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

use serde::{de::Visitor, Deserialize, Serialize};

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct OneBotBytes(pub Vec<u8>);

impl Serialize for OneBotBytes {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        if std::any::type_name::<S>().starts_with("&mut serde_json") {
            return serializer.serialize_str(&base64::encode(&self.0));
        }
        serializer.serialize_bytes(&self.0)
    }
}

impl From<Vec<u8>> for OneBotBytes {
    fn from(v: Vec<u8>) -> Self {
        Self(v)
    }
}

impl From<&[u8]> for OneBotBytes {
    fn from(v: &[u8]) -> Self {
        Self(v.to_vec())
    }
}

struct OBBVistor;

impl<'de> Visitor<'de> for OBBVistor {
    type Value = OneBotBytes;
    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
        formatter.write_str("expect json base64 or msgpack bytes")
    }

    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
    where
        E: serde::de::Error,
    {
        Ok(OneBotBytes(base64::decode(v).map_err(|_| {
            serde::de::Error::custom("Not a valid base64 String")
        })?))
    }

    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
    where
        E: serde::de::Error,
    {
        Ok(OneBotBytes(v.to_vec()))
    }

    fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
    where
        E: serde::de::Error,
    {
        Ok(OneBotBytes(v))
    }
}

impl<'de> Deserialize<'de> for OneBotBytes {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        deserializer.deserialize_any(OBBVistor)
    }
}

#[test]
fn sertest() {
    let bytes = OneBotBytes(vec![0, 1, 2, 3]);
    assert_eq!("\"AAECAw==\"", &serde_json::to_string(&bytes).unwrap());
    assert_eq!(vec![196, 4, 0, 1, 2, 3], rmp_serde::to_vec(&bytes).unwrap());
}

#[test]
fn detest() {
    let bytes = OneBotBytes(vec![0, 1, 2, 3]);
    let json = "\"AAECAw==\"";
    assert_eq!(bytes, serde_json::from_str::<OneBotBytes>(&json).unwrap());
    let msgpack = vec![196, 4, 0, 1, 2, 3];
    assert_eq!(
        bytes,
        rmp_serde::from_slice::<OneBotBytes>(&msgpack).unwrap()
    );
}