1 files changed, 77 insertions, 0 deletions
diff --git a/ops/src/convert.rs b/ops/src/convert.rs
new file mode 100644
index 0000000..15b4bb2
--- /dev/null
+++ b/ops/src/convert.rs
@@ -0,0 +1,77 @@
+//! Log format conversion
+use regex::Regex;
+
+use ilc_base::{self, Context, Decode, Encode, Event};
+use std::io::{BufRead, Write};
+
+#[derive(Copy, Clone)]
+pub enum Subject {
+    Nick,
+    Time,
+    Type,
+    Text,
+}
+
+pub enum Operator {
+    Exactly(String),
+    Contains(String),
+    Matches(Regex),
+    Equal(i64),
+    Greater(i64),
+    Less(i64),
+}
+
+pub struct Filter(pub Subject, pub Operator);
+
+impl Filter {
+    pub fn satisfied_by(&self, e: &Event) -> bool {
+        use self::Subject::*;
+        use self::Operator::*;
+
+        match (self.0, &self.1) {
+            (Nick, &Exactly(ref s)) => e.ty.actor().map_or(false, |e| e == s),
+            (Nick, &Contains(ref s)) => e.ty.actor().map_or(false, |e| e.contains(s)),
+            (Nick, &Matches(ref r)) => e.ty.actor().map_or(false, |e| r.is_match(e)),
+            (Nick, _op) => false,
+            (Time, &Equal(t)) => e.time.as_timestamp() == t,
+            (Time, &Greater(t)) => e.time.as_timestamp() > t,
+            (Time, &Less(t)) => e.time.as_timestamp() < t,
+            (Time, _op) => false,
+            (Type, &Exactly(ref s)) => e.ty.type_desc() == s,
+            (Type, &Contains(ref s)) => e.ty.type_desc().contains(s),
+            (Type, &Matches(ref r)) => r.is_match(e.ty.type_desc()),
+            (Type, _op) => false,
+            (Text, &Exactly(ref s)) => e.ty.text().map_or(false, |t| t == s),
+            (Text, &Contains(ref s)) => e.ty.text().map_or(false, |t| t.contains(s)),
+            (Text, &Matches(ref r)) => e.ty.text().map_or(false, |t| r.is_match(t)),
+            (Text, _op) => false,
+        }
+    }
+}
+
+/// Convert from one format to another, not necessarily different, format. In combination with a
+/// timezone offset, this can be used to correct the timestamps.
+/// Will return `Err` and abort conversion if the decoder yields `Err` or re-encoding fails.
+pub fn convert(ctx: &Context,
+               input: &mut BufRead,
+               decoder: &mut Decode,
+               output: &mut Write,
+               encoder: &Encode,
+               filter: Option<Filter>,
+               not: bool)
+               -> ilc_base::Result<()> {
+    if let Some(f) = filter {
+        for e in decoder.decode(&ctx, input) {
+            let e = try!(e);
+            if not ^ f.satisfied_by(&e) {
+                try!(encoder.encode(&ctx, output, &e))
+            }
+        }
+    } else {
+        // fast path for filter-less conversion, probably premature
+        for e in decoder.decode(&ctx, input) {
+            try!(encoder.encode(&ctx, output, &try!(e)));
+        }
+    }
+    Ok(())
+}