package DBIx::Custom;

use strict;

use warnings;

use base 'Object::Simple';

use Carp 'croak';

use DBI;

use DBIx::Custom::Result;

use DBIx::Custom::SQLTemplate;

use DBIx::Custom::Query;

use Encode qw/encode_utf8 decode_utf8/;

__PACKAGE__->attr('dbh');

__PACKAGE__->attr([qw/user password data_source/]);

__PACKAGE__->attr([qw/default_query_filter default_fetch_filter/]);

__PACKAGE__->dual_attr('filters', default => sub { {} },

                                  inherit => 'hash_copy');

__PACKAGE__->register_filter(

    encode_utf8 => sub { encode_utf8($_[0]) },

    decode_utf8 => sub { decode_utf8($_[0]) }

);

__PACKAGE__->attr(result_class => 'DBIx::Custom::Result');

__PACKAGE__->attr(sql_template => sub { DBIx::Custom::SQLTemplate->new });

__PACKAGE__->attr(cache => 1);

__PACKAGE__->attr(cache_method => sub {

    sub {

        my $self = shift;

        $self->{_cached} ||= {};

        if (@_ > 1) {

            $self->{_cached}{$_[0]} = $_[1] 

        }

        else {

            return $self->{_cached}{$_[0]}

        }

    }

});

sub connect {

    my $proto = shift;

    # Create

    my $self = ref $proto ? $proto : $proto->new(@_);

    # Information

    my $data_source = $self->data_source;

    my $user        = $self->user;

    my $password    = $self->password;

    # Connect

    my $dbh = eval {DBI->connect(

        $data_source,

        $user,

        $password,

        {

            RaiseError => 1,

            PrintError => 0,

            AutoCommit => 1,

        }

    )};

    # Connect error

    croak $@ if $@;

    # Database handle

    $self->dbh($dbh);

    return $self;

}

sub register_filter {

    my $invocant = shift;

    # Add filter

    my $filters = ref $_[0] eq 'HASH' ? $_[0] : {@_};

    $invocant->filters({%{$invocant->filters}, %$filters});

    return $invocant;

}

our %VALID_INSERT_ARGS = map { $_ => 1 } qw/table param append filter/;

sub insert {

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

    # Check arguments

    foreach my $name (keys %args) {

        croak "\"$name\" is invalid name"

          unless $VALID_INSERT_ARGS{$name};

    }

    # Arguments

    my $table  = $args{table} || '';

    my $param  = $args{param} || {};

    my $append = $args{append} || '';

    my $filter = $args{filter};

    # Insert keys

    my @insert_keys = keys %$param;

    # Not exists insert keys

    croak("Key-value pairs for insert must be specified to 'insert' second argument")

      unless @insert_keys;

    # Templte for insert

    my $template = "insert into $table {insert "

                   . join(' ', @insert_keys) . '}';

    $template .= " $append" if $append;

    # Execute query

    my $ret_val = $self->execute($template, param  => $param, 

                                            filter => $filter);

    return $ret_val;

}

our %VALID_UPDATE_ARGS

  = map { $_ => 1 } qw/table param where append filter allow_update_all/;

sub update {

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

    # Check arguments

    foreach my $name (keys %args) {

        croak "\"$name\" is invalid name"

          unless $VALID_UPDATE_ARGS{$name};

    }

    # Arguments

    my $table            = $args{table} || '';

    my $param            = $args{param} || {};

    my $where            = $args{where} || {};

    my $append_statement = $args{append} || '';

    my $filter           = $args{filter};

    my $allow_update_all = $args{allow_update_all};

    # Update keys

    my @update_keys = keys %$param;

    # Not exists update kyes

    croak("Key-value pairs for update must be specified to 'update' second argument")

      unless @update_keys;

    # Where keys

    my @where_keys = keys %$where;

    # Not exists where keys

    croak("Key-value pairs for where clause must be specified to 'update' third argument")

      if !@where_keys && !$allow_update_all;

    # Update clause

    my $update_clause = '{update ' . join(' ', @update_keys) . '}';

    # Where clause

    my $where_clause = '';

    my $new_where = {};

    if (@where_keys) {

        $where_clause = 'where ';

        foreach my $where_key (@where_keys) {

            $where_clause .= "{= $where_key} and ";

        }

        $where_clause =~ s/ and $//;

