'use strict';

const express = require('express');
const graphqlHTTP = require('express-graphql');
const {
  GraphQLBoolean,
  GraphQLID,
  GraphQLInt,
  GraphQLList,
  GraphQLNonNull,
  GraphQLObjectType,
  GraphQLSchema,
  GraphQLString,
} = require('graphql');
const {
  createVideo,
  getVideoById,
  getVideos
} = require('./src/data/index');

const PORT = process.env.PORT || 3000;

const server = express();

const videoType = new GraphQLObjectType({
  name: 'Video',
  description: 'A video on egghead.io',
  fields: {
    id: {
      type: GraphQLID,
      description: 'The ID of the video'
    },
    title: {
      type: GraphQLString,
      description: 'The title of the video'
    },
    duration: {
      type: GraphQLInt,
      description: 'The duration of the video, in seconds',
    },
    watched: {
      type: GraphQLBoolean,
      description: 'Whether or not the viewer has watched the video'
    }
  }
});

const queryType = new GraphQLObjectType({
  name: 'QueryType',
  description: 'The root query  type',
  fields: {
    video: {
      type: videoType,
      args: {
        id: {
          type: new GraphQLNonNull(GraphQLID),
          description: 'The ID of the video'
        }
      },
      resolve: (_, args) => {
        return getVideoById(args.id);
      }
    },
    videos: {
      type: new GraphQLList(videoType),
      // General form:
      // resolve: () => getVideos()
      // Shortcut:
      resolve: getVideos
    }
  }
});

/* Example mutation use:

mutation M {
 createVideo(
   title: "A new hope",
   duration: 7260,
   released: true
 ) {
   id,
   title
   }
 }


 */
const mutationType = new GraphQLObjectType({
  name: 'Mutation',
  description: "The root Mutation type",
  fields: {
    createVideo: {
      type: videoType,
      args: {
        title: {
          type: new GraphQLNonNull(GraphQLString),
          description: 'The title of the video'
        },
        duration: {
          type: new GraphQLNonNull(GraphQLInt),
          description: 'The duration of the video, in seconds'
        },
        released: {
          type: new GraphQLNonNull(GraphQLBoolean),
          description: "Whether or not the video is released"
        }
      },
      resolve: (_, args) => {
        return createVideo(args);
      }
    }
  }
});

const schema = new GraphQLSchema({
  mutation: mutationType,
  query: queryType
  // Also available:
  // subscription: ...
});

server.use('/graphql', graphqlHTTP({
  schema,
  graphiql: true
}));

server.listen(PORT, () => {
  console.log(`Listening on http://localhost:${PORT}`);
});