<?php
/**
 * Badges: earned automatically at a milestone, or given by the community team.
 *
 * @package SpaceBay
 */

namespace SpaceBay\Gamification;

use SpaceBay\Core\Settings;
use SpaceBay\Database\Tables;
use SpaceBay\Support\Slug;
use SpaceBay\Support\Time;

defined( 'ABSPATH' ) || exit;

/**
 * Badge catalogue and awards.
 */
final class Badges {

	/**
	 * Most badges a community can define.
	 *
	 * @var int
	 */
	const MAX = 40;

	/**
	 * What a badge can be earned for. "manual" badges are only given by the team.
	 *
	 * @var string[]
	 */
	const METRICS = array( 'manual', 'posts', 'comments', 'likes', 'points', 'visits', 'events' );

	/**
	 * Colours offered for badges. Each has at least 4.5:1 contrast with white.
	 *
	 * @var string[]
	 */
	const COLORS = array( '#3f22ff', '#0369a1', '#6d28d9', '#b45309', '#be123c', '#0f766e', '#4338ca', '#a21caf', '#475569' );

	/**
	 * The badges new communities start with.
	 *
	 * @return array[]
	 */
	public static function defaults() {
		$badges = array(
			self::row( 'first-post', __( 'First post', 'spacebay' ), __( 'Published a first post.', 'spacebay' ), 'megaphone', '#3f22ff', 'posts', 1 ),
			self::row( 'first-comment', __( 'First reply', 'spacebay' ), __( 'Wrote a first comment.', 'spacebay' ), 'chat', '#0369a1', 'comments', 1 ),
			self::row( 'storyteller', __( 'Storyteller', 'spacebay' ), __( 'Published 10 posts.', 'spacebay' ), 'book', '#6d28d9', 'posts', 10 ),
			self::row( 'conversationalist', __( 'Conversationalist', 'spacebay' ), __( 'Wrote 50 comments.', 'spacebay' ), 'wave', '#0f766e', 'comments', 50 ),
			self::row( 'well-liked', __( 'Well liked', 'spacebay' ), __( 'Got 25 likes on posts and comments.', 'spacebay' ), 'heart', '#be123c', 'likes', 25 ),
			self::row( 'crowd-favourite', __( 'Crowd favourite', 'spacebay' ), __( 'Got 100 likes on posts and comments.', 'spacebay' ), 'star', '#b45309', 'likes', 100 ),
			self::row( 'regular', __( 'Regular', 'spacebay' ), __( 'Visited the community on 30 different days.', 'spacebay' ), 'coffee', '#4338ca', 'visits', 30 ),
			self::row( 'event-goer', __( 'Event goer', 'spacebay' ), __( 'Said they were going to 5 events.', 'spacebay' ), 'party', '#a21caf', 'events', 5 ),
			self::row( 'champion', __( 'Community champion', 'spacebay' ), __( 'Earned 1,000 points.', 'spacebay' ), 'trophy', '#b45309', 'points', 1000 ),
		);

		/**
		 * Filters the badges new communities start with. SpaceBay Pro adds
		 * badges the team gives by hand.
		 *
		 * @since 1.0.0
		 *
		 * @param array[] $badges Badge definitions.
		 */
		return (array) apply_filters( 'spacebay_default_badges', $badges );
	}

	/**
	 * One badge definition.
	 *
	 * @param string $key         Key.
	 * @param string $name        Name.
	 * @param string $description Description.
	 * @param string $icon        Icon key from the space icon set.
	 * @param string $color       Colour.
	 * @param string $metric      One of METRICS.
	 * @param int    $threshold   Number to reach.
	 * @return array
	 */
	public static function row( $key, $name, $description, $icon, $color, $metric, $threshold ) {
		return array(
			'key'         => $key,
			'name'        => $name,
			'description' => $description,
			'icon'        => $icon,
			'color'       => $color,
			'metric'      => $metric,
			'threshold'   => $threshold,
			'enabled'     => true,
		);
	}

	/**
	 * Cleans the badge list from the settings screen.
	 *
	 * New badges get a key from their name. Keys never change after that,
	 * so members keep badges when a badge is renamed.
	 *
	 * @param array $input Raw rows.
	 * @return array[]|null
	 */
	public static function sanitize( array $input ) {
		$rows = array();
		$keys = array();

		foreach ( array_slice( array_values( $input ), 0, self::MAX ) as $row ) {
			if ( ! is_array( $row ) ) {
				continue;
			}

			$name = mb_substr( trim( sanitize_text_field( (string) ( $row['name'] ?? '' ) ) ), 0, 40 );

			if ( '' === $name ) {
				continue;
			}

			$key = substr( Slug::make( (string) ( $row['key'] ?? '' ) ), 0, 40 );

			if ( '' === $key ) {
				$key = substr( Slug::make( $name ), 0, 32 );
				$key = '' === $key ? 'badge' : $key;
			}

