package main

import (
	"encoding/base64"
	"encoding/json"
	"io"
	"log"
	"maps"
	"net/http"
	trmaps "shellixa/puvetra/internal/maps"
	"shellixa/puvetra/internal/types"
	"slices"
	"strings"
	"time"
)

func main() {

	mux := http.NewServeMux()

	server := &http.Server{
		Handler: mux,
		Addr:    ":8080",
	}

	mux.HandleFunc("POST /line", GetLineTrams)

	err := server.ListenAndServe()
	if err != nil {
		log.Println(err)
	}
}

func GetLineTrams(w http.ResponseWriter, r *http.Request) {

	// log.Printf("%+v\n", r)
	b64Body := base64.NewDecoder(base64.StdEncoding, r.Body)
	defer r.Body.Close()

	body, _ := io.ReadAll(b64Body)

	stationSeq := strings.Split(string(body), ";")

	tramLine := r.URL.Query().Get("number")

	trams := trmaps.GetTrips()

	var allTrams []types.MapTrip

	for _, t := range trams {
		if t.Mode == "TRAM" && t.Trips[0].RouteShortName == tramLine {
			allTrams = append(allTrams, t)
		}
	}


	var traminfo = make(map[string]types.MapTrip)

	now := time.Now()
	for _, tr := range allTrams {
		// Überschreibe [tripId] nur, wenn (OR)
		// - [tripId] == nil
		// - departure < now && arrival > [tripId].departure
		storedTram := traminfo[tr.Trips[0].TripId]

		if tr.Departure.Sub(now).Abs() < storedTram.Departure.Sub(now).Abs() {
			// Current is past now, Stored is future now
			traminfo[tr.Trips[0].TripId] = tr
		}
	}

	stationLookupTable := make(map[string]int)
	for i, v := range stationSeq {
		stationLookupTable[strings.ToLower(v)] = i
	}

	activeLights := make(map[int]bool)
	for _, tram := range slices.Collect(maps.Values(traminfo)) {
		// Calculate current Station name depending on current time
		realStation := tram.From
		if tram.Departure.Sub(now).Abs() > tram.Arrival.Sub(now).Abs() {
			//		log.Printf(">  %v, %v\n", now.Sub(depTime), arrTime.Sub(now))
			realStation = tram.To
		}
		// log.Printf("From='%s' To='%s' Real='%s'\n", tram.From.Name, tram.To.Name, realStation.Name)
		activeLights[stationLookupTable[strings.ToLower(realStation.Name)]] = true

	}

	lightIds := slices.Collect(maps.Keys(activeLights))
	// log.Println(lightIds)

	enc := json.NewEncoder(w)
	err := enc.Encode(lightIds)
	if err != nil {
		log.Println(err)
	}
}