<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Ledger;

defined('ABSPATH') || exit;

final class AssetAmount {
	private function __construct(
		private readonly AssetType $asset,
		private readonly int $minor
	) {}

	public static function points(int $points): self {
		if ($points < 0) {
			throw new \InvalidArgumentException('points_must_be_non_negative');
		}
		return new self(AssetType::POINTS, $points);
	}

	public static function balance(string $decimal): self {
		$decimal = trim($decimal);
		if (!preg_match('/^(0|[1-9]\d*)(?:\.(\d{1,2}))?$/', $decimal, $matches)) {
			throw new \InvalidArgumentException('balance_decimal_invalid');
		}
		$whole = (int) $matches[1];
		$fraction = str_pad((string) ($matches[2] ?? ''), 2, '0');
		if ($whole > intdiv(PHP_INT_MAX - (int) $fraction, 100)) {
			throw new \InvalidArgumentException('balance_decimal_overflow');
		}
		return new self(AssetType::BALANCE, ($whole * 100) + (int) $fraction);
	}

	public static function balance_minor(string $decimal): int {
		return self::balance($decimal)->minor();
	}

	public static function decimal_from_minor(int $minor): string {
		return self::from_minor(AssetType::BALANCE, $minor)->decimal();
	}

	/**
	 * Apply an integer percentage using half-up rounding without floats.
	 */
	public static function percentage(int $minor, int $percent): int {
		if ($minor < 0) {
			throw new \InvalidArgumentException('asset_minor_must_be_non_negative');
		}
		if ($percent < 0 || $percent > 100) {
			throw new \InvalidArgumentException('asset_percentage_invalid');
		}

		$whole = intdiv($minor, 100) * $percent;
		$remainder = ($minor % 100) * $percent;
		return $whole + intdiv($remainder + 50, 100);
	}

	public static function from_minor(AssetType|string $asset, int $minor): self {
		if ($minor < 0) {
			throw new \InvalidArgumentException('asset_minor_must_be_non_negative');
		}
		return new self(AssetType::from_value($asset), $minor);
	}

	public function asset(): AssetType {
		return $this->asset;
	}

	public function minor(): int {
		return $this->minor;
	}

	public function decimal(): string {
		if ($this->asset === AssetType::POINTS) {
			return (string) $this->minor;
		}
		return sprintf('%d.%02d', intdiv($this->minor, 100), $this->minor % 100);
	}

	public function formatted(): string {
		if ($this->asset === AssetType::POINTS) {
			return number_format_i18n($this->minor);
		}
		global $wp_locale;
		$decimal_point = isset($wp_locale->number_format['decimal_point']) ? $wp_locale->number_format['decimal_point'] : '.';
		return number_format_i18n(intdiv($this->minor, 100)) . $decimal_point . sprintf('%02d', $this->minor % 100);
	}
}