feat: implement web service

Signed-off-by: The one with the braid <info@braid.business>

lib/pkpass.dart

@@ -3,11 +3,11 @@
 /// More dartdocs go here.
 library pkpass;
 
-export 'src/error.dart';
-export 'src/models/barcode.dart';
-export 'src/models/beacon.dart';
-export 'src/models/location.dart';
-export 'src/models/pass.dart';
-export 'src/models/pass_structure_dictionary.dart';
-export 'src/models/pass_web_service.dart';
-export 'src/pass_file.dart';
+export 'pkpass/error.dart';
+export 'pkpass/models/barcode.dart';
+export 'pkpass/models/beacon.dart';
+export 'pkpass/models/location.dart';
+export 'pkpass/models/pass.dart';
+export 'pkpass/models/pass_structure_dictionary.dart';
+export 'pkpass/models/pass_web_service.dart';
+export 'pkpass/pass_file.dart';

lib/pkpass/models/pass.dart

@@ -1,7 +1,7 @@
 import 'package:intl/locale.dart';
 
 import 'package:pkpass/pkpass.dart';
-import 'package:pkpass/src/utils/mabe_decode.dart';
+import 'package:pkpass/pkpass/utils/mabe_decode.dart';
 
 /// Information that is required for all passes.
 class PassMetadata {

lib/pkpass/models/pass_structure_dictionary.dart

@@ -1,7 +1,7 @@
 import 'package:intl/locale.dart';
 
 import 'package:pkpass/pkpass.dart';
-import 'package:pkpass/src/utils/mabe_decode.dart';
+import 'package:pkpass/pkpass/utils/mabe_decode.dart';
 
 /// Keys that define the structure of the pass.
 ///

lib/pkpass/models/pass_web_service.dart

@@ -1,5 +1,3 @@
-/// TODO: implement PassKit Web Service Reference
-///
 /// Metadata required for Pass Web Service
 ///
 /// https://developer.apple.com/library/archive/documentation/PassKit/Reference/PassKit_WebService/WebService.html#//apple_ref/doc/uid/TP40011988

lib/pkpass/pass_file.dart

@@ -6,8 +6,8 @@ import 'package:crypto/crypto.dart';
 import 'package:intl/locale.dart';
 
 import 'package:pkpass/pkpass.dart';
-import 'package:pkpass/src/utils/file_matcher.dart';
-import 'package:pkpass/src/utils/lproj_parser.dart';
+import 'package:pkpass/pkpass/utils/file_matcher.dart';
+import 'package:pkpass/pkpass/utils/lproj_parser.dart';
 
 final _utf8codec = Utf8Codec();
 final _jsonCodec = JsonCodec();

lib/pkpass_web_service.dart

@@ -0,0 +1,9 @@
+/// The PkPass Web Service.
+///
+/// So far only supports update check but no push service.
+///
+/// https://developer.apple.com/library/archive/documentation/PassKit/Reference/PassKit_WebService/WebService.html#//apple_ref/doc/uid/TP40011988
+library pkpass_web_service;
+
+export 'pkpass_web_wervice/web_service.dart';
+export 'pkpass_web_wervice/web_service_error.dart';

