From 8e71512f123bed8a99b0890a8a3f1541174fb59a Mon Sep 17 00:00:00 2001
From: Christian Burger <christian@krikkel.de>
Date: Wed, 13 Apr 2022 13:10:55 +0200
Subject: [PATCH] cmake: locate or build `libvterm` dependency

There is no version detection. If there is any vterm library, it is
used. If it is the wrong version, there will be an build error.
`libvterm.so.0.0.2` is preferred, which hopefully is compatible to
revision 740 or Ubuntu `libvterm0` version 0.1.2-2.

If no library is found, the correct one is downloaded and build.
---
 CMakeLists.txt       |  8 ++++++--
 cmake/gsl.cmake      |  2 ++
 cmake/libvterm.cmake | 21 +++++++++++++++++++++
 cmake/ncurses.cmake  |  2 ++
 4 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 cmake/libvterm.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e8be85d..37de1f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,3 +1,5 @@
+# @author Christian Burger <christian@krikkel.de>
+
 cmake_minimum_required(VERSION 3.16.3)
 project(NCursesPtyWindow VERSION 0.1.0)
 
@@ -6,15 +8,17 @@ set(CMAKE_CXX_STANDARD 17)
 include(CTest)
 enable_testing()
 
+include(ExternalProject)
 include("cmake/ncurses.cmake")
 include("cmake/gsl.cmake")
 
+add_library(NCursesPtyWindow NCursesPtyWindow.cpp SingleUserInput.cpp Debug.cpp)
 
 ### libraries
-find_library(LIBVTERM_LIBRARY vterm)
+
+include("cmake/libvterm.cmake")
 find_library(UTIL_LIBRARY util)
 
-add_library(NCursesPtyWindow NCursesPtyWindow.cpp SingleUserInput.cpp Debug.cpp)
 target_link_libraries(NCursesPtyWindow ${CURSES_LIBRARIES} ${LIBVTERM_LIBRARY} ${UTIL_LIBRARY})
 
 ### threads
diff --git a/cmake/gsl.cmake b/cmake/gsl.cmake
index f55f87b..dd4cd95 100644
--- a/cmake/gsl.cmake
+++ b/cmake/gsl.cmake
@@ -1,3 +1,5 @@
+# @author Christian Burger <christian@krikkel.de>
+
 find_path(GSL_INCLUDE_DIR "gsl")
 if(GSL_INCLUDE_DIR STREQUAL "GSL_INCLUDE_DIR-NOTFOUND")
     message(SEND_ERROR "Microsoft GSL not found.")
diff --git a/cmake/libvterm.cmake b/cmake/libvterm.cmake
new file mode 100644
index 0000000..95e6eb3
--- /dev/null
+++ b/cmake/libvterm.cmake
@@ -0,0 +1,21 @@
+# @author Christian Burger <christian@krikkel.de>
+# @brief searches for libvterm and builds it if not found
+#
+# requires NCursesPtyWindow target; provides LIBVTERM_LIBRARY
+
+find_library(LIBVTERM_LIBRARY NAMES libvterm.so.0.0.2 vterm)
+
+if(LIBVTERM_LIBRARY STREQUAL "LIBVTERM_LIBRARY-NOTFOUND")
+    message(STATUS "libvterm not found — building it")
+    ExternalProject_Add(
+        libvtermProject
+        DOWNLOAD_COMMAND URL "https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/libvterm/0.1.2-2/libvterm_0.1.2.orig.tar.gz"
+        CONFIGURE_COMMAND ""
+        BUILD_IN_SOURCE true
+        INSTALL_COMMAND ""
+    )
+    ExternalProject_Get_property(libvtermProject SOURCE_DIR)
+    set(LIBVTERM_LIBRARY "${SOURCE_DIR}/.libs/libvterm.a")
+    include_directories(SYSTEM "${SOURCE_DIR}/include")
+    add_dependencies(NCursesPtyWindow libvtermProject)
+endif()
diff --git a/cmake/ncurses.cmake b/cmake/ncurses.cmake
index 1069824..6643fa1 100644
--- a/cmake/ncurses.cmake
+++ b/cmake/ncurses.cmake
@@ -1,3 +1,5 @@
+# @author Christian Burger <christian@krikkel.de>
+
 ### ncurses
 set(CURSES_NEED_NCURSES TRUE)
 set(CURSES_NEED_WIDE TRUE)