#!/bin/sh
#
#   Copyright (C) 2006 Jarosław Staniek <staniek@kde.org>
#
#   This program 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 (at your option) any later version.
#
#   This program 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; see the file COPYING.  If not, write to
#   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
#   Boston, MA 02110-1301, USA.
#

function usage {
	echo "This script adds a new empty column to a table in a .kexi (SQLite 3)
	database file without removing data from the table.

Usage:
 $0 database_name table_name new_column_name new_column_type 
    [new_column_caption]

- {database_name}.old backup file is created before proceeding
- database_name and table_name must exist
- new_column_name must not exist and should be valid idetifier
- new_column_type must be one of:
   Byte, ShortInteger, Integer, BigInteger, Boolean, Date, DateTime, Time,
   Float, Double, Text, LongText, BLOB (for images)
- new_column_caption can be any text; enclose it in \" \" if you want to use
   spaces there

Example: to append a column 'photo' of type BLOB to the table 'cars', type
 $0 db.kexi cars photo BLOB Photo"
}

function exit_with_error {
	rm -f "$temp_db"
	echo $*
	echo "Error."
	exit 1
}

function check {
	[ -n "$*" ] && exit_with_error "$*"
}

ksqlite="sqlite3 -noheader"

if [ $# -lt 4 ] ; then
	usage
	exit 0
fi
database_name=$1
table_name=$2
new_column_name=$3
new_column_type=$4
new_column_caption=$5

# get numeric value for the data type
case $new_column_type in
 Byte) typenum=1;;
 ShortInteger) typenum=2;;
 Integer) typenum=3;;
 BigInteger) typenum=4;;
 Boolean) typenum=5;;
 Date) typenum=6;;
 DateTime) typenum=7;;
 Time) typenum=8;;
 Float) typenum=9;;
 Double) typenum=10;;
 Text) typenum=11;;
 LongText) typenum=12;;
 BLOB) typenum=13;;
 *) echo "Unknown type name '$new_column_type'"; exit 1;;
esac

temp_db=`mktemp "$database_name"XXXXXXXX` || exit_with_error
cp "$database_name" "$temp_db" || exit_with_error
msg=`echo "DROP TABLE '$table_name';" | $ksqlite "$temp_db"`
check "$msg"

# 1. Recreate table with new field appended
msg=`echo ".schema '$table_name'" | $ksqlite "$database_name" | grep "^CREATE TABLE $table_name " | \
 sed -e "s/);/, $new_column_name $new_column_type);/g" | $ksqlite "$temp_db"`
check "$msg"

# 2.1. Get table's ID
table_id=`echo "SELECT o_id FROM kexi__objects WHERE o_type=1 AND o_name='$table_name';" | \
 $ksqlite "$temp_db" || exit_with_error`

# 2.2. Get the new field's order
order=`echo "SELECT MAX(f_order)+1 FROM kexi__fields WHERE t_id=$table_id;" | $ksqlite "$temp_db" || exit_with_error`

# 2.3. Add the new column information to kexi__fields metadata table
msg=`echo "INSERT INTO kexi__fields (t_id, f_type, f_name, f_length, f_precision, f_constraints, \
 f_options, f_default, f_order, f_caption, f_help) \
 VALUES ($table_id, $typenum, '$new_column_name', \
 0, 0, 0, 0, NULL, $order, '$new_column_caption', NULL);" | $ksqlite "$temp_db"`
check "$msg"

# 3. Copy the old data
msg=`echo ".dump '$table_name'" | $ksqlite "$database_name" | grep -v "^CREATE TABLE " | \
 sed -e "s/\(^INSERT.*\));$/\\1, NULL);/g" | $ksqlite "$temp_db"`
check "$msg"

# 4. Copy the original database file to .old file and replace the original with the new one
cp "$database_name" "$database_name.old" || exit_with_error
mv "$temp_db" "$database_name" || exit_with_error
