package DBI::Custom;

use Object::Simple;

our $VERSION = '0.0101';

use Carp 'croak';

use DBI;

# Model

sub prototype : ClassAttr { auto_build => \&_inherit_prototype }

# Inherit super class prototype

sub _inherit_prototype {

    my $class = shift;

    my $super = do {

        no strict 'refs';

        ${"${class}::ISA"}[0];

    };

    my $prototype = eval{$super->can('prototype')}

                         ? $super->prototype->clone

                         : $class->Object::Simple::new;

    $class->prototype($prototype);

}

# New

sub new {

    my $self = shift->Object::Simple::new(@_);

    my $class = ref $self;

    return bless {%{$class->prototype->clone}, %{$self}}, $class;

}

# Initialize class

sub initialize_class {

    my ($class, $callback) = @_;

    # Callback to initialize prototype

    $callback->($class->prototype);

}

# Clone

sub clone {

    my $self = shift;

    my $new = $self->Object::Simple::new;

    $new->connect_info(%{$self->connect_info || {}});

    $new->filters(%{$self->filters || {}});

    $new->bind_filter($self->bind_filter);

    $new->fetch_filter($self->fetch_filter);

    $new->result_class($self->result_class);

}

# Attribute

sub connect_info       : Attr { type => 'hash',  auto_build => sub { shift->connect_info({}) } }

sub bind_filter  : Attr {}

sub fetch_filter : Attr {}

sub filters : Attr { type => 'hash', deref => 1, auto_build => sub { shift->filters({}) } }

sub add_filter { shift->filters(@_) }

sub result_class : Attr { auto_build => sub { shift->result_class('DBI::Custom::Result') }}

sub dbh          : Attr {}

sub sql_template : Attr { auto_build => sub { shift->sql_template(DBI::Custom::SQL::Template->new) } }

# Auto commit

sub auto_commit {

    my $self = shift;

    croak("Cannot change AutoCommit becouse of not connected")

        unless $self->dbh;

    if (@_) {

        $self->dbh->{AutoCommit} = $_[0];

        return $self;

    }

    return $self->dbh->{AutoCommit};

}

our %VALID_CONNECT_INFO = map {$_ => 1} qw/data_source user password options/;

# Connect

sub connect {

    my $self = shift;

    my $connect_info = $self->connect_info;

    foreach my $key (keys %{$self->connect_info}) {

        croak("connect_info '$key' is wrong name")

          unless $VALID_CONNECT_INFO{$key};

    }

    my $dbh = DBI->connect(

        $connect_info->{data_source},

        $connect_info->{user},

        $connect_info->{password},

        {

            RaiseError => 1,

            PrintError => 0,

            AutoCommit => 1,

            %{$connect_info->{options} || {} }

        }

    );

    $self->dbh($dbh);

    return $self;

}

sub DESTROY {

    my $self = shift;

    $self->disconnect if $self->connected;

}

# Is connected?

sub connected {

    my $self = shift;

    return exists $self->{dbh} && eval {$self->{dbh}->can('prepare')};

}

# Disconnect

sub disconnect {

    my $self = shift;

    if ($self->connected) {

        $self->dbh->disconnect;

        delete $self->{dbh};

    }

}

# Reconnect

sub reconnect {

    my $self = shift;

    $self->disconnect if $self->connected;

    $self->connect;

}

# Commit

sub commit {

    my $self = shift;

    croak("Connection is not established") unless $self->connected;

    return $self->dbh->commit;

}

# Rollback

sub rollback {

    my $self = shift;

    croak("Connection is not established") unless $self->connected;

    return $self->dbh->rollback;

}

sub dbh_option {

    my $self = shift;

    croak("Not connected") unless $self->connected;

    my $dbh = $self->dbh;

    if (@_ > 1) {

        $dbh->{$_[0]} = $_[1];

        return $self;

    }

    return $dbh->{$_[0]}

}

# Create SQL from SQL template

sub create_sql {

    my $self = shift;

    my ($sql, @bind) = $self->sql_template->create_sql(@_);

    return ($sql, @bind);

