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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169

pub const LOCAL_FILE_SIGNATURE: [u8; 4] = [0x50, 0x4b, 0x03, 0x04];
pub const CENTRAL_DIRECTORY_FILE_SIGNATURE: [u8; 4] = [0x50, 0x4b, 0x01, 0x02];
pub const DATA_DESCRIPTOR_SIGNATURE: [u8; 4] = [0x08, 0x07, 0x4b, 0x50];
pub const END_CENTRAL_DIRECTORY_SIGNATURE: [u8; 4] = [0x50, 0x4b, 0x05, 0x06];

#[repr(transparent)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Os(pub u8);

impl Os {
    pub fn name(self) -> OsName {
        OsName::from_u8(self.0)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]
pub enum OsName {
    Dos = 0,
    Amiga = 1,
    OpenVMS = 2,
    Unix = 3,
    VM = 4,
    AtariST = 5,
    OS2HPFS = 6,
    Macintosh = 7,
    ZSystem = 8,
    Cpm = 9,
    WindowsNtfs = 10,
    Mvs = 11,
    Vse = 12,
    AcornRisc = 13,
    Vfat = 14,
    AlternateMVS = 15,
    BeOS = 16,
    Tandem = 17,
    OS400 = 18,
    Darwin = 19,
    Unused,
}

impl OsName {
    pub fn from_u8(n: u8) -> OsName {
        match n {
            0 => OsName::Dos,
            1 => OsName::Amiga,
            2 => OsName::OpenVMS,
            3 => OsName::Unix,
            4 => OsName::VM,
            5 => OsName::AtariST,
            6 => OsName::OS2HPFS,
            7 => OsName::Macintosh,
            8 => OsName::ZSystem,
            9 => OsName::Cpm,
            10 => OsName::WindowsNtfs,
            11 => OsName::Mvs,
            12 => OsName::Vse,
            13 => OsName::AcornRisc,
            14 => OsName::Vfat,
            15 => OsName::AlternateMVS,
            16 => OsName::BeOS,
            17 => OsName::Tandem,
            18 => OsName::OS400,
            19 => OsName::Darwin,
            20..=255 => OsName::Unused,
        }
    }
}

#[repr(transparent)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct DateTimeModified(u32);

impl DateTimeModified {
    pub fn from_u32(b: u32) -> DateTimeModified {
        Self(b)
    }
}

#[repr(transparent)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct CompressionMethod(pub u16);

impl CompressionMethod {
    pub fn name(self) -> CompressionMethodName {
        CompressionMethodName::from_u16(self.0)
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum CompressionMethodName {
    None = 0,
    Shrink = 1,
    Factor1 = 2,
    Factor2 = 3,
    Factor3 = 4,
    Factor4 = 5,
    Implode = 6,
    Reserved = 7,
    Deflate = 8,
    EnhancedDeflate = 9,
    PKWareDclImplode = 10,
    Bzip2 = 12,
    Lzma = 14,
    IbmTerse = 18,
    IbmLZ77z = 19,
    PPMd = 98,
    Unknown,
}

impl CompressionMethodName {
    pub fn from_u16(n: u16) -> CompressionMethodName {
        match n {
            0 => CompressionMethodName::None,
            1 => CompressionMethodName::Shrink,
            2 => CompressionMethodName::Factor1,
            3 => CompressionMethodName::Factor2,
            4 => CompressionMethodName::Factor3,
            5 => CompressionMethodName::Factor4,
            6 => CompressionMethodName::Implode,
            7 | 11 | 13 | 15..=17 => CompressionMethodName::Reserved,
            8 => CompressionMethodName::Deflate,
            9 => CompressionMethodName::EnhancedDeflate,
            10 => CompressionMethodName::PKWareDclImplode,
            12 => CompressionMethodName::Bzip2,
            14 => CompressionMethodName::Lzma,
            18 => CompressionMethodName::IbmTerse,
            19 => CompressionMethodName::IbmLZ77z,
            98 => CompressionMethodName::PPMd,
            _ => CompressionMethodName::Unknown,
        }
    }
}

/// General purpose bit flags related to encoding
#[repr(transparent)]
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct ZipFlags(pub u16);

impl ZipFlags {
    pub const ENCRYPTED_FILE: u16 = 1 << 0;
    pub const COMPRESSION_OPTION1: u16 = 1 << 1;
    pub const COMPRESSION_OPTION2: u16 = 1 << 2;
    pub const DATA_DESCRIPTOR: u16 = 1 << 3;
    pub const ENHANCED_DEFLATION: u16 = 1 << 4;
    pub const COMPRESSED_PATCHED_DATA: u16 = 1 << 5;
    pub const STRONG_ENCRYPTION: u16 = 1 << 6;
    pub const LANGUAGE_ENCODING: u16 = 1 << 11;
    pub const RESERVED: u16 = 1 << 12;
    pub const MASK_HEADER_VALUES: u16 = 1 << 13;

    pub fn has_data_descriptor(&self) -> bool {
        (self.0 & Self::DATA_DESCRIPTOR) != 0
    }
}

#[repr(transparent)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct ExternalAttributes(pub u32);

#[repr(transparent)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct InternalAttributes(pub u16);

impl InternalAttributes {
    pub const IS_ASCII: u16 = 1 << 0;
    pub const RESERVED: u16 = 1 << 1;
    pub const CONTROL_FIELD_RECORDS_PRECEDE_LOGICAL_RECORDS: u16 = 1 << 2;
}