import gql from 'graphql-tag';
import { Kind, graphql, DocumentNode, execute } from 'graphql';
import { buildFederatedSchema } from '../buildFederatedSchema';
import { typeSerializer } from '../../snapshotSerializers';

expect.addSnapshotSerializer(typeSerializer);

const EMPTY_DOCUMENT = {
  kind: Kind.DOCUMENT,
  definitions: [],
};

describe('buildFederatedSchema', () => {
  it(`should mark a type with a key field as an entity`, () => {
    const schema = buildFederatedSchema(gql`
      type Product @key(fields: "upc") {
        upc: String!
        name: String
        price: Int
      }
    `);

    expect(schema.getType('Product')).toMatchInlineSnapshot(`
type Product {
  upc: String!
  name: String
  price: Int
}
`);

    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
  });

  it(`should mark a type with multiple key fields as an entity`, () => {
    const schema = buildFederatedSchema(gql`
      type Product @key(fields: "upc") @key(fields: "sku") {
        upc: String!
        sku: String!
        name: String
        price: Int
      }
    `);

    expect(schema.getType('Product')).toMatchInlineSnapshot(`
type Product {
  upc: String!
  sku: String!
  name: String
  price: Int
}
`);

    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
  });

  it(`should not mark a type without a key field as an entity`, () => {
    const schema = buildFederatedSchema(gql`
      type Money {
        amount: Int!
        currencyCode: String!
      }
    `);

    expect(schema.getType('Money')).toMatchInlineSnapshot(`
type Money {
  amount: Int!
  currencyCode: String!
}
`);
  });

  it('should preserve description text in generated SDL', async () => {
    const query = `query GetServiceDetails {
      _service {
        sdl
      }
    }`;
    const schema = buildFederatedSchema(gql`
      "A user. This user is very complicated and requires so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so much description text"
      type User @key(fields: "id") {
        """
        The unique ID of the user.
        """
        id: ID!
        "The user's name."
        name: String
        username: String
        foo(
          "Description 1"
          arg1: String
          "Description 2"
          arg2: String
          "Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3"
          arg3: String
        ): String
      }
    `);

    const { data, errors } = await graphql(schema, query);
    expect(errors).toBeUndefined();
    expect(data?._service.sdl).toEqual(`"""
A user. This user is very complicated and requires so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so much description text
"""
type User @key(fields: "id") {
  """The unique ID of the user."""
  id: ID!

  """The user's name."""
  name: String
  username: String
  foo(
    """Description 1"""
    arg1: String

    """Description 2"""
    arg2: String

    """
    Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3 Description 3
    """
    arg3: String
  ): String
}
`);
  });

  describe(`should add an _entities query root field to the schema`, () => {
    it(`when a query root type with the default name has been defined`, () => {
      const schema = buildFederatedSchema(gql`
        type Query {
          rootField: String
        }
        type Product @key(fields: "upc") {
          upc: ID!
        }
      `);

      expect(schema.getQueryType()).toMatchInlineSnapshot(`
type Query {
  _entities(representations: [_Any!]!): [_Entity]!
  _service: _Service!
  rootField: String
}
`);
    });

    it(`when a query root type with a non-default name has been defined`, () => {
      const schema = buildFederatedSchema(gql`
        schema {
          query: QueryRoot
        }

        type QueryRoot {
          rootField: String
        }
        type Product @key(fields: "upc") {
          upc: ID!
        }
      `);

      expect(schema.getQueryType()).toMatchInlineSnapshot(`
type QueryRoot {
  _entities(representations: [_Any!]!): [_Entity]!
  _service: _Service!
  rootField: String
}
`);
    });
  });
  describe(`should not add an _entities query root field to the schema`, () => {
    it(`when no query root type has been defined`, () => {
      const schema = buildFederatedSchema(EMPTY_DOCUMENT);

      expect(schema.getQueryType()).toMatchInlineSnapshot(`
type Query {
  _service: _Service!
}
`);
    });
    it(`when no types with keys are found`, () => {
      const schema = buildFederatedSchema(gql`
        type Query {
          rootField: String
        }
      `);