}

# Prepare and execute SQL

sub query {

    my ($self, $template, $values, $filter)  = @_;

    my $sth_options;

    # Rearrange when argumets is hash referecne 

    if (ref $template eq 'HASH') {

        my $args = $template;

        ($template, $values, $filter, $sth_options)

          = @{$args}{qw/template values filter sth_options/};

    }

    $filter ||= $self->bind_filter;

    my ($sql, @bind) = $self->create_sql($template, $values, $filter);

    $self->connect unless $self->connected;

    my $sth = $self->dbh->prepare($sql);

    if ($sth_options) {

        foreach my $key (keys %$sth_options) {

            $sth->{$key} = $sth_options->{$key};

        }

    }

    # Execute

    my $ret_val = $sth->execute(@bind);

    # Return resultset if select statement is executed

    if ($sth->{NUM_OF_FIELDS}) {

        my $result_class = $self->result_class;

        my $result = $result_class->new({

            sth => $sth,

            fetch_filter => $self->fetch_filter

        });

        return $result;

    }

    return $ret_val;

}

# Prepare and execute raw SQL

sub query_raw_sql {

    my ($self, $sql, @bind_values) = @_;

    # Connect

    $self->connect unless $self->connected;

    # Add semicolon if not exist;

    $sql .= ';' unless $sql =~ /;$/;

    # Prepare

    my $sth = $self->dbh->prepare($sql);

    # Execute

    $sth->execute(@bind_values);

    return $sth;

}

Object::Simple->build_class;

package DBI::Custom::Result;

use Object::Simple;

# Attributes

sub sth          : Attr {}

sub fetch_filter : Attr {}

# Fetch (array)

sub fetch {

    my ($self, $type) = @_;

    my $sth = $self->sth;

    my $fetch_filter = $self->fetch_filter;

    # Fetch

    my $row = $sth->fetchrow_arrayref;

    # Cannot fetch

    return unless $row;

    # Filter

    if ($fetch_filter) {

        my $keys  = $sth->{NAME_lc};

        my $types = $sth->{TYPE};

        for (my $i = 0; $i < @$keys; $i++) {

            $row->[$i]= $fetch_filter->($keys->[$i], $row->[$i], $types->[$i],

                                        $sth, $i);

        }

    }

    return wantarray ? @$row : $row;

}

# Fetch (hash)

sub fetch_hash {

    my $self = shift;

    my $sth = $self->sth;

    my $fetch_filter = $self->fetch_filter;

    # Fetch

    my $row = $sth->fetchrow_arrayref;

    # Cannot fetch

    return unless $row;

    # Keys

    my $keys  = $sth->{NAME_lc};

    # Filter

    my $row_hash = {};

    if ($fetch_filter) {

        my $types = $sth->{TYPE};

        for (my $i = 0; $i < @$keys; $i++) {

            $row_hash->{$keys->[$i]} = $fetch_filter->($keys->[$i], $row->[$i],

                                                       $types->[$i], $sth, $i);

        }

    }

    # No filter

    else {

        for (my $i = 0; $i < @$keys; $i++) {

            $row_hash->{$keys->[$i]} = $row->[$i];

        }

    }

    return wantarray ? %$row_hash : $row_hash;

}

# Fetch all (array)

sub fetch_all {

    my $self = shift;

    my $rows = [];

    while(my @row = $self->fetch) {

        push @$rows, [@row];

    }

    return wantarray ? @$rows : $rows;

}

# Fetch all (hash)

sub fetch_all_hash {

    my $self = shift;

    my $rows = [];

    while(my %row = $self->fetch_hash) {

        push @$rows, {%row};

    }

    return wantarray ? @$rows : $rows;

}

# Finish

sub finish { shift->sth->finish }

# Error

sub error { 

    my $self = shift;

    my $sth  = $self->sth;

    wantarray ? ($sth->errstr, $sth->err, $sth->state) : $sth->errstr;

}

Object::Simple->build_class;

package DBI::Custom::SQL::Template;

use Object::Simple;

use Carp 'croak';

