<?php
/**
 * Plugin Name:       Code Live Snow
 * Plugin URI:        https://mycodelive.com/code-live-snow
 * Description:       Lightweight falling snow effect with built-in snowflake styles, multiple custom images, direction, speed, flake count for mobile/desktop, page targeting and date scheduling.
 * Version:           1.4.0
 * Requires at least: 5.0
 * Requires PHP:      7.0
 * Author:            Code Live
 * Author URI:        https://mycodelive.com
 * License:           GPLv2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain:       code-live-snow
 *
 * @package Code_Live_Snow
 */

defined( 'ABSPATH' ) || exit;

define( 'CODE_LIVE_SNOW_VERSION', '1.4.0' );
define( 'CODE_LIVE_SNOW_URL', plugin_dir_url( __FILE__ ) );

/**
 * Built-in snowflake styles. "dot" is drawn on the canvas, the others are bundled SVG files.
 *
 * @return array slug => array( label, file ).
 */
function code_live_snow_styles() {
	return array(
		'dot'     => array(
			'label' => __( 'Soft dot', 'code-live-snow' ),
			'file'  => '',
		),
		'classic' => array(
			'label' => __( 'Classic flake', 'code-live-snow' ),
			'file'  => 'flake-classic.svg',
		),
		'crystal' => array(
			'label' => __( 'Crystal flake', 'code-live-snow' ),
			'file'  => 'flake-crystal.svg',
		),
		'simple'  => array(
			'label' => __( 'Simple flake', 'code-live-snow' ),
			'file'  => 'flake-simple.svg',
		),
		'sparkle' => array(
			'label' => __( 'Sparkle', 'code-live-snow' ),
			'file'  => 'flake-sparkle.svg',
		),
	);
}

/**
 * URL of a bundled style image.
 *
 * @param string $slug Style slug.
 * @return string Empty for canvas-drawn styles.
 */
function code_live_snow_style_url( $slug ) {
	$styles = code_live_snow_styles();
	if ( empty( $styles[ $slug ]['file'] ) ) {
		return '';
	}
	return CODE_LIVE_SNOW_URL . 'assets/images/' . $styles[ $slug ]['file'];
}

/**
 * Default option values.
 *
 * @return array
 */
function code_live_snow_defaults() {
	return array(
		'enabled'       => '1',
		'pages'         => '',
		'desktop_count' => 80,
		'mobile_count'  => 35,
		'speed'         => 1.2,
		'direction'     => 'down',
		'styles'        => array( 'dot', 'classic', 'crystal' ),
		'images'        => array(),
		'min_size'      => 8,
		'max_size'      => 22,
		'zindex'        => 9999,
		'start_date'    => '',
		'end_date'      => '',
	);
}

/**
 * Allowed snow directions.
 *
 * @return array
 */
function code_live_snow_directions() {
	return array(
		'down'     => __( 'Top to Bottom', 'code-live-snow' ),
		'left'     => __( 'Right to Left', 'code-live-snow' ),
		'right'    => __( 'Left to Right', 'code-live-snow' ),
		'diagonal' => __( 'Diagonal', 'code-live-snow' ),
	);
}

/**
 * Get saved options merged with defaults.
 *
 * @return array
 */
function code_live_snow_get_options() {
	$saved = get_option( 'code_live_snow_options', array() );
	if ( ! is_array( $saved ) ) {
		$saved = array();
	}

	// Upgrade from 1.3.x, which stored a single image URL.
	if ( ! isset( $saved['images'] ) && ! empty( $saved['image'] ) ) {
		$id              = attachment_url_to_postid( $saved['image'] );
		$saved['images'] = $id ? array( $id ) : array();
	}
	unset( $saved['image'] );

	$options = wp_parse_args( $saved, code_live_snow_defaults() );

	if ( ! is_array( $options['styles'] ) ) {
		$options['styles'] = array();
	}
	if ( ! is_array( $options['images'] ) ) {
		$options['images'] = array();
	}

	return $options;
}

/**
 * Validate a Y-m-d date string.
 *
 * @param mixed $value Raw value.
 * @return string Valid date or empty string.
 */
function code_live_snow_sanitize_date( $value ) {
	$value = sanitize_text_field( (string) $value );
	if ( '' === $value ) {
		return '';
	}
	$date = DateTime::createFromFormat( 'Y-m-d', $value );
	if ( $date && $date->format( 'Y-m-d' ) === $value ) {
		return $value;
	}
	return '';
}

