#!/usr/bin/env bash

# Author        : Allan Christensen
# First Created : 12-03-2001 (DD-MM-YYYY)
# Description   : Clears rotated logfiles and reports large unrotated logs in /var/log
# License       : MIT License

#
# Are we root
#
if [[ $(id -u) -ne 0 ]]; then echo "" && echo "Must be root or use sudo" && echo "" ; exit ; fi

#
# Safety controls
#

#
# Dry run mode
#
# true  = simulate deletions, nothing is removed
# false = real run (cron)
#
dryrun=true

#
# Extended rotated log cleanup
#
# Controls deletion of non-logrotate files like:
#   app.log.1234
#   installer-debug.log.9876
#
# false = report only (safe default)
# true  = delete during real runs (dryrun must also be false)
#
extended_cleanup=false

#
# Define variables
#
logdir="/var/log"

#
# Warning threshold for unrotated logs (megabytes)
#
warning=200

resultlog="/var/log/clear-log-files.log"

#
# Initialize log file
#
: > "$resultlog"
chmod 644 "$resultlog"

{
  echo "Clear logfiles run : $(date)"
  echo "Log Directory      : $logdir"
  echo "Warning threshold  : ${warning} MB"
  echo "Dry run            : $dryrun"
  echo "Extended cleanup   : $extended_cleanup"
  echo ""
} >> "$resultlog"

#
# Safety check
#
if [[ ! "$logdir" =~ ^/var/log(/|$) ]]; then
  echo "ERROR: Refusing to operate outside /var/log: $logdir" >> "$resultlog"
  exit 1
fi

#
# Pass 1 — classic rotated logs (logrotate style)
#
echo "Classic rotated log files:" >> "$resultlog"
found=false

while IFS= read -r file; do
  found=true
  if [[ "$dryrun" == true ]]; then
    echo "  $file (dry-run)" >> "$resultlog"
  else
    echo "  $file" >> "$resultlog"
    rm -f "$file"
  fi
done < <(
  find "$logdir" -type f \
    \( \
       -name "*.log.[1-9]" -o -name "*.log.[1-9][0-9]" \
    -o -name "*.log.[1-9].gz" -o -name "*.log.[1-9][0-9].gz" \
    -o -name "*.log.[1-9].xz" -o -name "*.log.[1-9][0-9].xz" \
    -o -name "*.log.[1-9].bz2" -o -name "*.log.[1-9][0-9].bz2" \
    -o -name "*.log.[1-9].zst" -o -name "*.log.[1-9][0-9].zst" \
    \
    -o -name "syslog.[1-9]" -o -name "syslog.[1-9][0-9]" \
    -o -name "syslog.[1-9].gz" -o -name "syslog.[1-9][0-9].gz" \
    -o -name "syslog.[1-9].xz" -o -name "syslog.[1-9][0-9].xz" \
    -o -name "syslog.[1-9].bz2" -o -name "syslog.[1-9][0-9].bz2" \
    -o -name "syslog.[1-9].zst" -o -name "syslog.[1-9][0-9].zst" \
    \) \
    ! -name "clear-log-files.log*" \
    2>/dev/null
)

[[ "$found" == false ]] && echo "  None" >> "$resultlog"
echo "" >> "$resultlog"

#
# Pass 2 — extended rotated logs (non-standard)
#
echo "Extended rotated log files:" >> "$resultlog"
found=false

while IFS= read -r file; do
  found=true
  if [[ "$dryrun" == true || "$extended_cleanup" == false ]]; then
    echo "  $file (reported only)" >> "$resultlog"
  else
    echo "  $file" >> "$resultlog"
    rm -f "$file"
  fi
done < <(
  find "$logdir" -type f \
    -name "*.log.*" \
    ! -name "*.log.[1-9]*" \
    ! -name "clear-log-files.log*" \
    2>/dev/null
)

[[ "$found" == false ]] && echo "  None" >> "$resultlog"
echo "" >> "$resultlog"

#
# Detect large unrotated logs
#
echo "Large unrotated log files detected:" >> "$resultlog"
found=false

while IFS= read -r file; do
  size_mb=$(( $(stat -c %s "$file") / 1024 / 1024 ))
  if (( size_mb >= warning )); then
    echo "  WARNING: $file (${size_mb} MB)" >> "$resultlog"
    found=true
  fi
done < <(
  find "$logdir" -type f \
    -name "*.log" \
    ! -name "clear-log-files.log" \
    2>/dev/null
)

[[ "$found" == false ]] && echo "  None" >> "$resultlog"
echo "" >> "$resultlog"

#
# End of script
#