#!/bin/bash

set -e
#set -v

SUDO=""
if [ -f "/usr/bin/sudo" ]; then
    SUDO="/usr/bin/sudo"
fi
PKGMGR=""
if [ -f "/usr/bin/dnf" ]; then
    PKGMGR="/usr/bin/dnf"
elif [ -f "/usr/bin/yum" ]; then
    PKGMGR="/usr/bin/yum"
fi

# Function to get the distribution name from /etc/os-release
get_distro_name() {
    if [ -f /etc/os-release ]; then
        . /etc/os-release
        echo "$NAME"
    elif [ -f /etc/redhat-release ]; then
        # Older versions of CentOS might use /etc/redhat-release
        cat /etc/redhat-release
    else
        echo "Unknown"
    fi
}

OS=$(uname)
distro_name=""
distro_type=""

if [ "$OS" = "Linux" ]; then
    if [ "$PKGMGR" = "" ]; then
        echo "ERROR: No package manager found, dnf and yum don't exist!!!"
        exit 1
    fi

    distro_name=$(get_distro_name)
    distro_type="unknown"

    if [[ "$distro_name" == *"CentOS"* ]]; then
        echo "This is a CentOS system."
        distro_type="centos"
    elif [[ "$distro_name" == *"AlmaLinux"* ]]; then
        echo "This is an AlmaLinux system."
        distro_type="alma"
    else
        echo "This is a Linux system, but not CentOS or AlmaLinux."
    fi
fi

CPUS=
if [ "$OS" == "Linux" ]; then
    CPUS=$(nproc)
else
    CPUS=$(sysctl -n hw.ncpu)
fi

O0PENCV_VERSION=4.5.5
CMAKE=cmake
PREFIX=/opt/rsprobe

if [ "$OS" == "Linux" -a "$distro_type" = "centos" ]; then
    export CMAKE=cmake3
else
    if [ "$OS" == "Darwin" ]; then
        brew install cmake
    fi
    export CMAKE=cmake
fi

run_with_scl() {
    OS="$(uname -s)"
    if [ "$OS" == "Linux" -a "$distro_type" = "centos" ]; then
        scl enable devtoolset-11 llvm-toolset-7.0 -- "$@"
    else
        "$@"
    fi
}

# CMD LINE ARGS
if [ "$1" == "" ]; then
    if [ ! -d "build" ]; then
        mkdir -p build
    fi

    cd build
    echo "Building OpenCV"
else
    echo "Building OpenCV"
    PREFIX=$1
fi

## Install OpenCV with perceptual image hashing
if [ ! -d "opencv" ]; then
    git clone https://github.com/opencv/opencv.git
    git checkout $OPENCV_VERSION
fi
if [ ! -d "opencv_contrib" ]; then
    git clone https://github.com/opencv/opencv_contrib.git
    git checkout $OPENCV_VERSION
fi

if [ -d "opencv/build" ]; then
    rm -rf opencv/build # fresh build
    mkdir opencv/build
else
    mkdir opencv/build
fi

export GST_PLUGIN_PATH=$PREFIX/lib64/gstreamer-1.0
export LD_LIBRARY_PATH=$PREFIX/lib64:$PREFIX/lib:$LD_LIBRARY_PATH
export PATH=$PREFIX/bin:$PATH

# For pkg-config to find .pc files
export PKG_CONFIG_PATH=$PREFIX/lib64/pkgconfig:$PREFIX/lib/pkgconfig:$PKG_CONFIG_PATH

cd opencv/build

CMAKE_C_COMPILER_VAR=
CMAKE_CXX_COMPILER_VAR=
if [ "$OS" == "Linux" -a "$distro_type" = "centos" ]; then
     CMAKE_C_COMPILER_VAR=-DCMAKE_C_COMPILER=/opt/rh/llvm-toolset-7.0/root/usr/bin/clang
     CMAKE_CXX_COMPILER_VAR=-DCMAKE_CXX_COMPILER=/opt/rh/llvm-toolset-7.0/root/usr/bin/clang++
fi

run_with_scl $CMAKE \
    -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=$PREFIX \
    -D INSTALL_C_EXAMPLES=OFF \
    -D INSTALL_PYTHON_EXAMPLES=OFF \
    -DBUILD_opencv_core=ON \
    -DBUILD_opencv_imgproc=ON \
    -DBUILD_opencv_img_hash=ON \
    -DBUILD_opencv_imgcodecs=ON \
    -DBUILD_opencv_highgui=ON $CMAKE_C_COMPILER_VAR $CMAKE_CXX_COMPILER_VAR \
    -DWITH_TBB=ON \
    -DWITH_V4L=OFF \
    -DWITH_QT=OFF \
    -DWITH_OPENGL=ON \
    -DOPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules \
    -DWITH_GSTREAMER=OFF \
    -DWITH_FFMPEG=OFF \
    -DOPENCV_GENERATE_PKGCONFIG=ON \
    -DBUILD_EXAMPLES=OFF .. --log-level=ERROR

echo "Configured OpenCV"
run_with_scl make -j $CPUS --silent
echo "Built OpenCV"
make install --silent
echo "OpenCV installed to $PREFIX"