> $rows Rows of one product and currency, oldest first.
*/
public static function render( array $rows, Reference $reference, int $window_days, int $now ): string {
if ( empty( $rows ) ) {
return '';
}
$segments = array();
foreach ( $rows as $row ) {
$from = Repository::to_timestamp( $row['valid_from'] );
$to = null === $row['valid_to'] ? $now : Repository::to_timestamp( $row['valid_to'] );
if ( $to > $from ) {
$segments[] = array(
'from' => $from,
'to' => $to,
'price' => (float) $row['price'],
'reduced' => (bool) $row['is_reduced'],
);
}
}
if ( empty( $segments ) ) {
return '';
}
$t0 = $reference->t0;
$window_start = null === $t0 ? null : $t0 - $window_days * DAY_IN_SECONDS;
$desired = null === $window_start ? $now - 60 * DAY_IN_SECONDS : min( $window_start - 5 * DAY_IN_SECONDS, $now - 45 * DAY_IN_SECONDS );
$start = max( $segments[0]['from'], $desired );
if ( $now - $start < DAY_IN_SECONDS ) {
$start = $now - DAY_IN_SECONDS;
}
$end = $now + (int) round( ( $now - $start ) * 0.02 );
// Value range of everything visible.
$values = array();
foreach ( $segments as $segment ) {
if ( $segment['to'] > $start ) {
$values[] = $segment['price'];
}
}
if ( $reference->has_price() ) {
$values[] = (float) $reference->price;
}
$low = min( $values );
$high = max( $values );
$pad = $high > $low ? ( $high - $low ) * 0.25 : max( 1, $high * 0.1 );
$low = max( 0, $low - $pad );
$high = $high + $pad;
$plot_w = self::WIDTH - self::LEFT - self::RIGHT;
$plot_h = self::HEIGHT - self::TOP - self::BOTTOM;
$x = static function ( int $ts ) use ( $start, $end, $plot_w ) {
return round( self::LEFT + ( max( $start, min( $end, $ts ) ) - $start ) / ( $end - $start ) * $plot_w, 1 );
};
$y = static function ( float $price ) use ( $low, $high, $plot_h ) {
return round( self::TOP + ( 1 - ( $price - $low ) / ( $high - $low ) ) * $plot_h, 1 );
};
$bottom = self::TOP + $plot_h;
$svg = '';
}
public static function legend( bool $reduced ): string {
$html = '' . esc_html__( 'Price incl. VAT', 'strikewise' ) . '';
if ( $reduced ) {
$html .= '' . esc_html__( 'Reduced', 'strikewise' ) . '';
$html .= '' . esc_html__( '30 days before the reduction', 'strikewise' ) . '';
$html .= '' . esc_html__( 'Lowest price in that window', 'strikewise' ) . '';
}
return $html . '
';
}
public static function price( float $amount ): string {
return html_entity_decode( wp_strip_all_tags( wc_price( $amount ) ), ENT_QUOTES, 'UTF-8' );
}
/**
* Two to four round values inside the range: steps of 1, 2, 2.5 or 5 times a power of ten.
*
* @return float[]
*/
private static function ticks( float $low, float $high ): array {
$raw = ( $high - $low ) / 3;
$power = 10 ** floor( log10( $raw ) );
$step = 10 * $power;
foreach ( array( 1, 2, 2.5, 5 ) as $factor ) {
if ( $factor * $power >= $raw ) {
$step = $factor * $power;
break;
}
}
$ticks = array();
for ( $value = ceil( $low / $step ) * $step; $value < $high; $value += $step ) {
if ( $value > $low ) {
$ticks[] = round( $value, 2 );
}
}
return $ticks;
}
private static function short_price( float $amount ): string {
return number_format_i18n( $amount, $amount >= 100 || floor( $amount ) === $amount ? 0 : 2 ) . ' ' . html_entity_decode( get_woocommerce_currency_symbol(), ENT_QUOTES, 'UTF-8' );
}
private static function day( int $timestamp ): string {
return wp_date( _x( 'M j', 'short date in the price chart', 'strikewise' ), $timestamp );
}
}