/**
 * Clamp an integer to a range.
 *
 * @param mixed $value Raw value.
 * @param int   $min   Minimum.
 * @param int   $max   Maximum.
 * @return int
 */
function code_live_snow_clamp( $value, $min, $max ) {
	return min( max( absint( $value ), $min ), $max );
}

/**
 * Sanitize settings.
 *
 * @param mixed $input Raw input from the settings form.
 * @return array
 */
function code_live_snow_sanitize( $input ) {
	$defaults = code_live_snow_defaults();

	if ( ! is_array( $input ) ) {
		return $defaults;
	}

	// Page IDs: keep only positive integers, comma separated.
	$pages = '';
	if ( isset( $input['pages'] ) ) {
		$parts = array_map( 'trim', explode( ',', sanitize_text_field( wp_unslash( $input['pages'] ) ) ) );
		$ids   = array_map( 'absint', array_filter( $parts, 'ctype_digit' ) );
		$ids   = array_filter( $ids );
		$pages = implode( ',', array_unique( $ids ) );
	}

	$direction = isset( $input['direction'] ) ? sanitize_key( $input['direction'] ) : $defaults['direction'];
	if ( ! array_key_exists( $direction, code_live_snow_directions() ) ) {
		$direction = $defaults['direction'];
	}

	// Built-in styles: whitelist only.
	$styles = array();
	if ( isset( $input['styles'] ) && is_array( $input['styles'] ) ) {
		$allowed = array_keys( code_live_snow_styles() );
		foreach ( $input['styles'] as $slug ) {
			$slug = sanitize_key( $slug );
			if ( in_array( $slug, $allowed, true ) ) {
				$styles[] = $slug;
			}
		}
	}
	$styles = array_values( array_unique( $styles ) );

	// Custom images: existing image attachments only, max 20.
	$images = array();
	if ( isset( $input['images'] ) && is_array( $input['images'] ) ) {
		foreach ( $input['images'] as $id ) {
			$id = absint( $id );
			if ( $id && wp_attachment_is_image( $id ) ) {
				$images[] = $id;
			}
		}
	}
	$images = array_slice( array_values( array_unique( $images ) ), 0, 20 );

	// Never leave the snow without anything to draw.
	if ( empty( $styles ) && empty( $images ) ) {
		$styles = array( 'dot' );
	}

	$min_size = isset( $input['min_size'] ) ? code_live_snow_clamp( $input['min_size'], 2, 100 ) : $defaults['min_size'];
	$max_size = isset( $input['max_size'] ) ? code_live_snow_clamp( $input['max_size'], 2, 150 ) : $defaults['max_size'];
	if ( $max_size < $min_size ) {
		$max_size = $min_size;
	}

	$speed = isset( $input['speed'] ) ? (float) $input['speed'] : $defaults['speed'];

	return array(
		'enabled'       => ! empty( $input['enabled'] ) ? '1' : '0',
		'pages'         => $pages,
		'desktop_count' => isset( $input['desktop_count'] ) ? code_live_snow_clamp( $input['desktop_count'], 1, 500 ) : $defaults['desktop_count'],
		'mobile_count'  => isset( $input['mobile_count'] ) ? code_live_snow_clamp( $input['mobile_count'], 1, 500 ) : $defaults['mobile_count'],
		'speed'         => min( max( round( $speed, 1 ), 0.1 ), 20 ),
		'direction'     => $direction,
		'styles'        => $styles,
		'images'        => $images,
		'min_size'      => $min_size,
		'max_size'      => $max_size,
		'zindex'        => isset( $input['zindex'] ) ? min( absint( $input['zindex'] ), 2147483647 ) : $defaults['zindex'],
		'start_date'    => isset( $input['start_date'] ) ? code_live_snow_sanitize_date( $input['start_date'] ) : '',
		'end_date'      => isset( $input['end_date'] ) ? code_live_snow_sanitize_date( $input['end_date'] ) : '',
	);
}