    }

    # Template for update

    my $template = "update $table $update_clause $where_clause";

    $template .= " $append_statement" if $append_statement;

    # Rearrange parammeters

    foreach my $wkey (@where_keys) {

        if (exists $param->{$wkey}) {

            $param->{$wkey} = [$param->{$wkey}]

              unless ref $param->{$wkey} eq 'ARRAY';

            push @{$param->{$wkey}}, $where->{$wkey};

        }

        else {

            $param->{$wkey} = $where->{$wkey};

        }

    }

    # Execute query

    my $ret_val = $self->execute($template, param  => $param, 

                                            filter => $filter);

    return $ret_val;

}

sub update_all { shift->update(allow_update_all => 1, @_) };

our %VALID_DELETE_ARGS

  = map { $_ => 1 } qw/table where append filter allow_delete_all/;

sub delete {

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

    # Check arguments

    foreach my $name (keys %args) {

        croak "\"$name\" is invalid name"

          unless $VALID_DELETE_ARGS{$name};

    }

    # Arguments

    my $table            = $args{table} || '';

    my $where            = $args{where} || {};

    my $append_statement = $args{append};

    my $filter           = $args{filter};

    my $allow_delete_all = $args{allow_delete_all};

    # Where keys

    my @where_keys = keys %$where;

    # Not exists where keys

    croak("Key-value pairs for where clause must be specified to 'delete' second argument")

      if !@where_keys && !$allow_delete_all;

    # Where clause

    my $where_clause = '';

    if (@where_keys) {

        $where_clause = 'where ';

        foreach my $wkey (@where_keys) {

            $where_clause .= "{= $wkey} and ";

        }

        $where_clause =~ s/ and $//;

    }

    # Template for delete

    my $template = "delete from $table $where_clause";

    $template .= " $append_statement" if $append_statement;

    # Execute query

    my $ret_val = $self->execute($template, param  => $where, 

                                            filter => $filter);

    return $ret_val;

}

sub delete_all { shift->delete(allow_delete_all => 1, @_) }

our %VALID_SELECT_ARGS

  = map { $_ => 1 } qw/table column where append relation filter param/;

sub select {

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

    # Check arguments

    foreach my $name (keys %args) {

        croak "\"$name\" is invalid name"

          unless $VALID_SELECT_ARGS{$name};

    }

    # Arguments

    my $tables = $args{table} || [];

    $tables = [$tables] unless ref $tables eq 'ARRAY';

    my $columns  = $args{column} || [];

    my $where    = $args{where} || {};

    my $relation = $args{relation};

    my $append   = $args{append};

    my $filter   = $args{filter};

    my $param    = $args{param} || {};

    # SQL template for select statement

    my $template = 'select ';

    # Column clause

    if (@$columns) {

        foreach my $column (@$columns) {

            $template .= "$column, ";

        }

        $template =~ s/, $/ /;

    }

    else {

        $template .= '* ';

    }

    # Table

    $template .= 'from ';

    foreach my $table (@$tables) {

        $template .= "$table, ";

    }

    $template =~ s/, $/ /;

    # Where clause

    my @where_keys = keys %$where;

    if (@where_keys) {

        $template .= 'where ';

        foreach my $where_key (@where_keys) {

            $template .= "{= $where_key} and ";

        }

    }

    $template =~ s/ and $//;

    # Relation

    if ($relation) {

        $template .= @where_keys ? "and " : "where ";

        foreach my $rkey (keys %$relation) {

            $template .= "$rkey = " . $relation->{$rkey} . " and ";

        }

    }

    $template =~ s/ and $//;

    # Append some statement

    $template .= " $append" if $append;

    # Execute query

    my $result = $self->execute($template, param  => $where, 

                                           filter => $filter);

    return $result;

}

sub create_query {

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

    # Create query from SQL template

    my $sql_template = $self->sql_template;

    my $cache = $self->cache;

    # Create query

    my $query;

    if ($cache) {

        # Cached query

        my $q = $self->cache_method->($self, $template);

        # Create query

        $query = DBIx::Custom::Query->new($q) if $q;

    }

    unless ($query) {

        # Create query

        $query = eval{$sql_template->create_query($template)};

        croak($@) if $@;

