module.exports = (app, client) => {
    const constant = require('./constant'),
        zlib = require('zlib'),
        { pick } = require('stream-json/filters/Pick'),
        { parser } = require('stream-json'),
        { streamArray } = require('stream-json/streamers/StreamArray'),
        { chain } = require('stream-chain'),
        clean = str => {
            return str.replace(/[/\\^$+?()`'¡¿¨!"·%&=;,\|\[\]{}]+/gmi, '')
        }
    /**
     * @swagger
     * /api/stats:
     *   get:
     *     summary: Retrieve stats of instances.
     *     description: Retrieve stats of total instances.
     *     responses:
     *       200:
     *         description: A object with stats parameters.
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 data:
     *                   type: object
     *                   properties:
     *                     instance_count:
     *                       type: integer
     *                       description: Count of instances.
     *                       example: 0
     *                     status_avg:
     *                       type: float
     *                       description: Average statuses of total instances.
     *                       example: 0
     *                     status_max:
     *                       type: integer
     *                       description: Max of total statuses instances.
     *                       example: 0
     *                     user_avg:
     *                       type: float
     *                       description: Average users of total instances.
     *                       example: 0
     *                     user_max:
     *                       type: integer
     *                       description: Max of total users instances.
     *                       example: 0
     *                     domain_avg:
     *                       type: float
     *                       description: Number of average domains instances.
     *                       example: 0
     *                     domain_max:
     *                       type: integer
     *                       description: Number of max domains instances.
     *                       example: 0
     *                     stats_filtered:
     *                       type: integer
     *                       description: Number of instances stats.
     *                       example: 0
     */
    app.use('/api/stats', async (req, res) => {
        const result = await client.search({
            index: constant.index,
            body: {
                size: 0,
                aggs: {
                    instance_count: {
                        value_count: {
                            field: '_id'
                        }
                    },
                    stats_filtered: {
                        filter: {
                            exists: {
                                field: 'api.stats'
                            }
                        }
                    },
                    user_avg: {
                        avg: {
                            field: 'api.stats.user_count'
                        }
                    },
                    user_max: {
                        max: {
                            field: 'api.stats.user_count'
                        }
                    },
                    domain_avg: {
                        avg: {
                            field: 'api.stats.domain_count'
                        }
                    },
                    domain_max: {
                        max: {
                            field: 'api.stats.domain_count'
                        }
                    },
                    status_avg: {
                        avg: {
                            field: 'api.stats.status_count'
                        }
                    },
                    status_max: {
                        max: {
                            field: 'api.stats.status_count'
                        }
                    }

                }
            }
        })
        res.json(Object.keys(result.aggregations).reduce((prev, curr) => ({
            ...prev, [curr]: result.aggregations[curr][Object.keys(result.aggregations[curr])[0]]
        }), {}))
    })
    /**
     * @swagger
     * /api/count:
     *   get:
     *     summary: Retrieve count of instances.
     *     description: Retrieve a number of total instances.
     *     responses:
     *       200:
     *         description: A object with count parameter.
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 data:
     *                   type: object
     *                   properties:
     *                     count:
     *                       type: integer
     *                       description: Number of instances.
     *                       example: 0
     */
    app.use('/api/count', async (req, res) => {
        res.json({ count: (await client.count({ index: constant.index })).count })
    })
    /**
     * @swagger
     * /api/ranking:
     *   get:
     *     summary: Retrieve one ranking of instances.
     *     description: Retrieve a top ten ranking of total fediblock instances.
     *     responses:
     *       200:
     *         description: A object with count parameter.
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 data:
     *                   type: object
     *                   properties:
     *                     domain:
     *                       type: string
     *                       description: Domain of the instance.
     *                       example: "mastodon.social"
     *                     count:
     *                       type: integer
     *                       description: Number of fediblocks.
     *                       example: 0
     */
    app.use('/api/ranking', async (req, res) => {
        const result = await client.search({
            index: constant.index,
            body: {
                size: 0,
                aggs: {
                    blocks: {
                        nested: {
                            path: 'blocks'
                        },
                        aggs: {
                            ranking: {
                                terms: {
                                    field: 'blocks.domain',
                                    size: 100
                                }
                            }
                        }
                    }
                }
            }
        })
        const ranking = result.aggregations?.blocks?.ranking?.buckets
        res.json(ranking.map(r => ({ domain: r.key, count: r.doc_count })))
    })
    /**
    * @swagger
    * /api/list/{instance}:
    *   get:
    *     summary: Search result array of intances.
