[PATCH v5.2 3/7] reply: Add a JSON reply format.

[Adam Wolfe Gordon <awg+notmuch@xvx.ca>]

This new JSON format for replies includes headers generated for a
reply message as well as the headers of the original message.  Using
this data, a client can intelligently create a reply. For example, the
emacs client will be able to create replies with quoted HTML parts by
parsing the HTML parts.

Reply now enforces that only one message is returned, as the semantics
of replying to multiple messages are not well-defined.
---
 notmuch-client.h |    3 +
 notmuch-reply.c  |  121 ++++++++++++++++++++++++++++++++++++++++++++++-------
 notmuch-show.c   |    2 +-
 3 files changed, 109 insertions(+), 17 deletions(-)

diff --git a/notmuch-client.h b/notmuch-client.h
index 60828aa..d28ea07 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -344,6 +344,9 @@ typedef struct mime_node {
     int next_part_num;
 } mime_node_t;
 
+void
+format_part_json (const void *ctx, mime_node_t *node, notmuch_bool_t first);
+
 /* Construct a new MIME node pointing to the root message part of
  * message.  If cryptoctx is non-NULL, it will be used to verify
  * signatures on any child parts.  If decrypt is true, then cryptoctx
diff --git a/notmuch-reply.c b/notmuch-reply.c
index 8e56245..6670288 100644
--- a/notmuch-reply.c
+++ b/notmuch-reply.c
@@ -572,30 +572,115 @@ notmuch_reply_format_default(void *ctx,
     notmuch_message_t *message;
     const notmuch_show_format_t *format = &format_reply;
 
-    for (messages = notmuch_query_search_messages (query);
-	 notmuch_messages_valid (messages);
-	 notmuch_messages_move_to_next (messages))
-    {
-	message = notmuch_messages_get (messages);
+    if (notmuch_query_count_messages (query) != 1) {
+	fprintf (stderr, "Error: search term did not match precisely one message.\n");
+	return 1;
+    }
 
-	reply = create_reply_message (ctx, config, message, reply_all);
+    messages = notmuch_query_search_messages (query);
+    message = notmuch_messages_get (messages);
 
-	if (!reply)
-	    continue;
+    reply = create_reply_message (ctx, config, message, reply_all);
 
-	show_reply_headers (reply);
+    if (!reply)
+	return 1;
 
-	g_object_unref (G_OBJECT (reply));
-	reply = NULL;
+    show_reply_headers (reply);
 
-	printf ("On %s, %s wrote:\n",
-		notmuch_message_get_header (message, "date"),
-		notmuch_message_get_header (message, "from"));
+    g_object_unref (G_OBJECT (reply));
+    reply = NULL;
 
-	show_message_body (message, format, params);
+    printf ("On %s, %s wrote:\n",
+	    notmuch_message_get_header (message, "date"),
+	    notmuch_message_get_header (message, "from"));
 
-	notmuch_message_destroy (message);
+    show_message_body (message, format, params);
+
+    notmuch_message_destroy (message);
+
+    return 0;
+}
+
+static void
+format_reply_headers_json (const void *ctx, GMimeMessage *message)
+{
+    void *local = talloc_new (ctx);
+    InternetAddressList *recipients;
+    const char *recipients_string;
+
+    printf ("{%s: %s",
+	    json_quote_str (local, "Subject"),
+	    json_quote_str (local, g_mime_message_get_subject (message)));
+    printf (", %s: %s",
+	    json_quote_str (local, "From"),
+	    json_quote_str (local, g_mime_message_get_sender (message)));
+    recipients = g_mime_message_get_recipients (message, GMIME_RECIPIENT_TYPE_TO);
+    recipients_string = internet_address_list_to_string (recipients, 0);
+    if (recipients_string)
+	printf (", %s: %s",
+		json_quote_str (local, "To"),
+		json_quote_str (local, recipients_string));
+    recipients = g_mime_message_get_recipients (message, GMIME_RECIPIENT_TYPE_CC);
+    recipients_string = internet_address_list_to_string (recipients, 0);
+    if (recipients_string)
+	printf (", %s: %s",
+		json_quote_str (local, "Cc"),
+		json_quote_str (local, recipients_string));
+
+    printf (", %s: %s",
+	    json_quote_str (local, "In-reply-to"),
+	    json_quote_str (local, g_mime_object_get_header (GMIME_OBJECT (message), "In-reply-to")));
+
+    printf (", %s: %s",
+	    json_quote_str (local, "References"),
+	    json_quote_str (local, g_mime_object_get_header (GMIME_OBJECT (message), "References")));
+
+    talloc_free (local);
+}
+
+static int
+notmuch_reply_format_json(void *ctx,
+			  notmuch_config_t *config,
+			  notmuch_query_t *query,
+			  notmuch_show_params_t *params,
+			  notmuch_bool_t reply_all)
+{
+    GMimeMessage *reply;
+    notmuch_messages_t *messages;
+    notmuch_message_t *message;
+    mime_node_t *node;
+
+    if (notmuch_query_count_messages (query) != 1) {
+	fprintf (stderr, "Error: search term did not match precisely one message.\n");
+	return 1;
     }
+
+    messages = notmuch_query_search_messages (query);
+    message = notmuch_messages_get (messages);
+    if (mime_node_open (ctx, message, params->cryptoctx, params->decrypt,
+			&node) != NOTMUCH_STATUS_SUCCESS)
+	return 1;
+
+    reply = create_reply_message (ctx, config, message, reply_all);
+    if (!reply)
+	return 1;
+
+    /* The headers of the reply message we've created */
+    printf ("{\"reply-headers\": ");
+    format_reply_headers_json (ctx, reply);
+    printf ("}");
+    g_object_unref (G_OBJECT (reply));
+    reply = NULL;
+
+    /* Start the original */
+    printf (", \"original\": ");
+
+    format_part_json (ctx, node, TRUE);
+
+    /* End */
+    printf ("}\n");
+    notmuch_message_destroy (message);
+
     return 0;
 }
 
@@ -661,6 +746,7 @@ notmuch_reply_format_headers_only(void *ctx,
 
 enum {
     FORMAT_DEFAULT,
+    FORMAT_JSON,
     FORMAT_HEADERS_ONLY,
 };
 
@@ -680,6 +766,7 @@ notmuch_reply_command (void *ctx, int argc, char *argv[])
     notmuch_opt_desc_t options[] = {
 	{ NOTMUCH_OPT_KEYWORD, &format, "format", 'f',
 	  (notmuch_keyword_t []){ { "default", FORMAT_DEFAULT },
+				  { "json", FORMAT_JSON },
 				  { "headers-only", FORMAT_HEADERS_ONLY },
 				  { 0, 0 } } },
 	{ NOTMUCH_OPT_KEYWORD, &reply_all, "reply-to", 'r',
@@ -698,6 +785,8 @@ notmuch_reply_command (void *ctx, int argc, char *argv[])
 
     if (format == FORMAT_HEADERS_ONLY)
 	reply_format_func = notmuch_reply_format_headers_only;
+    else if (format == FORMAT_JSON)
+	reply_format_func = notmuch_reply_format_json;
     else
 	reply_format_func = notmuch_reply_format_default;
 
diff --git a/notmuch-show.c b/notmuch-show.c
index 6a171a4..c570a16 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -652,7 +652,7 @@ format_part_text (const void *ctx, mime_node_t *node,
     printf ("\f%s}\n", part_type);
 }
 
-static void
+void
 format_part_json (const void *ctx, mime_node_t *node, notmuch_bool_t first)
 {
     /* Any changes to the JSON format should be reflected in the file
-- 
1.7.5.4