/* ---------------- ADMIN ---------------- */

/**
 * Register the settings page.
 */
function code_live_snow_admin_menu() {
	add_options_page(
		__( 'Code Live Snow', 'code-live-snow' ),
		__( 'Code Live Snow', 'code-live-snow' ),
		'manage_options',
		'code-live-snow',
		'code_live_snow_settings_page'
	);
}
add_action( 'admin_menu', 'code_live_snow_admin_menu' );

/**
 * Register the option.
 */
function code_live_snow_register_settings() {
	register_setting(
		'code_live_snow_group',
		'code_live_snow_options',
		array(
			'type'              => 'array',
			'sanitize_callback' => 'code_live_snow_sanitize',
			'default'           => code_live_snow_defaults(),
		)
	);
}
add_action( 'admin_init', 'code_live_snow_register_settings' );

/**
 * Enqueue admin assets only on our settings page.
 *
 * @param string $hook Current admin page hook.
 */
function code_live_snow_admin_assets( $hook ) {
	if ( 'settings_page_code-live-snow' !== $hook ) {
		return;
	}

	wp_enqueue_media();

	wp_enqueue_style(
		'code-live-snow-admin',
		CODE_LIVE_SNOW_URL . 'assets/css/admin.css',
		array(),
		CODE_LIVE_SNOW_VERSION
	);

	// Previews of the bundled styles, shown as CSS backgrounds.
	$css = '';
	foreach ( array_keys( code_live_snow_styles() ) as $slug ) {
		$url = code_live_snow_style_url( $slug );
		if ( $url ) {
			$css .= sprintf( '.cls-style-preview--%s{background-image:url("%s")}', sanitize_html_class( $slug ), esc_url( $url ) );
		}
	}
	wp_add_inline_style( 'code-live-snow-admin', $css );

	wp_enqueue_script(
		'code-live-snow-admin',
		CODE_LIVE_SNOW_URL . 'assets/js/admin.js',
		array( 'jquery' ),
		CODE_LIVE_SNOW_VERSION,
		true
	);

	wp_localize_script(
		'code-live-snow-admin',
		'codeLiveSnowAdmin',
		array(
			'title'  => __( 'Select Snow Images', 'code-live-snow' ),
			'button' => __( 'Use these images', 'code-live-snow' ),
			'remove' => __( 'Remove image', 'code-live-snow' ),
			'name'   => 'code_live_snow_options[images][]',
			'max'    => 20,
		)
	);
}
add_action( 'admin_enqueue_scripts', 'code_live_snow_admin_assets' );

/**
 * Add a "Settings" link on the Plugins screen.
 *
 * @param array $links Existing links.
 * @return array
 */
function code_live_snow_action_links( $links ) {
	$url = admin_url( 'options-general.php?page=code-live-snow' );
	array_unshift( $links, '<a href="' . esc_url( $url ) . '">' . esc_html__( 'Settings', 'code-live-snow' ) . '</a>' );
	return $links;
}
add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), 'code_live_snow_action_links' );