### Attributes;

sub tag_start   : Attr { default => '{' }

sub tag_end     : Attr { default => '}' }

sub template    : Attr {};

sub tree        : Attr { auto_build => sub { shift->tree([]) } }

sub bind_filter : Attr {}

sub values      : Attr {}

sub upper_case  : Attr {default => 0}

sub create_sql {

    my ($self, $template, $values, $filter)  = @_;

    $filter ||= $self->bind_filter;

    $self->parse($template);

    my ($sql, @bind) = $self->build_sql({bind_filter => $filter, values => $values});

    return ($sql, @bind);

}

our $TAG_SYNTAX = <<'EOS';

[tag]            [expand]

{? name}         ?

{= name}         name = ?

{<> name}        name <> ?

{< name}         name < ?

{> name}         name > ?

{>= name}        name >= ?

{<= name}        name <= ?

{like name}      name like ?

{in name}        name in [?, ?, ..]

{insert_values}  (key1, key2, key3) values (?, ?, ?)

{update_values}  set key1 = ?, key2 = ?, key3 = ?

EOS

our %VALID_TAG_NAMES = map {$_ => 1} qw/= <> < > >= <= like in insert_values update_set/;

sub parse {

    my ($self, $template) = @_;

    $self->template($template);

    # Clean start;

    delete $self->{tree};

    # Tags

    my $tag_start = quotemeta $self->tag_start;

    my $tag_end   = quotemeta $self->tag_end;

    # Tokenize

    my $state = 'text';

    # Save original template

    my $original_template = $template;

    # Text

    while ($template =~ s/([^$tag_start]*?)$tag_start([^$tag_end].*?)$tag_end//sm) {

        my $text = $1;

        my $tag  = $2;

        push @{$self->tree}, {type => 'text', args => [$text]} if $text;

        if ($tag) {

            my ($tag_name, @args) = split /\s+/, $tag;

            $tag ||= '';

            croak("Tag '$tag' in SQL template is not exist.\n\n" .

                  "SQL template tag syntax\n$TAG_SYNTAX\n\n" .

                  "Your SQL template is \n$original_template\n\n")

              unless $VALID_TAG_NAMES{$tag_name};

            push @{$self->tree}, {type => 'tag', tag_name => $tag_name, args => [@args]};

        }

    }

    push @{$self->tree}, {type => 'text', args => [$template]} if $template;

}

our %EXPAND_PLACE_HOLDER = map {$_ => 1} qw/= <> < > >= <= like/;

sub build_sql {

    my ($self, $args) = @_;

    my $tree        = $args->{tree} || $self->tree;

    my $bind_filter = $args->{bind_filter} || $self->bind_filter;

    my $values      = exists $args->{values} ? $args->{values} : $self->values;

    my @bind_values;

    my $sql = '';

    foreach my $node (@$tree) {

        my $type     = $node->{type};

        my $tag_name = $node->{tag_name};

        my $args     = $node->{args};

        if ($type eq 'text') {

            # Join text

            $sql .= $args->[0];

        }

        elsif ($type eq 'tag') {

            if ($EXPAND_PLACE_HOLDER{$tag_name}) {

                my $key = $args->[0];

                # Filter Value

                if ($bind_filter) {

                    push @bind_values, scalar $bind_filter->($key, $values->{$key});

                }

                else {

                    push @bind_values, $values->{$key};

                }

                $tag_name = uc $tag_name if $self->upper_case;

                my $place_holder = "$key $tag_name ?";

                $sql .= $place_holder;

            }

            elsif ($tag_name eq 'insert_values') {

                my $statement_keys          = '(';

                my $statement_place_holders = '(';

                $values = $values->{insert_values};

                foreach my $key (sort keys %$values) {

                    if ($bind_filter) {

                        push @bind_values, scalar $bind_filter->($key, $values->{$key});

                    }

                    else {

                        push @bind_values, $values->{$key};

                    }

                    $statement_keys          .= "$key, ";

                    $statement_place_holders .= "?, ";

                }

                $statement_keys =~ s/, $//;

                $statement_keys .= ')';