lib/pkpass_web_wervice/utils/http_date.dart

@@ -0,0 +1,219 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// copied from dart:io
+
+/// Utility functions for working with dates with HTTP specific date
+/// formats.
+class HttpDate {
+  // From RFC-2616 section "3.3.1 Full Date",
+  // http://tools.ietf.org/html/rfc2616#section-3.3.1
+  //
+  // HTTP-date    = rfc1123-date | rfc850-date | asctime-date
+  // rfc1123-date = wkday "," SP date1 SP time SP "GMT"
+  // rfc850-date  = weekday "," SP date2 SP time SP "GMT"
+  // asctime-date = wkday SP date3 SP time SP 4DIGIT
+  // date1        = 2DIGIT SP month SP 4DIGIT
+  //                ; day month year (e.g., 02 Jun 1982)
+  // date2        = 2DIGIT "-" month "-" 2DIGIT
+  //                ; day-month-year (e.g., 02-Jun-82)
+  // date3        = month SP ( 2DIGIT | ( SP 1DIGIT ))
+  //                ; month day (e.g., Jun  2)
+  // time         = 2DIGIT ":" 2DIGIT ":" 2DIGIT
+  //                ; 00:00:00 - 23:59:59
+  // wkday        = "Mon" | "Tue" | "Wed"
+  //              | "Thu" | "Fri" | "Sat" | "Sun"
+  // weekday      = "Monday" | "Tuesday" | "Wednesday"
+  //              | "Thursday" | "Friday" | "Saturday" | "Sunday"
+  // month        = "Jan" | "Feb" | "Mar" | "Apr"
+  //              | "May" | "Jun" | "Jul" | "Aug"
+  //              | "Sep" | "Oct" | "Nov" | "Dec"
+
+  /// Format a date according to
+  /// [RFC-1123](http://tools.ietf.org/html/rfc1123 "RFC-1123"),
+  /// e.g. `Thu, 1 Jan 1970 00:00:00 GMT`.
+  static String format(DateTime date) {
+    const List wkday = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
+    const List month = [
+      "Jan",
+      "Feb",
+      "Mar",
+      "Apr",
+      "May",
+      "Jun",
+      "Jul",
+      "Aug",
+      "Sep",
+      "Oct",
+      "Nov",
+      "Dec",
+    ];
+
+    DateTime d = date.toUtc();
+    StringBuffer sb = StringBuffer()
+      ..write(wkday[d.weekday - 1])
+      ..write(", ")
+      ..write(d.day <= 9 ? "0" : "")
+      ..write(d.day.toString())
+      ..write(" ")
+      ..write(month[d.month - 1])
+      ..write(" ")
+      ..write(d.year.toString())
+      ..write(d.hour <= 9 ? " 0" : " ")
+      ..write(d.hour.toString())
+      ..write(d.minute <= 9 ? ":0" : ":")
+      ..write(d.minute.toString())
+      ..write(d.second <= 9 ? ":0" : ":")
+      ..write(d.second.toString())
+      ..write(" GMT");
+    return sb.toString();
+  }
+
+  /// Parse a date string in either of the formats
+  /// [RFC-1123](http://tools.ietf.org/html/rfc1123 "RFC-1123"),
+  /// [RFC-850](http://tools.ietf.org/html/rfc850 "RFC-850") or
+  /// ANSI C's asctime() format. These formats are listed here.
+  ///
+  ///     Thu, 1 Jan 1970 00:00:00 GMT
+  ///     Thursday, 1-Jan-1970 00:00:00 GMT
+  ///     Thu Jan  1 00:00:00 1970
+  ///
+  /// For more information see [RFC-2616 section
+  /// 3.1.1](http://tools.ietf.org/html/rfc2616#section-3.3.1
+  /// "RFC-2616 section 3.1.1").
+  static DateTime parse(String date) {
+    final int sp = 32;
+    const List wkdays = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];
+    const List weekdays = [
+      "Monday",
+      "Tuesday",
+      "Wednesday",
+      "Thursday",
+      "Friday",
+      "Saturday",
+      "Sunday",
+    ];
+    const List months = [
+      "Jan",
+      "Feb",
+      "Mar",
+      "Apr",
+      "May",
+      "Jun",
+      "Jul",
+      "Aug",
+      "Sep",
+      "Oct",
+      "Nov",
+      "Dec",
+    ];
+
+    final int formatRfc1123 = 0;
+    final int formatRfc850 = 1;
+    final int formatAsctime = 2;
+
+    int index = 0;
+    String tmp;
+
+    void expect(String s) {
+      if (date.length - index < s.length) {
+        throw Exception("Invalid HTTP date $date");
+      }
+      String tmp = date.substring(index, index + s.length);
+      if (tmp != s) {
+        throw Exception("Invalid HTTP date $date");
+      }
+      index += s.length;
+    }
+
+    int expectWeekday() {
+      int weekday;
+      // The formatting of the weekday signals the format of the date string.
+      int pos = date.indexOf(",", index);
+      if (pos == -1) {
+        int pos = date.indexOf(" ", index);
+        if (pos == -1) throw Exception("Invalid HTTP date $date");
+        tmp = date.substring(index, pos);
+        index = pos + 1;
+        weekday = wkdays.indexOf(tmp);
+        if (weekday != -1) {
+          return formatAsctime;
+        }
+      } else {
+        tmp = date.substring(index, pos);
+        index = pos + 1;
+        weekday = wkdays.indexOf(tmp);
+        if (weekday != -1) {
+          return formatRfc1123;
+        }
+        weekday = weekdays.indexOf(tmp);
+        if (weekday != -1) {
+          return formatRfc850;
+        }
+      }
+      throw Exception("Invalid HTTP date $date");
+    }
+
+    int expectMonth(String separator) {
+      int pos = date.indexOf(separator, index);
+      if (pos - index != 3) throw Exception("Invalid HTTP date $date");
+      tmp = date.substring(index, pos);
+      index = pos + 1;
+      int month = months.indexOf(tmp);
+      if (month != -1) return month;
+      throw Exception("Invalid HTTP date $date");
+    }
+
+    int expectNum(String separator) {
+      int pos;
+      if (separator.isNotEmpty) {
+        pos = date.indexOf(separator, index);
+      } else {
+        pos = date.length;
+      }
+      String tmp = date.substring(index, pos);
+      index = pos + separator.length;
+      try {
+        int value = int.parse(tmp);
+        return value;
+      } on FormatException {
+        throw Exception("Invalid HTTP date $date");
+      }
+    }
+
+    void expectEnd() {
+      if (index != date.length) {
+        throw Exception("Invalid HTTP date $date");
+      }
+    }
+
+    int format = expectWeekday();
+    int year;
+    int month;
+    int day;
+    int hours;
+    int minutes;
+    int seconds;
+    if (format == formatAsctime) {
+      month = expectMonth(" ");
+      if (date.codeUnitAt(index) == sp) index++;
+      day = expectNum(" ");
+      hours = expectNum(":");
+      minutes = expectNum(":");
+      seconds = expectNum(" ");
+      year = expectNum("");
+    } else {
+      expect(" ");
+      day = expectNum(format == formatRfc1123 ? " " : "-");
+      month = expectMonth(format == formatRfc1123 ? " " : "-");
+      year = expectNum(" ");
+      hours = expectNum(":");
+      minutes = expectNum(":");
+      seconds = expectNum(" ");
+      expect("GMT");
+    }
+    expectEnd();
+    return DateTime.utc(year, month + 1, day, hours, minutes, seconds, 0);
+  }
+}

