#!/usr/bin/env bash

# ############################################################################
# Standard startup, find the branch's root directory
# ############################################################################

EXIT_STATUS=0

die() {
   echo $1  >&2
   exit 1
}

warn() {
   echo $1 >&2
   EXIT_STATUS=$((EXIT_STATUS | 1))
}

cwd="$PWD"
if [ -n "$PERCONA_TOOLKIT_BRANCH" ]; then
   BRANCH=$PERCONA_TOOLKIT_BRANCH
else
   while [ ! -f Makefile.PL ] && [ $(pwd) != "/" ]; do
      cd ..
   done
   if [ ! -f Makefile.PL ]; then
      die "Cannot find the root directory of the Percona Toolkit branch"
   fi
   BRANCH=`pwd`
fi
cd "$cwd"

# ############################################################################
# Global variables
# ############################################################################

# None

# ############################################################################
# Subroutines
# ############################################################################

pkgs_in_tool() {
   local tool=$1
   if [ "$tool_lang" = "perl" ]; then
      pkgs=$(grep '^package [A-Za-z:]*;' $tool | cut -d' ' -f2 | cut -d';' -f1)
   else
      pkgs=$(grep '^# [a-z_]* package' $tool | awk '{print $2}')
   fi
}

replace_pkg_in_tool() {
   local tool_file=$1
   local tmp_file="$tool_file.tmp"

   local pkg_start_line=$(grep -n "^# $pkg package" $tool_file | cut -d':' -f1)
   if [ -z "$pkg_start_line" ]; then
      warn "$tool does not use $pkg"
      return 1
   fi
   pkg_start_line=$((pkg_start_line - 1))

   local pkg_end_line=$(grep -n "^# End $pkg package" $tool_file | cut -d':' -f1)
   if [ -z "$pkg_end_line" ]; then
      warn "Cannot find 'End $pkg' in $tool"
      return 1
   fi
   pkg_end_line=$((pkg_end_line + 1))

   head -n $pkg_start_line $tool_file > $tmp_file

   if [ "$tool_lang" = "perl" ]; then
      echo "# $pkg package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the GitHub repository at,
#   lib/$pkg_file_base.pm
#   t/lib/$pkg_file_base.t
# See https://github.com/percona/percona-toolkit for more information.
# ###########################################################################
{" >> $tmp_file
   else
      echo "# $pkg package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the GitHub repository at,
#   lib/bash/$pkg.sh
#   t/lib/bash/$pkg.sh
# See https://github.com/percona/percona-toolkit for more information.
# ###########################################################################
" >> $tmp_file
   fi

   $BRANCH/util/extract-package $pkg $pkg_file | grep -v '^ *#' >> $tmp_file

   if [ "$tool_lang" = "perl" -a $pkg != "HTTP::Micro" ]; then
      echo "}" >> $tmp_file
   fi

echo "# ###########################################################################
# End $pkg package" >> $tmp_file

   tail -n +$pkg_end_line  $tool_file >> $tmp_file

   mv $tmp_file $tool_file
}

update_tool_header() {
   local tool_file=$1

   local start_line=$(grep -m 1 -n "^# ###" $tool_file | cut -d':' -f1)
   if [ -z "$start_line" ]; then
      warn "$tool_file does not have a package header line"
      return 1
   fi
   start_line=$((start_line - 1))

   tail -n +$start_line $tool_file > $tool_file-code
   $BRANCH/util/tool-header $tool_file > $tool_file-header
   if [ $? -ne 0 ]; then
      warn "Failed to update tool header for $tool_file"
      return 1
   fi
   cat $tool_file-header $tool_file-code > $tool_file
   [ $? -eq 0 ] && rm $tool_file-header $tool_file-code
}

# ############################################################################
# Script starts here
# ############################################################################

tool_file=$1

if [ -z "$tool_file" ]; then
   die "Usage: $0 TOOL [MODULES]"
fi

if [ ! -f $tool_file ]; then
   die "$tool_file does not exist"
fi

if [ -n "$(head -n 1 $tool_file | grep perl)" ]; then
   tool_lang="perl"
else
   tool_lang="bash"
fi

tool=$(basename $tool_file)
tmp_tool_file="/tmp/$tool.tmp";
cp $tool_file $tmp_tool_file

shift
pkgs="$@"
if [ -z "$pkgs" ]; then
   pkgs_in_tool $tool_file
fi

echo "Updating modules in $tool..."
pkgs_updated=0
for pkg in $pkgs; do
   if [ "$pkg" == "main" ]; then
      continue
   fi

   if [ "$tool_lang" = "perl" ]; then
      # Perl :: package separators translate to directory slashes.
      pkg_file="$BRANCH/lib/$pkg.pm"
      pkg_file=${pkg_file//"::"/"/"}
      pkg_file_base=${pkg//"::"/"/"}
   else
      pkg_file="$BRANCH/lib/bash/$pkg.sh"
   fi

   if [ ! -f $pkg_file ]; then
      warn "$pkg_file does not exist"
      continue
   fi

   replace_pkg_in_tool $tmp_tool_file
   if [ $? -eq 0 ]; then
      echo "Updated $pkg"
      pkgs_updated=$((pkgs_updated+1))
   fi
done

if [ $pkgs_updated -gt 0 ]; then
   if [ "$tool_lang" = "perl" ]; then
      update_tool_header $tmp_tool_file
      if [ $? -ne 0 ]; then
         warn "Failed to update tool header"
      fi
   fi
   if [ $EXIT_STATUS -eq 0 ]; then
      cp $tmp_tool_file $tool_file
      EXIT_STATUS=$((EXIT_STATUS | $?))
      if [ $? -ne 0 ]; then
         warn "Failed to copy $tmp_tool_file to $tool_file"
      fi
   fi
fi

[ -f "$tmp_tool_file" ] && rm $tmp_tool_file

exit $EXIT_STATUS