<?php

namespace Alexr\Settings\Traits;


trait ManageOffers
{
	use MatchesScheduleRule;

	public function isOffersActive()
	{
		return $this->offers_active == 'yes';
	}

	public function getOffersRules()
	{
		$rules = $this->offers_rules;
		if (is_array($rules)) {
			return $rules;
		}
		return [];
	}

	/**
	 * Iterate the offer rules and return the first matching for the given
	 * date/time and (optionally) party size. Returns null if no offer rule
	 * matches or offers are disabled.
	 *
	 * @param string $date Y-m-d
	 * @param int $time seconds from midnight
	 * @param int|null $party party size; when null the min/max_guests check
	 *                        on each rule is skipped.
	 *
	 * @return array|null
	 */
	public function getOfferRuleMatched($date, $time, $party = null)
	{
		if (!defined('ALEXR_PRO_VERSION')) return null;

		if (!$this->isOffersActive()) return null;

		foreach ($this->getOffersRules() as $rule) {
			if ($this->matchesScheduleRule($rule, $date, $time, $party)) {
				return $rule;
			}
		}

		return null;
	}

	public function getOfferRuleMatchedForBooking($booking)
	{
		return $this->getOfferRuleMatched($booking->date, $booking->time, $booking->party);
	}

	/**
	 * Compute the amount to charge for an offer rule.
	 *
	 * Pricing modes:
	 *  - 'fixed'              : flat amount per reservation
	 *  - 'per_seat'           : price per cover * party
	 *  - 'percentage_of_menu' : percentage of the menu subtotal selected by the customer
	 *
	 * @param array $rule
	 * @param int $party
	 * @param float $menu_subtotal subtotal of the offer/menu selection coming from the booking
	 *
	 * @return float
	 */
	public function getOfferRulePrice($rule, $party, $menu_subtotal = 0)
	{
		if (!isset($rule['payment_type'])) return 0;

		$payment_type = $rule['payment_type'];

		if ($payment_type == 'fixed') {
			return isset($rule['price_fixed']) ? floatval($rule['price_fixed']) : 0;
		}

		if ($payment_type == 'per_seat') {
			return isset($rule['price_per_seat']) ? intval($party) * floatval($rule['price_per_seat']) : 0;
		}

		if ($payment_type == 'percentage_of_menu') {
			$pct = isset($rule['price_percentage']) ? floatval($rule['price_percentage']) : 0;
			if ($pct <= 0) return 0;
			return floatval($menu_subtotal) * $pct / 100;
		}

		return 0;
	}

	/**
	 * Build a public payload for an offer ({id, name, enabled, sections}),
	 * suitable for rendering the menu selector in the widget / booking view.
	 * Returns null when the offer cannot be located for the restaurant.
	 *
	 * @param int $offer_id
	 *
	 * @return array|null
	 */
	public function getOfferPayload($offer_id)
	{
		$offer_id = intval($offer_id);
		if ($offer_id <= 0) return null;

		$restaurant_id = $this->restaurant_id ?? null;
		if (!$restaurant_id) return null;

		$offer = \Alexr\Settings\Offer::where('restaurant_id', $restaurant_id)
		                              ->where('id', $offer_id)
		                              ->first();
		if (!$offer) return null;

		$sections = $offer->sections;
		if (is_string($sections) && $sections !== '') {
			$decoded = json_decode($sections, true);
			if (is_array($decoded)) $sections = $decoded;
		}
		if (!is_array($sections)) $sections = [];

		return [
			'id'       => $offer->id,
			'name'     => $offer->name,
			'enabled'  => (bool) $offer->enabled,
			'sections' => $sections,
		];
	}

	/**
	 * Load and decode the sections of an offer.
	 * Returns an empty array when the offer cannot be located for the restaurant.
	 *
	 * @param int $offer_id
	 *
	 * @return array
	 */
	protected function loadOfferSections($offer_id)
	{
		$offer_id = intval($offer_id);
		if ($offer_id <= 0) return [];

		$restaurant_id = $this->restaurant_id ?? null;
		if (!$restaurant_id) return [];

		$offer = \Alexr\Settings\Offer::where('restaurant_id', $restaurant_id)
		                              ->where('id', $offer_id)
		                              ->first();
		if (!$offer) return [];

		$sections = $offer->sections;
		if (is_string($sections) && $sections !== '') {
			$decoded = json_decode($sections, true);
			if (is_array($decoded)) $sections = $decoded;
		}
		if (!is_array($sections)) return [];

		return $sections;
	}

	/**
	 * Build a lookup map [section_id][item_id] => item from offer sections.
	 *
	 * @param array $sections
	 *
	 * @return array
	 */
	protected function indexOfferItems($sections)
	{
		$index = [];
		foreach ($sections as $section) {
			if (!isset($section['id']) || !isset($section['items'])) continue;
			$index[$section['id']] = [];
			foreach ($section['items'] as $item) {
				if (!isset($item['id'])) continue;
				$index[$section['id']][$item['id']] = $item;
			}
		}
		return $index;
	}

