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

use humantime;
use std::fmt;
use std::time::{Duration, SystemTime, UNIX_EPOCH};

/// A UTC timestamp. Used for serialization to and from the plist date type.
#[derive(Clone, Copy, Hash, PartialEq)]
pub struct Date {
    inner: SystemTime,
}

impl Date {
    pub(crate) fn from_rfc3339(date: &str) -> Result<Self, ()> {
        Ok(Date {
            inner: humantime::parse_rfc3339(date).map_err(|_| ())?,
        })
    }

    pub(crate) fn to_rfc3339(&self) -> String {
        format!("{}", humantime::format_rfc3339(self.inner))
    }

    pub(crate) fn from_seconds_since_plist_epoch(timestamp: f64) -> Result<Date, ()> {
        // `timestamp` is the number of seconds since the plist epoch of 1/1/2001 00:00:00.
        // `PLIST_EPOCH_UNIX_TIMESTAMP` is the unix timestamp of the plist epoch.
        const PLIST_EPOCH_UNIX_TIMESTAMP: u64 = 978_307_200;
        let plist_epoch = UNIX_EPOCH + Duration::from_secs(PLIST_EPOCH_UNIX_TIMESTAMP);

        if !timestamp.is_finite() {
            return Err(());
        }

        let is_negative = timestamp < 0.0;
        let timestamp = timestamp.abs();
        let seconds = timestamp.floor() as u64;
        let subsec_nanos = (timestamp.fract() * 1e9) as u32;

        let dur_since_plist_epoch = Duration::new(seconds, subsec_nanos);

        let inner = if is_negative {
            plist_epoch - dur_since_plist_epoch
        } else {
            plist_epoch + dur_since_plist_epoch
        };

        Ok(Date { inner })
    }
}

impl fmt::Debug for Date {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        let rfc3339 = humantime::format_rfc3339(self.inner);
        <humantime::Rfc3339Timestamp as fmt::Display>::fmt(&rfc3339, f)
    }
}

impl From<SystemTime> for Date {
    fn from(date: SystemTime) -> Self {
        Date { inner: date }
    }
}

impl Into<SystemTime> for Date {
    fn into(self) -> SystemTime {
        self.inner
    }
}

#[cfg(feature = "serde")]
pub mod serde_impls {
    use serde::de::{Deserialize, Deserializer, Error, Unexpected, Visitor};
    use serde::ser::{Serialize, Serializer};
    use std::fmt;

    use Date;

    pub const DATE_NEWTYPE_STRUCT_NAME: &str = "PLIST-DATE";

    impl Serialize for Date {
        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
        where
            S: Serializer,
        {
            let date_str = self.to_rfc3339();
            serializer.serialize_newtype_struct(DATE_NEWTYPE_STRUCT_NAME, &date_str)
        }
    }

    struct DateNewtypeVisitor;

    impl<'de> Visitor<'de> for DateNewtypeVisitor {
        type Value = Date;

        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
            formatter.write_str("a plist date newtype")
        }

        fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
        where
            D: Deserializer<'de>,
        {
            deserializer.deserialize_str(DateStrVisitor)
        }
    }

    struct DateStrVisitor;

    impl<'de> Visitor<'de> for DateStrVisitor {
        type Value = Date;

        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
            formatter.write_str("a plist date string")
        }

        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
        where
            E: Error,
        {
            Date::from_rfc3339(v).map_err(|()| E::invalid_value(Unexpected::Str(v), &self))
        }
    }

    impl<'de> Deserialize<'de> for Date {
        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
        where
            D: Deserializer<'de>,
        {
            deserializer.deserialize_newtype_struct(DATE_NEWTYPE_STRUCT_NAME, DateNewtypeVisitor)
        }
    }
}