/**
 * Render the settings page.
 */
function code_live_snow_settings_page() {
	if ( ! current_user_can( 'manage_options' ) ) {
		return;
	}
	$o = code_live_snow_get_options();
	?>
	<div class="wrap">
		<h1><?php esc_html_e( 'Code Live Snow Settings', 'code-live-snow' ); ?></h1>
		<form method="post" action="options.php">
			<?php settings_fields( 'code_live_snow_group' ); ?>
			<table class="form-table" role="presentation">
				<tr>
					<th scope="row"><label for="cls-enabled"><?php esc_html_e( 'Enable Snow', 'code-live-snow' ); ?></label></th>
					<td><input type="checkbox" id="cls-enabled" name="code_live_snow_options[enabled]" value="1" <?php checked( $o['enabled'], '1' ); ?>></td>
				</tr>
				<tr>
					<th scope="row"><?php esc_html_e( 'Snowflake Styles', 'code-live-snow' ); ?></th>
					<td>
						<fieldset class="cls-styles">
							<legend class="screen-reader-text"><?php esc_html_e( 'Snowflake Styles', 'code-live-snow' ); ?></legend>
							<?php foreach ( code_live_snow_styles() as $slug => $style ) : ?>
								<label class="cls-style">
									<input type="checkbox" name="code_live_snow_options[styles][]" value="<?php echo esc_attr( $slug ); ?>" <?php checked( in_array( $slug, $o['styles'], true ) ); ?>>
									<span class="cls-style-preview cls-style-preview--<?php echo esc_attr( $slug ); ?>" aria-hidden="true"></span>
									<span class="cls-style-label"><?php echo esc_html( $style['label'] ); ?></span>
								</label>
							<?php endforeach; ?>
						</fieldset>
						<p class="description"><?php esc_html_e( 'Pick one or more built-in styles. Each flake randomly uses one of the selected styles or custom images.', 'code-live-snow' ); ?></p>
					</td>
				</tr>
				<tr>
					<th scope="row"><?php esc_html_e( 'Custom Snow Images', 'code-live-snow' ); ?></th>
					<td>
						<ul class="cls-images" id="cls-images">
							<?php foreach ( $o['images'] as $image_id ) : ?>
								<?php
								$thumb = wp_get_attachment_image( $image_id, 'thumbnail', false, array( 'class' => 'cls-image-thumb' ) );
								if ( ! $thumb ) {
									continue;
								}
								?>
								<li class="cls-image">
									<?php echo $thumb; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Core function output. ?>
									<input type="hidden" name="code_live_snow_options[images][]" value="<?php echo esc_attr( $image_id ); ?>">
									<button type="button" class="cls-image-remove" aria-label="<?php esc_attr_e( 'Remove image', 'code-live-snow' ); ?>">&times;</button>
								</li>
							<?php endforeach; ?>
						</ul>
						<button type="button" class="button cls-add-images"><?php esc_html_e( 'Add Images', 'code-live-snow' ); ?></button>
						<p class="description"><?php esc_html_e( 'Optional. Select up to 20 images from your Media Library. Small transparent PNG or WebP images work best.', 'code-live-snow' ); ?></p>
					</td>
				</tr>
				<tr>
					<th scope="row"><?php esc_html_e( 'Flake Size (px)', 'code-live-snow' ); ?></th>
					<td>
						<label for="cls-min-size"><?php esc_html_e( 'Min', 'code-live-snow' ); ?></label>
						<input type="number" id="cls-min-size" class="small-text" min="2" max="100" name="code_live_snow_options[min_size]" value="<?php echo esc_attr( $o['min_size'] ); ?>">
						<label for="cls-max-size"><?php esc_html_e( 'Max', 'code-live-snow' ); ?></label>
						<input type="number" id="cls-max-size" class="small-text" min="2" max="150" name="code_live_snow_options[max_size]" value="<?php echo esc_attr( $o['max_size'] ); ?>">
					</td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-desktop"><?php esc_html_e( 'Desktop Snow Count', 'code-live-snow' ); ?></label></th>
					<td><input type="number" id="cls-desktop" min="1" max="500" name="code_live_snow_options[desktop_count]" value="<?php echo esc_attr( $o['desktop_count'] ); ?>"></td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-mobile"><?php esc_html_e( 'Mobile Snow Count', 'code-live-snow' ); ?></label></th>
					<td><input type="number" id="cls-mobile" min="1" max="500" name="code_live_snow_options[mobile_count]" value="<?php echo esc_attr( $o['mobile_count'] ); ?>"></td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-speed"><?php esc_html_e( 'Snow Speed', 'code-live-snow' ); ?></label></th>
					<td><input type="number" id="cls-speed" step="0.1" min="0.1" max="20" name="code_live_snow_options[speed]" value="<?php echo esc_attr( $o['speed'] ); ?>"></td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-direction"><?php esc_html_e( 'Snow Direction', 'code-live-snow' ); ?></label></th>
					<td>
						<select id="cls-direction" name="code_live_snow_options[direction]">
							<?php foreach ( code_live_snow_directions() as $value => $label ) : ?>
								<option value="<?php echo esc_attr( $value ); ?>" <?php selected( $o['direction'], $value ); ?>><?php echo esc_html( $label ); ?></option>
							<?php endforeach; ?>
						</select>
					</td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-pages"><?php esc_html_e( 'Show only on IDs', 'code-live-snow' ); ?></label></th>
					<td>
						<input type="text" id="cls-pages" class="regular-text" name="code_live_snow_options[pages]" value="<?php echo esc_attr( $o['pages'] ); ?>" placeholder="12,34,56">
						<p class="description"><?php esc_html_e( 'Comma-separated page or post IDs. Leave empty to show snow on the whole site.', 'code-live-snow' ); ?></p>
					</td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-start"><?php esc_html_e( 'Start Date', 'code-live-snow' ); ?></label></th>
					<td><input type="date" id="cls-start" name="code_live_snow_options[start_date]" value="<?php echo esc_attr( $o['start_date'] ); ?>"></td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-end"><?php esc_html_e( 'End Date', 'code-live-snow' ); ?></label></th>
					<td><input type="date" id="cls-end" name="code_live_snow_options[end_date]" value="<?php echo esc_attr( $o['end_date'] ); ?>"></td>
				</tr>
				<tr>
					<th scope="row"><label for="cls-zindex"><?php esc_html_e( 'Z-index', 'code-live-snow' ); ?></label></th>
					<td><input type="number" id="cls-zindex" min="0" name="code_live_snow_options[zindex]" value="<?php echo esc_attr( $o['zindex'] ); ?>"></td>
				</tr>
			</table>
			<?php submit_button(); ?>
		</form>
	</div>
	<?php
}