	/**
	 * Per-unit price for an offer item, taking the section type and the item's
	 * price_mode into account. Mirrors the front-end pricing
	 * (OfferPreviewModal / WidgetMenuSelectionStep):
	 *
	 *  - per_guest_required / per_guest_optional: flat item price per unit.
	 *  - reservation_optional / single_offer_choice: price_mode aware
	 *      · flat               → price
	 *      · per_guest          → price * party
	 *      · base_plus_per_guest → base_price + per_guest_price * party
	 *
	 * @param string|null $section_type
	 * @param array $item
	 * @param int $party
	 *
	 * @return float
	 */
	protected function unitPriceForItem($section_type, $item, $party)
	{
		$party = max(1, intval($party));

		if ($section_type === 'reservation_optional' || $section_type === 'single_offer_choice') {
			$mode = isset($item['price_mode']) ? $item['price_mode'] : 'flat';
			if ($mode === 'per_guest') {
				return floatval($item['price'] ?? 0) * $party;
			}
			if ($mode === 'base_plus_per_guest') {
				return floatval($item['base_price'] ?? 0) + floatval($item['per_guest_price'] ?? 0) * $party;
			}
			return floatval($item['price'] ?? 0);
		}

		// per_guest_required / per_guest_optional / booking_optional (legacy)
		return floatval($item['price'] ?? 0);
	}

	/**
	 * Recompute the authoritative menu subtotal from a list of selected items.
	 * Client-side prices in $menu_lines are ignored — the price stored in the
	 * offer record (server side) is the source of truth.
	 *
	 * @param int $offer_id
	 * @param array $menu_lines each line: ['section_id' => string, 'item_id' => string, 'quantity' => int]
	 * @param int $party number of guests (needed for per_guest pricing modes)
	 *
	 * @return float
	 */
	public function recomputeMenuSubtotal($offer_id, $menu_lines, $party = 1)
	{
		if (!is_array($menu_lines) || empty($menu_lines)) return 0;

		$sections = $this->loadOfferSections($offer_id);
		if (empty($sections)) return 0;

		$section_by_id = [];
		foreach ($sections as $section) {
			if (isset($section['id'])) $section_by_id[$section['id']] = $section;
		}
		$index = $this->indexOfferItems($sections);

		$subtotal = 0;
		foreach ($menu_lines as $line) {
			if (!is_array($line)) continue;
			$section_id = isset($line['section_id']) ? $line['section_id'] : null;
			$item_id    = isset($line['item_id']) ? $line['item_id'] : null;
			$qty        = isset($line['quantity']) ? intval($line['quantity']) : 0;
			if (!$section_id || !$item_id || $qty <= 0) continue;
			if (!isset($index[$section_id][$item_id])) continue;
			$item = $index[$section_id][$item_id];
			$section_type = isset($section_by_id[$section_id]['type']) ? $section_by_id[$section_id]['type'] : null;
			$subtotal += $this->unitPriceForItem($section_type, $item, $party) * $qty;
		}

		return $subtotal;
	}

	/**
	 * Sanitise the menu lines for persistence: only keep lines that map to a
	 * known offer item, and replace the price/subtotal with the server price.
	 *
	 * @param int $offer_id
	 * @param array $menu_lines
	 * @param int $party number of guests (needed for per_guest pricing modes)
	 *
	 * @return array list of clean lines
	 */
	public function sanitiseMenuLines($offer_id, $menu_lines, $party = 1)
	{
		if (!is_array($menu_lines) || empty($menu_lines)) return [];

		$sections = $this->loadOfferSections($offer_id);
		if (empty($sections)) return [];

		$section_by_id = [];
		foreach ($sections as $section) {
			if (isset($section['id'])) $section_by_id[$section['id']] = $section;
		}
		$index = $this->indexOfferItems($sections);

		$clean = [];
		foreach ($menu_lines as $line) {
			if (!is_array($line)) continue;
			$section_id = isset($line['section_id']) ? $line['section_id'] : null;
			$item_id    = isset($line['item_id']) ? $line['item_id'] : null;
			$qty        = isset($line['quantity']) ? intval($line['quantity']) : 0;
			if (!$section_id || !$item_id || $qty <= 0) continue;
			if (!isset($index[$section_id][$item_id])) continue;

			$item = $index[$section_id][$item_id];
			$section_type = isset($section_by_id[$section_id]['type']) ? $section_by_id[$section_id]['type'] : null;
			$unit_price = $this->unitPriceForItem($section_type, $item, $party);

			$clean[] = [
				'section_id'   => $section_id,
				'section_type' => $section_type,
				'item_id'      => $item_id,
				'name'         => isset($item['name']) ? $item['name'] : null,
				'quantity'     => $qty,
				'unit_price'   => $unit_price,
				'subtotal'     => $unit_price * $qty,
			];
		}

		return $clean;
	}
}