<?php

    define( 'MAIL_TO',   'user@example.com' );
    define( 'MAIL_FROM', 'info@example.com' );
    define( 'SUBJECT',   'Website Feedback' );

    // Set default values and define what can be accepted via post
    $aryData = array_fill_keys( [ 'Name', 'Email', 'Discourse' ], '' );
    $aryData['Options'] = [];

    $aryErr = [];

    $bPosted = ( count( $_POST ) > 0 );
    $bValidated = false;


    function clean_string( $string, $bad = [ 'content-type', 'bcc:', 'to:', 'cc:', 'href' ] ) {
        return str_replace( $bad, '', $string );
    }

    if ( $bPosted ) {

        // Move POST values into main Data array
        foreach( $_POST as $key => $val ) {
            if ( preg_match( '/^(txt|drp|hid|chk|rad)([a-zA-Z0-9_-]+)$/', $key, $regs ) && array_key_exists( $regs[2], $aryData ) ) {
                $aryData[ $regs[2] ] = ( is_string( $val ) ) ? trim( $val ) : $val;
            }
        }

        // Validate Information
        if ( $aryData['Name'] == '' ) {
            $aryErr['Name'] = 'Name is required';
        }
        elseif ( !preg_match( '/^[a-z .\'-]+$/i', $aryData['Name'] ) ) {
            $aryErr['Name'] = 'Name contains invalid characters';
        }

        if ( $aryData['Email'] == '' ) {
            $aryErr['Email'] = 'Email is required';
        }
        elseif ( !filter_var( $aryData['Email'], FILTER_VALIDATE_EMAIL ) ) {
            $aryErr['Email'] = 'Invalid Email address';
        }

        if ( $aryData['Discourse'] == '' ) {
            $aryErr['Discourse'] = 'Please provide some comments';
        }

        $bValidated = ( count( $aryErr ) == 0 );

    }

    if ( $bPosted && $bValidated ) {

        $aryMsg = [];
        $aryMsg[] = 'Form details below:';
        $aryMsg[] = "\n";
        $aryMsg[] = 'Name: ' . clean_string( $aryData['Name' ] );
        $aryMsg[] = 'Email: ' . clean_string( $aryData['Email'] );
        $aryMsg[] = 'Comments: ' .clean_string( $aryData['Discourse'] );
        $aryMsg[] = 'Options: ';
        if ( count( $aryData['Options'] ) == 0 ) {
            $aryMsg[] = '     (Non Selected)';
        }
        else {
            foreach( $aryData['Options'] as $val ) {
                $aryMsg[] = '     ' . $val;
            }
        }

        $strHeaders = 'From: ' . MAIL_FROM . "\r\n" .
                                    'Reply-To: ' . MAIL_FROM . "\r\n" .
                                    'X-Mailer: PHP/' . phpversion();

        // Commented out for testing...

//        if ( !mail( MAIL_TO, SUBJECT, implode( "\n", $aryMsg ), $strHeaders ) ) {
//            die( 'There was an unexpected error sending contact form' );
//        }

        // For Debug Only
        echo '<div style="white-space: pre; border: #000 1px solid; background-color: #ccc; font-family: monospace; padding: 20px;">';
        echo 'To: ' . MAIL_TO . "\n" . $strHeaders ;
        echo '<hr>';
        echo implode( "\n", $aryMsg );
        echo '</div>';

    }


    function echoTextInput( &$data, $field, $label = '', $placeholder = '', $extra = '' ) {
        if ( $label == '' ) { $label = $field; }
        if ( $placeholder == '' ) { $placeholder = $label; }

        echo '<label for="txt', $field, '">', htmlspecialchars( $label, ENT_QUOTES ), "</label>\n";
        echo '<input name="txt', $field, '" id="txt', $field, '" class="txtinput" ';
        echo   'placeholder="', htmlspecialchars( $placeholder, ENT_QUOTES ), '" ';
        echo   'value ="' . htmlspecialchars( $data[ $field ], ENT_QUOTES ), '" ', $extra;
        if ( strpos( $extra, 'type=' ) === false ) {
            echo ' type="text" ';
        }
        echo " >\n";
    }

    function echoCheckboxInput( &$data, $field, $value = '', $label = '', $extra = '' ) {
        static $ids = [];
        if ( !array_key_exists( $field, $ids ) ) { $ids[ $field ] = 0; }
        $ids[ $field ]++;

        if ( $value == '' ) { $value = $ids[ $field ]; }
        if ( $label == '' ) { $label = $field; }

        echo "<div>\n";
        echo '<label for="chk', $field, '-', $ids[ $field ], '" class="tag">', htmlspecialchars( $label, ENT_QUOTES ), "</label>\n";
        echo '<input type="checkbox" id="chk', $field, '-', $ids[ $field ], '" ';
        echo   'name="chk', $field, '[]" class="regular-checkbox big-checkbox" ';
        echo   'value="', htmlspecialchars( $value, ENT_QUOTES ), '" ';
        if ( in_array( $value, $data[ $field ] ) ) {
            echo ' checked="checked" ';
        }
        echo ">\n<div>\n";
    }

?><html>
<head><title>Contact</title></head>
<body>
    <h2>Contact</h2>

    <?php if ( $bPosted && $bValidated ) { ?>

        <p>Thank you for contacting us!</p>

    <?php } else { ?>

        <?php if ( $bPosted && !$bValidated ) { ?>
            <div class="errors">
                Check the following and try again:
                <ul><li><?php echo implode( '</li><li>', $aryErr ); ?></li></ul>
            </div>
        <?php } ?>

        <section class="contact">
            <form id="contact" action="" method="post">
                <fieldset title="About you">

                    <legend><span>About you</span></legend>

                    <?php echoTextInput( $aryData, 'Name', 'Name', 'Your Name', 'tabindex="10" required' ); ?>

                    <?php echoTextInput( $aryData, 'Email', 'Email', 'Valid Email', 'tabindex="20" required type="email"' ); ?>

                </fieldset>

                <fieldset title="Your turn">
                    <legend><span>Your turn</span></legend>

                    <p>What, exactly then, are you after?</p>

                    <?php echoCheckboxInput( $aryData, 'Options', 'salvation', 'Salvation' ); ?>

                    <?php echoCheckboxInput( $aryData, 'Options', 'question', 'Question' ); ?>

                    <?php echoCheckboxInput( $aryData, 'Options', 'other', 'Other' ); ?>

                    <label for="txtDiscourse">Write your comments here</label>
                    <textarea id="txtDiscourse" name="txtDiscourse" tabindex="30" class="txtinput" rows="7" placeholder="This is where your thoughts go"><?php echo htmlspecialchars( $aryData['Discourse'], ENT_QUOTES ); ?></textarea>

                    <section id="buttons">
                        <input type="reset" name="reset" id="resetbtn" class="resetbtn" value="Reset">
                        <input type="submit" name="submit" id="submitbtn" class="submitbtn" tabindex="40" value="Send away!">
                        <br style="clear:both;">
                    </section>
                </fieldset>
            </form>
        </section>

    <?php } // END: else: if( Posted and Valid ) ?>
</body>
</html>