[evolution-ews] Microsoft365: Correct task Due and Completed date read

[Milan Crha <mcrha src gnome org>]

commit 4b618674c7f69783288e789c16d5a1f56a04d0bf
Author: Milan Crha <mcrha redhat com>
Date:   Thu Oct 6 09:58:19 2022 +0200

    Microsoft365: Correct task Due and Completed date read
    
    They are stored as date/time in UTC, which needs to be converted
    to the user time zone and then to a date, to show the right value.

 .../calendar/e-cal-backend-m365-utils.c            | 37 +++++++++++++++-------
 src/Microsoft365/common/e-m365-tz-utils.c          | 26 +++++++++++++++
 src/Microsoft365/common/e-m365-tz-utils.h          |  2 ++
 3 files changed, 54 insertions(+), 11 deletions(-)
---
diff --git a/src/Microsoft365/calendar/e-cal-backend-m365-utils.c 
b/src/Microsoft365/calendar/e-cal-backend-m365-utils.c
index 6829a656..373fa277 100644
--- a/src/Microsoft365/calendar/e-cal-backend-m365-utils.c
+++ b/src/Microsoft365/calendar/e-cal-backend-m365-utils.c
@@ -116,6 +116,7 @@ ecb_m365_get_date_time_zone (EM365Connection *cnc,
        ICalTime *itt;
        time_t tt;
        const gchar *tzid, *zone;
+       gboolean use_user_timezone = FALSE;
        gboolean is_date;
 
        if (prop_kind == I_CAL_DTSTART_PROPERTY) {
@@ -129,6 +130,7 @@ ecb_m365_get_date_time_zone (EM365Connection *cnc,
                        value = e_m365_task_get_start_date_time (m365_object);
                        tzid = "UTC";
                        is_date = TRUE;
+                       use_user_timezone = TRUE;
                        break;
                default:
                        g_warn_if_reached ();
@@ -142,10 +144,12 @@ ecb_m365_get_date_time_zone (EM365Connection *cnc,
                value = e_m365_task_get_completed_date_time (m365_object);
                tzid = "UTC";
                is_date = TRUE;
+               use_user_timezone = TRUE;
        } else if (prop_kind == I_CAL_DUE_PROPERTY) {
                value = e_m365_task_get_due_date_time (m365_object);
                tzid = "UTC";
                is_date = TRUE;
+               use_user_timezone = TRUE;
        } else {
                g_warn_if_reached ();
                return;
@@ -155,27 +159,38 @@ ecb_m365_get_date_time_zone (EM365Connection *cnc,
                return;
 
        tt = e_m365_date_time_get_date_time (value);
-       zone = e_m365_date_time_get_time_zone (value);
+       if (use_user_timezone) {
+               tz = e_m365_tz_utils_get_user_timezone ();
+       } else {
+               zone = e_m365_date_time_get_time_zone (value);
 
-       if (zone && *zone)
-               zone = e_m365_tz_utils_get_ical_equivalent (zone);
+               if (zone && *zone)
+                       zone = e_m365_tz_utils_get_ical_equivalent (zone);
 
-       tz = zone && *zone ? e_timezone_cache_get_timezone (timezone_cache, zone) : NULL;
+               tz = zone && *zone ? e_timezone_cache_get_timezone (timezone_cache, zone) : NULL;
+       }
 
        if (!tz)
                tz = i_cal_timezone_get_utc_timezone ();
 
-       itt = i_cal_time_new_from_timet_with_zone (tt, is_date, tz);
+       itt = i_cal_time_new_from_timet_with_zone (tt, is_date && !use_user_timezone, tz);
 
-       tzid = e_m365_tz_utils_get_ical_equivalent (tzid);
+       if (is_date && use_user_timezone)
+               i_cal_time_set_is_date (itt, TRUE);
 
-       if (!tzid)
-               tzid = "UTC";
+       i_cal_time_set_timezone (itt, tz);
 
-       tz = e_timezone_cache_get_timezone (timezone_cache, tzid);
+       if (!is_date) {
+               tzid = e_m365_tz_utils_get_ical_equivalent (tzid);
 
-       if (tz && !is_date)
-               i_cal_time_convert_to_zone_inplace (itt, tz);
+               if (!tzid)
+                       tzid = "UTC";
+
+               tz = e_timezone_cache_get_timezone (timezone_cache, tzid);
+
+               if (tz && !is_date)
+                       i_cal_time_convert_to_zone_inplace (itt, tz);
+       }
 
        if (prop_kind == I_CAL_DTSTART_PROPERTY)
                i_cal_component_set_dtstart (inout_comp, itt);
diff --git a/src/Microsoft365/common/e-m365-tz-utils.c b/src/Microsoft365/common/e-m365-tz-utils.c
index bc0cf6bd..7a1d7f40 100644
--- a/src/Microsoft365/common/e-m365-tz-utils.c
+++ b/src/Microsoft365/common/e-m365-tz-utils.c
@@ -11,6 +11,8 @@
 #include <libxml/xpath.h>
 #include <libxml/xpathInternals.h>
 
+#include <gio/gio.h>
+
 #include "e-m365-tz-utils.h"
 
 /*
@@ -182,3 +184,27 @@ e_m365_tz_utils_get_ical_equivalent (const gchar *msdn_tz_location)
 
        return ical_tz_location;
 }
+
+ICalTimezone *
+e_m365_tz_utils_get_user_timezone (void)
+{
+       GSettings *settings;
+       gchar *location;
+       ICalTimezone *zone = NULL;
+
+       settings = g_settings_new ("org.gnome.evolution.calendar");
+
+       if (g_settings_get_boolean (settings, "use-system-timezone"))
+               location = e_cal_util_get_system_timezone_location ();
+       else
+               location = g_settings_get_string (settings, "timezone");
+
+       g_object_unref (settings);
+
+       if (location)
+               zone = i_cal_timezone_get_builtin_timezone (location);
+
+       g_free (location);
+
+       return zone;
+}
diff --git a/src/Microsoft365/common/e-m365-tz-utils.h b/src/Microsoft365/common/e-m365-tz-utils.h
index 0aa6002c..c6351800 100644
--- a/src/Microsoft365/common/e-m365-tz-utils.h
+++ b/src/Microsoft365/common/e-m365-tz-utils.h
@@ -8,6 +8,7 @@
 #define E_M365_TZ_UTILS_H
 
 #include <glib.h>
+#include <libecal/libecal.h>
 
 G_BEGIN_DECLS
 
@@ -15,6 +16,7 @@ void          e_m365_tz_utils_ref_windows_zones       (void);
 void           e_m365_tz_utils_unref_windows_zones     (void);
 const gchar *  e_m365_tz_utils_get_msdn_equivalent     (const gchar *ical_tz_location);
 const gchar *  e_m365_tz_utils_get_ical_equivalent     (const gchar *msdn_tz_location);
+ICalTimezone * e_m365_tz_utils_get_user_timezone       (void);
 
 G_END_DECLS