<?php
/**
 * Storage for coupon campaigns.
 *
 * @package CNWS\Coupons
 */

namespace CNWS\Coupons;

use WP_Error;

defined( 'ABSPATH' ) || exit;

// phpcs:disable WordPress.DB.DirectDatabaseQuery -- Plugin-owned table, named through the %i placeholder.

final class CampaignRepository {

	/**
	 * @var array<int, Campaign|null>
	 */
	private array $cache = array();

	public function __construct(
		private CategoryRepository $categories,
		private CodeRepository $codes
	) {}

	public function find( int $id ): ?Campaign {
		global $wpdb;

		if ( ! array_key_exists( $id, $this->cache ) ) {
			$row = $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM %i WHERE id = %d', Tables::campaigns(), $id ) );

			$this->cache[ $id ] = $row ? Campaign::from_row( $row ) : null;
		}

		return $this->cache[ $id ];
	}

	public function find_by_slug( string $slug ): ?Campaign {
		global $wpdb;

		$row = $wpdb->get_row( $wpdb->prepare( 'SELECT * FROM %i WHERE slug = %s', Tables::campaigns(), sanitize_title( $slug ) ) );

		return $row ? Campaign::from_row( $row ) : null;
	}

	/**
	 * @param string $status 'active', 'ended' or '' for all.
	 * @param string $type   'personal', 'shared' or '' for all.
	 * @return Campaign[] Newest first.
	 */
	public function all( string $status = '', string $type = '' ): array {
		global $wpdb;

		$rows = (array) $wpdb->get_results(
			$wpdb->prepare(
				"SELECT * FROM %i WHERE ( %s = '' OR status = %s ) AND ( %s = '' OR type = %s ) ORDER BY created_at DESC",
				Tables::campaigns(),
				$status,
				$status,
				$type,
				$type
			)
		);

		return array_map( array( Campaign::class, 'from_row' ), $rows );
	}

	/**
	 * Create a campaign from user input. A shared campaign gets its code right away.
	 *
	 * @param array $data Raw values, see sanitize(), plus 'category' (name) and 'shared_code'.
	 * @return Campaign|WP_Error
	 */
	public function create( array $data ) {
		global $wpdb;

		$row = self::sanitize( $data );

		if ( $row instanceof WP_Error ) {
			return $row;
		}

		if ( $this->find_by_slug( $row['slug'] ) ) {
			return new WP_Error( 'cnwscoupons_campaign_exists', __( 'A campaign with this slug already exists.', 'webstyle-coupons' ) );
		}

		$shared_code = '';

		if ( Campaign::TYPE_SHARED === $row['type'] ) {
			$shared_code = self::normalize_shared_code( (string) ( $data['shared_code'] ?? '' ) );

			if ( '' === $shared_code ) {
				return new WP_Error( 'cnwscoupons_shared_code', __( 'A shared code needs 3 to 40 letters, digits or hyphens.', 'webstyle-coupons' ) );
			}

			if ( ! $this->code_available( $shared_code ) ) {
				return new WP_Error( 'cnwscoupons_shared_code_taken', __( 'This code is already in use. Choose another.', 'webstyle-coupons' ) );
			}
		}

		$now = current_time( 'mysql', true );

		$category_id = $this->categories->find_or_create( (string) ( $data['category'] ?? '' ) );

		$row['category_id'] = $category_id ? $category_id : null;
		$row['status']      = 'active';
		$row['created_at']  = $now;
		$row['updated_at']  = $now;

		if ( ! $wpdb->insert( Tables::campaigns(), $row ) ) {
			return new WP_Error( 'cnwscoupons_campaign_failed', __( 'The campaign could not be saved.', 'webstyle-coupons' ) );
		}

		$campaign = $this->find( (int) $wpdb->insert_id );

		if ( $campaign && '' !== $shared_code ) {
			$this->codes->insert( $campaign->id, $shared_code, '', 'shared', Issuer::expires_at( $campaign, time() ) );
		}

		return $campaign;
	}

	/**
	 * Change a campaign. Its slug, type and shared code stay as they are: other plugins and printed
	 * material refer to them. Changing the end date or valid days moves the expiry of codes already
	 * issued, so customers get what the campaign now says.
	 *
	 * @param int   $id   Campaign ID.
	 * @param array $data Raw values as for create(); 'extensions' is kept when left out.
	 * @return Campaign|WP_Error
	 */
	public function update( int $id, array $data ) {
		global $wpdb;

