<?php

$pg_config = 'host=localhost dbname=dbname user=user password=password';

$dbh = pg_connect( $pg_config );

function import ( $arg_polls_struct ) {

    global $dbh;

    foreach( $arg_polls_struct as $poll_info ){

        // Check to see if user exists
        $user_name = pg_escape_string( $poll_info['user_name'] );
        $user_email = pg_escape_string( $poll_info['user_email'] );
        $query_string = <<<EOF
SELECT user_id FROM users WHERE user_name = '$user_name'
EOF;
        $result = pg_query( $dbh, $query_string );

        if( $row = pg_fetch_assoc( $result ) ){
            $poll_info['user_id'] = $row['user_id'];
        // Otherwise insert it
        } else {
            $poll_info['user_id'] = fetch_next_id( 'users_user_id_seq' );
            $query_string = <<<EOF
INSERT INTO users ( user_id, user_name, user_email )
    VALUES
( {$poll_info['user_id']}, '$user_name', '$user_email' )
EOF;
            $result = pg_query( $dbh, $query_string );
        }

        // Insert poll
        $question = pg_escape_string( $poll_info['question_string'] );
        $poll_info['poll_id'] = fetch_next_id( 'poll_poll_id_seq' );
        $query_string = <<<EOF
INSERT INTO poll ( poll_id, user_id, poll_question )
    VALUES
( {$poll_info['poll_id']}, '{$poll_info['user_id']}', '$question' )
EOF;
        $result = pg_query( $dbh, $query_string );

        // Insert options
        foreach( $poll_info['options'] as $poll_option_info ){
            $option_num = pg_escape_string( $poll_option_info['option_num'] );
            $option_string = pg_escape_string( $poll_option_info['option_string'] );
            $option_votes = pg_escape_string( $poll_option_info['option_votes'] );
            $option_votes = is_numeric( $option_votes ) ? $option_votes : 0;
            $query_string = <<<EOF
INSERT INTO poll_option ( poll_id, poll_option_num, poll_option_string, poll_option_votes )
    VALUES
( {$poll_info['poll_id']}, '$option_num', '$option_string', '$option_votes' )
EOF;
            $result = pg_query( $dbh, $query_string );
        }

    } // End each poll

}

// Not relying on RETURNING function found in postgres >= 8.2
function fetch_next_id ( $arg_seq ) {

    global $dbh;

    if( $arg_seq ){
        $fetch_id_result = pg_query( $dbh, "SELECT nextval('$arg_seq')" );
        $fetch_id_row = pg_fetch_row( $fetch_id_result );
        if( is_numeric( $fetch_id_row[0] ) ){
            return $fetch_id_row[0];
        }
    }
    return false;
}

?>