        # Cache query

        $self->cache_method->($self, $template,

                             {sql     => $query->sql, 

                              columns => $query->columns})

          if $cache;

    }

    # Prepare statement handle

    my $sth = eval {$self->dbh->prepare($query->{sql})};

    croak $@ if $@;

    # Set statement handle

    $query->sth($sth);

    return $query;

}

our %VALID_EXECUTE_ARGS = map { $_ => 1 } qw/param filter/;

sub execute{

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

    # Check arguments

    foreach my $name (keys %args) {

        croak "\"$name\" is invalid name"

          unless $VALID_EXECUTE_ARGS{$name};

    }

    my $params = $args{param} || {};

    # First argument is SQL template

    unless (ref $query eq 'DBIx::Custom::Query') {

        my $template;

        if (ref $query eq 'ARRAY') {

            $template = $query->[0];

        }

        else { $template = $query }

        $query = $self->create_query($template);

    }

    my $filter = $args{filter} || $query->filter || {};

    # Create bind value

    my $bind_values = $self->_build_bind_values($query, $params, $filter);

    # Execute

    my $sth      = $query->sth;

    my $affected = eval {$sth->execute(@$bind_values)};

    croak $@ if $@;

    # Return resultset if select statement is executed

    if ($sth->{NUM_OF_FIELDS}) {

        # Get result class

        my $result_class = $self->result_class;

        # Create result

        my $result = $result_class->new({

            sth             => $sth,

            default_filter  => $self->default_fetch_filter,

            filters         => $self->filters

        });

        return $result;

    }

    return $affected;

}

sub _build_bind_values {

    my ($self, $query, $params, $filter) = @_;

    # binding values

    my @bind_values;

    # Build bind values

    my $count = {};

    foreach my $column (@{$query->columns}) {

        croak "\"$column\" is not exists in params"

          unless exists $params->{$column};

        # Value

        my $value = ref $params->{$column} eq 'ARRAY'

                  ? $params->{$column}->[$count->{$column} || 0]

                  : $params->{$column};

        # Filter

        $filter ||= {};

        # Filter name

        my $fname = $filter->{$column} || $self->default_query_filter || '';

        my $filter_func;

        if ($fname) {

            if (ref $fname eq 'CODE') {

                $filter_func = $fname;

            }

            else {

                my $filters = $self->filters;

                croak "Not exists filter \"$fname\""

                  unless exists $filters->{$fname};

                $filter_func = $filters->{$fname};

            }            

        }

        push @bind_values, $filter_func

                         ? $filter_func->($value)

                         : $value;

        # Count up 

        $count->{$column}++;

    }

    return \@bind_values;

}

=head1 NAME

DBIx::Custom - DBI with hash parameter binding and filtering system

=cut

our $VERSION = '0.1604';

=head1 STABILITY

This module is not stable. Method name and implementations will be changed.

=head1 SYNOPSYS

    # Connect

    my $dbi = DBIx::Custom->connect(data_source => "dbi:mysql:database=books",

                                    user => 'ken', password => '!LFKD%$&');

    # Insert 

    $dbi->insert(table  => 'books',

                 param  => {title => 'perl', author => 'Ken'},

                 filter => {title => 'encode_utf8'});

    # Update 

    $dbi->update(table  => 'books', 

                 param  => {title => 'aaa', author => 'Ken'}, 

                 where  => {id => 5},

                 filter => {title => 'encode_utf8'});

    # Update all

    $dbi->update_all(table  => 'books',

                     param  => {title => 'aaa'},

                     filter => {title => 'encode_utf8'});

    # Delete

    $dbi->delete(table  => 'books',

                 where  => {author => 'Ken'},

                 filter => {title => 'encode_utf8'});

    # Delete all

    $dbi->delete_all(table => 'books');

    # Select

    my $result = $dbi->select(table => 'books');

    # Select(more complex)

    my $result = $dbi->select(

        table  => 'books',

        column => [qw/author title/],

        where  => {author => 'Ken'},

        append => 'order by id limit 1',

        filter => {tilte => 'encode_utf8'}

    );

    # Select(Join table)

    my $result = $dbi->select(

        table => ['books', 'rental'],

        column => ['books.name as book_name']

        relation => {'books.id' => 'rental.book_id'}

    );

    # Execute SQL

    $dbi->execute("select title from books");

