1 files changed, 92 insertions, 0 deletions
diff --git a/internals/src/bind/encoded_word/mod.rs b/internals/src/bind/encoded_word/mod.rs
new file mode 100644
index 0000000..ef61fc6
--- /dev/null
+++ b/internals/src/bind/encoded_word/mod.rs
@@ -0,0 +1,92 @@
+use soft_ascii_string::{ SoftAsciiStr, SoftAsciiChar };
+
+use super::{base64, quoted_printable};
+
+mod impls;
+pub use self::impls::*;
+
+#[derive(Debug, Copy, Clone, Hash, Eq, PartialEq)]
+pub enum EncodedWordEncoding {
+    Base64, QuotedPrintable
+}
+
+impl EncodedWordEncoding {
+
+    /// returns the acronym for the given encoding
+    /// used in a encoded word
+    pub fn acronym(&self) -> &'static SoftAsciiStr {
+        use self::EncodedWordEncoding::*;
+        match *self {
+            Base64 => SoftAsciiStr::from_unchecked("B"),
+            QuotedPrintable => SoftAsciiStr::from_unchecked("Q")
+        }
+    }
+
+    /// encodes a given utf8 string
+    ///
+    /// either `self::quoted_printable::encoded_word_encode`
+    /// or `self::base64::encoded_word_encode_utf8` is used
+    /// depending on which value `self` is.
+    ///
+    /// As both algorithm need to know about code point boundaries
+    /// only encoding utf8 is supported for now
+    ///
+    pub fn encode<R, O>(&self, input: R, out: &mut O)
+        where R: AsRef<str>, O: EncodedWordWriter
+    {
+        use self::EncodedWordEncoding::*;
+        let input: &str = input.as_ref();
+        match *self {
+            Base64 => {
+                base64::encoded_word_encode(input, out)
+            },
+            QuotedPrintable => {
+                quoted_printable::encoded_word_encode_utf8(input, out)
+            }
+        }
+    }
+}
+
+pub trait EncodedWordWriter {
+    fn write_char( &mut self, ch: SoftAsciiChar );
+    fn write_charset( &mut self );
+    fn encoding( &self ) -> EncodedWordEncoding;
+    fn write_ecw_seperator( &mut self );
+
+    /// Returns the maximal length of the paylod/encoded data
+    ///
+    /// Any number of calls to methods on in trait in any way
+    /// should never be able to change the returned value.
+    /// Only changing e.g. the charset or encoding should be
+    /// able to change what `max_paylod_len` returns.
+    fn max_payload_len( &self ) -> usize;
+
+    fn write_ecw_start( &mut self ) {
+        let qm = SoftAsciiChar::from_unchecked('?');
+        self.write_char(SoftAsciiChar::from_unchecked('='));
+        self.write_char(qm);
+        self.write_charset();
+        self.write_char(qm);
+        let acronym = self.encoding().acronym();
+        self.write_str( acronym );
+        self.write_char(qm);
+    }
+
+    fn write_ecw_end( &mut self ) {
+        self.write_char( SoftAsciiChar::from_unchecked('?') );
+        self.write_char( SoftAsciiChar::from_unchecked('=') );
+    }
+
+
+    fn start_next_encoded_word( &mut self )  {
+        self.write_ecw_end();
+        self.write_ecw_seperator();
+        self.write_ecw_start();
+    }
+
+    fn write_str( &mut self, s: &SoftAsciiStr ) {
+        for ch in s.chars() {
+            self.write_char(ch)
+        }
+    }
+}
+\ No newline at end of file