      expect(schema.getQueryType()).toMatchInlineSnapshot(`
type Query {
  _service: _Service!
  rootField: String
}
`);
    });
    it(`when only an interface with keys are found`, () => {
      const schema = buildFederatedSchema(gql`
        type Query {
          rootField: String
        }
        interface Product @key(fields: "upc") {
          upc: ID!
        }
      `);

      expect(schema.getQueryType()).toMatchInlineSnapshot(`
type Query {
  _service: _Service!
  rootField: String
}
`);
    });
  });
  describe('_entities root field', () => {
    it('executes resolveReference for a type if found', async () => {
      const query = `query GetEntities($representations: [_Any!]!) {
      _entities(representations: $representations) {
        ... on Product {
          name
        }
        ... on User {
          firstName
        }
      }
    }`;

      const variables = {
        representations: [
          { __typename: 'Product', upc: 1 },
          { __typename: 'User', id: 1 },
        ],
      };

      const schema = buildFederatedSchema([
        {
          typeDefs: gql`
            type Product @key(fields: "upc") {
              upc: Int
              name: String
            }
            type User @key(fields: "id") {
              firstName: String
            }
          `,
          resolvers: {
            Product: {
              __resolveReference(object) {
                expect(object.upc).toEqual(1);
                return { name: 'Apollo Gateway' };
              },
            },
            User: {
              __resolveReference(object) {
                expect(object.id).toEqual(1);
                return Promise.resolve({ firstName: 'James' });
              },
            },
          },
        },
      ]);
      const { data, errors } = await graphql(
        schema,
        query,
        null,
        null,
        variables,
      );
      expect(errors).toBeUndefined();
      expect(data._entities[0].name).toEqual('Apollo Gateway');
      expect(data._entities[1].firstName).toEqual('James');
    });
    it('executes resolveReference with default representation values', async () => {
      const query = `query GetEntities($representations: [_Any!]!) {
      _entities(representations: $representations) {
        ... on Product {
          upc
          name
        }
      }
    }`;

      const variables = {
        representations: [
          { __typename: 'Product', upc: 1, name: 'Apollo Gateway' },
        ],
      };

      const schema = buildFederatedSchema(gql`
        type Product @key(fields: "upc") {
          upc: Int
          name: String
        }
      `);
      const { data, errors } = await graphql(
        schema,
        query,
        null,
        null,
        variables,
      );
      expect(errors).toBeUndefined();
      expect(data._entities[0].name).toEqual('Apollo Gateway');
    });
  });
  describe('_service root field', () => {
    it('keeps extension types when owner type is not present', async () => {
      const query = `query GetServiceDetails {
      _service {
        sdl
      }
    }`;
      const schema = buildFederatedSchema(gql`
        type Review {
          id: ID
        }

        extend type Review {
          title: String
        }

        extend type Product @key(fields: "upc") {
          upc: String @external
          reviews: [Review]
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl)
        .toEqual(`extend type Product @key(fields: "upc") {
  upc: String @external
  reviews: [Review]
}

type Review {
  id: ID
  title: String
}
`);
    });
    it('keeps extension interface when owner interface is not present', async () => {
      const query = `query GetServiceDetails {
    _service {
      sdl
    }
  }`;
      const schema = buildFederatedSchema(gql`
        type Review {
          id: ID
        }

        extend type Review {
          title: String
        }

        interface Node @key(fields: "id") {
          id: ID!
        }

        extend interface Product @key(fields: "upc") {
          upc: String @external
          reviews: [Review]
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl).toEqual(`interface Node @key(fields: "id") {
  id: ID!
}

extend interface Product @key(fields: "upc") {
  upc: String @external
  reviews: [Review]
}

