import std/[asyncdispatch, asynchttpserver]
import std/[parseutils, strutils]
import std/[times, math]
import std/[json, options]

import threadvars, types, utils, fedi

proc saveState(state: JsonNode) = 
  var json_encoded: string
  toUgly(json_encoded, state)
  writeFile(storagePath & "/state.json", json_encoded)

proc requestHandler* (req: Request) {.async.} =
  echo $req.reqMethod & " " & $req.url.path & " " & req.headers.getOrDefault("user-agent") & ": " & req.body

  let headers = {"Content-type": "text/plain; charset=utf-8"}


  if config.ServerAccessToken.isSome:
    if not req.headers.hasKey("Authorization"):
      await req.respond(Http401, "Wrong access-token provided.", headers.newHttpHeaders())
      return
    else:
      if req.headers.getOrDefault("Authorization") != "Bearer " & config.ServerAccessToken.get:
        await req.respond(Http401, "Wrong access-token provided.", headers.newHttpHeaders())
        return

  try:
    let entityBodyJson = parseJson(req.body)
    var reason         = entityBodyJson["reason"].getStr

    if reason == "checkout": reason = "update" 

    case reason:
      of "ping":
        state = newJObject()
        saveState(state)

        var response = "[fedi-create-post] error: Unkown error happend!"

        let post = await fediPost(config, "This is a test post from travelynx2fedi!", PostDirect)

        if post["responseCode"].getStr != "200 OK":
          response = "[fedi-create-post] error: " & post["error"].getStr
        else:
          response = "[fedi-create-post] created post " & $post["id"] & ": " & $post["content"]

        await req.respond(Http200, response, headers.newHttpHeaders())
        return


      of "checkin":
        state = newJObject()
        saveState(state)
        await req.respond(Http200, "[checkin] recieved checkin!", headers.newHttpHeaders())
        return


      of "update":
        var statusUrl:        string
        var statusText:       string
        var statusVisibility: PostVisibility = PostDirect

        var response:     string
        var responseCode: HttpCode = Http200

        if state.hasKey("checkin_id") and state.hasKey("to_station"):

          if (
            state["checkin_id"].getStr      == entityBodyJson["status"]["fromStation"]["scheduledTime"].getStr and
            state["to_station"].getStr      == entityBodyJson["status"]["toStation"]["name"].getStr and
            state["comment"].getStr         == entityBodyJson["status"]["comment"].getStr and
            state["visibilityLevel"].getInt == entityBodyJson["status"]["visibility"]["level"].getInt
          ):
            await req.respond(Http200, "[checkin] Already posted!" & response, headers.newHttpHeaders())
            return

          if (
            state.hasKey("post_id") and
            (
              state["to_station"].getStr != entityBodyJson["status"]["toStation"]["name"].getStr or
              state["comment"].getStr    != entityBodyJson["status"]["comment"].getStr
            )
          ):
            let post = await fediDelete(config, state["post_id"].getStr)

            if post["responseCode"].getStr != "200 OK":
              responseCode = Http500
              response = "[fedi-delete-post] error: " & post["error"].getStr
              await req.respond(responseCode, "[checkin] " & response, headers.newHttpHeaders())
              return
            else:
              state = newJObject()
              saveState(state)
              response = "[fedi-delete-post] successfully deleted post " & $post["id"]


        if config.TravelynxUsername.isSome:
          let token = $entityBodyJson["status"]["fromStation"]["uic"] & "-" & $floorMod( entityBodyJson["status"]["actionTime"].getInt , 337 ) 
          statusUrl = "http://travelynx.de/status/" & config.TravelynxUsername.get & "/" & $entityBodyJson["status"]["fromStation"]["scheduledTime"] & "?token=" & token

        let vehicle = entityBodyJson["status"]["train"]["type"].getStr & " " & entityBodyJson["status"]["train"]["no"].getStr

        if config.FediUseMarkdown:
          statusText = "Ich bin gerade in [" & vehicle & " nach " & entityBodyJson["status"]["toStation"]["name"].getStr & "](" & statusUrl & ")"
        else:
          statusText = "Ich bin gerade in " & vehicle & " nach " & entityBodyJson["status"]["toStation"]["name"].getStr & " " & statusUrl

        if entityBodyJson["status"]{"comment"}.getStr != "":
          if config.FediUseMarkdown:
            statusText = entityBodyJson["status"]["comment"].getStr & " ([" & vehicle & " → " & entityBodyJson["status"]["toStation"]["name"].getStr & "](" & statusUrl & "))"
          else:
            statusText = entityBodyJson["status"]["comment"].getStr & " (" & vehicle & " → " & entityBodyJson["status"]["toStation"]["name"].getStr & " " & statusUrl & ")"

        if config.FediVisibility.isSome:
          if (entityBodyJson["status"]["visibility"]["level"].getInt <= 10):
            statusVisibility = PostDirect
          else:
            statusVisibility = config.FediVisibility.get
        else:
          if (entityBodyJson["status"]["visibility"]["level"].getInt <= 30):  statusVisibility = PostDirect
          if (entityBodyJson["status"]["visibility"]["level"].getInt <= 60):  statusVisibility = PostPrivate
          if (entityBodyJson["status"]["visibility"]["level"].getInt == 100): statusVisibility = PostUnlisted


        let post = await fediPost(config, statusText, statusVisibility)

        if post["responseCode"].getStr != "200 OK":
          response = "[fedi-create-post] error: " & post["error"].getStr
        else:
          state["checkin_id"]      = entityBodyJson["status"]["fromStation"]["scheduledTime"]
          state["to_station"]      = entityBodyJson["status"]["toStation"]["name"]
          state["post_id"]         = post["id"]
          state["post_time"]       = newJInt(toUnix(getTime()))
          state["comment"]         = entityBodyJson["status"]["comment"]
          state["visibilityLevel"] = entityBodyJson["status"]["visibility"]["level"]
          saveState(state)
          response = "[fedi-create-post] created post " & $post["id"] & ": " & $post["content"]


        await req.respond(responseCode, "[checkin] " & response, headers.newHttpHeaders())


      of "undo":
        var response:     string
        var responseCode: HttpCode = Http200

        if state.hasKey("post_id") and state.hasKey("post_time"):
          let currentTime = toUnix(getTime())

          if currentTime - state["post_time"].getInt < 15*60:
            let post = await fediDelete(config, state["post_id"].getStr)

            if post["responseCode"].getStr != "200 OK":
              responseCode = Http500
              response = "[fedi-delete-post] error: " & post["error"].getStr
            else:
              state = newJObject()
              saveState(state)
              response = "[fedi-delete-post] successfully deleted post " & $post["id"]

          else:
            response = "Post too old!"

        else:
          response = "Nothing posted yet!"

        await req.respond(responseCode, "[undo] " & response, headers.newHttpHeaders())

      else:
        await req.respond(Http400, "Invalid request", headers.newHttpHeaders())
        return


  except:
    let
      e   = getCurrentException()
      msg = getCurrentExceptionMsg()

    echo "Got exception ", repr(e), " with message ", msg

    await req.respond(Http500, "Internal server error, whoops", headers.newHttpHeaders())
    return