    *     description: Retrieve a result array of instances matching search input.
    *     parameters:
    *       - in: path
    *         name: instance
    *         required: true
    *         description: String for search instance
    *         schema:
    *           type: string
    *     responses:
    *       200:
    *         description: A list of instances.
    *         content:
    *           application/json:
    *             schema:
    *               type: object
    *               properties:
    *                 data:
    *                   type: array
    *                   items:
    *                     type: object
    *                     properties:
    *                       instances:
    *                         type: array
    *                         items:
    *                           type: data
    *                           description: List of instances.
    *                           example: "mastodon.social"
    *                       suggests:
    *                         type: array
    *                         items:
    *                           type: data
    *                           description: Suggest of the instance.
    *                           example: "mastodon.social"
    */
    app.use('/api/list/:instance', async (req, res) => {
        if (req.params.instance && req.params.instance.length > 0) {
            const result = await client.search({
                index: constant.index,
                size: 10,
                query: {
                    wildcard: {
                        instance: {
                            value: `*${clean(req.params.instance)}*`
                        }
                    },
                },
                suggest: {
                    suggests: {
                        text: req.params.instance,
                        term: {
                            field: 'instance',
                            size: 3,
                            sort: 'score',
                            suggest_mode: 'always',
                            max_edits: 2,
                            min_word_length: 1
                        }
                    }
                }
            })
            const instances = result.hits?.hits?.length > 0 ? result.hits.hits : [],
                suggests = result.suggest.suggests && result.suggest.suggests.length > 0 && result.suggest.suggests[0].options.length > 0 ? result.suggest.suggests[0].options : []
            res.json({
                instances: instances.map(instance => ({
                    domain: instance._source.instance,
                    api: instance._source.api ? instance._source.api : null,
                    blocks: instance._source.blocks && instance._source.blocks.length > 0 ? instance._source.blocks.length : null,
                    last: instance._source.last ? instance._source.last : null,
                    nodeinfo: instance._source.nodeinfo ? true : false
                })), suggests: suggests.map(instance => instance.text)
            })
        } else {
            res.status(404).end()
        }
    })
    /**
    * @swagger
    * /api/detail/{instance}:
    *   get:
    *     summary: Search result array of fediblocks intances.
    *     description: Retrieve a result array of fediblock instances matching search input.
    *     parameters:
    *       - in: path
    *         name: instance
    *         required: true
    *         description: String to detail of the instance
    *         schema:
    *           type: string
    *     responses:
    *       200:
    *         description: A list of instances.
    *         content:
    *           application/json:
    *             schema:
    *               type: object
    *               properties:
    *                 data:
    *                   type: array
    *                   items:
    *                     type: object
    *                     properties:
    *                       domain:
    *                         type: string
    *                         description: Domain of the block instance.
    *                         example: "mastodon.social"
    *                       comment:
    *                         type: string
    *                         description: Comment of the block instance.
    *                         example: "mastodon.social"
    *                       severity:
    *                         type: string
    *                         description: Severity of the block instance.
    *                         example: "mastodon.social"
    * 
    */
    app.use('/api/detail/:instance', async (req, res) => {
        if (req.params.instance && req.params.instance.length > 0) {
            const result = await client.search({
                index: constant.index,
                size: 1,
                query: {
                    term: {
                        instance: clean(req.params.instance)
                    }
                }
            })
            const instances = result.hits?.hits?.length > 0 ? result.hits.hits : []
            res.json(instances.length > 0 && instances[0]._source.blocks && instances[0]._source.blocks.length > 0 ?
                {
                    blocks: instances[0]._source.blocks.map(instance => ({ domain: instance.domain, comment: instance.comment, severity: instance.severity })),
                    last: instances[0]._source.last,
                    instance: instances[0]._source.instance,
                    nodeinfo: instances[0]._source.nodeinfo,
                    api: instances[0]._source.api,
                    took: result.took
                } : [])
        } else {
            res.status(404).end()
        }
    })
    /**
    * @swagger
    * /api/detail_api/{instance}:
    *   get:
    *     summary: Search result of detail's api intance.
    *     description: Retrieve a result of detail's api instance.
    *     parameters:
    *       - in: path
    *         name: instance
    *         required: true
    *         description: String to detail of the instance
    *         schema:
    *           type: string
    *     responses:
    *       200:
    *         description: Detail of the api instance.
