dva/dva.nim

import json, logging, os, strformat, times, uri
import bakalari, users

when not defined(release):
  let consoleLogger = newConsoleLogger()
  consoleLogger.addHandler

const
  iso8601 = initTimeFormat("yyyy-MM-dd'T'HH:mm:sszzz")

let
  configDir = getConfigDir() / "dva"
  userConfigDir = configDir / "userconfig"
  userCredentialsDir = configDir / "usercredentials"
  userDataDir = configDir / "userdata"

iterator usersFromUserConfigDir*(userConfigDir: string): User =
  if not existsDir(userConfigDir):
    fatal "User configuration diractory not found, quitting"
    quit QuitFailure
  for userConfigFile in walkFiles(userConfigDir / "*.json"):
    let userName = userConfigFile.extractFilename.changeFileExt("")
    info &"Loading configuration of user {userName}"
    let userConfigNode = userConfigFile.readFile.parseJson
    var userConfig: UserConfig
    userConfig.email = userConfigNode{"email"}.getStr
    for serviceNode in userConfigNode{"services"}:
      let kindStr = serviceNode{"kind"}.getStr
      case kindStr
      of "bakalari_message_forwarding":
        userConfig.services.add(Service(kind: srvBakalariMessageForwarding))
      of "bakalari_mark_forwarding":
        userConfig.services.add(Service(kind: srvBakalariMarkForwarding))
      of "bakalari_daily_timetable":
        userConfig.services.add(Service(kind: srvBakalariDailyTimetable))
      else:
        warn &"Unknown service kind: \"{kindStr}\""
    yield User(name: userName, config: userConfig, data: UserData(lastServeTime: 0.fromUnix.utc))

proc loadCredentials(user: User, userCredentialsDir: string) =
  info &"Loading credentials of user {user.name}"
  let userCredentialsFile = userCredentialsDir / user.name.addFileExt("json")
  if existsFile(userCredentialsFile):
    let userCredentialsNode = userCredentialsFile.readFile.parseJson
    let bakalariNode = userCredentialsNode{"bakalari"}
    block bakalari:
      if bakalariNode != nil:
        if "website" notin bakalariNode or "refresh_token" notin bakalariNode:
          error "Bakaláři credentials don't include website and refresh token"
          break bakalari
        user.bakalari = newBakalari(
          bakalariNode{"website"}.getStr.parseUri,
          bakalariNode{"refresh_token"}.getStr,
        )

proc storeCredentials(user: User, userCredentialsDir: string) =
  info &"Storing credentials of user {user.name}"
  let userCredentialsFile = userCredentialsDir / user.name.addFileExt("json")
  let userCredentialsNode = newJObject()
  block bakalari:
    if user.bakalari != nil:
      userCredentialsNode{"bakalari"} = %*{
        "website": $user.bakalari.website,
        "refresh_token": user.bakalari.refreshToken,
      }
  userCredentialsFile.writeFile userCredentialsNode.pretty

proc loadData(user: User, userDataDir: string) =
  info &"Loading data of user {user.name}"
  let userDataFile = userDataDir / user.name.addFileExt("json")
  if existsFile(userDataFile):
    let userDataNode = userDataFile.readFile.parseJson
    user.data.lastServeTime = userDataNode{"last_serve_time"}.getStr.parse(iso8601)

proc storeData(user: User, userDataDir: string) =
  info &"Storing data of user {user.name}"
  let userDataFile = userDataDir / user.name.addFileExt("json")
  let userDataNode = %*{
    "last_serve_time": user.data.lastServeTime.format(iso8601)
  }
  userDataFile.writeFile userDataNode.pretty

proc serve*(user: User, userCredentialsDir: string, userDataDir: string) =
  user.loadCredentials(userCredentialsDir)
  user.loadData(userDataDir)
  info &"Serving user {user.name}"
  let serveTime = now()
  for service in user.config.services:
    case service.kind
    of srvBakalariMessageForwarding:
      if user.bakalari == nil:
        error "Bakaláři message forwarding service is enabled, but user is not logged in to Bakaláři"
        continue
      for message in user.bakalari.messages:
        if message.sentTime >= user.data.lastServeTime:
          debug "Sending a message"
    else: discard
  user.data.lastServeTime = serveTime
  user.storeData(userDataDir)

when isMainModule:
  if "--login-bakalari" in commandLineParams():
    stdout.write "User: "
    let userName = stdin.readLine
    for user in usersFromUserConfigDir(userConfigDir):
      if user.name == userName:
        user.loadCredentials(userCredentialsDir)
        stdout.write "Bakalari website: "
        let bakalariWebsite = stdin.readLine.parseUri
        stdout.write "Bakalari username: "
        let bakalariUsername = stdin.readLine
        stdout.write "Bakalari password: "
        let bakalariPassword = stdin.readLine
        user.bakalari = newBakalari(bakalariWebsite, bakalariUsername, bakalariPassword)
        user.storeCredentials(userCredentialsDir)
        break
  for user in usersFromUserConfigDir(userConfigDir):
    try:
      user.serve(userCredentialsDir, userDataDir)
    except:
      error &"An exception was raised while processing user:\n  {getCurrentExceptionMsg()}\n{getCurrentException().getStackTrace}"