cli: replace committer email by author timestamp in log template

I've often missed not having the timestamp there. It gets too long
with both email and timestamp for both author and committer, so I
removed the committer email to make room for the author timestamp.

src/commands.rs

@@ -979,8 +979,8 @@ fn log_template(settings: &UserSettings) -> String {
             label(if(open, "open"),
             "commit: " commit_id "\n"
             "change: " change_id "\n"
-            "author: " author.name() " <" author.email() ">\n"
-            "committer: " committer.name() " <" committer.email() ">\n"
+            "author: " author.name() " <" author.email() "> " author.timestamp() "\n"
+            "committer: " committer.name() " <" committer.email() "> "  committer.timestamp() "\n"
             "git refs: " git_refs "\n"
             "open: " open "\n"
             "pruned: " pruned "\n"
@@ -1005,7 +1005,7 @@ fn graph_log_template(settings: &UserSettings) -> String {
             commit_id.short()
             " " change_id.short()
             " " author.email()
-            " " committer.email()
+            " " label("timestamp", author.timestamp())
             " " git_refs
             if(pruned, label("pruned", " pruned"))
             if(obsolete, label("obsolete", " obsolete"))

src/styler.rs

@@ -85,7 +85,9 @@ fn config_colors(user_settings: &UserSettings) -> HashMap<String, String> {
     result.insert(String::from("commit_id open"), String::from("green"));
     result.insert(String::from("change_id"), String::from("magenta"));
     result.insert(String::from("author"), String::from("yellow"));
+    result.insert(String::from("author timestamp"), String::from("cyan"));
     result.insert(String::from("committer"), String::from("yellow"));
+    result.insert(String::from("committer timestamp"), String::from("cyan"));
     result.insert(String::from("git_refs"), String::from("magenta"));
     result.insert(String::from("pruned"), String::from("red"));
     result.insert(String::from("obsolete"), String::from("red"));

src/template_parser.rs

@@ -14,6 +14,7 @@
 
 extern crate pest;
 
+use chrono::{FixedOffset, TimeZone, Utc};
 use jujube_lib::commit::Commit;
 use jujube_lib::repo::RepoRef;
 use jujube_lib::store::{CommitId, Signature};
@@ -93,6 +94,20 @@ impl TemplateProperty<Signature, String> for SignatureEmail {
     }
 }
 
+struct SignatureTimestamp;
+
+impl TemplateProperty<Signature, String> for SignatureTimestamp {
+    fn extract(&self, context: &Signature) -> String {
+        let utc = Utc
+            .timestamp(
+                context.timestamp.timestamp.0 as i64 / 1000,
+                (context.timestamp.timestamp.0 % 1000) as u32 * 1000000,
+            )
+            .with_timezone(&FixedOffset::east(context.timestamp.tz_offset * 60));
+        utc.format("%Y-%m-%d %H:%M:%S.%3f %:z").to_string()
+    }
+}
+
 fn parse_method_chain<'a, I: 'a>(
     pair: Pair<Rule>,
     input_property: Property<'a, I>,
@@ -177,6 +192,7 @@ fn parse_signature_method<'a>(method: Pair<Rule>) -> Property<'a, Signature> {
         //       `author % (name "<" email ">")`)?
         "name" => Property::String(Box::new(SignatureName)),
         "email" => Property::String(Box::new(SignatureEmail)),
+        "timestamp" => Property::String(Box::new(SignatureTimestamp)),
         name => panic!("no such commit id method: {}", name),
     };
     let chain_method = inner.last().unwrap();