import resync from '../resync'
import { setElevation } from '../actions/point'
import { setRegion, requestRegions, receiveRegions } from '../actions/region'
import { urlEncode } from '../io'
import config from '../config'

const pointSelect = ({ runConfiguration }: any) => {
  let { point } = runConfiguration

  if (point) {
    point = { x: point.x, y: point.y }
  }

  return { point }
}

export default (store: any) => {
  resync(store, pointSelect, (state, io, dispatch) => {
    const { point } = state
    const pointIsValid = point !== null && point.x && point.y

    if (pointIsValid) {
      dispatch(setElevation(null))
      dispatch(requestRegions())
      const regionUrl = `${config.apiRoot}regions/?${urlEncode({
        point: `${point.x},${point.y}`,
      })}`

      io.get(regionUrl)
        .then(response => response.json())
        .then(json => {
          const { results } = json
          const validRegions = results.map((region: any) => region.name)

          dispatch(receiveRegions(validRegions)) // Always update valid regions

          let region = null
          if (validRegions.length) {
            ;[region] = validRegions
          }

          if (store.getState().runConfiguration.regionMethod === 'auto') {
            dispatch(setRegion(region))
          }
          return region
        })
        .then(region => {
          if (region !== null) {
            const url = `/arcgis/rest/services/${region}_dem/MapServer/identify/?${urlEncode({
              f: 'json',
              tolerance: '2',
              imageDisplay: '1600,1031,96',
              geometryType: 'esriGeometryPoint',
              mapExtent: '0,0,0,0',
              geometry: JSON.stringify({ x: point.x, y: point.y }),
            })}`

            io.get(url)
              .then(response => response.json())
              .then(json => {
                const { results } = json
                let value = null

                if (results.length) {
                  value = results[0].attributes['Pixel value']
                }

                if (Number.isNaN(value)) {
                  value = null
                }

                dispatch(setElevation(value))
              })
          }
        })
    }
  })
}