From 473d3998ce9cae1a6eeb51867578af7cb4408834 Mon Sep 17 00:00:00 2001
From: "Dirk-Jan C. Binnema" <djcb@djcbsoftware.nl>
Date: Tue, 4 May 2021 17:34:47 +0300
Subject: [PATCH] mu: calculate thread subjects

Calculate the thread subject, that is, the subject of the (sub)thread _or_
empty if it's the same as the previous subject.

This is for the UI feature of _not_ showing the subject when it's just
repeating from the previous.
---
 lib/mu-query-results.hh |  5 ++---
 lib/mu-query-threads.cc | 24 ++++++++++++++++++------
 lib/mu-server.cc        | 16 ++++++++--------
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/lib/mu-query-results.hh b/lib/mu-query-results.hh
index 9376938b..30d47140 100644
--- a/lib/mu-query-results.hh
+++ b/lib/mu-query-results.hh
@@ -91,11 +91,10 @@ struct QueryMatch {
         // (ignoring prefixes such as Re:)
         //
         // otherwise, it is empty.
-        std::string     subject;
-        std::string     thread_subject; /**< the thread subject for this message */
+        std::string     subject;        /**< subject for this message */
         size_t          thread_level{}; /**< The thread level */
         std::string     thread_path;    /**< The hex-numerial path in the thread, ie. '00:01:0a' */
-        std::string     thread_date{};  /**< date of newest message in thread */
+        std::string     thread_date;    /**< date of newest message in thread */
 
         bool operator<(const QueryMatch& rhs) const {
                 return  date_key < rhs.date_key;
diff --git a/lib/mu-query-threads.cc b/lib/mu-query-threads.cc
index 947a7e8a..8c4759fc 100644
--- a/lib/mu-query-threads.cc
+++ b/lib/mu-query-threads.cc
@@ -394,11 +394,20 @@ update_container (Container& container, bool descending,
         if (!container.children.empty())
                 qmatch.flags |= QueryMatch::Flags::HasChild;
 
-        // calculate the "thread-subject", which is for UI
-        // purposes (future use)
+        // see whether this message has the has the thread
+        // subject, ie.. the first message in this thread with the
+        // given subject.
         if (qmatch.has_flag(QueryMatch::Flags::Root) ||
+            //qmatch.has_flag(QueryMatch::Flags::Orphan) ||
+            prev_subject.empty() ||
             (qmatch.subject.find(prev_subject) > 5))
-            qmatch.flags |= QueryMatch::Flags::ThreadSubject;
+                qmatch.flags |= QueryMatch::Flags::ThreadSubject;
+
+        // g_debug ("%c%c: '%s' vs '%s'",
+        //          any_of(qmatch.flags & QueryMatch::Flags::Root) ? 'r' : 'c',
+        //          any_of(qmatch.flags & QueryMatch::Flags::ThreadSubject) ? 'y' : 'n',
+        //          qmatch.subject.c_str(),
+        //          prev_subject.c_str());
 
         if (descending && container.parent) {
                 // trick xapian by giving it "inverse" sorting key so our
@@ -422,13 +431,16 @@ update_containers (Containers& children, bool descending, ThreadPath& tpath,
                    size_t seg_size)
 {
         size_t idx{0};
+        std::string last_subject;
 
         for (auto&& c: children) {
                 tpath.emplace_back(idx++);
 
-                if (c->query_match)
-                        update_container(*c, descending, tpath, seg_size);
-
+                if (c->query_match) {
+                        update_container(*c, descending, tpath, seg_size,
+                                         last_subject);
+                        last_subject = c->query_match->subject;
+                }
                 update_containers(c->children, descending, tpath, seg_size);
                 tpath.pop_back();
         }
diff --git a/lib/mu-server.cc b/lib/mu-server.cc
index fcf3d82d..32bac340 100644
--- a/lib/mu-server.cc
+++ b/lib/mu-server.cc
@@ -146,21 +146,21 @@ add_thread_info (Sexp::List& items, const QueryMatch& qmatch)
         info.add_prop(":date-tstamp", Sexp::make_list(std::move(dlist)));
 
         if (qmatch.has_flag(QueryMatch::Flags::Root))
-                info.add_prop( ":root", symbol_t());
+                info.add_prop(":root", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::Related))
-                info.add_prop( ":related", symbol_t());
+                info.add_prop(":related", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::First))
-                info.add_prop( ":first-child", symbol_t());
+                info.add_prop(":first-child", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::Last))
-                info.add_prop( ":last-child", symbol_t());
+                info.add_prop(":last-child", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::Orphan))
-                info.add_prop( ":orphan", symbol_t());
+                info.add_prop(":orphan", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::Duplicate))
-                info.add_prop( ":duplicate", symbol_t());
+                info.add_prop(":duplicate", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::HasChild))
-                info.add_prop( ":has-child", symbol_t());
+                info.add_prop(":has-child", symbol_t());
         if (qmatch.has_flag(QueryMatch::Flags::ThreadSubject))
-                info.add_prop( ":thread_subject", symbol_t());
+                info.add_prop(":thread-subject", symbol_t());
 
         items.add_prop(":thread", Sexp::make_list(std::move(info)));
 }