From 0dae28ea8da3296ec083293b41e158152c1d6bca Mon Sep 17 00:00:00 2001
From: Veloman Yunkan <veloman.yunkan@gmail.com>
Date: Thu, 8 Jul 2021 17:00:54 +0400
Subject: [PATCH] Languages OPDS feed includes book counts

---
 include/library.h                         |  9 +++++++++
 src/library.cpp                           | 21 +++++++++++++++++----
 src/opds_dumper.cpp                       |  5 ++++-
 static/templates/catalog_v2_languages.xml |  1 +
 test/server.cpp                           |  3 +++
 5 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/include/library.h b/include/library.h
index e98a96d72..9139405a2 100644
--- a/include/library.h
+++ b/include/library.h
@@ -152,6 +152,7 @@ class Library
 
  public:
   typedef std::vector<std::string> BookIdCollection;
+  typedef std::map<std::string, int> AttributeCounts;
 
  public:
   Library();
@@ -239,6 +240,13 @@ class Library
    */
   std::vector<std::string> getBooksLanguages() const;
 
+  /**
+   * Get all languagues of the books in the library with counts.
+   *
+   * @return A list of languages with the count of books in each language.
+   */
+  AttributeCounts getBooksLanguagesWithCounts() const;
+
   /**
    * Get all categories of the books in the library.
    *
@@ -342,6 +350,7 @@ class Library
   typedef const std::string& (Book::*BookStrPropMemFn)() const;
 
 private: // functions
+  AttributeCounts getBookAttributeCounts(BookStrPropMemFn p) const;
   std::vector<std::string> getBookPropValueSet(BookStrPropMemFn p) const;
   BookIdCollection filterViaBookDB(const Filter& filter) const;
   void updateBookDB(const Book& book);
diff --git a/src/library.cpp b/src/library.cpp
index 191b8ce6f..d1ed90d36 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -182,18 +182,26 @@ bool Library::writeBookmarksToFile(const std::string& path) const
   return writeTextFile(path, dumper.dumpLibXMLBookmark());
 }
 
-std::vector<std::string> Library::getBookPropValueSet(BookStrPropMemFn p) const
+Library::AttributeCounts Library::getBookAttributeCounts(BookStrPropMemFn p) const
 {
-  std::set<std::string> propValues;
+  AttributeCounts propValueCounts;
 
   for (const auto& pair: m_books) {
     const auto& book = pair.second;
     if (book.getOrigId().empty()) {
-      propValues.insert((book.*p)());
+      propValueCounts[(book.*p)()] += 1;
     }
   }
+  return propValueCounts;
+}
 
-  return std::vector<std::string>(propValues.begin(), propValues.end());
+std::vector<std::string> Library::getBookPropValueSet(BookStrPropMemFn p) const
+{
+  std::vector<std::string> result;
+  for ( const auto& kv : getBookAttributeCounts(p) ) {
+    result.push_back(kv.first);
+  }
+  return result;
 }
 
 std::vector<std::string> Library::getBooksLanguages() const
@@ -201,6 +209,11 @@ std::vector<std::string> Library::getBooksLanguages() const
   return getBookPropValueSet(&Book::getLanguage);
 }
 
+Library::AttributeCounts Library::getBooksLanguagesWithCounts() const
+{
+  return getBookAttributeCounts(&Book::getLanguage);
+}
+
 std::vector<std::string> Library::getBooksCategories() const
 {
   std::set<std::string> categories;
diff --git a/src/opds_dumper.cpp b/src/opds_dumper.cpp
index 2c560a7e3..8bf1147dc 100644
--- a/src/opds_dumper.cpp
+++ b/src/opds_dumper.cpp
@@ -159,11 +159,14 @@ std::string OPDSDumper::languagesOPDSFeed() const
 {
   const auto now = gen_date_str();
   kainjow::mustache::list languageData;
-  for ( const auto& languageCode : library->getBooksLanguages() ) {
+  for ( const auto& langAndBookCount : library->getBooksLanguagesWithCounts() ) {
+    const std::string languageCode = langAndBookCount.first;
+    const int bookCount = langAndBookCount.second;
     const auto languageSelfName = getLanguageSelfName(languageCode);
     languageData.push_back(kainjow::mustache::object{
       {"lang_code",  languageCode},
       {"lang_self_name", languageSelfName},
+      {"book_count", to_string(bookCount)},
       {"updated", now},
       {"id", gen_uuid(libraryId + "/languages/" + languageCode)}
     });
diff --git a/static/templates/catalog_v2_languages.xml b/static/templates/catalog_v2_languages.xml
index 64e24ac68..8a5b74cce 100644
--- a/static/templates/catalog_v2_languages.xml
+++ b/static/templates/catalog_v2_languages.xml
@@ -16,6 +16,7 @@
   <entry>
     <title>{{lang_self_name}}</title>
     <dc:language>{{{lang_code}}}</dc:language>
+    <thr:count>{{book_count}}</thr:count>
     <link rel="subsection"
           href="{{endpoint_root}}/entries?lang={{{lang_code}}}"
           type="application/atom+xml;profile=opds-catalog;kind=acquisition"/>
diff --git a/test/server.cpp b/test/server.cpp
index 34dad9346..bfa321cd8 100644
--- a/test/server.cpp
+++ b/test/server.cpp
@@ -1035,6 +1035,7 @@ TEST_F(LibraryServerTest, catalog_v2_languages)
   <entry>
     <title>English</title>
     <dc:language>eng</dc:language>
+    <thr:count>1</thr:count>
     <link rel="subsection"
           href="/catalog/v2/entries?lang=eng"
           type="application/atom+xml;profile=opds-catalog;kind=acquisition"/>
@@ -1044,6 +1045,7 @@ TEST_F(LibraryServerTest, catalog_v2_languages)
   <entry>
     <title>français</title>
     <dc:language>fra</dc:language>
+    <thr:count>1</thr:count>
     <link rel="subsection"
           href="/catalog/v2/entries?lang=fra"
           type="application/atom+xml;profile=opds-catalog;kind=acquisition"/>
@@ -1053,6 +1055,7 @@ TEST_F(LibraryServerTest, catalog_v2_languages)
   <entry>
     <title>русский</title>
     <dc:language>rus</dc:language>
+    <thr:count>1</thr:count>
     <link rel="subsection"
           href="/catalog/v2/entries?lang=rus"
           type="application/atom+xml;profile=opds-catalog;kind=acquisition"/>