lib/pkpass_web_wervice/web_service.dart

@@ -0,0 +1,69 @@
+import 'dart:typed_data';
+
+import 'package:http/http.dart';
+
+import 'package:pkpass/pkpass.dart';
+import 'package:pkpass/pkpass_web_wervice/utils/http_date.dart';
+import 'web_service_error.dart';
+
+/// PassKit WebService implementation
+///
+/// A Representational State Transfer (REST)–style web service protocol is used
+/// to communicate with your server about changes to passes, and to fetch the
+/// latest version of a pass when it has changed.
+///
+/// https://developer.apple.com/library/archive/documentation/PassKit/Reference/PassKit_WebService/WebService.html#//apple_ref/doc/uid/TP40011988
+class PkPassWebService {
+  static const _apiVersion = 'v1';
+  static Client? _client;
+
+  /// The [PassMetadata] to check for updates.
+  final PassMetadata metadata;
+
+  /// An optional [Client] used for any http requests
+  final Client? client;
+
+  const PkPassWebService(this.metadata, {this.client});
+
+  PassWebService get webService {
+    final service = metadata.webService;
+    if (service == null) noWebServiceProvided();
+    return service;
+  }
+
+  Client get httpClient {
+    final client = this.client;
+    if (client != null) return client;
+    return _client ??= Client();
+  }
+
+  /// Getting the Latest Version of a Pass
+  ///
+  /// Requests the latest version of the current PkPass file
+  ///
+  /// [modifiedSince] should be provided in order to support "304 Not Modified"
+  Future<Uint8List?> getLatestVersion([DateTime? modifiedSince]) async {
+    final identifier = metadata.passTypeIdentifier;
+    final serial = metadata.serialNumber;
+    final endpoint = '/$_apiVersion/passes/$identifier/$serial';
+
+    final response = await httpClient.get(
+      Uri.parse(webService.webServiceURL.toString() + endpoint),
+      headers: {
+        if (modifiedSince != null)
+          'If-Modified-Since': HttpDate.format(modifiedSince),
+        'Authorization': 'ApplePass ${webService.authenticationToken}',
+      },
+    );
+    switch (response.statusCode) {
+      case 200:
+        return response.bodyBytes;
+      case 304:
+        return null;
+      default:
+        throw WebServiceResponseError(response);
+    }
+  }
+
+  Never noWebServiceProvided() => throw WebServiceUnavailable();
+}

lib/pkpass_web_wervice/web_service_error.dart

@@ -0,0 +1,19 @@
+import 'package:http/http.dart';
+
+import 'package:pkpass/pkpass.dart';
+
+abstract class PkPassWebServiceError extends PKPassError {
+  PkPassWebServiceError({required super.message});
+}
+
+class WebServiceUnavailable extends PkPassWebServiceError {
+  WebServiceUnavailable()
+      : super(message: 'The PkPass file does not contain any web service.');
+}
+
+class WebServiceResponseError extends PkPassWebServiceError {
+  final Response response;
+
+  WebServiceResponseError(this.response)
+      : super(message: 'Unexpected response from web service');
+}