* mu-guile: shuffled functionality around a bit, and fixed a few bugs (WIP)

guile/mu/contact.scm

@@ -21,6 +21,7 @@
 
 (define-module (mu contact)
   :use-module (oop goops)
+  :use-module (mu message)
   :export ( ;; classes
 	    <mu-contact>
 	    ;; contact methods
@@ -33,3 +34,46 @@
   (tstamp #:init-value 0 #:accessor timestamp #:init-keyword #:timestamp)
   (last-seen #:init-value 0 #:accessor last-seen)
   (freq #:init-value 1 #:accessor frequency))
+
+
+(define* (mu:for-each-contact proc #:optional (expr #t))
+  "Execute PROC for each contact. PROC receives a <mu-contact> instance
+as parameter. If EXPR is specified, only consider contacts in messages
+matching EXPR."
+  (let ((c-hash (make-hash-table 4096)))
+    (mu:for-each-message
+      (lambda (msg)
+	(for-each
+	  (lambda (name-addr)
+	    (let ((contact (make <mu-contact>
+			     #:name      (car name-addr)
+			     #:email     (cdr name-addr)
+			     #:timestamp (date msg))))
+	      (update-contacts-hash c-hash contact)))
+	  (contacts msg #t)))
+      expr)
+    ;; c-hash now contains a map of email->contact
+    (hash-for-each
+      (lambda (email contact) (proc contact)) c-hash)))
+
+(define-method (update-contacts-hash c-hash (nc <mu-contact>))
+  "Update the contacts hash with a new and/or existing contact."
+  ;; xc: existing-contact, nc: new contact
+  (let ((xc (hash-ref c-hash (email nc))))
+    (if (not xc) ;; no existing contact with this email address?
+      (hash-set! c-hash (email nc) nc) ;; store the new contact.
+      ;; otherwise:
+      (begin
+	;; 1) update the frequency for the existing contact
+	(set! (frequency xc) (1+ (frequency xc)))
+	;; 2) update the name if the new one is not empty and its timestamp is newer
+	;;    in that case, also update the timestamp
+	(if (and (name nc) (> (string-length (name nc)))
+	      (> (timestamp nc) (timestamp xc)))
+	  (set! (name xc) (name nc))
+	  (set! (timestamp xc) (timestamp nc)))
+	;; 3) update last-seen with timestamp, if x's timestamp is newer
+	(if (> (timestamp nc) (last-seen xc))
+	  (set! (last-seen xc) (timestamp nc)))
+	;; okay --> now xc has been updated; but it back in the hash
+	(hash-set! c-hash (email xc) xc)))))