import 'dart:convert';

import 'package:icalserver/data.dart';
import 'package:icalserver/icalendar.dart';
import 'package:supabase/supabase.dart';
import 'package:shelf/shelf.dart';

class CalendarHandler {
  SupabaseClient getSupabaseClient(Request request) {
    // final supabaseUrl = request.headers['supabase-url'];
    // final authHeader = request.headers['authorization'];
    // final token = authHeader!.substring(7); // Remove 'Bearer ' prefix

    final supabaseUrl = 'http://baas.fares.cyou:8000';
    final token =
        "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyAgCiAgICAicm9sZSI6ICJzZXJ2aWNlX3JvbGUiLAogICAgImlzcyI6ICJzdXBhYmFzZS1kZW1vIiwKICAgICJpYXQiOiAxNjQxNzY5MjAwLAogICAgImV4cCI6IDE3OTk1MzU2MDAKfQ.DaYlNEoUrrEn2Ig7tqibS-PHK5vgusbcbo7X36XVt4Q";
    return SupabaseClient(
      supabaseUrl,
      token,
    );
  }

  // Handler for the /link route
  Future<Response> getCalendar(Request request) async {
    final credentials = _getBasicAuthCredentials(request);
    if (credentials == null) {
      return Response.unauthorized('Invalid credentials');
    }

    final (username, password) = credentials;
    if (username != password) {
      return Response.unauthorized('Invalid credentials');
    }

    final supabase = getSupabaseClient(request);

    //get licence_csv table into variable
    final licences = (await supabase.from('licences_csv').select());
    //print(licencesCsv);

    // Execute the query
    final rosterlist =
        await supabase.rpc('get_crew_roster', params: {'_tlc': username});

    // Handle the response
    final requester =
        licences.firstWhere((e) => e['tlc'] == username, orElse: () => {});
    print(
        'TLC: $username ...  EVENTS: ${rosterlist.length} ... Name: ${requester['lname']}, ${requester['fname']}');

    // Create an iCalendar object
    final ical = ICalendar();

    if (rosterlist is List) {
      for (var i = 0; i < rosterlist.length; i++) {
        final event = rosterlist[i];
        final pnleg = Pnleg(
            date: event['date'],
            tlc: username,
            actype: event['actype'],
            al: event['al'],
            fnum: event['fnum'],
            dep: event['dep'],
            arr: event['des'],
            depdate: event['ddep'],
            deptime: event['hdep'],
            arrdate: event['ddes'],
            arrtime: event['hdes'],
            label: event['label'],
            type: event['type']);
        final List<List<String>> crewlist = [];
        for (var j = 0; j < (event['crew'] as List).length; j++) {
          final crewmember = event['crew'][j] as String;
          final crewmemberDataAc = licences.firstWhere(
              (e) => (e['tlc'] == crewmember) && (e['ac'] == pnleg.ac),
              orElse: () => {});
          final crewmemberData = licences
              .firstWhere((e) => e['tlc'] == crewmember, orElse: () => {});
          crewlist.add([
            '${([
                  "F",
                  "G"
                ].contains(event['crewtype'][j]) ? "DH " : null) ?? (crewmemberDataAc["college"] ?? "--")}',
            '${crewmemberData["lname"] ?? "------"}',
            '${crewmemberData["fname"] ?? "Unknown"}'
          ]);
        }
        final crewlistdisplay = (crewlist
              ..sort((a, b) {
                const order = {
                  'CP': 0,
                  'FO': 1,
                  'PU': 2,
                  'SE': 3,
                  'ST': 4,
                  'JU': 5
                };
                return (order[a[0]] ?? 6).compareTo(order[b[0]] ?? 6);
              }))
            .map((e) => "${e[0]}: ${e[1]}, ${e[2]}")
            .join("\n");
        switch (pnleg.dutytype) {
          case "flight":
            ical.addEvent(
              summary: "${pnleg.dep}-${pnleg.arr}",
              description: """
Flight from ${pnleg.dep} to ${pnleg.arr}
Flight number: ${pnleg.al}${pnleg.fnum}
Aircraft type: ${pnleg.actype}

