#!/usr/bin/perl -w
# vim: set ft=perl:

# -------------------------------------------------------------------
# $Id: sqlt-diff,v 1.2 2004-01-25 18:16:57 kycl4rk Exp $
# -------------------------------------------------------------------
# Copyright (C) 2002 The SQLFairy Authors
#
# 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; version 2.
#
# 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; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
# 02111-1307  USA
# -------------------------------------------------------------------

=head1 NAME

sqlt-diff - find the differences b/w two schemas

=head1 SYNOPSIS

For help:

  sqlt-diff -h|--help

For a list of all valid parsers:

  sqlt -l|--list

To diff two schemas:

  sqlt-diff [options] file_name1=parser file_name2=parser

Options:

  -d|--debug   Show debugging info

=head1 DESCRIPTION

This script is part of the SQL Fairy project.  It will find the 
differences between two schemas.

=cut

# -------------------------------------------------------------------

use strict;
use Pod::Usage;
use Data::Dumper;
use SQL::Translator;

use vars qw( $VERSION );
$VERSION = sprintf "%d.%02d", q$Revision: 1.2 $ =~ /(\d+)\.(\d+)/;

my ( @input, $list, $help, $debug );
for my $arg ( @ARGV ) {
    if ( $arg =~ m/^-?-l(ist)?$/ ) {
        $list = 1;
    }
    elsif ( $arg =~ m/^-?-h(elp)?$/ ) {
        $help = 1;
    }
    elsif ( $arg =~ m/^-?-d(ebug)?$/ ) {
        $debug = 1; 
    }
    elsif ( $arg =~ m/^([^=]+)=(.+)$/ ) {
        push @input, { file => $1, parser => $2 };
    }
    else {
        pod2usage( msg => "Unknown argument '$arg'" );
    }
}

pod2usage(1) if $help;

my $tr            = SQL::Translator->new;
my @parsers       = $tr->list_parsers;
my %valid_parsers = map { $_, 1 } @parsers;

if ( $list ) {
    print "\nParsers:\n", map { "\t$_\n" } sort @parsers;
    print "\n";
    exit(0);
}

pod2usage( msg => 'Too many file args' ) if @input > 2;

my ( $schema1, $schema2 );
my $i = 1;
for my $in ( @input ) {
    my $file   = $in->{'file'};
    my $parser = $in->{'parser'};

    die "Unable to read file '$file'\n" unless -r $file;
    die "'$parser' is an invalid parser\n" unless $valid_parsers{ $parser };

    my $t = SQL::Translator->new;
    $t->debug( $debug );
    $t->parser( $parser )            or die $tr->error;
    $t->producer( 'YAML' )           or die $tr->error;
    my $out = $t->translate( $file ) or die $tr->error;
    my $schema = $t->schema;
    unless ( $schema->name ) {
        $schema->name( $file );
    }

    if ( $i == 1 ) {
        $schema1 = $schema;
    }
    else {
        $schema2 = $schema;
    }
    $i++;
}

#print "Schemas =\n", Dumper( \@schemas ), "\n" if $debug;

my @matrix = ( [ $schema1, $schema2 ], [ $schema2, $schema1 ] );

my @diffs;
for my $rec ( @matrix ) {
    my $s1      = $rec->[0];
    my $s2      = $rec->[1];
    my $s1_name = $s1->name;
    my $s2_name = $s2->name;
    print "Schema1 = '$s1_name', schema2 = '$s2_name'\n" if $debug;
    for my $t1 ( $s1->get_tables ) {
        my $t1_name = $t1->name;
        my $t2      = $s2->get_table( $t1_name );

        print "Checking '$s1_name' table '$t1_name'\n" if $debug;
        unless ( $t2 ) {
            push @diffs, "Schema '$s2_name' is missing table '$t1_name'";
            next;
        }

        my $t2_name = $t2->name;
        for my $t1_field ( $t1->get_fields ) {
            my $fname        = $t1_field->name;
            my $t2_field     = $t2->get_field( $fname );
            my $f1_full_name = "$s1_name.$t1_name.$fname";
            print "Checking '$f1_full_name'\n" if $debug;

            unless ( $t2_field ) {
                push @diffs, 
                    "Table '$s2_name.$t2_name' is missing field '$fname'";
                next;
            }

            my $f2_full_name = "$s2_name.$t2_name.$fname";
            my $t1_type      = $t1_field->data_type;
            my $t1_size      = $t1_field->size;
            my $t2_type      = $t2_field->data_type;
            my $t2_size      = $t2_field->size;

            if ( $t1_type ne $t2_type ) {
                push @diffs, "'$f1_full_name' type = '$t1_type' and ".
                    "'$f2_full_name' type = '$t2_type'";
            }

            if ( defined $t1_size && ( $t1_size ne $t2_size ) ) {
                push @diffs, "'$f1_full_name' size = '$t1_size' and ".
                    "'$f2_full_name' size = '$t2_size'";
            }
        }
    }
}

if ( @diffs ) {
    print "Diffs\n-----\n";
    print join( "\n", @diffs, '' );
}
else {
    print "There were no differences.\n";
}

# -------------------------------------------------------------------
# Bring out number weight & measure in a year of dearth.
# William Blake
# -------------------------------------------------------------------

=pod

=head1 AUTHOR

Ken Y. Clark E<lt>kclark@cpan.orgE<gt>.

=head1 SEE ALSO

SQL::Translator, L<http://sqlfairy.sourceforge.net>.

=cut