From ae4a73645bc12fbd511ab37b49f7045ebd3675be Mon Sep 17 00:00:00 2001
From: Arseny Smirnov <arseny30@gmail.com>
Date: Wed, 10 Jul 2019 20:11:16 +0200
Subject: [PATCH] Some parse_http_date implementation

GitOrigin-RevId: 153367519b120453d5bc80454f568e829a3f2e49
---
 test/mtproto.cpp | 102 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/test/mtproto.cpp b/test/mtproto.cpp
index fee85f048..5ace41626 100644
--- a/test/mtproto.cpp
+++ b/test/mtproto.cpp
@@ -36,6 +36,7 @@
 #include "td/utils/logging.h"
 #include "td/utils/port/IPAddress.h"
 #include "td/utils/port/SocketFd.h"
+#include "td/utils/Parser.h"
 #include "td/utils/Random.h"
 #include "td/utils/Status.h"
 #include "td/utils/Time.h"
@@ -120,6 +121,107 @@ TEST(Mtproto, GetHostByNameActor) {
   sched.finish();
 }
 
+class Date {
+ public:
+  static bool is_leap(int year) {
+    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
+  }
+  static int32 days_in_month(int year, int month) {
+    int cnt[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+    return cnt[month - 1] + (month == 2 && is_leap(year));
+  }
+  static int64 seconds_in_day() {
+    return 24 * 60 * 60;
+  }
+  static Result<int64> to_unix_time(int32 year, int32 month, int32 day, int32 hour, int32 minute, int32 second) {
+    int64 res = 0;
+    if (year < 1970 || year > 2037) {
+      return td::Status::Error("invalid year");
+    }
+    if (month < 1 || month > 12) {
+      return td::Status::Error("invalid month");
+    }
+    if (day < 1 || day > days_in_month(year, month)) {
+      return td::Status::Error("invalid day");
+    }
+    if (hour < 0 || hour > 24) {  // is hour == 24 possible?
+      return td::Status::Error("invalid hour");
+    }
+    if (minute < 0 || minute > 60) {
+      return td::Status::Error("invalid minute");
+    }
+    if (second < 0 || second > 60) {
+      return td::Status::Error("invalid second");
+    }
+    for (int y = 1970; y < year; y++) {
+      res += (is_leap(y) + 365) * seconds_in_day();
+    }
+    for (int m = 1; m < month; m++) {
+      res += days_in_month(year, m) * seconds_in_day();
+    }
+    res += (day - 1) * seconds_in_day();
+    res += hour * 60 * 60;
+    res += minute * 60;
+    res += second;
+    return res;
+  }
+};
+
+TEST(Time, to_unix_time) {
+  ASSERT_EQ(0, Date::to_unix_time(1970, 1, 1, 0, 0, 0).move_as_ok());
+  ASSERT_EQ(60 * 60 + 60 + 1, Date::to_unix_time(1970, 1, 1, 1, 1, 1).move_as_ok());
+  ASSERT_EQ(24 * 60 * 60, Date::to_unix_time(1970, 1, 2, 0, 0, 0).move_as_ok());
+  ASSERT_EQ(31 * 24 * 60 * 60, Date::to_unix_time(1970, 2, 1, 0, 0, 0).move_as_ok());
+  ASSERT_EQ(365 * 24 * 60 * 60, Date::to_unix_time(1971, 1, 1, 0, 0, 0).move_as_ok());
+  ASSERT_EQ(1562780559, Date::to_unix_time(2019, 7, 10, 17, 42, 39).move_as_ok());
+}
+
+Result<int64> parse_http_date(std::string slice) {
+  td::Parser p(slice);
+  p.read_till(',');  // ignore week day
+  p.skip(',');
+  p.skip_whitespaces();
+  TRY_RESULT(day, to_integer_safe<int32>(p.read_word()));
+  auto month_name = p.read_word();
+  to_lower_inplace(month_name);
+  TRY_RESULT(year, to_integer_safe<int32>(p.read_word()));
+  p.skip_whitespaces();
+  p.skip_nofail('0');
+  TRY_RESULT(hour, to_integer_safe<int32>(p.read_till(':')));
+  p.skip(':');
+  p.skip_nofail('0');
+  TRY_RESULT(minute, to_integer_safe<int32>(p.read_till(':')));
+  p.skip(':');
+  p.skip_nofail('0');
+  TRY_RESULT(second, to_integer_safe<int32>(p.read_word()));
+  auto gmt = p.read_word();
+  TRY_STATUS(std::move(p.status()));
+  if (gmt != "GMT") {
+    return Status::Error("timezone must be GMT");
+  }
+
+  Slice month_names[12] = {"jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"};
+
+  int month = 0;
+
+  for (int m = 1; m <= 12; m++) {
+    if (month_names[m - 1] == month_name) {
+      month = m;
+      break;
+    }
+  }
+
+  if (month == 0) {
+    return Status::Error("Unknown month name");
+  }
+
+  return Date::to_unix_time(year, month, day, hour, minute, second);
+}
+
+TEST(Time, parse_http_date) {
+  ASSERT_EQ(784887151, parse_http_date("Tue, 15 Nov 1994 08:12:31 GMT").move_as_ok());
+}
+
 TEST(Mtproto, config) {
   ConcurrentScheduler sched;
   int threads_n = 0;