#!/usr/bin/perl

# $Id$

# Database Updater
# This script checks for required updates to the database.

# Part of the Koha Library Software www.koha.org
# Licensed under the GPL.

# Bugs/ToDo:
# - Would also be a good idea to offer to do a backup at this time...

# NOTE:  If you do something more than once in here, make it table driven.
use strict;

# CPAN modules
use DBI;
use Getopt::Long;
# Koha modules
use C4::Context;

# FIXME - The user might be installing a new database, so can't rely
# on /etc/koha.conf anyway.

my $debug = 0;

my (
    $sth, $sti,
    $query,
    %existingtables,    # tables already in database
    %types,
    $table,
    $column,
    $type, $null, $key, $default, $extra,
    $prefitem,          # preference item in systempreferences table
);

my $silent;
GetOptions(
	's' =>\$silent
	);
my $dbh = C4::Context->dbh;
print "connected to your DB. Checking & modifying it\n" unless $silent;

#-------------------
# Defines

# Tables to add if they don't exist
my %requiretables = (
    categorytable       => "(categorycode char(5) NOT NULL default '',
                             description text default '',
                             itemtypecodes text default '',
                             PRIMARY KEY (categorycode)
                            )",
    subcategorytable       => "(subcategorycode char(5) NOT NULL default '',
                             description text default '',
                             itemtypecodes text default '',
                             PRIMARY KEY (subcategorycode)
                            )",
    mediatypetable       => "(mediatypecode char(5) NOT NULL default '',
                             description text default '',
                             itemtypecodes text default '',
                             PRIMARY KEY (mediatypecode)
                            )",
    action_logs 	=> "(
				    `timestamp` TIMESTAMP NOT NULL ,
				    `user` INT( 11 ) NOT NULL ,
				    `module` TEXT default '',
				    `action` TEXT default '' ,
				    `object` INT(11) default '' ,
				    `info` TEXT default '' ,
				    PRIMARY KEY ( `timestamp` , `user` )
			    )",
	letter		=> "(
					module varchar(20) NOT NULL default '',
					code varchar(20) NOT NULL default '',
					name varchar(100) NOT NULL default '',
					title varchar(200) NOT NULL default '',
					content text,
					PRIMARY KEY  (module,code)
				)",
	alert		=>"(
					alertid int(11) NOT NULL auto_increment,
					borrowernumber int(11) NOT NULL default '0',
					type varchar(10) NOT NULL default '',
					externalid varchar(20) NOT NULL default '',
					PRIMARY KEY  (alertid),
					KEY borrowernumber (borrowernumber),
					KEY type (type,externalid)
				)",

);

my %requirefields = (
	subscription => { 'letter' => 'char(20) NULL'},
#    tablename        => { 'field' => 'fieldtype' },
);

my %dropable_table = (
# tablename => 'tablename',
);

my %uselessfields = (
# tablename => "field1,field2",
	);
# the other hash contains other actions that can't be done elsewhere. they are done
# either BEFORE of AFTER everything else, depending on "when" entry (default => AFTER)

# The tabledata hash contains data that should be in the tables.
# The uniquefieldrequired hash entry is used to determine which (if any) fields
# must not exist in the table for this row to be inserted.  If the
# uniquefieldrequired entry is already in the table, the existing data is not
# modified, unless the forceupdate hash entry is also set.  Fields in the
# anonymous "forceupdate" hash will be forced to be updated to the default
# values given in the %tabledata hash.

my %tabledata = (
# tablename => [
#	{	uniquefielrequired => 'fieldname', # the primary key in the table
#		fieldname => fieldvalue,
#		fieldname2 => fieldvalue2,
#	},
# ],
    systempreferences => [
		{
            uniquefieldrequired => 'variable',
            variable            => 'Activate_Log',
            value               => 'On',
	    forceupdate		=> { 'explanation' => 1,
	    			     'type' => 1},
            explanation         => 'Turn Log Actions on DB On an Off',
	    type		=> 'YesNo',
        },
        {
            uniquefieldrequired => 'variable',
            variable            => 'IndependantBranches',
            value               => 0,
	    forceupdate		=> { 'explanation' => 1,
	    			     'type' => 1},
            explanation         => 'Turn Branch independancy management On an Off',
	    type		=> 'YesNo',
        },
		{
            uniquefieldrequired => 'variable',
            variable            => 'ReturnBeforeExpiry',
            value               => 'Off',
	    forceupdate		=> { 'explanation' => 1,
	    			     'type' => 1},
            explanation         => 'If Yes, Returndate on issuing can\'t be after borrower card expiry',
	    type		=> 'YesNo',
        },
    ],

);

my %fielddefinitions = (
# fieldname => [
#	{		  field => 'fieldname',
#             type    => 'fieldtype',
#             null    => '',
#             key     => '',
#             default => ''
#         },
#     ],
);

#-------------------
# Initialize

# Start checking

# Get version of MySQL database engine.
my $mysqlversion = `mysqld --version`;
$mysqlversion =~ /Ver (\S*) /;
$mysqlversion = $1;
if ( $mysqlversion ge '3.23' ) {
    print "Could convert to MyISAM database tables...\n" unless $silent;
}

