<?php
/**
 * Eventin Schedules Tool
 *
 * @package Aisentic\Integrations\Eventin
 */

declare(strict_types=1);

namespace Aisentic\Integrations\Eventin;

use Aisentic\Contracts\Read_Only_Tool_Contract;
use Aisentic\Util\Log;
use NeuronAI\Tools\PropertyType;
use NeuronAI\Tools\ToolProperty;

defined( 'ABSPATH' ) || exit;

/**
 * Schedules: how many, what one schedule holds, and an event's agenda.
 *
 * A schedule is one day of an agenda, with sessions in it. The question
 * type depends on what the model passes in:
 *
 *   nothing        How many schedules and sessions, how many are used by an
 *                  event, and the next few coming up.
 *   schedule_name  One schedule and its sessions.
 *   event          The agenda of that event: every schedule and session.
 */
class Eventin_Schedules_Tool extends Eventin_Stats_Base_Tool implements Read_Only_Tool_Contract {

	/**
	 * How many schedules go back to the model at most.
	 */
	private const SCHEDULE_LIMIT = 5;

	/**
	 * How many sessions of one schedule go back at most.
	 */
	private const SESSION_LIMIT = 15;

	/**
	 * Constructor.
	 *
	 * @param Eventin_Stats_Query|null $query Queries; tests pass a fake.
	 */
	public function __construct( ?Eventin_Stats_Query $query = null ) {
		parent::__construct(
			'eventin-schedules',
			'Answer questions about Eventin schedules (agenda days) and their sessions in one call. Pass nothing for how many schedules and sessions there are, how many are used by an event, and the next ones coming up. Pass schedule_name for one schedule and its sessions. Pass event_id or event_name for that event\'s agenda: each day, each session with time, room and speakers. Every result has a status: "ok" means say the facts from it; "needs_clarification" means ask the question it gives and never pick for them; "not_found" means say plainly you cannot find it and open the page in the result. To open a page, use the page url in the result.',
			$query
		);
	}

	/**
	 * Define tool properties.
	 *
	 * @return array
	 */
	protected function properties(): array {
		return [
			new ToolProperty(
				name: 'schedule_name',
				type: PropertyType::STRING,
				description: 'A schedule title, or part of it, to get that one schedule.',
				required: false
			),
			new ToolProperty(
				name: 'event_id',
				type: PropertyType::NUMBER,
				description: 'An event ID, to get that event\'s agenda.',
				required: false
			),
			new ToolProperty(
				name: 'event_name',
				type: PropertyType::STRING,
				description: 'An event title, or part of it, when you do not have the ID.',
				required: false
			),
		];
	}

	/**
	 * Execute the tool.
	 *
	 * @param string|null $schedule_name Schedule title.
	 * @param int|null    $event_id      Event ID.
	 * @param string|null $event_name    Event title.
	 * @return array
	 */
	public function __invoke( ?string $schedule_name = null, ?int $event_id = null, ?string $event_name = null ): array {
		return $this->answer( $schedule_name, $event_id, $event_name );
	}

	/**
	 * Work out the answer.
	 *
	 * @param string|null $schedule_name Schedule title.
	 * @param int|null    $event_id      Event ID.
	 * @param string|null $event_name    Event title.
	 * @return array
	 */
	private function answer( ?string $schedule_name, ?int $event_id, ?string $event_name ): array {
		$check = $this->guard( 'etn_manage_schedule', 'etn_manage_event' );
		if ( $check ) {
			return $check;
		}

		try {
			if ( ( null !== $event_id && $event_id > 0 ) || '' !== trim( (string) $event_name ) ) {
				return $this->agenda( $event_id, $event_name );
			}

			if ( '' !== trim( (string) $schedule_name ) ) {
				return $this->one_schedule( trim( (string) $schedule_name ) );
			}

			return $this->overview();
		} catch ( \Throwable $e ) {
			Log::error( 'Eventin_Schedules_Tool error', [ 'error' => $e->getMessage() ] );

			return [ 'error' => 'Could not read schedules: ' . $e->getMessage() ];
		}
	}

	/**
	 * How many schedules and sessions, and what is coming up.
	 *
	 * @return array
	 */
	private function overview(): array {
		$schedules = $this->query->schedules();
		$used      = array_unique( array_merge( [], ...array_values( $this->query->event_schedules() ) ) );
		$today     = current_time( 'Y-m-d' );
		$upcoming  = array_filter( $schedules, static fn( $s ) => '' !== $s['date'] && $s['date'] >= $today );

		uasort( $upcoming, static fn( $a, $b ) => strcmp( $a['date'], $b['date'] ) );

		return [
			'status'           => 'ok',
			'total'            => count( $schedules ),
			'sessions'         => array_sum( array_map( static fn( $s ) => count( $s['sessions'] ), $schedules ) ),
			'used_by_an_event' => count( array_intersect( array_keys( $schedules ), $used ) ),
			'upcoming'         => count( $upcoming ),
			'next'             => array_map(
				static fn( $s ) => [
					'title'    => $s['title'],
					'date'     => $s['date'],
					'sessions' => count( $s['sessions'] ),
				],
				array_values( array_slice( $upcoming, 0, self::SCHEDULE_LIMIT ) )
			),
			'today'            => $today,
			'definitions'      => [
				'total'    => 'Every schedule. One schedule is one day of an agenda.',
				'sessions' => 'Sessions (talks, slots) across all schedules.',
				'upcoming' => 'Schedules dated today or later.',
			],
			'page'             => $this->schedules_page(),
		];
	}