    *         content:
    *           application/json:
    *             schema:
    *               type: object
    *               properties:
    *                 data:
    *                   type: object
    */
    app.use('/api/detail_api/:instance', async (req, res) => {
        if (req.params.instance && req.params.instance.length > 0) {
            const result = await client.search({
                index: constant.index,
                size: 1,
                query: {
                    term: {
                        instance: clean(req.params.instance)
                    }
                }
            })
            const instances = result.hits?.hits?.length > 0 ? result.hits.hits : []
            res.json(instances.length > 0 ? instances[0]._source.api : {})
        } else {
            res.status(404).end()
        }
    })
    /**
    * @swagger
    * /api/detail_nodeinfo/{instance}:
    *   get:
    *     summary: Search result of detail's nodeinfo intance.
    *     description: Retrieve a result of detail's nodeinfo instance.
    *     parameters:
    *       - in: path
    *         name: instance
    *         required: true
    *         description: String to detail of the instance
    *         schema:
    *           type: string
    *     responses:
    *       200:
    *         description: Detail of the nodeinfo instance.
    *         content:
    *           application/json:
    *             schema:
    *               type: object
    *               properties:
    *                 data:
    *                   type: object
    */
    app.use('/api/detail_nodeinfo/:instance', async (req, res) => {
        if (req.params.instance && req.params.instance.length > 0) {
            const result = await client.search({
                index: constant.index,
                size: 1,
                query: {
                    term: {
                        instance: clean(req.params.instance)
                    }
                }
            })
            const instances = result.hits?.hits?.length > 0 ? result.hits.hits : []
            res.json(instances.length > 0 ? instances[0]._source.nodeinfo : {})
        } else {
            res.status(404).end()
        }
    })
    /**
    * @swagger
    * /api/block_count/{instance}:
    *   get:
    *     summary: Retrieve count of fediblocked instances.
    *     description: Retrieve a number of total fediblocked instances.
    *     parameters:
    *       - in: path
    *         name: instance
    *         required: true
    *         description: String to search fediblocks of the instance
    *         schema:
    *           type: string
    *     responses:
    *       200:
    *         description: A object with block_count parameter.
    *         content:
    *           application/json:
    *             schema:
    *               type: object
    *               properties:
    *                 data:
    *                   type: array
    *                   items:
    *                     type: object
    *                     properties:
    *                       instance:
    *                         type: string
    *                         description: Instance of the block.
    *                         example: mastodon.social
    *                       comment:
    *                         type: string
    *                         description: Comment about the block.
    *                         example: spam
    */
    app.use('/api/block_count/:instance', async (req, res) => {
        if (req.params.instance && req.params.instance.length > 0) {
            const result = await client.search({
                index: constant.index,
                size: 9999,
                query: {
                    nested: {
                        path: 'blocks',
                        query: {
                            term: {
                                'blocks.domain': clean(req.params.instance)
                            }
                        }
                    }
                }
            }, { asStream: true, meta: false }),
                pipeline = chain([
                    parser(),
                    pick({ filter: 'hits.hits' }),
                    streamArray(),
                    data => ({ instance: data.value._source.instance, comment: data.value._source.blocks.find(block => block.domain === clean(req.params.instance)).comment })
                ])
            result.on('readable', () => res.write('['))
            pipeline.on('data', data => res.write(data.toString() + ','))
            pipeline.on('end', () => res.end(']'))
            result.pipe(pipeline)
        } else {
            res.status(404).end()
        }
    })
    /**
    * @swagger
    * /api/download_index:
    *   get:
    *     summary: Retrieve all content of ElasticSearch index.
    *     description: Retrieve all content of ElasticSearch index.
    *     responses:
    *       200:
    *         description: A file compressed with gzip.
    *         content:
    *           application/gzip:
    */
    app.use('/api/download_index', async (req, res) => {
        try {
            res.setHeader('Content-Type', 'application/gzip')
            res.setHeader('Content-disposition', 'attachment; filename=fediblock-index.jsonl.gz')
            const result = await client.search({
                index: constant.index,
                size: 9999,
                query: {
                    match_all: {}
                }
            }, { asStream: true, meta: false }),
                pipeline = chain([
                    parser(),
                    pick({ filter: 'hits.hits' }),
                    streamArray(),
                    data => JSON.stringify(data.value._source) + '\n',
                    zlib.createGzip()
                ])
            result.pipe(pipeline).pipe(res)
        } catch (e) {
            console.error(e)
            res.status(404).end()
        }
    })
}