<?php

namespace RoosterLMS\Learn;

use RoosterLMS\Assessment\AssignmentService;
use RoosterLMS\Assessment\SubmissionStatus;
use RoosterLMS\Blocks\Context;
use RoosterLMS\Blocks\Markup;
use RoosterLMS\Content\Item;
use RoosterLMS\Content\UnitType;
use RoosterLMS\Core\Clock;
use RoosterLMS\Core\Settings;
use RoosterLMS\Domain\Services;
use RoosterLMS\Enrolment\AccessReason;
use RoosterLMS\I18n\Format;
use RoosterLMS\UI\Ui;

defined( 'ABSPATH' ) || exit;

final class AssignmentView {

	public const NAME = 'assignment';

	public const SHORTCODE = 'rooster_lms_assignment';

	public static function attributes( array $attributes ): array {
		return array( 'lessonPost' => isset( $attributes['lessonPost'] ) ? max( 0, (int) $attributes['lessonPost'] ) : 0 );
	}

	public static function render( array $attributes, string $content = '', ?\WP_Block $block = null ): string {
		unset( $content );
		$item_id = Context::item_id( self::attributes( $attributes ), $block );
		$item    = $item_id > 0 ? ( Services::curriculum_repo()->items( array( $item_id ) )[ $item_id ] ?? null ) : null;
		if ( null === $item ) {
			return '';
		}
		LessonExtras::rendered( self::NAME, $item->id );
		$unit = Services::unit_repo()->get_many( array( $item->unit_id ) )[ $item->unit_id ] ?? null;
		if ( null === $unit || UnitType::ASSIGNMENT !== $unit->type ) {
			return '';
		}
		$user     = get_current_user_id();
		$settings = Services::assignments()->settings( $item->unit_id );
		if ( $user <= 0 ) {
			return self::wrap( $block, 'guest', self::facts( $settings, -2 ) . Markup::login_prompt( __( 'Log in to hand in this assignment.', 'rooster-lms' ) ) );
		}
		$open = Services::gate()->can_open_item( $user, $item->id );
		if ( $open->allowed && $open->reason->is_staff() ) {
			return self::wrap( $block, 'staff', self::facts( $settings, -2 ) . Ui::notice( __( 'Learners hand in their answers here. You grade them in the grading queue.', 'rooster-lms' ), 'info' ) );
		}
		$decision = Services::gate()->can_complete_item( $user, $item->id );
		if ( $decision->allowed || AccessReason::CONTENT_CONTROLLED !== $decision->reason ) {
			return '';
		}
		$state = Services::assignments()->state( $user, $item->id );
		return self::learner( $item, $block, $settings, $state );
	}

	private static function learner( Item $item, ?\WP_Block $block, array $settings, array $state ): string {
		$tries  = $state['tries'];
		$latest = array() === $tries ? null : $tries[ count( $tries ) - 1 ];
		$status = null === $latest ? null : ( self::status_of( (string) $latest['status'] ) ?? SubmissionStatus::DRAFT );
		$body   = self::facts( $settings, $state['left'] );
		$config = array(
			'item' => $item->id,
			'i18n' => self::texts(),
		);
		$mode   = 'start';
		if ( null === $latest ) {
			$body .= self::start_button( $settings, false );
		} elseif ( SubmissionStatus::DRAFT === $status ) {
			$mode   = 'draft';
			$config = array_merge( $config, self::draft_config( $latest ) );
			$body  .= self::draft( $latest );
		} elseif ( SubmissionStatus::SUBMITTED === $status ) {
			$mode = 'submitted';
			/* translators: %s: date and time. */
			$body .= Ui::notice( sprintf( __( 'Handed in on %s. Your answer is waiting for grading.', 'rooster-lms' ), Front::when( $latest['submitted_at'] ?? null ) ), 'info' ) . self::answer( $latest );
		} else {
			$mode  = 'graded';
			$body .= self::result( $latest );
			if ( SubmissionStatus::FAILED === $status && 0 !== $state['left'] ) {
				$body .= self::start_button( $settings, true );
			} elseif ( SubmissionStatus::FAILED === $status ) {
				$body .= Ui::notice( __( 'You have no tries left.', 'rooster-lms' ), 'warning' );
			}
		}
		if ( count( $tries ) > 1 ) {
			$body .= self::history( array_slice( $tries, 0, -1 ) );
		}
		if ( in_array( $mode, array( 'start', 'draft', 'graded' ), true ) ) {
			Front::enqueue( self::NAME );
		}
		return self::wrap( $block, $mode, $body, array( 'data-rl-assignment' => (string) wp_json_encode( Front::config( $config ) ) ) );
	}

	private static function draft_config( array $try ): array {
		$remaining = -1;
		if ( null !== $try['deadline_at'] ) {
			$deadline  = strtotime( $try['deadline_at'] . ' UTC' );
			$remaining = false === $deadline ? 0 : max( 0, $deadline - Clock::timestamp() );
		}
		return array(
			'submission' => (int) $try['id'],
			'files'      => $try['files'],
			'remaining'  => $remaining,
			'maxFiles'   => (int) Settings::get( 'assignment_max_files' ),
			'maxFileMb'  => (int) Settings::get( 'assignment_max_file_mb' ),
			'maxMediaMb' => (int) Settings::get( 'assignment_media_max_mb' ),
			'audio'      => (bool) Settings::get( 'assignment_audio' ),
			'video'      => (bool) Settings::get( 'assignment_video' ),
			'exts'       => AssignmentService::upload_extensions( true ),
		);
	}

