From c631e5c4fea63df28ae01dac2483c3f91eaff2ea Mon Sep 17 00:00:00 2001
From: tastytea <tastytea@tastytea.de>
Date: Tue, 24 Dec 2019 18:53:45 +0100
Subject: [PATCH] Add debug logging.

---
 man/mastorss.1.adoc | 14 +++++++++++++-
 src/CMakeLists.txt  |  9 +++++++--
 src/document.cpp    |  6 +++++-
 src/main.cpp        | 21 ++++++++++++++++++++-
 4 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/man/mastorss.1.adoc b/man/mastorss.1.adoc
index 15c6d92..4d15d64 100644
--- a/man/mastorss.1.adoc
+++ b/man/mastorss.1.adoc
@@ -2,7 +2,7 @@
 :doctype:       manpage
 :Author:        tastytea
 :Email:         tastytea@tastytea.de
-:Date:          2019-12-20
+:Date:          2019-12-24
 :Revision:      0.0.0
 :man source:    mastorss
 :man manual:    General Commands Manual
@@ -71,6 +71,18 @@ Example: `http_proxy="http://localhost:3128/" mastorss`
 |    9 | Unknown error.
 |===========================================================
 
+== DEBUGGING
+
+Define the variable `MASTORSS_DEBUG` to enable debug output.
+
+.Debug mastorss while using the profile “example”.
+================================================================================
+[source,shell]
+--------------------------------------------------------------------------------
+MASTORSS_DEBUG=1 mastorss example
+--------------------------------------------------------------------------------
+================================================================================
+
 == SEE ALSO
 
 *curl*(1), *crontab*(1), *crontab*(5)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index dca891e..e1ac829 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,7 +1,7 @@
 include(GNUInstallDirs)
 
 # The minimum versions should be in Debian oldstable, if possible.
-find_package(Boost 1.62 REQUIRED COMPONENTS system filesystem)
+find_package(Boost 1.62 REQUIRED COMPONENTS system filesystem log)
 find_package(jsoncpp 1.7 REQUIRED CONFIG)
 find_package(CURL 7.52 REQUIRED)
 find_package(Threads REQUIRED)
@@ -18,7 +18,12 @@ include_directories("${PROJECT_BINARY_DIR}")
 file(GLOB sources *.cpp)
 add_executable(mastorss ${sources})
 target_link_libraries(mastorss
-  mastodon-cpp::mastodon-cpp Boost::system Boost::filesystem restclient-cpp)
+  PRIVATE
+  jsoncpp restclient-cpp mastodon-cpp::mastodon-cpp
+  Boost::filesystem Boost::log)
+if(BUILD_SHARED_LIBS)
+  target_compile_definitions(mastorss PRIVATE "BOOST_ALL_DYN_LINK=1")
+endif()
 install(TARGETS mastorss DESTINATION "${CMAKE_INSTALL_BINDIR}")
 
 install(FILES watchwords.json
diff --git a/src/document.cpp b/src/document.cpp
index 0bf97e9..bd7531b 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -18,13 +18,15 @@
 #include "exceptions.hpp"
 #include "version.hpp"
 
+#include <boost/log/trivial.hpp>
 #include <restclient-cpp/connection.h>
 #include <restclient-cpp/restclient.h>
 
 #include <string>
 #include <utility>
 
-using namespace mastorss;
+namespace mastorss
+{
 using std::string;
 using std::move;
 
@@ -54,6 +56,7 @@ void Document::download()
     case 200:
     {
         _raw_doc = response.body;
+        BOOST_LOG_TRIVIAL(debug) << "Downloaded feed: " << _uri;
         break;
     }
     case 301:
@@ -73,3 +76,4 @@ void Document::download()
     }
     }
 }
+} // namespace mastorss
diff --git a/src/main.cpp b/src/main.cpp
index 4e5c6d3..0f6d1de 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3,13 +3,21 @@
 #include "exceptions.hpp"
 #include "version.hpp"
 
+#include <boost/log/core.hpp>
+#include <boost/log/trivial.hpp>
+#include <boost/log/utility/setup/console.hpp>
+
+#include <cstdlib>
 #include <iostream>
+#include <stdexcept>
 #include <string_view>
 #include <vector>
 
 using namespace mastorss;
+using std::getenv;
 using std::cout;
 using std::cerr;
+using std::runtime_error;
 using std::string_view;
 using std::vector;
 
@@ -40,7 +48,7 @@ void print_version()
 
 void print_help(const string_view &command)
 {
-    cerr << "Usage: " << command << " [--version] <profile>\n";
+    cerr << "Usage: " << command << " [--version|--help] <profile>\n";
 }
 } // namespace mastorss
 
@@ -48,6 +56,17 @@ int main(int argc, char *argv[])
 {
     const vector<string_view> args(argv, argv + argc);
 
+    if (getenv("MASTORSS_DEBUG") == nullptr)
+    {
+        boost::log::core::get()->set_filter
+            (boost::log::trivial::severity >= boost::log::trivial::info);
+    }
+    else
+    {
+        boost::log::core::get()->set_filter
+            (boost::log::trivial::severity >= boost::log::trivial::debug);
+    }
+
     if (args.size() == 1)
     {
         print_help(args[0]);