Really rough bart implementation

2022-10-16 00:21:28 -07:00
parent ac9f37487e
commit e85241c998
3 changed files with 140 additions and 9 deletions
--- a/bart.nim
+++ b/bart.nim
@@ -0,0 +1,109 @@
+import std/[json, httpclient, sequtils, strformat, strutils]
+
+type Station = object
+  id: string
+  name: string
+
+type Departure = ref object
+  destination: string
+  color: string
+  estimates: seq[uint] 
+
+proc newStation(id: string, name: string): Station =
+  Station(id: id, name: name)
+
+
+const bart_stations = @[
+  newStation("12th", "12th St. Oakland City Center"),
+  newStation("16th", "16th St. Mission (SF)"),
+  newStation("19th", "19th St. Oakland"),
+  newStation("24th", "24th St. Mission (SF)"),
+  newStation("ashb", "Ashby (Berkeley)"),
+  newStation("antc", "Antioch"),
+  newStation("balb", "Balboa Park (SF)"),
+  newStation("bayf", "Bay Fair (San Leandro)"),
+  newStation("bery", "Berryessa / North San Jose"),
+  newStation("cast", "Castro Valley"),
+  newStation("civc", "Civic Center (SF)"),
+  newStation("cols", "Coliseum"),
+  newStation("colm", "Colma"),
+  newStation("conc", "Concord"),
+  newStation("daly", "Daly City"),
+  newStation("dbrk", "Downtown Berkeley"),
+  newStation("dubl", "Dublin/Pleasanton"),
+  newStation("deln", "El Cerrito del Norte"),
+  newStation("plza", "El Cerrito Plaza"),
+  newStation("embr", "Embarcadero (SF)"),
+  newStation("frmt", "Fremont"),
+  newStation("ftvl", "Fruitvale (Oakland)"),
+  newStation("glen", "Glen Park (SF)"),
+  newStation("hayw", "Hayward"),
+  newStation("lafy", "Lafayette"),
+  newStation("lake", "Lake Merritt (Oakland)"),
+  newStation("mcar", "MacArthur (Oakland)"),
+  newStation("mlbr", "Millbrae"),
+  newStation("mlpt", "Milpitas"),
+  newStation("mont", "Montgomery St. (SF)"),
+  newStation("nbrk", "North Berkeley"),
+  newStation("ncon", "North Concord/Martinez"),
+  newStation("oakl", "Oakland Int'l Airport"),
+  newStation("orin", "Orinda"),
+  newStation("pitt", "Pittsburg/Bay Point"),
+  newStation("pctr", "Pittsburg Center"),
+  newStation("phil", "Pleasant Hill"),
+  newStation("powl", "Powell St. (SF)"),
+  newStation("rich", "Richmond"),
+  newStation("rock", "Rockridge (Oakland)"),
+  newStation("sbrn", "San Bruno"),
+  newStation("sfia", "San Francisco Int'l Airport"),
+  newStation("sanl", "San Leandro"),
+  newStation("shay", "South Hayward"),
+  newStation("ssan", "South San Francisco"),
+  newStation("ucty", "Union City"),
+  newStation("warm", "Warm Springs/South Fremont"),
+  newStation("wcrk", "Walnut Creek"),
+  newStation("wdub", "West Dublin"),
+  newStation("woak", "West Oakland"),
+]
+
+proc bart_station_names*(): seq[string] =
+  bart_stations.map(proc(s: Station): string = s.name)
+
+proc get_departures(client: HTTPClient, station: Station): JSONNode =
+  let id = station.id
+  let response = client.get(&"http://api.bart.gov/api/etd.aspx?cmd=etd&orig={id}&key=MW9S-E7SL-26DU-VV8V&json=y")
+  parseJSON(response.body)
+
+proc format_estimate_minutes(minutes: string): uint =
+  case minutes:
+    of "Leaving":
+      return 0.uint
+    else:
+     return parseUInt(minutes) 
+
+proc parse_departures(etd: JSONNode): seq[Departure] =
+  if not etd["root"].hasKey("station"):
+    return @[]
+
+  let lines = etd["root"]["station"][0]["etd"].getElems
+
+  lines.map(proc (line: JSONNode): Departure = 
+    let dest = line["destination"].getStr
+    let color = line["estimate"][0]["color"].getStr
+
+    let estimates = line["estimate"].getElems.map(proc(estimate: JSONNode): uint =
+      format_estimate_minutes(estimate["minutes"].getStr)
+    )
+
+    Departure(destination: dest, color: color, estimates: estimates) 
+  )
+
+proc format_departures(departures: seq[Departure]): string =
+  departures.map(proc (d: Departure): string =
+    let estimates = d.estimates.join(", ")
+    &"{d.destination}\t{estimates}"
+  ).join("\n")
+
+proc prediction_for_station_idx*(client: HTTPClient, idx: int): string =
+  let station = bart_stations[idx]
+  client.get_departures(station).parse_departures().format_departures()