# This can probably be executed as a script instead of being run by hand,
# but odds are something is going wrong, so I wouldn't recommend it. :-)
# If this doesn't work for you, feel free to send corrections, but any
# issues here do not count as a bug.

# Create the directory
sudo mkdir /opt/qt-cross
sudo chown $USER /opt/qt-cross
chmod 0755 /opt/qt-cross

# Get MinGW
sudo apt install wine64 g++-mingw-w64
sudo update-alternatives --config x86_64-w64-mingw32-gcc  # choose posix
sudo update-alternatives --config x86_64-w64-mingw32-g++  # choose posix

# Build sqlite3
wget https://www.sqlite.org/2023/sqlite-autoconf-3420000.tar.gz
tar axvf sqlite-autoconf-3420000.tar.gz
cd sqlite-autoconf-3420000
./configure --host x86_64-w64-mingw32 --prefix /opt/qt-cross
make -j32
make install
cd ..

# Set up CMake cross-compiler file
cat <<'EOF' >/tmp/profile.cmake
set(CMAKE_SYSTEM_NAME Windows)
set(TOOLCHAIN_PREFIX x86_64-w64-mingw32)
set(CMAKE_C_COMPILER ${TOOLCHAIN_PREFIX}-gcc)
set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}-g++)
set(CMAKE_Fortran_COMPILER ${TOOLCHAIN_PREFIX}-gfortran)
set(CMAKE_RC_COMPILER ${TOOLCHAIN_PREFIX}-windres)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH /usr/x86_64-w64-mingw32)
EOF

# Build Qt (completely crazy)
sudo apt-get build-dep qt6-base
sudo apt install qt6-base-dev-tools
apt-get source qt6-base
cd qt6-base-6.4.2+dfsg
wget https://download.firedaemon.com/FireDaemon-OpenSSL/openssl-1.1.1u.zip
unzip openssl-1.1.1u.zip
mkdir src/3rdparty/sqlite/
cp ../sqlite-autoconf-3420000/sqlite3.[ch] src/3rdparty/sqlite/
./configure -prefix /opt/qt-cross -no-feature-sql-odbc -platform linux-g++-64 -qt-host-path /usr -xplatform win32-g++ -device-option CROSS_COMPILE=x86_64-w64-mingw32- -release -opengl desktop -nomake examples -no-icu -- -DQT_FORCE_BUILD_TOOLS=ON  -DCMAKE_TOOLCHAIN_FILE=/tmp/profile.cmake -DQt6HostInfo_DIR=/usr/lib/x86_64-linux-gnu/cmake/Qt6HostInfo -DOPENSSL_ROOT_DIR=`pwd`/openssl-1.1 -DFEATURE_vulkan=OFF -DFEATURE_tabletevent=OFF
ninja
ninja install
cd ..

# Various hacks to get Qt build tools to run properly under Meson
ln -s /usr/lib/qt6/libexec/uic /opt/qt-cross/bin/uic
cp /usr/lib/gcc/x86_64-w64-mingw32/12-posix/{libstdc++-6,libgcc_s_seh-1}.dll /opt/qt-cross/bin
cp /usr/x86_64-w64-mingw32/lib/libwinpthread-1.dll /opt/qt-cross/bin

# Build FFmpeg
git clone https://git.ffmpeg.org/ffmpeg.git
cd ffmpeg
./configure --prefix=/opt/qt-cross --disable-crystalhd --enable-cross-compile --disable-vaapi --disable-vdpau --target-os=mingw64 --cross-prefix=x86_64-w64-mingw32- --arch=x86_64
make -j32
make install
cd ..