		$campaign = $this->find( $id );

		if ( ! $campaign ) {
			return new WP_Error( 'cnwscoupons_campaign_missing', __( 'The campaign does not exist.', 'webstyle-coupons' ) );
		}

		$data['slug'] = $campaign->slug;
		$data['type'] = $campaign->type;
		$row          = self::sanitize( $data );

		if ( $row instanceof WP_Error ) {
			return $row;
		}

		unset( $row['slug'], $row['type'] );

		if ( ! array_key_exists( 'extensions', $data ) ) {
			unset( $row['extensions'] );
		}

		$category_id = $this->categories->find_or_create( (string) ( $data['category'] ?? '' ) );

		$row['category_id'] = $category_id ? $category_id : null;
		$row['updated_at']  = current_time( 'mysql', true );

		if ( false === $wpdb->update( Tables::campaigns(), $row, array( 'id' => $id ) ) ) {
			return new WP_Error( 'cnwscoupons_campaign_failed', __( 'The campaign could not be saved.', 'webstyle-coupons' ) );
		}

		unset( $this->cache[ $id ] );
		$updated = $this->find( $id );

		if ( $updated && ( $updated->expires_on !== $campaign->expires_on || $updated->valid_days !== $campaign->valid_days ) ) {
			$this->codes->refresh_expiry( $updated );
		}

		return $updated;
	}

	/**
	 * End a campaign, or start it again. An ended campaign issues no new codes; issued personal
	 * codes keep working until they expire, a shared code stops.
	 *
	 * @param int    $id     Campaign ID.
	 * @param string $status 'active' or 'ended'.
	 */
	public function set_status( int $id, string $status ): bool {
		global $wpdb;

		if ( ! in_array( $status, Campaign::STATUSES, true ) || ! $this->find( $id ) ) {
			return false;
		}

		$saved = false !== $wpdb->update(
			Tables::campaigns(),
			array(
				'status'     => $status,
				'updated_at' => current_time( 'mysql', true ),
			),
			array( 'id' => $id )
		);

		unset( $this->cache[ $id ] );

		return $saved;
	}

	/**
	 * Whether a code is free: not one of ours and not one of the shop's own WooCommerce coupons.
	 *
	 * @param string $code Code in any case.
	 */
	public function code_available( string $code ): bool {
		return ! $this->codes->code_exists( $code ) && ! ( function_exists( 'wc_get_coupon_id_by_code' ) && wc_get_coupon_id_by_code( $code ) );
	}

	/**
	 * Store an add-on's settings on a campaign, e.g. Checkout Optimizer Pro's free-shipping choice.
	 * The settings stay when the add-on is deactivated, so they work again when it comes back.
	 *
	 * @param int    $campaign_id Campaign ID.
	 * @param string $key         Add-on key, e.g. 'cnws-checkout-optimizer-pro'.
	 * @param array  $settings    Settings; an empty array removes them.
	 */
	public function save_extension( int $campaign_id, string $key, array $settings ): bool {
		global $wpdb;

		$campaign = $this->find( $campaign_id );
		$key      = sanitize_key( $key );

		if ( ! $campaign || '' === $key ) {
			return false;
		}

		$extensions = $campaign->extensions;

		if ( $settings ) {
			$extensions[ $key ] = $settings;
		} else {
			unset( $extensions[ $key ] );
		}

		$saved = false !== $wpdb->update(
			Tables::campaigns(),
			array(
				'extensions' => wp_json_encode( $extensions ),
				'updated_at' => current_time( 'mysql', true ),
			),
			array( 'id' => $campaign_id )
		);

		unset( $this->cache[ $campaign_id ] );

		return $saved;
	}

	/**
	 * Validate and normalize campaign input into a database row.
	 *
	 * @param array $data Raw values: name, slug, type, discount_type, amount, starts_on, expires_on,
	 *                    valid_days, code_prefix, max_codes, uses_per_code, max_redemptions,
	 *                    max_per_email, restrictions (see Restrictions::from_array()),
	 *                    email_restricted, extensions.
	 * @return array|WP_Error
	 */
	public static function sanitize( array $data ) {
		$name = sanitize_text_field( (string) ( $data['name'] ?? '' ) );
		$slug = sanitize_title( (string) ( $data['slug'] ?? $name ) );
		$type = (string) ( $data['type'] ?? Campaign::TYPE_PERSONAL );
		$kind = (string) ( $data['discount_type'] ?? 'percent' );

