1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

// timespan - A simple timespan for chrono times.
//
// Copyright (C) 2017
//     Fin Christensen <christensen.fin@gmail.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

use Error;
use Spanable;
use Formatable;
use Parsable;
use Span;
use NaiveDateTimeSpan;
use chrono::offset::{Local, Utc, FixedOffset};
use chrono::format::{DelayedFormat, StrftimeItems};
use chrono::{ParseResult, DateTime, TimeZone, Duration};
use std;

impl<T: TimeZone> Spanable for DateTime<T> where <T as TimeZone>::Offset: std::marker::Copy {
    #[inline]
    fn signed_duration_since(self, other: Self) -> Duration {
        DateTime::signed_duration_since(self, other)
    }
}

impl<T: TimeZone> Formatable for DateTime<T> where <T as TimeZone>::Offset: std::fmt::Display {
    #[inline]
    fn format<'a>(&self, fmt: &'a str) -> DelayedFormat<StrftimeItems<'a>> {
        DateTime::format(self, fmt)
    }
}

impl Parsable for DateTime<Local> {
    #[inline]
    fn parse_from_str(s: &str, fmt: &str) -> ParseResult<DateTime<Local>> {
        Local.datetime_from_str(s, fmt)
    }
}

impl Parsable for DateTime<Utc> {
    #[inline]
    fn parse_from_str(s: &str, fmt: &str) -> ParseResult<DateTime<Utc>> {
        Utc.datetime_from_str(s, fmt)
    }
}

impl Parsable for DateTime<FixedOffset> {
    #[inline]
    fn parse_from_str(s: &str, fmt: &str) -> ParseResult<DateTime<FixedOffset>> {
        DateTime::parse_from_str(s, fmt)
    }
}

/// The `DateTimeSpan` alias is a span consisting of `chrono::DateTime`s.
///
/// It can be used to represent datetime spans that depend on a specific time zone.
///
/// The `DateTimeSpan` can be formatted and parsed from a string. It can be used for serialization
/// and deserialization with `serde`. The deserialization is currently only supported for the
/// `Utc`, `Local` and `FixedOffset` time zones. The time zones provided by `chrono-tz` do not
/// implement `from_str` and `parse_from_str` for `chrono::DateTime<Tz>` and can therefore not be
/// deserialized.
///
/// # Example
///
/// ~~~~
/// # extern crate timespan; extern crate chrono; fn main() {
/// use timespan::DateTimeSpan;
/// use chrono::Utc;
///
/// let a: DateTimeSpan<Utc> = "2017-01-01T15:10:00 +0200 - 2017-01-02T09:30:00 +0200"
///    .parse().unwrap();
///
/// assert!(
///     format!("{}", a.format("{start} to {end}", "%c", "%c")) ==
///     "Sun Jan  1 13:10:00 2017 to Mon Jan  2 07:30:00 2017"
/// );
/// # }
/// ~~~~
pub type DateTimeSpan<T> = Span<DateTime<T>>;

impl<T: TimeZone> DateTimeSpan<T> {
    /// Create a `DateTimeSpan` from a `NaiveDateTimeSpan` with the time zone set to the local time zone.
    ///
    /// Currently the result handling of the internally used `TimeZone::from_local_datetime` is not
    /// implemented properly. Therefore only date spans with a single local time zone can be created.
    /// Ambigious local time zones will lead to `Error::LocalAmbigious`.
    ///
    /// To avoid this `from_utc_datetimespan` should be prefered.
    pub fn from_local_datetimespan(span: &NaiveDateTimeSpan, tz: &T) -> Result<Self, Error> {
        Ok(DateTimeSpan {
            start: tz.from_local_datetime(&span.start).single().ok_or(Error::LocalAmbigious)?,
            end: tz.from_local_datetime(&span.end).single().ok_or(Error::LocalAmbigious)?,
        })
    }

    /// Create a `DateTimeSpan` from a `NaiveDateTimeSpan` with the time zone set to UTC.
    ///
    /// # Example
    ///
    /// ~~~~
    /// # extern crate timespan; extern crate chrono_tz; fn main() {
    /// use timespan::DateTimeSpan;
    /// use chrono_tz::America::Puerto_Rico;
    ///
    /// let a = DateTimeSpan::from_utc_datetimespan(
    ///     &"2017-03-12T12:00:00 - 2017-03-15T14:00:00".parse().unwrap(),
    ///     &Puerto_Rico,
    /// );
    ///
    /// assert!(format!("{}", a) == "2017-03-12 08:00:00 AST - 2017-03-15 10:00:00 AST");
    /// # }
    /// ~~~~
    pub fn from_utc_datetimespan(span: &NaiveDateTimeSpan, tz: &T) -> Self {
        DateTimeSpan {
            start: tz.from_utc_datetime(&span.start),
            end: tz.from_utc_datetime(&span.end),
        }
    }
}