Departure time: ${pnleg.jdep?.Hm}
Arrival time: ${pnleg.jarr?.Hm}

Crew: 
$crewlistdisplay
"""
                  .replaceAll("\n", "\\n"),
              startTime: pnleg.jdep!.dateTime,
              endTime: pnleg.jarr!.dateTime,
              attendees: event['crew'],
            );
            break;
          case "dhflight":
            ical.addEvent(
              summary: "DH ${pnleg.dep}-${pnleg.arr}",
              description: """
DH Flight from ${pnleg.dep} to ${pnleg.arr}
Flight number: ${pnleg.al}${pnleg.fnum}
Aircraft type: ${pnleg.actype}

Departure time: ${pnleg.jdep?.Hm}
Arrival time: ${pnleg.jarr?.Hm}

Crew: 
$crewlistdisplay
"""
                  .replaceAll("\n", "\\n"),
              startTime: pnleg.jdep!.dateTime,
              endTime: pnleg.jarr!.dateTime,
              attendees: event['crew'],
            );
            break;
          case "dhlimo":
            ical.addEvent(
              summary: "${pnleg.dep}-${pnleg.arr}",
              description: """
DH Limo from ${pnleg.dep} to ${pnleg.arr}

Departure time: ${pnleg.jdep?.Hm}
Arrival time: ${pnleg.jarr?.Hm}

Crew: 
$crewlistdisplay
"""
                  .replaceAll("\n", "\\n"),
              startTime: pnleg.jdep!.dateTime,
              endTime: pnleg.jarr!.dateTime,
              attendees: event['crew'],
            );
            break;
          case "standby":
            ical.addEvent(
              summary: "STDBY ${pnleg.label}",
              description: """
Stand By ${pnleg.label} at ${pnleg.dep}

Start time: ${pnleg.jdep?.Hm}
End time: ${pnleg.jarr?.Hm}
"""
                  .replaceAll("\n", "\\n"),
              startTime: pnleg.jdep!.dateTime,
              endTime: pnleg.jarr!.dateTime,
              attendees: event['crew'],
            );
            break;
          case "ground":
            ical.addEvent(
              summary: "${pnleg.label}",
              description: """
${pnleg.label} at ${pnleg.dep}

Start time: ${pnleg.jdep?.Hm}
End time: ${pnleg.jarr?.Hm}

Attendee: 
$crewlistdisplay

"""
                  .replaceAll("\n", "\\n"),
              startTime: pnleg.jdep!.dateTime,
              endTime: pnleg.jarr!.dateTime,
              attendees: event['crew'],
            );
            break;
          case "day":
            ical.addEvent(
                summary: "${pnleg.label}",
                description: """
${pnleg.label} at ${pnleg.dep}

Attendee: 
$crewlistdisplay

"""
                    .replaceAll("\n", "\\n"),
                startTime: pnleg.jdep!.dateTime,
                endTime: pnleg.jarr!.dateTime,
                attendees: event['crew'],
                allday: true);
            break;
          default:
        }
      }
    }

    // Return the response with the iCalendar content
    await supabase.dispose();
    return Response.ok(
      ical.serialize(),
      headers: {'Content-Type': 'text/calendar; charset=utf-8'},
    );
  }

  (String, String)? _getBasicAuthCredentials(Request request) {
    // Get Authorization header
    if (!request.headers.containsKey('authorization')) {
      return null;
    }
    String authHeader = request.headers['authorization'] ?? "";
    if (!authHeader.startsWith('Basic ')) {
      return null;
    }

    // Extract and decode credentials
    try {
      String base64Credentials = authHeader.substring('Basic '.length);
      String credentials = utf8.decode(base64.decode(base64Credentials));
      List<String> userPass = credentials.split(':');

      if (userPass.length != 2) return null;

      return (userPass[0], userPass[1]);
    } catch (e) {
      return null;
    }
  }
}