			$base   = $key;
			$suffix = 2;

			while ( isset( $keys[ $key ] ) ) {
				$key = substr( $base, 0, 36 ) . '-' . $suffix;
				++$suffix;
			}

			$keys[ $key ] = true;
			$metric       = sanitize_key( (string) ( $row['metric'] ?? 'manual' ) );
			$metric       = in_array( $metric, self::METRICS, true ) ? $metric : 'manual';
			$color        = sanitize_hex_color( (string) ( $row['color'] ?? '' ) );

			$rows[] = array(
				'key'         => $key,
				'name'        => $name,
				'description' => mb_substr( trim( sanitize_text_field( (string) ( $row['description'] ?? '' ) ) ), 0, 140 ),
				'icon'        => substr( sanitize_key( (string) ( $row['icon'] ?? '' ) ), 0, 32 ),
				'color'       => $color ? strtolower( $color ) : self::COLORS[0],
				'metric'      => $metric,
				'threshold'   => 'manual' === $metric ? 0 : max( 1, min( 1000000, (int) ( $row['threshold'] ?? 1 ) ) ),
				'enabled'     => ! isset( $row['enabled'] ) || rest_sanitize_boolean( $row['enabled'] ),
			);
		}

		return $rows;
	}

	/**
	 * Every badge definition, keyed by key.
	 *
	 * @param bool $enabled_only Leave out switched-off badges.
	 * @return array<string, array>
	 */
	public static function all( $enabled_only = false ) {
		$badges = Settings::get( 'badges' );
		$badges = is_array( $badges ) ? $badges : self::defaults();
		$map    = array();

		foreach ( $badges as $badge ) {
			if ( ! is_array( $badge ) || empty( $badge['key'] ) || ( $enabled_only && empty( $badge['enabled'] ) ) ) {
				continue;
			}

			$map[ $badge['key'] ] = $badge;
		}

		return $map;
	}

	/**
	 * The numbers badges look at for one member.
	 *
	 * @param int $user_id Member.
	 * @return array<string, int>
	 */
	public static function metrics( $user_id ) {
		$counts = Points::counts( $user_id );

		return array(
			'posts'    => $counts['post'],
			'comments' => $counts['comment'],
			'likes'    => $counts['like'],
			'visits'   => $counts['daily'],
			'events'   => $counts['event'],
			'points'   => Points::total( $user_id ),
		);
	}

	/**
	 * Gives a member every automatic badge they have reached.
	 *
	 * @param int  $user_id Member.
	 * @param bool $notify  Whether to send a notification for new badges.
	 * @return string[] Keys of new badges.
	 */
	public static function check( $user_id, $notify = true ) {
		$user_id = absint( $user_id );

		if ( ! $user_id ) {
			return array();
		}

		$metrics = self::metrics( $user_id );
		$owned   = self::keys_of( $user_id );
		$new     = array();

		foreach ( self::all( true ) as $key => $badge ) {
			if ( 'manual' === $badge['metric'] || in_array( $key, $owned, true ) ) {
				continue;
			}

			if ( ( $metrics[ $badge['metric'] ] ?? 0 ) >= (int) $badge['threshold'] && self::award( $user_id, $key, 0, $notify ) ) {
				$new[] = $key;
			}
		}

		return $new;
	}

	/**
	 * Gives a badge to a member.
	 *
	 * @param int    $user_id    Member.
	 * @param string $key        Badge key.
	 * @param int    $awarded_by Team member who gave it, 0 when earned.
	 * @param bool   $notify     Whether to notify the member.
	 * @return bool Whether the badge is new for the member.
	 */
	public static function award( $user_id, $key, $awarded_by = 0, $notify = true ) {
		global $wpdb;

		$badges = self::all();

		if ( ! isset( $badges[ $key ] ) ) {
			return false;
		}

		$added = $wpdb->query( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table; the unique key keeps one row per badge.
			$wpdb->prepare(
				'INSERT IGNORE INTO %i (user_id, badge, awarded_by, created_at) VALUES (%d, %s, %d, %s)',
				Tables::name( 'user_badges' ),
				absint( $user_id ),
				$key,
				absint( $awarded_by ),
				Time::now()
			)
		);

		if ( ! $added ) {
			return false;
		}

		/**
		 * Fires after a member gets a badge.
		 *
		 * @since 1.0.0
		 *
		 * @param int    $user_id    Member.
		 * @param string $key        Badge key.
		 * @param int    $awarded_by Team member who gave it, 0 when earned.
		 * @param int    $row_id     Award ID.
		 * @param bool   $notify     Whether the member should be notified.
		 */
		do_action( 'spacebay_badge_awarded', absint( $user_id ), $key, absint( $awarded_by ), (int) $wpdb->insert_id, $notify );

		return true;
	}

	/**
	 * Takes a badge away.
	 *
	 * @param int    $user_id Member.
	 * @param string $key     Badge key.
	 * @return bool
	 */
	public static function revoke( $user_id, $key ) {
		global $wpdb;

		return (bool) $wpdb->delete( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table.
			Tables::name( 'user_badges' ),
			array(
				'user_id' => absint( $user_id ),
				'badge'   => (string) $key,
			)
		);
	}

