const CouchDB = require("../../db")
const {
  generateDatasourceID,
  getDatasourceParams,
  getQueryParams,
} = require("../../db/utils")
const { integrations } = require("../../integrations")
const plusIntegrations = require("../../integrations/plus")

exports.fetch = async function (ctx) {
  const database = new CouchDB(ctx.appId)
  ctx.body = (
    await database.allDocs(
      getDatasourceParams(null, {
        include_docs: true,
      })
    )
  ).rows.map(row => row.doc)
}

exports.save = async function (ctx) {
  const db = new CouchDB(ctx.appId)

  const datasource = {
    _id: generateDatasourceID(),
    type: "datasource",
    ...ctx.request.body,
  }

  const response = await db.post(datasource)
  datasource._rev = response.rev

  // Drain connection pools when configuration is changed
  if (datasource.source) {
    const source = integrations[datasource.source]
    if (source && source.pool) {
      await source.pool.end()
    }
  }

  ctx.status = 200
  ctx.message = "Datasource saved successfully."
  ctx.body = datasource
}

exports.destroy = async function (ctx) {
  const db = new CouchDB(ctx.appId)

  // Delete all queries for the datasource
  const rows = await db.allDocs(getQueryParams(ctx.params.datasourceId, null))
  await db.bulkDocs(rows.rows.map(row => ({ ...row.doc, _deleted: true })))

  // delete the datasource
  await db.remove(ctx.params.datasourceId, ctx.params.revId)

  ctx.message = `Datasource deleted.`
  ctx.status = 200
}

exports.find = async function (ctx) {
  const database = new CouchDB(ctx.appId)
  ctx.body = await database.get(ctx.params.datasourceId)
}

// dynamic query functionality
exports.query = async function (ctx) {
  const queryJson = ctx.request.body
  const datasourceId = queryJson.endpoint.datasourceId
  const database = new CouchDB(ctx.appId)
  const datasource = await database.get(datasourceId)
  const source = integrations[datasource.source]
  // query is the opinionated function
  if (source.query) {
    ctx.body = await source.query(queryJson)
  } else {
    ctx.throw(400, "Datasource does not support query.")
  }
}

// TODO: merge endpoint with main datasource endpoint
exports.plus = async function (ctx) {
  const db = new CouchDB(ctx.appId)

  const PlusConnector = plusIntegrations[ctx.request.body.source]

  const connector = new PlusConnector(ctx.request.body)
  await connector.init()

  const datasource = {
    _id: generateDatasourceID({ plus: true }),
    type: "datasource_plus",
    relationships: [],
    ...ctx.request.body,
    entities: connector.tables,
  }

  const response = await db.post(datasource)
  datasource._rev = response.rev

  ctx.body = datasource
}