<?php
/**
 * Display formatting for report values.
 *
 * @package AdPix\Analytics
 */

declare( strict_types = 1 );

namespace AdPix\Analytics\View;

defined( 'ABSPATH' ) || exit;

/**
 * Renders numbers, dates and metric names the way the reader's locale writes them.
 *
 * Every number here goes through WordPress's own localisation, which matters more than it looks:
 * a Persian admin expects ۱۲٬۳۴۵ and an Arabic one ١٢٬٣٤٥, and a report that showed 12,345 to both
 * would read as somebody else's dashboard bolted onto their site.
 */
final class Format {

	/**
	 * A count, grouped for the reader's locale.
	 *
	 * @param float $value Raw number.
	 * @return string
	 */
	public static function number( float $value ): string {
		return number_format_i18n( $value, self::decimals( $value ) );
	}

	/**
	 * A count shortened to fit an axis label.
	 *
	 * Charts get one line of room per gridline, and "1.2K" fits where "1,234,567" does not. Only the
	 * axis uses this; every figure a reader might quote is written out in full in the table below.
	 *
	 * @param float $value Raw number.
	 * @return string
	 */
	public static function compact( float $value ): string {
		$abs = abs( $value );

		if ( $abs >= 1000000 ) {
			/* translators: %s: a number of millions, e.g. "1.2". */
			return sprintf( __( '%sM', 'adpix-analytics' ), number_format_i18n( $value / 1000000, $abs >= 10000000 ? 0 : 1 ) );
		}

		if ( $abs >= 1000 ) {
			/* translators: %s: a number of thousands, e.g. "1.2". */
			return sprintf( __( '%sK', 'adpix-analytics' ), number_format_i18n( $value / 1000, $abs >= 10000 ? 0 : 1 ) );
		}

		return number_format_i18n( $value, self::decimals( $value ) );
	}

	/**
	 * An amount of money.
	 *
	 * The currency is shown as the code the property reports in rather than a symbol, because the
	 * property's currency is not necessarily the site's, and a "$" in front of a figure denominated
	 * in something else is worse than no symbol at all.
	 *
	 * @param float  $value    Amount.
	 * @param string $currency ISO 4217 code, may be empty.
	 * @return string
	 */
	public static function money( float $value, string $currency ): string {
		$amount = number_format_i18n( $value, 2 );

		if ( '' === $currency ) {
			return $amount;
		}

		/* translators: 1: formatted amount, 2: ISO currency code. */
		return sprintf( _x( '%1$s %2$s', 'money with currency code', 'adpix-analytics' ), $amount, $currency );
	}

	/**
	 * A share of a total.
	 *
	 * @param float $value Zero to one hundred.
	 * @return string
	 */
	public static function percent( float $value ): string {
		/* translators: %s: a percentage figure, without the sign. */
		return sprintf( __( '%s%%', 'adpix-analytics' ), number_format_i18n( $value, $value > 0.0 && $value < 10.0 ? 1 : 0 ) );
	}

	/**
	 * A calendar day, short.
	 *
	 * @param string $ymd Date as YYYY-MM-DD.
	 * @return string The localised day, or the input when it cannot be parsed.
	 */
	public static function day( string $ymd ): string {
		$stamp = strtotime( $ymd . ' 00:00:00 UTC' );

		if ( false === $stamp ) {
			return $ymd;
		}

		// Formatted in UTC because the date is already the property's own calendar day: shifting it into
		// the site's timezone would move half the year's points onto the day before.
		return (string) wp_date( 'j M', $stamp, new \DateTimeZone( 'UTC' ) );
	}

	/**
	 * A calendar day, written out.
	 *
	 * @param string $ymd Date as YYYY-MM-DD.
	 * @return string
	 */
	public static function date( string $ymd ): string {
		$stamp = strtotime( $ymd . ' 00:00:00 UTC' );

		if ( false === $stamp ) {
			return $ymd;
		}

		return (string) wp_date( (string) get_option( 'date_format' ), $stamp, new \DateTimeZone( 'UTC' ) );
	}

	/**
	 * The readable name of a metric.
	 *
	 * @param string $metric Metric key as the API names it.
	 * @return string The translated name, or the key when it is one this screen does not show.
	 */
	public static function metric( string $metric ): string {
		$names = array(
			'totalUsers'      => __( 'Visitors', 'adpix-analytics' ),
			'users'           => __( 'Visitors', 'adpix-analytics' ),
			'activeUsers'     => __( 'Active visitors', 'adpix-analytics' ),
			'sessions'        => __( 'Visits', 'adpix-analytics' ),
			'pageviews'       => __( 'Page views', 'adpix-analytics' ),
			'eventCount'      => __( 'Events', 'adpix-analytics' ),
			'conversions'     => __( 'Conversions', 'adpix-analytics' ),
			'conversionValue' => __( 'Conversion value', 'adpix-analytics' ),
			'revenue'         => __( 'Revenue', 'adpix-analytics' ),
		);

		return $names[ $metric ] ?? $metric;
	}

	/**
	 * Whether a metric is money rather than a count.
	 *
	 * @param string $metric Metric key.
	 * @return bool
	 */
	public static function is_money( string $metric ): bool {
		return in_array( $metric, array( 'conversionValue', 'revenue' ), true );
	}

	/**
	 * One metric value, formatted according to what it is.
	 *
	 * @param string $metric   Metric key.
	 * @param float  $value    Value.
	 * @param string $currency Property currency.
	 * @return string
	 */
	public static function value( string $metric, float $value, string $currency = '' ): string {
		return self::is_money( $metric ) ? self::money( $value, $currency ) : self::number( $value );
	}

	/**
	 * How many decimal places a value deserves.
	 *
	 * Counts are whole things — half a visit does not exist — so they are shown whole. A value that
	 * genuinely has a fraction keeps two places rather than being rounded into looking exact.
	 *
	 * @param float $value Raw number.
	 * @return int
	 */
	private static function decimals( float $value ): int {
		return abs( $value - round( $value ) ) < 0.005 ? 0 : 2;
	}
}