#---------------------------------
# Tables

# Collect all tables into a list
$sth = $dbh->prepare("show tables");
$sth->execute;
while ( my ($table) = $sth->fetchrow ) {
    $existingtables{$table} = 1;
}


# Now add any missing tables
foreach $table ( keys %requiretables ) {
    unless ( $existingtables{$table} ) {
	print "Adding $table table...\n" unless $silent;
        my $sth = $dbh->prepare("create table $table $requiretables{$table}");
        $sth->execute;
        if ( $sth->err ) {
            print "Error : $sth->errstr \n";
            $sth->finish;
        }    # if error
    }    # unless exists
}    # foreach

# now drop useless tables
foreach $table ( keys %dropable_table ) {
	if ( $existingtables{$table} ) {
		print "Dropping unused table $table\n" if $debug and not $silent;
		$dbh->do("drop table $table");
		if ( $dbh->err ) {
			print "Error : $dbh->errstr \n";
		}
	}
}

#---------------------------------
# Columns

foreach $table ( keys %requirefields ) {
    print "Check table $table\n" if $debug and not $silent;
    $sth = $dbh->prepare("show columns from $table");
    $sth->execute();
    undef %types;
    while ( ( $column, $type, $null, $key, $default, $extra ) = $sth->fetchrow )
    {
        $types{$column} = $type;
    }    # while
    foreach $column ( keys %{ $requirefields{$table} } ) {
        print "  Check column $column  [$types{$column}]\n" if $debug and not $silent;
        if ( !$types{$column} ) {

            # column doesn't exist
            print "Adding $column field to $table table...\n" unless $silent;
            $query = "alter table $table
			add column $column " . $requirefields{$table}->{$column};
            print "Execute: $query\n" if $debug;
            my $sti = $dbh->prepare($query);
            $sti->execute;
            if ( $sti->err ) {
                print "**Error : $sti->errstr \n";
                $sti->finish;
            }    # if error
        }    # if column
    }    # foreach column
}    # foreach table

foreach $table ( keys %fielddefinitions ) {
	print "Check table $table\n" if $debug;
	$sth = $dbh->prepare("show columns from $table");
	$sth->execute();
	my $definitions;
	while ( ( $column, $type, $null, $key, $default, $extra ) = $sth->fetchrow )
	{
		$definitions->{$column}->{type}    = $type;
		$definitions->{$column}->{null}    = $null;
		$definitions->{$column}->{key}     = $key;
		$definitions->{$column}->{default} = $default;
		$definitions->{$column}->{extra}   = $extra;
	}    # while
	my $fieldrow = $fielddefinitions{$table};
	foreach my $row (@$fieldrow) {
		my $field   = $row->{field};
		my $type    = $row->{type};
		my $null    = $row->{null};
		my $key     = $row->{key};
		my $default = $row->{default};
		$default="''" unless $default;
		my $extra   = $row->{extra};
		my $def     = $definitions->{$field};
		unless ( $type eq $def->{type}
			&& $null eq $def->{null}
			&& $key eq $def->{key}
			&& $default eq $def->{default}
			&& $extra eq $def->{extra} )
		{

			if ( $null eq '' ) {
				$null = 'NOT NULL';
			}
			if ( $key eq 'PRI' ) {
				$key = 'PRIMARY KEY';
			}
			unless ( $extra eq 'auto_increment' ) {
				$extra = '';
			}
			# if it's a new column use "add", if it's an old one, use "change".
			my $action;
			if ($definitions->{$field}->{type}) {
				$action="change $field"
			} else {
				$action="add";
			}
# if it's a primary key, drop the previous pk, before altering the table
			my $sth;
			if ($key ne 'PRIMARY KEY') {
				$sth =$dbh->prepare("alter table $table $action $field $type $null $key $extra default ?");
			} else {
				$sth =$dbh->prepare("alter table $table drop primary key, $action $field $type $null $key $extra default ?");
			}
			$sth->execute($default);
			print "  Alter $field in $table\n" unless $silent;
		}
	}
}


# Populate tables with required data
foreach my $table ( keys %tabledata ) {
    print "Checking for data required in table $table...\n" unless $silent;
    my $tablerows = $tabledata{$table};
    foreach my $row (@$tablerows) {
        my $uniquefieldrequired = $row->{uniquefieldrequired};
        my $uniquevalue         = $row->{$uniquefieldrequired};
        my $forceupdate         = $row->{forceupdate};
        my $sth                 =
          $dbh->prepare(
"select $uniquefieldrequired from $table where $uniquefieldrequired=?"
        );
        $sth->execute($uniquevalue);
	if ($sth->rows) {
	    foreach my $field (keys %$forceupdate) {
		if ($forceupdate->{$field}) {
		    my $sth=$dbh->prepare("update systempreferences set $field=? where $uniquefieldrequired=?");
		    $sth->execute($row->{$field}, $uniquevalue);
		}
	    }
	} else {
            print "Adding row to $table: " unless $silent;
            my @values;
            my $fieldlist;
            my $placeholders;
            foreach my $field ( keys %$row ) {
                next if $field eq 'uniquefieldrequired';
		next if $field eq 'forceupdate';
                my $value = $row->{$field};
                push @values, $value;
                print "  $field => $value" unless $silent;
                $fieldlist .= "$field,";
                $placeholders .= "?,";
            }
            print "\n" unless $silent;
            $fieldlist    =~ s/,$//;
            $placeholders =~ s/,$//;
            my $sth =
              $dbh->prepare(
                "insert into $table ($fieldlist) values ($placeholders)");
            $sth->execute(@values);
        }
    }
}