    # Execute SQL with parameters and filter

    $dbi->execute("select id from books where {= author} && {like title}",

                  param  => {author => 'ken', title => '%Perl%'},

                  filter => {tilte => 'encode_utf8'});

    # Create query and execute it

    my $query = $dbi->create_query(

        "select id from books where {= author} && {like title}"

    );

    $dbi->execute($query, param => {author => 'ken', title => '%Perl%'})

    # Default filter

    $dbi->default_query_filter('encode_utf8');

    $dbi->default_fetch_filter('decode_utf8');

    # Fetch

    while (my $row = $result->fetch) {

        # ...

    }

    # Fetch hash

    while (my $row = $result->fetch_hash) {

    }

    # Get DBI object

    my $dbh = $dbi->dbh;

=head1 DESCRIPTION

L<DBIx::Custom> is useful L<DBI> extention.

This module have hash parameter binding and filtering system.

Normally, binding parameter is array.

L<DBIx::Custom> enable you to pass binding parameter as hash.

This module also provide filtering system.

You can filter the binding parameter

or the value of fetching row.

And have useful method such as insert(), update(), delete(), and select().

=head2 Features

=over 4

=item *

Hash parameter binding.

=item *

Value filtering.

=item *

Provide suger methods, such as insert(), update(), delete(), and select().

=back

=head1 ATTRIBUTES

=head2 C<user>

    $dbi  = $dbi->user('Ken');

    $user = $dbi->user;

Database user name.

This is used for connect().

=head2 C<password>

    $dbi      = $dbi->password('lkj&le`@s');

    $password = $dbi->password;

Database password.

This is used for connect().

=head2 C<data_source>

    $dbi         = $dbi->data_source("dbi:mysql:dbname=$database");

    $data_source = $dbi->data_source;

Database data source.

This is used for connect().

=head2 C<dbh>

    $dbi = $dbi->dbh($dbh);

    $dbh = $dbi->dbh;

Database handle. This is a L<DBI> object.

You can call all methods of L<DBI>

    my $sth    = $dbi->dbh->prepare("...");

    my $errstr = $dbi->dbh->errstr;

    $dbi->dbh->begin_work;

    $dbi->dbh->commit;

    $dbi->dbh->rollback;

=head2 C<filters>

    $dbi     = $dbi->filters({%filters});

    $filters = $dbi->filters;

Filter functions.

By default, "encode_utf8" and "decode_utf8" is registered.

    $encode_utf8 = $dbi->filters->{encode_utf8};

    $decode_utf8 = $dbi->filters->{decode_utf8};

=head2 C<default_query_filter>

    $dbi                  = $dbi->default_query_filter('encode_utf8');

    $default_query_filter = $dbi->default_query_filter

Default filter for value binding

=head2 C<default_fetch_filter>

    $dbi                  = $dbi->default_fetch_filter('decode_utf8');

    $default_fetch_filter = $dbi->default_fetch_filter;

Default filter for fetching.

=head2 C<result_class>

    $dbi          = $dbi->result_class('DBIx::Custom::Result');

    $result_class = $dbi->result_class;

Result class for select statement.

Default to L<DBIx::Custom::Result>

=head2 C<sql_template>

    $dbi          = $dbi->sql_template(DBIx::Cutom::SQLTemplate->new);

    $sql_template = $dbi->sql_template;

SQLTemplate instance. sql_template attribute must be 

the instance of L<DBIx::Cutom::SQLTemplate> subclass.

Default to DBIx::Cutom::SQLTemplate object

=head1 METHODS

This class is L<Object::Simple> subclass.

You can use all methods of L<Object::Simple>

=head2 C<connect>

    my $dbi = DBIx::Custom->connect(data_source => "dbi:mysql:database=books",

                                    user => 'ken', password => '!LFKD%$&');

Connect to database.

"AutoCommit" and "RaiseError" option is true, 

and "PrintError" option is false by default.

=head2 C<insert>

    $affected = $dbi->insert(table  => $table, 

                             param  => {%param},

                             append => $append,

                             filter => {%filter});

Insert row.

Retrun value is the count of affected rows.

B<Example:>

    $dbi->insert(table  => 'books', 

                 param  => {title => 'Perl', author => 'Taro'},

                 append => "some statement",

                 filter => {title => 'encode_utf8'})

=head2 C<update>

    $affected = $dbi->update(table  => $table, 

                             param  => {%params},

                             where  => {%where},

                             append => $append,

                             filter => {%filter})

Update rows.

