function install_required_packages()
% install_required_packages()
% Install packages required to build Techunited software
%
% Written by M. Briegel, Eindhoven, 2-Feb-2020

%% Parameters
required_packages = {
    'gcc-4.7';
    'g++-4.7';
    'libjson0';
    'libjson0-dev';
    'cmake';
    'flex;';
    'glade';
    'automake';
    'openssh-server';
    'libcv-dev';
    'libcvaux-dev';
    'libhighgui-dev';
    'ffmpeg';
    'libusb-1.0-0-dev';
    'bison';
    'valgrind';
    'ccache';
    'gconf-editor';
    'nfs-common';
    'zlib1g-dev';
    'openjdk-8-jre-headless';
    'libpng12-dev';
    'libjson0-dev';
    'gksu';
    'libsdl-image1.2';
    'cpufrequtils';
    'libssl-dev';
    'libxml2';
    'libxml2-dev'
};

%% Identify packages that need to be installed
missing_packages = {};
for idx = 1 : length(required_packages)
    package = required_packages{idx};
    % Check if packages is installed
    cmd = ['dpkg -l ', package];
    [ret, ~] = system(cmd);
    % If not add it to list of packages that need to be installed
    if ret ~= 0
        missing_packages = [missing_packages; package];
    end
end
% Give feedback to the user
if isempty(missing_packages)
    fprintf('All required packages are installed!\n');
    return;
else
    fprintf('The following packages need to be installed:\n');
    for idx = 1 : length(missing_packages)
        fprintf('- %s\n', missing_packages{idx});
    end
end

%% Install missing packages
% Ping Google DNS server to determine if we are connected to the internet
[ret, ~] = system('ping -c 1 -w 1 8.8.8.8');
if ret ~= 0
    fprintf('WARNING: No connection to the internet!\nCannot install all required packages! The build can possibly fail!\n');
    return;
end
% Update package database
[ret, output] = system('apt update');
if ret ~= 0
    fprintf('Error while updating apt database!\n%s\n\nWill not attempt to install missing packages!\n', output);
    return;
end
% Install missing packages
n_packages_installed = 0;
for idx = 1 : length(missing_packages)
    package = missing_packages{idx};
    cmd = ['apt -y install ', package];
    [ret, ~] = system(cmd);
    if ret ~= 0
        fprintf('Error while installing package ''%s''! Please try to install it manually!\n', package);
        continue;
    end
    n_packages_installed = n_packages_installed + 1;
end

%% Check if all packages were installed
if n_packages_installed == length(missing_packages)
    fprintf('All missing packages were installed successfully!\n');
else
    fprintf('The installation of %d packages failed (see output above)!\n', ...
        length(missing_packages) - n_packages_installed);
end
end