/* ---------------- FRONTEND ---------------- */

/**
 * Whether snow should display on the current request.
 *
 * @return bool
 */
function code_live_snow_should_display() {
	$o = code_live_snow_get_options();

	if ( '1' !== $o['enabled'] ) {
		return false;
	}

	$today = current_time( 'Y-m-d' );
	if ( $o['start_date'] && $today < $o['start_date'] ) {
		return false;
	}
	if ( $o['end_date'] && $today > $o['end_date'] ) {
		return false;
	}

	if ( '' !== $o['pages'] ) {
		$allowed = array_map( 'absint', explode( ',', $o['pages'] ) );
		if ( ! is_singular() || ! in_array( (int) get_queried_object_id(), $allowed, true ) ) {
			return false;
		}
	}

	return true;
}

/**
 * Build the list of flake sources for the front end.
 * An empty string means "draw a soft dot on the canvas".
 *
 * @param array $o Options.
 * @return array
 */
function code_live_snow_sources( $o ) {
	$sources = array();

	foreach ( $o['styles'] as $slug ) {
		$sources[] = esc_url_raw( code_live_snow_style_url( $slug ) );
	}

	foreach ( $o['images'] as $image_id ) {
		$url = wp_get_attachment_image_url( $image_id, 'thumbnail' );
		if ( $url ) {
			$sources[] = esc_url_raw( $url );
		}
	}

	if ( empty( $sources ) ) {
		$sources[] = '';
	}

	return array_values( array_unique( $sources ) );
}

/**
 * Enqueue front-end script and styles.
 */
function code_live_snow_frontend_assets() {
	if ( ! code_live_snow_should_display() ) {
		return;
	}

	$o = code_live_snow_get_options();

	wp_register_style( 'code-live-snow', false, array(), CODE_LIVE_SNOW_VERSION );
	wp_enqueue_style( 'code-live-snow' );
	wp_add_inline_style(
		'code-live-snow',
		sprintf( '#code-live-snow{position:fixed;top:0;left:0;width:100%%;height:100%%;pointer-events:none;z-index:%d}', absint( $o['zindex'] ) )
	);

	wp_enqueue_script(
		'code-live-snow',
		CODE_LIVE_SNOW_URL . 'assets/js/snow.js',
		array(),
		CODE_LIVE_SNOW_VERSION,
		true
	);

	wp_localize_script(
		'code-live-snow',
		'codeLiveSnow',
		array(
			'desktopCount' => absint( $o['desktop_count'] ),
			'mobileCount'  => absint( $o['mobile_count'] ),
			'speed'        => (float) $o['speed'],
			'direction'    => $o['direction'],
			'minSize'      => absint( $o['min_size'] ),
			'maxSize'      => absint( $o['max_size'] ),
			'sources'      => code_live_snow_sources( $o ),
		)
	);
}
add_action( 'wp_enqueue_scripts', 'code_live_snow_frontend_assets' );