# at last, remove useless fields
foreach $table ( keys %uselessfields ) {
	my @fields = split /,/,$uselessfields{$table};
	my $fields;
	my $exists;
	foreach my $fieldtodrop (@fields) {
		$fieldtodrop =~ s/\t//g;
		$fieldtodrop =~ s/\n//g;
		$exists =0;
		$sth = $dbh->prepare("show columns from $table");
		$sth->execute;
		while ( my ( $column, $type, $null, $key, $default, $extra ) = $sth->fetchrow )
		{
			$exists =1 if ($column eq $fieldtodrop);
		}
		if ($exists) {
			print "deleting $fieldtodrop field in $table...\n" unless $silent;
			my $sth = $dbh->prepare("alter table $table drop $fieldtodrop");
			$sth->execute;
		}
	}
}    # foreach


$sth->finish;

exit;

# $Log$
# Revision 1.119  2005/08/04 16:07:58  tipaul
# Synch really broke this script...
#
# Revision 1.118  2005/08/04 16:02:55  tipaul
# oops... error in synch between 2.2 and head
#
# Revision 1.117  2005/08/04 14:24:39  tipaul
# synch'ing 2.2 and head
#
# Revision 1.116  2005/08/04 08:55:54  tipaul
# Letters / alert system, continuing...
#
# * adding a package Letters.pm, that manages Letters & alerts.
# * adding feature : it's now possible to define a "letter" for any subscription created. If a letter is defined, users in OPAC can put an alert on the subscription. When an issue is marked "arrived", all users in the alert will recieve a mail (as defined in the "letter"). This last part (= send the mail) is not yet developped. (Should be done this week)
# * adding feature : it's now possible to "put to an alert" in OPAC, for any serial subscription. The alert is stored in a new table, called alert. An alert can be put only if the librarian has activated them in subscription (and they activate it just by choosing a "letter" to sent to borrowers on new issues)
# * adding feature : librarian can see in borrower detail which alerts they have put, and a user can see in opac-detail which alert they have put too.
#
# Note that the system should be generic enough to manage any type of alert.
# I plan to extend it soon to virtual shelves : a borrower will be able to put an alert on a virtual shelf, to be warned when something is changed in the virtual shelf (mail being sent once a day by cron, or manually by the shelf owner. Anyway, a mail won't be sent on every change, users would be spammed by Koha ;-) )
#
# Revision 1.115  2005/08/02 16:15:34  tipaul
# adding 2 fields to letter system :
# * module (acquisition, catalogue...) : it will be usefull to show the librarian only letters he may be interested by.
# * title, that will be used as mail subject.
#
# Revision 1.114  2005/07/28 15:10:13  tipaul
# Introducing new "Letters" system : Letters will be used everytime you want to sent something to someone (through mail or paper). For example, sending a mail for overdues use letter that you can put as parameters. Sending a mail to a borrower when a suggestion is validated uses a letter too.
# the letter table contains 3 fields :
# * code => the code of the letter
# * name => the complete name of the letter
# * content => the complete text. It's a TEXT field type, so has no limits.
#
# My next goal now is to work on point 2-I "serial issue alert"
# With this feature, in serials, a user can subscribe the "issue alert". For every issue arrived/missing, a mail is sent to all subscribers of this list. The mail warns the user that the issue is arrive or missing. Will be in head.
# (see mail on koha-devel, 2005/04/07)
#
# The "serial issue alert" will be the 1st to use this letter system that probably needs some tweaking ;-)
#
# Once it will be stabilised default letters (in any languages) could be added during installer to help the library begin with this new feature.
#
# Revision 1.113  2005/07/28 08:38:41  tipaul
# For instance, the return date does not rely on the borrower expiration date. A systempref will be added in Koha, to modify return date calculation schema :
# * ReturnBeforeExpiry = yes => return date can't be after expiry date
# * ReturnBeforeExpiry = no  => return date can be after expiry date
#
# Revision 1.112  2005/07/26 08:19:47  hdl
# Adding IndependantBranches System preference variable in order to manage Branch independancy.
#
# Revision 1.111  2005/07/25 15:35:38  tipaul
# we have decided that moving to Koha 3.0 requires being already in Koha 2.2.x
# So, the updatedatabase script can highly be cleaned (90% removed).
# Let's play with the new Koha DB structure now ;-)
#