<?php
namespace Advently\Calendar;

defined( 'ABSPATH' ) || exit;

/**
 * The ready-made calendar the setup wizard creates: a rhythm of offers a
 * store owner can keep as it is or edit door by door.
 *
 * Pure PHP. It decides what kind of door each day is; the WordPress layer
 * puts real products and translated texts in (see Rest\AdminController).
 */
final class Seed {

	/**
	 * 24 days of December. Small offers most days, a free gift now and then,
	 * gift ideas that link to products, a bigger offer halfway and on the last day.
	 * Free shipping lands near the end, when it matters most.
	 */
	const PLAN = [
		[ 'percent', 10 ],
		[ 'free_shipping', 0, 30 ],
		[ 'percent', 5, 0, 'gift' ],
		[ 'fixed_cart', 5, 40 ],
		[ 'percent', 15 ],
		[ 'free_product' ],
		[ 'content', 0, 0, 'gift' ],
		[ 'percent', 10 ],
		[ 'fixed_cart', 10, 60 ],
		[ 'free_shipping' ],
		[ 'percent', 10, 0, 'gift' ],
		[ 'percent', 20, 0, 'halfway' ],
		[ 'percent', 10 ],
		[ 'content', 0, 0, 'gift' ],
		[ 'fixed_cart', 5, 40 ],
		[ 'free_shipping' ],
		[ 'percent', 15 ],
		[ 'free_product' ],
		[ 'percent', 10, 0, 'gift' ],
		[ 'free_shipping', 0, 0, 'last_shipping' ],
		[ 'fixed_cart', 10, 60 ],
		[ 'percent', 15 ],
		[ 'free_shipping' ],
		[ 'percent', 25, 0, 'finale' ],
	];

	/**
	 * One spec per door: what kind of door it is and which text it carries.
	 * Calendars longer than the plan repeat its middle; the last door is always the finale.
	 *
	 * @return array<int, array{type:string, kind:?string, amount:float, min_spend:float, note:?string}>
	 */
	public static function plan( int $doors ): array {
		$doors = max( 1, $doors );
		$specs = [];
		for ( $n = 1; $n <= $doors; $n++ ) {
			if ( $n === $doors && $doors > 1 ) {
				$row = self::PLAN[ count( self::PLAN ) - 1 ];
			} elseif ( $n <= count( self::PLAN ) - 1 ) {
				$row = self::PLAN[ $n - 1 ];
			} else {
				// Past day 23: cycle days 5–23 again.
				$row = self::PLAN[ 4 + ( ( $n - 24 ) % 19 ) ];
			}
			$specs[ $n ] = self::spec( $row );
		}
		return $specs;
	}

	/**
	 * Turns specs into a door_list for Config::sanitize(). $gifts are product ids
	 * for gift-idea doors (used in turn), $freeProduct the product a free-gift
	 * door gives away (0 = none, the door falls back to 10% off), $texts the
	 * translated wording keyed by note.
	 *
	 * @param int[] $gifts
	 * @param array<string, array{title:string, message:string, button:string}> $texts
	 */
	public static function doors( int $doors, array $gifts, int $freeProduct, array $texts ): array {
		$list = [];
		$gift = 0;
		foreach ( self::plan( $doors ) as $n => $spec ) {
			$door = Config::defaultDoor();
			$kind = $spec['kind'];

			if ( 'free_product' === $kind && $freeProduct <= 0 ) {
				$kind           = 'percent';
				$spec['amount'] = 10.0;
			}

			$door['type'] = $spec['type'];
			// Content doors keep the default coupon, ready if the owner adds one later.
			if ( null !== $kind ) {
				$door['coupon']['kind']           = $kind;
				$door['coupon']['amount']         = $spec['amount'];
				$door['coupon']['min_spend']      = $spec['min_spend'];
				$door['coupon']['validity_hours'] = 'finale' === $spec['note'] ? 0 : 24;
				if ( 'free_product' === $kind ) {
					// Only reached when an add-on registers the kind and supplies the product.
					$door['coupon']['product_id'] = $freeProduct;
				}
			}

			$note = $spec['note'];
			if ( 'gift' === $note && ! $gifts ) {
				// No products to suggest: a gift-idea door without a product is just a coupon.
				$note         = null;
				$door['type'] = 'coupon';
			}

			if ( null !== $note && isset( $texts[ $note ] ) ) {
				$product = 0;
				if ( 'gift' === $note ) {
					$product = $gifts[ $gift % count( $gifts ) ];
					++$gift;
				}

				$door['content'] = [
					'title'        => $texts[ $note ]['title'],
					'message'      => $texts[ $note ]['message'],
					'image_id'     => 0,
					'product_id'   => $product,
					'button_label' => $texts[ $note ]['button'],
				];
				if ( 'coupon' === $door['type'] ) {
					$door['type'] = 'coupon_content';
				}
			}

			$list[ $n ] = $door;
		}
		return $list;
	}

	private static function spec( array $row ): array {
		$kind = $row[0];
		return [
			'type'      => 'content' === $kind ? 'content' : 'coupon',
			'kind'      => 'content' === $kind ? null : $kind,
			'amount'    => (float) ( $row[1] ?? 0 ),
			'min_spend' => (float) ( $row[2] ?? 0 ),
			'note'      => $row[3] ?? null,
		];
	}
}