<?php
namespace Strikewise\Migration;

defined( 'ABSPATH' ) || exit;

/**
 * One price record of the "Omnibus — show the lowest price" plugin (iworks),
 * normalized to what Strikewise stores.
 *
 * Omnibus writes snapshots in several shapes over its versions:
 * - 3.x: price (effective), price_regular, price_sale, price_including_tax, currency, timestamp, user_id
 * - _iwo_price_last_change: price (= REGULAR price), price_sale, price_including_tax, timestamp
 * - older 2.x: price (effective), price_sale, timestamp
 *
 * Pure PHP; the conversion of net to gross prices is injected.
 */
final class OmnibusSnapshot {

	/** @var int */
	public $timestamp;

	/** @var float Final consumer price incl. VAT. */
	public $price;

	/** @var float|null */
	public $regular_price;

	/** @var bool */
	public $reduced;

	/** @var string|null Null if the record has no currency (older versions). */
	public $currency;

	/** @var int|null */
	public $user_id;

	/**
	 * @param array<string,mixed> $data             One Omnibus record.
	 * @param int|null            $fallback_ts      E.g. the post date of a 3.x log post.
	 * @param bool                $price_is_regular True for _iwo_price_last_change records.
	 * @param callable            $to_gross         float $net -> float $gross, using the current tax setup.
	 */
	public static function from_record( array $data, ?int $fallback_ts, bool $price_is_regular, callable $to_gross ): ?self {
		$timestamp = isset( $data['timestamp'] ) && is_numeric( $data['timestamp'] ) && (int) $data['timestamp'] > 0
			? (int) $data['timestamp']
			: $fallback_ts;

		if ( null === $timestamp ) {
			return null;
		}

		$sale = self::number( $data['price_sale'] ?? null );

		if ( array_key_exists( 'price_regular', $data ) ) {
			$effective = self::number( $data['price'] ?? null );
			$regular   = self::number( $data['price_regular'] );
		} elseif ( $price_is_regular ) {
			$regular   = self::number( $data['price'] ?? null );
			$effective = null !== $sale && null !== $regular && $sale < $regular ? $sale : $regular;
		} else {
			$effective = self::number( $data['price'] ?? null );
			$regular   = null;
		}

		if ( null === $effective ) {
			return null;
		}

		// The gross price Omnibus stored is the effective price incl. VAT at that time.
		$stored_gross = self::number( $data['price_including_tax'] ?? null );
		if ( null !== $stored_gross && $stored_gross > 0 && $effective > 0 ) {
			$gross     = $stored_gross;
			$tax_ratio = $stored_gross / $effective;
		} else {
			$gross     = (float) $to_gross( $effective );
			$tax_ratio = $effective > 0 ? $gross / $effective : 1.0;
		}

		$snapshot                = new self();
		$snapshot->timestamp     = $timestamp;
		$snapshot->price         = round( $gross, 4 );
		$snapshot->regular_price = null === $regular ? null : round( $regular * $tax_ratio, 4 );
		$snapshot->reduced       = null !== $sale && abs( $effective - $sale ) < 0.005 && ( null === $regular || $sale < $regular );
		$snapshot->currency      = isset( $data['currency'] ) && is_string( $data['currency'] ) && '' !== $data['currency'] ? strtoupper( $data['currency'] ) : null;
		$snapshot->user_id       = isset( $data['user_id'] ) && (int) $data['user_id'] > 0 ? (int) $data['user_id'] : null;

		return $snapshot;
	}

	public function same_price_as( self $other ): bool {
		return abs( $this->price - $other->price ) < 0.00005
			&& $this->reduced === $other->reduced
			&& ( null === $this->regular_price ) === ( null === $other->regular_price )
			&& ( null === $this->regular_price || abs( $this->regular_price - (float) $other->regular_price ) < 0.00005 );
	}

	/**
	 * @param mixed $value
	 */
	private static function number( $value ): ?float {
		if ( is_int( $value ) || is_float( $value ) ) {
			return (float) $value;
		}
		if ( is_string( $value ) ) {
			$value = trim( str_replace( ',', '.', $value ) );
			if ( '' !== $value && is_numeric( $value ) ) {
				return (float) $value;
			}
		}
		return null;
	}
}