                $statement_place_holders =~ s/, $//;

                $statement_place_holders .= ')';

                $sql .= "$statement_keys values $statement_place_holders";

            }

            elsif ($tag_name eq 'update_set') {

                my $statement          = 'set ';

                $values = $values->{update_set};

                foreach my $key (sort keys %$values) {

                    if ($bind_filter) {

                        push @bind_values, scalar $bind_filter->($key, $values->{$key});

                    }

                    else {

                        push @bind_values, $values->{$key};

                    }

                    $statement          .= "$key = ?, ";

                }

                $statement =~ s/, $//;

                $sql .= $statement;

            }

        }

    }

    $sql .= ';' unless $sql =~ /;$/;

    return ($sql, @bind_values);

}

sub tag_processors : Attr {type => 'hash', deref => 1, auto_build => sub { 

    shift->tag_processors(

        '='    => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        '<>'   => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        '<'    => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        '>='   => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        '<='   => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        'like' => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder,

        'in'   => \&DBI::Custom::SQL::Template::TagProcessor::expand_place_holder

    );

}}

sub add_tag_processor {

}

Object::Simple->build_class;

package DBI::Custom::SQL::Template::TagProcessor;

sub expand_place_holder {

    my ($tag_name, $args, $values, $bind_filter, $sql_tmpl_obj) = @_;

    my $key = $args->[0];

    my @bind_values;

    # Filter Value

    if ($tag_name eq 'in') {

        $values->{$key} = [$values->{$key}] unless ref $values->{$key} eq 'ARRAY';

        if ($bind_filter) {

            for (my $i = 0; $i < @$values; $i++) {

                push @bind_values, scalar $bind_filter->($key, $values->{$key}->[$i]);

            }

        }

        else {

            for (my $i = 0; $i < @$values; $i++) {

                push @bind_values, $values->{$key}->[$i];

            }

        }

    }

    else {

        if ($bind_filter) {

            push @bind_values, scalar $bind_filter->($key, $values->{$key});

        }

        else {

            push @bind_values, $values->{$key};

        }

    }

    if ($bind_filter) {

        if ($tag_name eq 'in') {

            for (my $i = 0; $i < @$values; $i++) {

                push @bind_values, scalar $bind_filter->($key, $values->{$key}->[$i]);

            }

        }

        else {

            push @bind_values, scalar $bind_filter->($key, $values->{$key});

        }

    }

    else {

        push @bind_values, $values->{$key};

    }

    $tag_name = uc $tag_name if $sql_tmpl_obj->upper_case;

    my $expand;

    if ($tag_name eq '?') {

        $expand = '?';

    }

    elsif ($tag_name eq 'in') {

        $expand = '(';

        for (my $i = 0; $i < @$values; $i++) {

            $expand .= '?, ';

        }

        $expand =~ s/, $'//;

        $expand .= ')';

    }

    else {

        $expand = "$key $tag_name ?";

    }

    return ($expand, \@bind_values);

}

package DBI::Custom;

1;

=head1 NAME

DBI::Custom - Customizable simple DBI

=head1 VERSION

Version 0.0101

=cut

=head1 SYNOPSIS

  my $dbi = DBI::Custom->new;

=head1 METHODS

=head2 add_filter

=head2 bind_filter

=head2 clone

=head2 connect

=head2 connect_info

=head2 dbh

=head2 fetch_filter

=head2 filters

=head2 initialize_class

=head2 prototype

=head2 new

=head2 query

=head2 create_sql

=head2 query_raw_sql

=head2 sql_template

=head2 auto_commit

=head2 connected

=head2 dbh_option

=head2 disconnect

=head2 reconnect

=head2 result_class

=head2 commit

=head2 rollback

=head1 AUTHOR

Yuki Kimoto, C<< <kimoto.yuki at gmail.com> >>

=head1 COPYRIGHT & LICENSE

Copyright 2009 Yuki Kimoto, all rights reserved.

This program is free software; you can redistribute it and/or modify it

under the same terms as Perl itself.

=cut

1; # End of DBI::Custom