	/**
	 * One schedule, found by title.
	 *
	 * @param string $name Title, or part of it.
	 * @return array
	 */
	private function one_schedule( string $name ): array {
		$schedules = $this->query->schedules();
		$exact     = array_filter( $schedules, static fn( $s ) => 0 === strcasecmp( trim( $s['title'] ), $name ) );
		$matches   = ! empty( $exact ) ? $exact : array_filter( $schedules, static fn( $s ) => false !== mb_stripos( $s['title'], $name ) );

		if ( empty( $matches ) ) {
			return $this->not_found( "No schedule title contains \"{$name}\".", $this->schedules_page() );
		}

		if ( count( $matches ) > 1 ) {
			return [
				'status'  => 'needs_clarification',
				'reason'  => "More than one schedule matches \"{$name}\".",
				'matches' => array_map(
					static fn( $s ) => [
						'title' => $s['title'],
						'date'  => $s['date'],
					],
					array_values( array_slice( $matches, 0, self::SCHEDULE_LIMIT * 2 ) )
				),
				'say'     => 'Do not pick one. Read out the titles with their dates and ask which one they mean.',
				'page'    => $this->schedules_page(),
			];
		}

		$schedule = reset( $matches );
		$events   = [];

		foreach ( $this->query->event_schedules() as $event_id => $ids ) {
			if ( in_array( $schedule['id'], $ids, true ) ) {
				$events[] = $event_id;
			}
		}

		return [
			'status'   => 'ok',
			'schedule' => $this->described( $schedule ),
			'events'   => array_values( $this->query->event_titles( $events ) ),
			'page'     => $this->schedules_page(),
		];
	}

	/**
	 * The agenda of one event.
	 *
	 * @param int|null    $event_id   Event ID.
	 * @param string|null $event_name Event title.
	 * @return array
	 */
	private function agenda( ?int $event_id, ?string $event_name ): array {
		list( $event_id, $title, $stop ) = $this->resolve_event( $event_id, $event_name, $this->page( __( 'Events', 'aisentic' ), '/events' ) );
		if ( null !== $stop ) {
			return $stop;
		}

		$schedules = $this->query->schedules();
		$days      = [];

		foreach ( $this->query->event_schedules()[ $event_id ] ?? [] as $id ) {
			if ( isset( $schedules[ $id ] ) ) {
				$days[] = $schedules[ $id ];
			}
		}

		usort( $days, static fn( $a, $b ) => strcmp( $a['date'], $b['date'] ) );

		return [
			'status'    => 'ok',
			'event'     => $title,
			'days'      => count( $days ),
			'sessions'  => array_sum( array_map( static fn( $s ) => count( $s['sessions'] ), $days ) ),
			'schedules' => array_map( fn( $s ) => $this->described( $s ), array_slice( $days, 0, self::SCHEDULE_LIMIT ) ),
			'say'       => empty( $days ) ? 'Say this event has no schedule set. Do not say the site has none.' : '',
			'page'      => $this->event_page( $event_id, $title ),
		];
	}

	/**
	 * A schedule with its sessions, speakers named.
	 *
	 * @param array $schedule One entry of schedules().
	 * @return array
	 */
	private function described( array $schedule ): array {
		$speakers = $this->query->people( 'speaker' );
		$sessions = [];

		foreach ( array_slice( $schedule['sessions'], 0, self::SESSION_LIMIT ) as $session ) {
			$sessions[] = [
				'topic'    => $session['topic'],
				'start'    => $session['start'],
				'end'      => $session['end'],
				'room'     => $session['room'],
				'speakers' => array_values(
					array_filter(
						array_map( static fn( $id ) => $speakers[ $id ]['name'] ?? '', $session['speakers'] )
					)
				),
			];
		}

		return [
			'title'          => $schedule['title'],
			'date'           => $schedule['date'],
			'total_sessions' => count( $schedule['sessions'] ),
			'sessions'       => $sessions,
		];
	}

	/**
	 * Page that lists schedules.
	 *
	 * @return array{title:string,url:string}
	 */
	private function schedules_page(): array {
		return $this->page( __( 'Schedules', 'aisentic' ), '/schedules' );
	}
}