type Review {
  id: ID
  title: String
}
`);
    });
    it('returns valid sdl for @key directives', async () => {
      const query = `query GetServiceDetails {
      _service {
        sdl
      }
    }`;
      const schema = buildFederatedSchema(gql`
        type Product @key(fields: "upc") {
          upc: String!
          name: String
          price: Int
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl).toEqual(`type Product @key(fields: "upc") {
  upc: String!
  name: String
  price: Int
}
`);
    });
    it('returns valid sdl for multiple @key directives', async () => {
      const query = `query GetServiceDetails {
      _service {
        sdl
      }
    }`;
      const schema = buildFederatedSchema(gql`
        type Product @key(fields: "upc") @key(fields: "name") {
          upc: String!
          name: String
          price: Int
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl)
        .toEqual(`type Product @key(fields: "upc") @key(fields: "name") {
  upc: String!
  name: String
  price: Int
}
`);
    });
    it('supports all federation directives', async () => {
      const query = `query GetServiceDetails {
        _service {
          sdl
        }
      }`;

      const schema = buildFederatedSchema(gql`
        type Review @key(fields: "id") {
          id: ID!
          body: String
          author: User @provides(fields: "email")
          product: Product @provides(fields: "upc")
        }

        extend type User @key(fields: "email") {
          email: String @external
          reviews: [Review]
        }

        extend type Product @key(fields: "upc") {
          upc: String @external
          reviews: [Review]
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl)
        .toEqual(`extend type Product @key(fields: "upc") {
  upc: String @external
  reviews: [Review]
}

type Review @key(fields: "id") {
  id: ID!
  body: String
  author: User @provides(fields: "email")
  product: Product @provides(fields: "upc")
}

extend type User @key(fields: "email") {
  email: String @external
  reviews: [Review]
}
`);
    });
    it('keeps custom directives', async () => {
      const query = `query GetServiceDetails {
        _service {
          sdl
        }
      }`;

      const schema = buildFederatedSchema(gql`
        directive @custom on FIELD

        extend type User @key(fields: "email") {
          email: String @external
        }
      `);

      const { data, errors } = await graphql(schema, query);
      expect(errors).toBeUndefined();
      expect(data._service.sdl).toEqual(`directive @custom on FIELD

extend type User @key(fields: "email") {
  email: String @external
}
`);
    });
  });
});

describe('legacy interface', () => {
  const resolvers = {
    Query: {
      product: () => ({}),
    },
    Product: {
      upc: () => '1234',
      price: () => 10,
    },
  };
  const typeDefs: DocumentNode[] = [
    gql`
      type Query {
        product: Product
      }
      type Product @key(fields: "upc") {
        upc: String!
        name: String
      }
    `,
    gql`
      extend type Product {
        price: Int
      }
    `,
  ];
  it('allows legacy schema module interface as an input with an array of typeDefs and resolvers', async () => {
    const schema = buildFederatedSchema({ typeDefs, resolvers });
    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
    expect(
      await execute(
        schema,
        gql`
          {
            product {
              price
              upc
            }
          }
        `,
      ),
    ).toEqual({
      data: {
        product: { upc: '1234', price: 10 },
      },
    });
  });
  it('allows legacy schema module interface as a single module', async () => {
    const schema = buildFederatedSchema({
      typeDefs: gql`
        type Query {
          product: Product
        }
        type Product @key(fields: "upc") {
          upc: String!
          name: String
          price: Int
        }
      `,
      resolvers,
    });
    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
    expect(
      await execute(
        schema,
        gql`
          {
            product {
              price
              upc
            }
          }
        `,
      ),
    ).toEqual({
      data: {
        product: { upc: '1234', price: 10 },
      },
    });
  });
  it('allows legacy schema module interface as a single module without resolvers', async () => {
    const schema = buildFederatedSchema({
      typeDefs: gql`
        type Query {
          product: Product
        }
        type Product @key(fields: "upc") {
          upc: String!
          name: String
          price: Int
        }
      `,
    });
    expect(schema.getType('Product')).toMatchInlineSnapshot(`
type Product {
  upc: String!
  name: String
  price: Int
}
`);
    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
  });
  it('allows legacy schema module interface as a simple array of documents', async () => {
    const schema = buildFederatedSchema({ typeDefs });
    expect(schema.getType('Product')).toMatchInlineSnapshot(`
type Product {
  upc: String!
  name: String
  price: Int
}
`);
    expect(schema.getType('_Entity')).toMatchInlineSnapshot(
      `union _Entity = Product`,
    );
  });
});