		if ( '' === $name || '' === $slug ) {
			return new WP_Error( 'cnwscoupons_campaign_name', __( 'The campaign needs a name.', 'webstyle-coupons' ) );
		}

		if ( ! in_array( $type, Campaign::TYPES, true ) ) {
			return new WP_Error( 'cnwscoupons_campaign_type', __( 'Unknown campaign type.', 'webstyle-coupons' ) );
		}

		if ( ! in_array( $kind, Campaign::DISCOUNT_TYPES, true ) ) {
			return new WP_Error( 'cnwscoupons_campaign_discount_type', __( 'Unknown discount type.', 'webstyle-coupons' ) );
		}

		$amount = (float) ( $data['amount'] ?? 0 );

		if ( $amount <= 0 || ( 'percent' === $kind && $amount > 100 ) ) {
			return new WP_Error( 'cnwscoupons_campaign_amount', __( 'The discount must be above zero, and at most 100 for a percentage.', 'webstyle-coupons' ) );
		}

		$starts_on  = (string) ( $data['starts_on'] ?? '' );
		$expires_on = (string) ( $data['expires_on'] ?? '' );

		foreach ( array( $starts_on, $expires_on ) as $date ) {
			if ( '' !== $date && ! preg_match( '/^\d{4}-\d{2}-\d{2}$/', $date ) ) {
				return new WP_Error( 'cnwscoupons_campaign_date', __( 'Dates must be written as YYYY-MM-DD.', 'webstyle-coupons' ) );
			}
		}

		if ( '' !== $starts_on && '' !== $expires_on && $expires_on < $starts_on ) {
			return new WP_Error( 'cnwscoupons_campaign_dates', __( 'The end date is before the start date.', 'webstyle-coupons' ) );
		}

		$shared       = Campaign::TYPE_SHARED === $type;
		$restrictions = Restrictions::from_array( $data['restrictions'] ?? array() );

		if ( null !== $restrictions->minimum_amount && null !== $restrictions->maximum_amount && $restrictions->maximum_amount < $restrictions->minimum_amount ) {
			return new WP_Error( 'cnwscoupons_campaign_amounts', __( 'The maximum cart amount is below the minimum.', 'webstyle-coupons' ) );
		}

		return array(
			'slug'             => substr( $slug, 0, 100 ),
			'name'             => substr( $name, 0, 190 ),
			'type'             => $type,
			'discount_type'    => $kind,
			'amount'           => $amount,
			'starts_on'        => '' !== $starts_on ? $starts_on : null,
			'expires_on'       => '' !== $expires_on ? $expires_on : null,
			'valid_days'       => ! $shared && absint( $data['valid_days'] ?? 0 ) ? absint( $data['valid_days'] ) : null,
			'code_prefix'      => $shared ? '' : CodeGenerator::normalize_prefix( (string) ( $data['code_prefix'] ?? '' ) ),
			'max_codes'        => ! $shared && absint( $data['max_codes'] ?? 0 ) ? absint( $data['max_codes'] ) : null,
			'uses_per_code'    => $shared ? 1 : max( 1, absint( $data['uses_per_code'] ?? 1 ) ),
			'max_redemptions'  => $shared && absint( $data['max_redemptions'] ?? 0 ) ? absint( $data['max_redemptions'] ) : null,
			'max_per_email'    => $shared && absint( $data['max_per_email'] ?? 0 ) ? absint( $data['max_per_email'] ) : null,
			'restrictions'     => wp_json_encode( $restrictions->to_array() ),
			// A shared code is used by many people, so it cannot be bound to one address.
			'email_restricted' => $shared ? 0 : ( array_key_exists( 'email_restricted', $data ) ? (int) (bool) $data['email_restricted'] : 1 ),
			'extensions'       => wp_json_encode( is_array( $data['extensions'] ?? null ) ? $data['extensions'] : array() ),
		);
	}

	/**
	 * A shop-chosen code such as FOD20: upper case letters, digits and hyphens, 3 to 40 characters.
	 *
	 * @param string $code Code as typed.
	 * @return string The code, or '' when it is not usable.
	 */
	public static function normalize_shared_code( string $code ): string {
		$code = strtoupper( trim( $code ) );

		return preg_match( '/^[A-Z0-9][A-Z0-9-]{1,38}[A-Z0-9]$/', $code ) ? $code : '';
	}
}