#!/bin/bash

# Author:      wanlinwang
# Date  :      Nov 30, 2023
# Description: This script is to make newly added group(s) available in newly created gnome-terminal on CentOS 6.10. Run me once.

#################
# Update .cshrc.
CSHRC=~/.cshrc
if [ ! -f "$CSHRC" ]; then
    touch "$CSHRC"
fi
# The line to add if it doesn't exist
LINE="source ~/.flush_groups.csh"
if ! grep -Fxq "$LINE" "$CSHRC"; then
    # If the line doesn't exist, add it to the file
    echo "$LINE" >> "$CSHRC"
fi

# Add ~/.flush_groups.csh
cat > ~/.flush_groups.csh << 'EOF'
#!/bin/csh

# Writen by wanlinwang.
# Date: Dec 1, 2023
# Description: Dec 1, 2023：支持自动将新增群组刷新到新terminal中，对研发人员透明。提升研发人员效率，降低支持工作量。
#              Jan 24, 2024：去掉临时文件的读写，以子shell(bash)来替代，以提升性能。

if ( ! $?new_grp_array) then

    # 获取当前用户在当前session的主群组以及全部群组
    setenv primary_group  `id -gn`
    set    current_groups=`sh -c 'id -Gn 2> /dev/null' | tr ' ' '\n' | sort`
   
    # 获取当前用户最新的全部群组
    set login_groups=`sh -c 'id -Gn $USER 2> /dev/null' | tr ' ' '\n' | sort`
   
    # 使用comm比较临时变量的内容
    setenv new_grp_array `bash --noprofile -c "comm -13 <(echo $current_groups) <(echo $login_groups) | tr '\n' ' '"`
endif

# iterate new_grp_array
if ("$new_grp_array" != "") then
    set new_group=`echo $new_grp_array | awk '{print $1}'`
    setenv new_grp_array `echo $new_grp_array | awk '{$1=""; print $0}' | sed 's/^[ \t]*//'`

    if ("$new_group" != "") then
        # 切换群组，使其生效
        exec newgrp $new_group
    endif
else
    set current_group=`id -gn`
    if ( $?primary_group ) then
        if ( "$primary_group" != "$current_group" ) then
            exec newgrp $primary_group
        endif
    endif
    unset current_group
    unsetenv primary_group
endif

unsetenv new_grp_array
EOF
#################
# Update .bashrc.
BASHRC=~/.bashrc
if [ ! -f "$BASHRC" ]; then
    touch "$BASHRC"
fi
# The line to add if it doesn't exist
LINE="source ~/.flush_groups.sh"
if ! grep -Fxq "$LINE" "$BASHRC"; then
    # If the line doesn't exist, add it to the file
    echo "$LINE" >> "$BASHRC"
fi

# Add ~/.flush_groups.sh
cat > ~/.flush_groups.sh << 'EOF'
# Written by wanlinwang.
# Date: Dec 6, 2023
# Description: Automates the process of refreshing newly added groups in new terminal sessions.

# Check if new groups array exists
if [ -z "$new_grp_array" ]; then

    # Retrieve the current user's primary group and all groups in the current session
    primary_group=$(id -gn)
    current_groups=$(id -Gn 2>/dev/null| tr ' ' '\n' | sort)

    # Get the current user's latest complete group list
    login_groups=$(id -Gn $USER 2>/dev/null| tr ' ' '\n' | sort)

    # Compare file contents using 'comm'
    export new_grp_array=$(comm -13 <(echo $current_groups) <(echo $login_groups) | tr '\n' ' ')
fi

# Iterate over new_grp_array
if [ ! -z "$new_grp_array" ]; then
    new_group=$(echo $new_grp_array | awk '{print $1}')
    new_grp_array=$(echo $new_grp_array | awk '{$1=""; print $0}' | sed 's/^[ \t]*//')

    if [ ! -z "$new_group" ]; then
        # Switch to the new group to activate it
        exec newgrp $new_group
    fi
else
    current_group=$(id -gn)
    if [ -n "$primary_group" ]; then
        if [ "$primary_group" != "$current_group" ]; then
            exec newgrp $primary_group
        fi
    fi
    unset current_group
    unset primary_group
fi

unset new_grp_array
EOF

# Install krusader, a file manager. If you want to use this tool, please contact your system administrator to install.
sudo yum install epel-release
sudo yum localinstall http://rpms.plnet.rs/plnet-centos6-x86_64/RPMS.plnet-compiled/krusader-2.3.0-0.1.beta1.el6.x86_64.rpm