#!/bin/bash
#
# mkpatch: Simple patch program to .mkbuild models
# feedback: rudsonaalves at yahoo.com.br | gpl
#
#  mkbuild is free software; you can redistribute it and/or modify it under the
#  terms of the GNU General Public License as published by the Free Software
#  Foundation; either version 2 of the License, or any later version.
#
#  mkbuild is distributed in the hope that it will be useful, but WITHOUT ANY
#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
#  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License along with
#  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
#  Place - Suite 330, Boston, MA 02111-1307, USA
#
# Input:
#   - $1 Diff_File
#   - #2 Source_File
#
# Version:
PROG_VERSION=1.1
BASENAME=`basename $0`

function get_line {

    # get a line $1 from file $2
    [ $# -ne 2 ] && exit $ERROR_PAR_NUMBER
    ! is_number $1 && exit $ERROR_NOT_NUMBER
    [ ! -e $2 ] && exit $ERROR_FILE_NOTFOUND

    sed "$1 q;d" $2
}

function get_diff_line {

    # get diff line e return:
    #  - Action in Diff_Action
    #  - Diff Line in Diff_Str_Line
    if [ $1 -gt $Diff_N_Lines ]; then
        Diff_Action=" "
        Diff_Str_Line=""
        return 0
    fi
    Line=`get_line $1 $2`
    Diff_Action=`echo "$Line" | cut -c1`
    Diff_Str_Line=`echo "$Line" | cut -c2-`
}


# ----------------------------------------------------------------
# ------------------- mkpatch program ----------------------------
# common.sh library start
COMMON_SH="/usr/libexec/simplepkg/common.sh"
if [ -f "$COMMON_SH" ]; then
  source $COMMON_SH
else
  echo "$BASENAME: file $COMMON_SH not found. Check your $BASENAME installation"
fi

# Load error codes
error_codes
# ----------------

if [ "$1" = "--help" -o "$1" = "-h" ]; then
    echo "Use: $BASENAME <diff_file> <source_file>"
    exit $ERROR_HELP
fi

# Check input parameters
[ $# -ne 2 ] && exit $ERROR_PAR_NUMBER
[ ! -e $1 ] && exit $ERROR_FILE_NOTFOUND
[ ! -e $2 ] && exit $ERROR_FILE_NOTFOUND

# Start variables
Diff_File=$1
Source_File=$2
Diff_N_Lines=`wc -l $1 | cut -f1 -d" "`
Source_N_Lines=`wc -l $2 | cut -f1 -d" "`

# Start vars
Diff_Line=1
Diff_Pointer=1
Status_Diff=0

# Get frist Diff_File line
get_diff_line $Diff_Line $Diff_File || exit $?

Source_Line=1
# Get frist Source_File line
Source_Str_Line=`get_line $Source_Line $Source_File` || exit $?
while [ $Source_Line -le $Source_N_Lines ];  do
    # make Actions
    case $Diff_Action in
        '-')
            if [ "$Source_Str_Line" = "$Diff_Str_Line" ]; then
                Status_Diff=1
                let Diff_Line++
            else
                Diff_Line=$Diff_Pointer
                Status_Diff=0
                echo "$Source_Str_Line"
            fi
            get_diff_line $Diff_Line $Diff_File || exit $?
            let Source_Line++
            Source_Str_Line=`get_line $Source_Line $Source_File` || exit $?
        ;;
        '+')
            echo "$Diff_Str_Line"
            let Diff_Line++
            get_diff_line $Diff_Line $Diff_File || exit $?
        ;;
        ' ')
            if [ "$Source_Str_Line" = "$Diff_Str_Line" ]; then
                Status_Diff=1
                let Diff_Line++
            else
                Status_Diff=0
                Diff_Line=$Diff_Pointer
            fi
            echo "$Source_Str_Line"
            get_diff_line $Diff_Line $Diff_File || exit $?
            let Source_Line++
            Source_Str_Line=`get_line $Source_Line $Source_File` || exit $?
        ;;
        '=')
            let Diff_Line++
            Status_Diff=0
            Diff_Pointer=$Diff_Line
            get_diff_line $Diff_Line $Diff_File || exit $?
        ;;
        *)
            echo "Invalid diff action."
            exit $ERROR_MKPATCH
        ;;
    esac
done

# Make others addline "+" in the end file
while [ "$Diff_Action" = "+" -a $Diff_Line -le $Diff_N_Lines ]; do
    echo "$Diff_Str_Line"
    let Diff_Line++
    get_diff_line $Diff_Line $Diff_File || exit $?
done