if (!event.body.lat || !event.body.long) {
  $end("Please pass both a lat and long to this workflow")
}

// To perform intersection queries with the SF Data API below,
// we need to create a box around the point where the recording was taken,
// and ask if any of our street segments (LineStrings) intersect with it
// We create a box with corners roughly 10 meters in every cardinal 
// direction from the original point

const lat = parseFloat(event.body.lat)
const long = parseFloat(event.body.long)
const DISTANCE_IN_EACH_DIRECTION = .0002

// Simple math to generate box around the point (for San Francisco)
this.topLeftCorner = [lat + DISTANCE_IN_EACH_DIRECTION, long - DISTANCE_IN_EACH_DIRECTION]
this.topRightCorner = [lat + DISTANCE_IN_EACH_DIRECTION, long + DISTANCE_IN_EACH_DIRECTION]
this.bottomRightCorner = [lat - DISTANCE_IN_EACH_DIRECTION, long + DISTANCE_IN_EACH_DIRECTION]
this.bottomLeftCorner = [lat - DISTANCE_IN_EACH_DIRECTION, long - DISTANCE_IN_EACH_DIRECTION]

// Generate WKT (well-known text represenation of a geometry) POLYGON
// that corresponds to the box. WKT orders coordinates as (long, lat)
this.POLYGON = `POLYGON((${this.topLeftCorner[1]} ${this.topLeftCorner[0]},${this.topRightCorner[1]} ${this.topRightCorner[0]},${this.bottomRightCorner[1]} ${this.bottomRightCorner[0]},${this.bottomLeftCorner[1]} ${this.bottomLeftCorner[0]},${this.topLeftCorner[1]} ${this.topLeftCorner[0]}))`

// Street Sweeping schedules, by street
// https://data.sfgov.org/City-Infrastructure/Street-Sweeping-Schedule/yhqp-riqs

this.intersectionString = `intersects(line, '${steps.calculate_box_around_point.POLYGON}')`

return await require("@pipedreamhq/platform").axios(this, {
  url: `https://data.sfgov.org/resource/yhqp-riqs`,
  headers: {
    "X-App-Token": `${auths.san_francisco_open_data_datasf.app_token}`,
  },
  params: {
    "$where": this.intersectionString
  },
})

// For each street within our bounding box, generate a
// string in the format of our street cleaning signs:
//
//   ${START_TIME} to ${END_TIME} ${WEEKDAY(S)}
//
// First, DataSF returns an entry per (street segment, side of street, cleaning day).
// Segments are referred to by Centerline Network Number. See
// https://data.sfgov.org/City-Infrastructure/Street-Sweeping-Schedule/yhqp-riqs .
// If a single side of a street is cleaned on Monday and Thursday, DataSF returns two
// entries. We need coalesce these entries into a single string.
// 
// Moreover, times returned from DataSF are in 24-hour clock time,
// But the time on signs are in 12-hour time, so we convert.

const capitalize = require("lodash.capitalize")
const includes = require("lodash.includes")
const uniq = require('lodash.uniq')

this.cleaningTimes = {}

const matchingStreets = steps.get_streets_within_bounding_box.$return_value
if (!matchingStreets.length) {
  $end("No streets returned from DataSF within bounding box")
}

for (const record of matchingStreets) {
  const { cnn, cnnrightleft, fromhour, tohour, weekday } = record

  // Street segment : side of street
  const key = `${cnn}:${cnnrightleft}`

  const cleaningTimeInstance = `${convert24HourTimeTo12HourTime(fromhour)} to ${convert24HourTimeTo12HourTime(tohour)}`
  const weekdayLower = weekday.toLowerCase()

  // If we've already stored the time portion of the string, add the day to the end
  if (key in this.cleaningTimes) {
    if (!(includes(this.cleaningTimes[key]["weekdays"], weekdayLower))) {
      this.cleaningTimes[key]["weekdays"].push(weekdayLower)
      this.cleaningTimes[key]["instances"].push({ fromhour, tohour, weekday })
    }
    continue
  }

  // Otherwise, add the time / date of this record
  this.cleaningTimes[key] = {
    schedule: cleaningTimeInstance,
    weekdays: [weekdayLower],
    instances: [{ fromhour, tohour, weekday }]
  }
}

this.scheduleArray = []
this.instances = {}

for (const { schedule, weekdays, instances } of Object.values(this.cleaningTimes)) {
  const uniqueWeekdays = uniq(weekdays.sort(compareWeekdays)).map(capitalize)
  const scheduleString = `${schedule} ${uniqueWeekdays.join(", ")}`
  if (includes(this.scheduleArray, scheduleString)) {
    continue
  }
  this.scheduleArray.push(scheduleString)
  this.instances[scheduleString] = instances
}

// HTTP RESPONSE
$respond({
  body: { 
    schedules: this.scheduleArray,
    instances: this.instances,
  },
})

function convert24HourTimeTo12HourTime(stringHour) {
  const hour = parseInt(stringHour)
  if (hour >= 0 && hour <= 11) {
    return `${hour}AM`
  }
  if (hour === 12) {
    return `${hour}PM`
  }
  return `${hour - 12}PM`
}

function compareWeekdays(a, b) {
  const weekdayNum = {
    // Schedules contain abbreviated and full weekdays
    'sun': 0,
    'sunday': 0,
    'mon': 1,
    'monday': 1,
    'tues': 2,
    'tuesday': 2,
    'wed': 3,
    'wednesday': 3,
    'thu': 4,
    'thursday': 4,
    'fri': 6,
    'friday': 6,
    'sat': 7,
    'saturday': 7,
  }

  return weekdayNum[a.toLowerCase()] - weekdayNum[b.toLowerCase()]
}