delete-old-git-branches

#!/bin/bash

#  This is an automated bash script to delete git branches older than some specific time period.
#  The default set time is 4 months, but you can pass the period in months as a first parameter while running the shell script

declare -l -r scriptName="delete-old-git-branches" # Set to lowers and read-only
declare -l -r logFileName="$scriptName-logs.txt" # Set to lowers and read-only
declare -i numberOfMonths # Declare the default period in months
declare blackListedBranches # Blacklisted branches
declare forceDeleteBranch=false # Force delete flag default value
declare -r numberExpression='^[0-9]+$' # Number expression
declare -l -r networktestURL="www.google.com" # Network test URL
declare -l -r gitRemoteURL="YOUR_REMOTE_OR_LOCAL_GIT_URL" # Remote git URL example 192.168.178.20
clear=clear # Command to clear terminal
ECHO='echo ' # Custom echo
${clear} # Clear terminal

# Set branches to exclude in deletion
blackListedBranches="main,master,development"


# Function to initiate logfile
function initLogFile(){
    cd ~ || exit # Change directory to users' home directory
    # Delete log file if/not it exists to prevent appending to previous logs
    rm -f $logFileName
    touch $logFileName # Creating log file
    currentDate="Date : `date`\n\n" # Get current date
    # Add script actions to script actions array
    scriptActions=( "${scriptActions[@]}" "Created log file" )
    # Log date without displaying on terminal
    printf $currentDate &>> $logFileName
}

# Function to hold terminal with simple terminal animation
function customAnimatedSleep(){

  local -r initialTime=`date +%s` # Get start time
  local -r characters=" //--\\|| "
  while :
  do
      local currentTime=`date +%s`
      for (( i=0; i<${#characters}; i++ ))
      do
          sleep .1
          echo -en "  ${characters:$i:1}" "\r"
      done
      difference=$((currentTime-initialTime))
      if [[ "$difference" -eq $1 ]]
      then
          break
      fi
  done
}

# Function to create a custom coloured print
function customEcho(){
    RED="\033[0;31m"    # 31 - red    : "\e[1;31m$1\e[0m"
    GREEN="\033[0;32m"  # 32 - green  : "\e[1;32m$1\e[0m"
    YELLOW="\033[1;33m" # 33 - yellow : "\e[1;33m$1\e[0m"
    BLUE="\033[1;34m"   # 34 - blue   : "\e[1;34m$1\e[0m"
    PURPLE="\033[1;35m" # 35 - purple : "\e[1;35m$1\e[0m"
    NC="\033[0m"        # No Color    : "\e[0m$1\e[0m"
    # Display coloured text setting its background color to black
    printf "\e[48;5;0m${!1}\n ${2} ${NC}\n" || exit
}

# Function to display connection established message
function connectionEstablishedMessage(){
  # Check first parameter
  if [[ "$1" = "--network" ]]; 
  then
    customEcho "GREEN" "Internet connection established.\n" |& tee -a $logFileName
  elif [[ "$1" = "--git-remote" ]]; 
  then
    customEcho "GREEN" "Remote url connection established.\n" |& tee -a $logFileName
  fi
    customAnimatedSleep 2 # Hold for user to read
}

# Function to display connection failed message
function connectionFailedMessage(){

  # Check first parameter
  if [[ "$1" = "--network" ]]; 
  then
    customEcho "RED" "Internet connection failed!!!" |& tee -a $logFileName
  elif [[ "$1" = "--git-remote" ]]; 
  then
    customEcho "RED" "Cannot connect to git remote url : [$gitRemoteURL] !!!" |& tee -a $logFileName
  fi

  customAnimatedSleep 2 # Hold 
}

# Function to check for internet connection and validate security on connection
function isConnected(){

  ${clear} # Clear terminal

  # Creating integer variable
  local -i loopcount=0 # Declare loop count variable
  local -i -r retryCount=4 # Declare and set number of retries to read-only
  local -i -r maxRetry=$[retryCount + 1] # Declare and set max retry to read-only
  local -i -r countDownTime=30 # Declare and set retry to read-only

  while :
  do # Starting infinite loop
      
      ${clear} # Clear terminal
      
      local url;
      local isInternetConnectionCheck=false

      # Check first parameter
      if [[ "$1" = "--network" ]]; 
      then
        url="$networktestURL"
        isInternetConnectionCheck=true
      elif [[ "$1" = "--git-remote" ]]; 
      then
        url="$gitRemoteURL"
        isInternetConnectionCheck=false
      fi

      customEcho "YELLOW" "\nChecking for internet connection ($1) !!" |& tee -a $logFileName
      if `nc -zw1 $url 443` && echo |openssl s_client -connect $url:443 2>&1 |awk '
        handshake && $1 == "Verification" { if ($2=="OK") exit; exit 1 }
        $1 $2 == "SSLhandshake" { handshake = 1 }'
      then # Internet connection established
        connectionEstablishedMessage $1 # Display connection established message
        return $(true) # Exit loop returning true
      else

        connectionFailedMessage $1 # Display connection failed message

        # Check first parameter
        if [[ "$isInternetConnectionCheck" = true ]]; 
        then

          # Start count to re-try connection
          if [ "$loopcount" == 0 ];
          then
              customEcho "YELLOW" "Attemting re-connection...\n Max number of retries : \e[0m$maxRetry\e[0m\n" |& tee -a $logFileName
          fi
          
          # Check for max number of retries
          if [ "$loopcount" -gt "$retryCount" ];
          then
              customEcho "YELLOW" "Number of retries: $loopcount" |& tee -a $logFileName # Display number of retries
              return $(false) # Exit loop returning false
          else
              loopcount=$[loopcount + 1] # Increment loop counter variable

