {
        $query  = '
        query HeroSpaceshipQuery {
          hero {
            favoriteSpaceship
          }
        }
        ';
        $errors = $this->validationErrors($query);
        self::assertEquals(false, empty($errors));
    }

    /**
     * @see it('Requires fields on objects')
     */
    public function testRequiresFieldsOnObjects() : void
    {
        $query = '
        query HeroNoFieldsQuery {
          hero
        }
        ';

        $errors = $this->validationErrors($query);
        self::assertEquals(false, empty($errors));
    }

    /**
     * @see it('Disallows fields on scalars')
     */
    public function testDisallowsFieldsOnScalars() : void
    {
        $query  = '
        query HeroFieldsOnScalarQuery {
          hero {
            name {
              firstCharacterOfName
            }
          }
        }
        ';
        $errors = $this->validationErrors($query);
        self::assertEquals(false, empty($errors));
    }

    /**
     * @see it('Disallows object fields on interfaces')
     */
    public function testDisallowsObjectFieldsOnInterfaces() : void
    {
        $query  = '
        query DroidFieldOnCharacter {
          hero {
            name
            primaryFunction
          }
        }
        ';
        $errors = $this->validationErrors($query);
        self::assertEquals(false, empty($errors));
    }

    /**
     * @see it('Allows object fields in fragments')
     */
    public function testAllowsObjectFieldsInFragments() : void
    {
        $query  = '
        query DroidFieldInFragment {
          hero {
            name
            ...DroidFields
          }
        }

        fragment DroidFields on Droid {
          primaryFunction
        }
        ';
        $errors = $this->validationErrors($query);
        self::assertEquals(true, empty($errors));
    }

    /**
     * @see it('Allows object fields in inline fragments')
     */
    public function testAllowsObjectFieldsInInlineFragments() : void
    {
        $query  = '
        query DroidFieldInFragment {
          hero {
            name
            ... on Droid {
              primaryFunction
            }
          }
        }
        ';
        $errors = $this->validationErrors($query);
        self::assertEquals(true, empty($errors));
    }
}