import {
    FastifyInstance,
    RouteShorthandOptions,
    Plugin,
    DefaultQuery,
    DefaultParams,
    DefaultHeaders,
    DefaultBody,
    JSONSchema,
} from 'fastify'
import { Server, IncomingMessage, ServerResponse } from 'http'
import request from 'request'
import { PluginOptions, GiphyResponse } from '../../types'

interface FetchOptions {
    url: string
    params?: string[][]
    method?: string
}

const paramsToString = (params: string[][]) => params.map(p => p.join('=')).join('&')

const giphyGifSchema: JSONSchema = {
    type: 'object',
    properties: {
        type: { type: 'string' },
        id: { type: 'string' },
        slug: { type: 'string' },
        url: { type: 'string' },
        bitly_url: { type: 'string' },
        embed_url: { type: 'string' },
        title: { type: 'string' },
        images: {
            type: 'object',
            properties: {
                fixed_height: {
                    type: 'object',
                    properties: {
                        url: { type: 'string' },
                    },
                },
                fixed_height_still: {
                    type: 'object',
                    properties: {
                        url: { type: 'string' },
                    },
                },
                fixed_height_downsampled: {
                    type: 'object',
                    properties: {
                        url: { type: 'string' },
                    },
                },
            },
        },
    },
}

async function fetch<T = any>(options: FetchOptions) {
    const { url, params = [], method = 'get' } = options
    const uri = params.length > 0 ? `${url}?${paramsToString(params)}` : url

    return new Promise<T>((resolve, reject) => {
        request({
            uri,
            method,
            json: true,
        }, function(error, response, body) {
            if (error) {
                reject(error)
                return
            }

            resolve(body)
        })
    })
}

function gifHomeRoute(server: FastifyInstance<Server, IncomingMessage, ServerResponse>) {
    const options: RouteShorthandOptions = {
        schema: {
            response: {
                200: {
                    type: 'array',
                    items: giphyGifSchema,
                },
            },
        },
    }

    server.get<DefaultQuery, DefaultParams, DefaultHeaders, DefaultBody>('/api/gifs/home', options, async (request, reply) => {
        const response = await fetch<GiphyResponse>({
            url: `${process.env.GIPHY_API_ENDPOINT!}/v1/gifs/trending`,
            params: [['api_key', process.env.GIPHY_API_KEY!], ['limit', '20']],
        })

        return response.data
    })
}

function gifSearchRoute(server: FastifyInstance<Server, IncomingMessage, ServerResponse>) {
    interface Query {
        q: string
    }

    const options: RouteShorthandOptions = {
        schema: {
            querystring: {
                type: 'object',
                properties: {
                    q: { type: 'string' },
                },
            },
            response: {
                200: {
                    type: 'array',
                    items: giphyGifSchema,
                },
            },
        },
    }

    server.get<Query, DefaultParams, DefaultHeaders, DefaultBody>('/api/gifs/search', options, async (request, reply) => {
        const q = request.query.q ? request.query.q.trim() : ''

        if (q.length < 3) {
            reply.code(400)
            return
        }

        const response = await fetch<GiphyResponse>({
            url: `${process.env.GIPHY_API_ENDPOINT!}/v1/gifs/search`,
            params: [['api_key', process.env.GIPHY_API_KEY!], ['limit', '20'], ['q', q]],
        })

        return response.data
    })
}

const plugin: Plugin<Server, IncomingMessage, ServerResponse, PluginOptions> = async server => {
    gifHomeRoute(server)
    gifSearchRoute(server)
}

export default plugin