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

use std::{fmt, io};

use crate::{Atom, Data};

/// A structure representing the different types of content an Atom might have.
#[derive(Clone)]
pub enum Content {
    /// A value containing `Vec<Atom>`.
    Atoms(Vec<Atom>),
    /// A value containing raw `Data`.
    RawData(Data),
    /// A value containing `Data` defined by a [Table 3-5 Well-known data types](https://developer.apple.com/library/archive/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW34) code.
    TypedData(Data),
    /// Empty `Content`.
    Empty,
}

impl Content {
    /// Creates a new content of type `Content::Atoms` containing an empty `Vec`.
    pub fn atoms() -> Content {
        Content::Atoms(Vec::new())
    }

    /// Creates a new content of type `Content::Atoms` containing the atom.
    pub fn atom(atom: Atom) -> Content {
        Content::Atoms(vec![atom])
    }

    /// Creates a new content of type `Content::Atoms` containing a data `Atom`.
    pub fn data_atom() -> Content { Content::atom(Atom::data_atom()) }

    /// Creates a new content of type `Content::Atoms` containing a data `Atom` with the data.
    pub fn data_atom_with(data: Data) -> Content { Content::atom(Atom::data_atom_with(data)) }

    /// Creates a new `Content` of type `Content::Atoms` containing a new `Atom` with the head,
    /// offset and content.
    pub fn atom_with(head: [u8; 4], offset: usize, content: Content) -> Content {
        Content::atom(Atom::with(head, offset, content))
    }

    /// Adds the atom to the list of children atoms if `self` is of type `Content::Atoms`.
    pub fn add_atom(self, atom: Atom) -> Content {
        if let Content::Atoms(mut atoms) = self {
            atoms.push(atom);
            Content::Atoms(atoms)
        } else {
            self
        }
    }

    /// Adds a data `Atom` to the list of children if `self` is of type `Content::Atoms`.
    pub fn add_data_atom(self) -> Content {
        self.add_atom(Atom::data_atom())
    }

    /// Adds a new `Atom` with the provided head, offset and content to the list of children if
    /// `self` is of type `Content::Atoms`.
    pub fn add_atom_with(self, head: [u8; 4], offset: usize, content: Content) -> Content {
        self.add_atom(Atom::with(head, offset, content))
    }

    /// Returns the length in bytes.
    pub fn len(&self) -> usize {
        match self {
            Content::Atoms(v) => v.iter().map(|a| a.len()).sum(),
            Content::TypedData(d) => 8 + d.len(),
            Content::RawData(d) => d.len(),
            Content::Empty => 0,
        }
    }

    /// Attempts to parse itself from the reader.
    pub fn parse(&mut self, reader: &mut (impl io::Read + io::Seek), length: usize) -> crate::Result<()> {
        match self {
            Content::Atoms(v) => Atom::parse_atoms(v, reader, length)?,
            Content::RawData(d) => d.parse(reader, length)?,
            Content::TypedData(d) => d.parse(reader, length)?,
            Content::Empty => (),
        }

        Ok(())
    }

    pub fn write_to(&self, writer: &mut impl io::Write) -> crate::Result<()> {
        match self {
            Content::Atoms(v) => for a in v {
                a.write_to(writer)?;
            }
            Content::RawData(d) => d.write_raw(writer)?,
            Content::TypedData(d) => d.write_typed(writer)?,
            Content::Empty => (),
        }

        Ok(())
    }
}

impl PartialEq for Content {
    fn eq(&self, other: &Self) -> bool {
        match self {
            Content::Atoms(v) => if let Content::Atoms(ov) = other {
                return v == ov;
            }
            Content::RawData(d) => if let Content::RawData(od) = other {
                return d == od;
            }
            Content::TypedData(d) => if let Content::TypedData(od) = other {
                return d == od;
            }
            Content::Empty => if let Content::Empty = other { return true; }
        }

        false
    }

    fn ne(&self, other: &Self) -> bool {
        match self {
            Content::Atoms(v) => if let Content::Atoms(ov) = other {
                return v != ov;
            }
            Content::RawData(d) => if let Content::RawData(od) = other {
                return d != od;
            }
            Content::TypedData(d) => if let Content::TypedData(od) = other {
                return d != od;
            }
            Content::Empty => if let Content::Empty = other { return true; }
        }

        true
    }
}

impl fmt::Debug for Content {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Content::Atoms(a) => write!(f, "Content::Atoms{{ {:#?} }}", a),
            Content::TypedData(d) => write!(f, "Content::TypedData{{ {:?} }}", d),
            Content::RawData(d) => write!(f, "Content::RawData{{ {:?} }}", d),
            Content::Empty => write!(f, "Content::Empty")
        }
    }
}