Retrun value is the count of affected rows.

B<Example:>

    $dbi->update(table  => 'books',

                 param  => {title => 'Perl', author => 'Taro'},

                 where  => {id => 5},

                 append => "some statement",

                 filter => {title => 'encode_utf8'});

=head2 C<update_all>

    $affected = $dbi->update_all(table  => $table, 

                                 param  => {%params},

                                 filter => {%filter},

                                 append => $append);

Update all rows.

Retrun value is the count of affected rows.

B<Example:>

    $dbi->update_all(table  => 'books', 

                     param  => {author => 'taro'},

                     filter => {author => 'encode_utf8'});

=head2 C<delete>

    $affected = $dbi->delete(table  => $table,

                             where  => {%where},

                             append => $append,

                             filter => {%filter});

Delete rows.

Retrun value is the count of affected rows.

B<Example:>

    $dbi->delete(table  => 'books',

                 where  => {id => 5},

                 append => 'some statement',

                 filter => {id => 'encode_utf8'});

=head2 C<delete_all>

    $affected = $dbi->delete_all(table => $table);

Delete all rows.

Retrun value is the count of affected rows.

B<Example:>

    $dbi->delete_all(table => 'books');

=head2 C<select>

    $result = $dbi->select(table    => $table,

                           column   => [@column],

                           where    => {%where},

                           append   => $append,

                           relation => {%relation},

                           filter   => {%filter});

Select rows.

Return value is the instance of L<DBIx::Custom::Result>.

B<Example:>

    # select * from books;

    $result = $dbi->select(table => 'books');

    # select * from books where title = 'Perl';

    $result = $dbi->select(table => 'books', where => {title => 1});

    # select title, author from books where id = 1 for update;

    $result = $dbi->select(

        table  => 'books',

        column => ['title', 'author'],

        where  => {id => 1},

        appned => 'for update'

    );

    # select books.name as book_name from books, rental 

    # where books.id = rental.book_id;

    my $result = $dbi->select(

        table    => ['books', 'rental'],

        column   => ['books.name as book_name']

        relation => {'books.id' => 'rental.book_id'}

    );

=head2 C<create_query>

    my $query = $dbi->create_query(

        "select * from authors where {= name} and {= age};"

    );

Create the instance of L<DBIx::Custom::Query>. 

This receive the string written by SQL template.

=head2 C<execute>

    $result = $dbi->execute($query,    param => $params, filter => {%filter});

    $result = $dbi->execute($template, param => $params, filter => {%filter});

Execute the instace of L<DBIx::Custom::Query> or

the string written by SQL template.

Return value is the instance of L<DBIx::Custom::Result>.

B<Example:>

    $result = $dbi->execute("select * from authors where {= name} and {= age}", 

                            param => {name => 'taro', age => 19});

    while (my $row = $result->fetch) {

        # do something

    }

See also L<DBIx::Custom::SQLTemplate> to know how to write SQL template.

=head2 C<register_filter>

    $dbi->register_filter(%filters);

    $dbi->register_filter(\%filters);

Resister filter.

B<Example:>

    $dbi->register_filter(

        encode_utf8 => sub {

            my $value = shift;

            require Encode;

            return Encode::encode('UTF-8', $value);

        },

        decode_utf8 => sub {

            my $value = shift;

            require Encode;

            return Encode::decode('UTF-8', $value)

        }

    );

=head2 C<cache>

    $dbi   = $dbi->cache(1);

    $cache = $dbi->cache;

Cache the result of parsing SQL template.

Default to 1.

=head2 C<cache_method>

    $dbi          = $dbi->cache_method(\&cache_method);

    $cache_method = $dbi->cache_method

Method for cache.

B<Example:>

    $dbi->cache_method(

        sub {

            my $self = shift;

            $self->{_cached} ||= {};

            if (@_ > 1) {

                $self->{_cached}{$_[0]} = $_[1] 

            }

            else {

                return $self->{_cached}{$_[0]}

            }

        }

    );

=head1 BUGS

Please tell me bugs.

C<< <kimoto.yuki at gmail.com> >>

L<http://github.com/yuki-kimoto/DBIx-Custom>

=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