              # Run countdown
              date1=$((`date +%s` + $countDownTime))
              while [ "$date1" -ge "$(date +%s)" ];
              do
                echo -ne " \e[1;32mRetrying connection after :\e[0m \e[1;33m$(date -u --date @$(($date1 - `date +%s`)) +%H:%M:%S)\r\e[0m" |& tee -a $logFileName
                sleep 0.1
              done
          fi 
        elif [[ "$isInternetConnectionCheck" = false ]]; 
        then
          connectionFailedMessage "--git-remote" # Display internet connection failed message
          return $(false) # Exit loop returning true
        fi  
      fi  
      

      customAnimatedSleep 2 # Hold loop
  done
}



: ' 
  Start of script
'
initLogFile # Create log file

# Check if first parameter is not empty
if [ ! -z "$1" ];
then
  # Check for set force delete branch command
  if [[ "$1" = "-f" ]]; 
  then
    forceDeleteBranch=true # Set force delete to true
  elif [[ $1 =~ $numberExpression ]]; # Check first parameter is a number
  then # First choice is a number
    numberOfMonths=$1 # Set passed period
  fi
fi

# Check if second parameter is not empty
if [ ! -z "$2" ];
then
  # Check if second parameter is a number expressions
  if [[ $2 =~ $numberExpression ]];  
  then
    numberOfMonths=$2 # Set passed period
  else
    # Second parameter should only be a digit assuming force flag was 
    # passed as first and not viceversa
    ${clear} # Clear terminal
    customEcho "RED" "\nSecond parameter should be a digit(time in months)\n assuming -f(force delete) was passed as first parameter!\n" |& tee -a $logFileName
    exit # Exit script
  fi
fi

# Check if both first and second parameters are empty
if [[ -z $1 && -z $2  ]]
then # Both first and second parameters not set
    customEcho "GREEN" "\nPeriod not set. Assuming delete period to the default $numberOfMonths months period!\n" |& tee -a $logFileName
    customAnimatedSleep 4 # Hold   
    numberOfMonths=4 # Set default period
fi

# Check for internet connection
if isConnected "--network"
then

  # Check if endpoint exists or is up
  if isConnected "--git-remote"
  then

    ${clear} # Clear terminal
    customEcho "RED" "\nDeleting branches older than $numberOfMonths months!\n" |& tee -a $logFileName
    customAnimatedSleep 2 # Hold 

    # Check for trailing commas to remove them
    if [[ "$blackListedBranches" == *, ]]; 
    then
      declare trimmedValue
      trimmedValue=$(sed 's/.\{1\}$//' <<< "$blackListedBranches") # Remove last character
      blackListedBranches="$trimmedValue" # Re-assign value
    fi

    # Start loop to search for commas
    while true
    do
      # Switch case to check for commas in case of comma separated list to 
      # create a list for GREP
      case "$blackListedBranches" in 
        *,*)
          declare branchSeparator="$\|" # Declare separator syntax
          blackListedBranches=${blackListedBranches/,/$branchSeparator} # Replace comma with GREP separator syntax
          ;;
        *) # Default
          break # Break loop
        ;;
      esac
    done

    blackListedBranches="${blackListedBranches}$" # Append dollar sign at the end of GREP list

    customEcho "YELLOW" "\nThe branches [ $blackListedBranches ] will not be deleted!\n" |& tee -a $logFileName
    customAnimatedSleep 4 # Hold 

    
    # Fetch branches
    customEcho "YELLOW" "\nFetching branches!\n"
    customAnimatedSleep 2 # Hold 
    git fetch
    git fetch -a

    : '
      Initiate loop scanning for branches older than passed time or set default while excluding the below branches
      main, master
    '
    for target_branch in $(git branch -a | sed 's/^\s*//' | sed 's/^remotes\///' | grep -v $blackListedBranches); 
    do
      # Check period
      if ! ( [[ -f "$target_branch" ]] || [[ -d "$target_branch" ]] ) && [[ "$(git log $target_branch --since "$numberOfMonths month ago" | wc -l)" -eq 0 ]];
      then
        if [[ "$DRY_RUN" = "false" ]]; 
        then
          ECHO="" # Empty echo
        fi

        local_target_branch_name=$(echo "$target_branch" | sed 's/remotes\/origin\///') # Get target branch in iteration
        local_target_branch_name=${local_target_branch_name/origin\//} # Replace string "origin/" with empty(string)
       
        customEcho "YELLOW" "Deleting Local Branch : $local_target_branch_name\n" |& tee -a $logFileName # Print message
        customAnimatedSleep 1 # Hold
        
        # Check for force delete value
        if [[ "$forceDeleteBranch" = "false" ]]
        then
          git branch -d "${local_target_branch_name}" # Delete local branch
        elif [[ "$forceDeleteBranch" = "true" ]]
        then
          git branch -D "${local_target_branch_name}" # Force elete local branch
        fi

        customEcho "GREEN" "\n---------------------------------\n" |& tee -a $logFileName

        customEcho "YELLOW" "Deleting Remote Branch : $local_target_branch_name\n" |& tee -a $logFileName # Print message
        customAnimatedSleep 2 # Hold 
        git push origin --delete "${local_target_branch_name}" # Delete remote branch

        customEcho "GREEN" "\n---------------------------------\n" |& tee -a $logFileName
      fi
    done
  else
    customEcho "RED" "\nHalting script execution!\n" |& tee -a $logFileName
    customAnimatedSleep 2 # Hold 
    exit # Exit script
  fi
else 
  customEcho "RED" "\nCannot establish internet connection!\n" |& tee -a $logFileName
  customAnimatedSleep 2 # Hold 
  exit # Exit script
fi