	/**
	 * Keys of the badges a member has.
	 *
	 * @param int $user_id Member.
	 * @return string[]
	 */
	public static function keys_of( $user_id ) {
		global $wpdb;

		return array_map(
			'strval',
			(array) $wpdb->get_col( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Fresh read.
				$wpdb->prepare( 'SELECT badge FROM %i WHERE user_id = %d', Tables::name( 'user_badges' ), absint( $user_id ) )
			)
		);
	}

	/**
	 * A member's badges with their definition, newest first. Badges that were
	 * deleted or switched off are left out.
	 *
	 * @param int $user_id Member.
	 * @return array[]
	 */
	public static function of_user( $user_id ) {
		global $wpdb;

		$rows   = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Fresh read for one profile.
			$wpdb->prepare( 'SELECT badge, awarded_by, created_at FROM %i WHERE user_id = %d ORDER BY created_at DESC, id DESC', Tables::name( 'user_badges' ), absint( $user_id ) ),
			ARRAY_A
		);
		$badges = self::all( true );
		$items  = array();

		foreach ( (array) $rows as $row ) {
			if ( isset( $badges[ $row['badge'] ] ) ) {
				$items[] = array_merge(
					self::format( $badges[ $row['badge'] ] ),
					array(
						'earned'     => true,
						'given'      => (int) $row['awarded_by'] > 0,
						'awarded_at' => Time::iso( $row['created_at'] ),
					)
				);
			}
		}

		return $items;
	}

	/**
	 * Number of badges per member for a list of members.
	 *
	 * @param int[] $user_ids Members.
	 * @return array<int, int>
	 */
	public static function count_many( array $user_ids ) {
		global $wpdb;

		$user_ids = array_values( array_filter( array_map( 'absint', $user_ids ) ) );
		$keys     = array_keys( self::all( true ) );

		if ( ! $user_ids || ! $keys ) {
			return array();
		}

		$placeholders = implode( ',', array_fill( 0, count( $user_ids ), '%d' ) );
		$rows         = $wpdb->get_results( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One query per leaderboard page.
			$wpdb->prepare( // phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber -- The IN() list has one %d per ID.
				"SELECT user_id, badge FROM %i WHERE user_id IN ($placeholders)", // phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare, WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber, WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Placeholders are built from %d only.
				array_merge( array( Tables::name( 'user_badges' ) ), $user_ids )
			),
			ARRAY_A
		);
		$counts       = array();

		foreach ( (array) $rows as $row ) {
			if ( in_array( $row['badge'], $keys, true ) ) {
				$counts[ (int) $row['user_id'] ] = ( $counts[ (int) $row['user_id'] ] ?? 0 ) + 1;
			}
		}

		return $counts;
	}

	/**
	 * Every enabled badge with a member's progress, for their own profile.
	 *
	 * @param int $user_id Member.
	 * @return array[]
	 */
	public static function progress( $user_id ) {
		$metrics = self::metrics( $user_id );
		$owned   = array();
		$items   = array();

		foreach ( self::of_user( $user_id ) as $badge ) {
			$owned[ $badge['key'] ] = $badge;
		}

		foreach ( self::all( true ) as $key => $badge ) {
			if ( isset( $owned[ $key ] ) ) {
				$items[] = $owned[ $key ];
				continue;
			}

			// Badges the team gives by hand are only listed to members once given.
			if ( 'manual' === $badge['metric'] ) {
				continue;
			}

			$current = (int) ( $metrics[ $badge['metric'] ] ?? 0 );
			$items[] = array_merge(
				self::format( $badge ),
				array(
					'earned'  => false,
					'given'   => false,
					'current' => min( $current, (int) $badge['threshold'] ),
				)
			);
		}

		return $items;
	}

	/**
	 * Public fields of a badge.
	 *
	 * @param array $badge Definition.
	 * @return array
	 */
	public static function format( array $badge ) {
		return array(
			'key'         => (string) $badge['key'],
			'name'        => (string) $badge['name'],
			'description' => (string) $badge['description'],
			'icon'        => (string) $badge['icon'],
			'color'       => (string) $badge['color'],
			'metric'      => (string) $badge['metric'],
			'threshold'   => (int) $badge['threshold'],
		);
	}

	/**
	 * Removes every badge of a member.
	 *
	 * @param int $user_id Member.
	 * @return void
	 */
	public static function delete_for_user( $user_id ) {
		global $wpdb;

		$wpdb->delete( Tables::name( 'user_badges' ), array( 'user_id' => absint( $user_id ) ) ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Custom table.
	}
}