	private static function facts( array $settings, int $left ): string {
		$items = array();
		if ( -2 === $left ) {
			$items[] = null === $settings['tries']
				? __( 'Unlimited tries', 'rooster-lms' )
				/* translators: %s: number of tries. */
				: sprintf( _n( '%s try', '%s tries', (int) $settings['tries'], 'rooster-lms' ), Format::number( (int) $settings['tries'] ) );
		} elseif ( -1 === $left ) {
			$items[] = __( 'Unlimited tries', 'rooster-lms' );
		} else {
			/* translators: %s: number of tries left. */
			$items[] = sprintf( _n( '%s try left', '%s tries left', $left, 'rooster-lms' ), Format::number( $left ) );
		}
		if ( null !== $settings['time_limit_sec'] ) {
			/* translators: %s: a duration such as "1 hour 30 minutes". */
			$items[] = sprintf( __( 'Time limit: %s', 'rooster-lms' ), self::duration( (int) $settings['time_limit_sec'] ) );
		}
		if ( null !== $settings['pass_percent'] ) {
			/* translators: %s: a percentage. */
			$items[] = sprintf( __( 'Pass mark: %s', 'rooster-lms' ), Format::percent( (int) $settings['pass_percent'] ) );
		}
		$html = '<ul class="rooster-lms-assignment__facts">';
		foreach ( $items as $text ) {
			$html .= '<li>' . esc_html( $text ) . '</li>';
		}
		return $html . '</ul>';
	}

	private static function start_button( array $settings, bool $again ): string {
		$warn = null === $settings['time_limit_sec'] ? '' : '<p class="rooster-lms-field__help">'
			/* translators: %s: a duration. */
			. esc_html( sprintf( __( 'When you start, you have %s to hand in your answer.', 'rooster-lms' ), self::duration( (int) $settings['time_limit_sec'] ) ) ) . '</p>';
		return $warn . '<p class="rooster-lms-assignment__actions">' . Ui::button( $again ? __( 'Try again', 'rooster-lms' ) : __( 'Start the assignment', 'rooster-lms' ), 'primary', array( 'data-rl-asg' => 'start' ) ) . '</p>'
			. '<p class="rooster-lms-message" role="alert" data-rl-asg-msg></p>';
	}

	private static function draft( array $try ): string {
		$id   = 'rl-asg-' . (int) $try['id'];
		$html = '';
		if ( null !== $try['deadline_at'] ) {
			$html .= '<p class="rooster-lms-assignment__timer" role="timer" aria-live="off">' . esc_html__( 'Time left:', 'rooster-lms' ) . ' <strong data-rl-asg-clock>' . esc_html( self::clock( (int) max( 0, (int) strtotime( $try['deadline_at'] . ' UTC' ) - Clock::timestamp() ) ) ) . '</strong></p>';
		}
		$html .= '<form class="rooster-lms-assignment__form" data-rl-asg-form novalidate>';
		$html .= '<p class="rooster-lms-field"><label class="rooster-lms-field__label" for="' . esc_attr( $id . '-body' ) . '">' . esc_html__( 'Your answer', 'rooster-lms' ) . '</label>'
			. '<textarea class="rooster-lms-textarea" id="' . esc_attr( $id . '-body' ) . '" name="body" rows="8" maxlength="' . esc_attr( (string) AssignmentService::BODY_MAX ) . '">' . esc_textarea( wp_strip_all_tags( (string) $try['body'] ) ) . '</textarea></p>';
		$exts  = AssignmentService::upload_extensions( true );
		$html .= '<fieldset class="rooster-lms-assignment__files"><legend class="rooster-lms-field__label">' . esc_html__( 'Files', 'rooster-lms' ) . '</legend>'
			. '<ul class="rooster-lms-assignment__filelist" data-rl-asg-files>' . self::file_items( (int) $try['id'], $try['files'], true ) . '</ul>'
			. '<p class="rooster-lms-field"><label class="rooster-lms-field__label" for="' . esc_attr( $id . '-file' ) . '">' . esc_html__( 'Add a file', 'rooster-lms' ) . '</label>'
			. '<input class="rooster-lms-input" type="file" id="' . esc_attr( $id . '-file' ) . '" data-rl-asg-upload accept="' . esc_attr( implode( ',', array_map( static fn( string $e ): string => '.' . $e, $exts ) ) ) . '" /></p>'
			/* translators: 1: file types, 2: size in MB, 3: number of files. */
			. '<p class="rooster-lms-field__help">' . esc_html( sprintf( __( 'Allowed types: %1$s. Up to %2$s MB a file, %3$s files.', 'rooster-lms' ), implode( ', ', (array) Settings::get( 'assignment_file_types' ) ), Format::number( (int) Settings::get( 'assignment_max_file_mb' ) ), Format::number( (int) Settings::get( 'assignment_max_files' ) ) ) ) . '</p>';
		foreach ( array(
			'audio' => array( (bool) Settings::get( 'assignment_audio' ), __( 'Record an audio answer', 'rooster-lms' ) ),
			'video' => array( (bool) Settings::get( 'assignment_video' ), __( 'Record a video answer', 'rooster-lms' ) ),
		) as $kind => $spec ) {
			if ( ! $spec[0] ) {
				continue;
			}
			$html .= '<div class="rooster-lms-assignment__recorder" data-rl-asg-recorder="' . esc_attr( $kind ) . '">'
				. Ui::button( $spec[1], 'outline', array( 'size' => 'sm', 'data-rl-asg-rec' => 'start' ) )
				. Ui::button( __( 'Stop recording', 'rooster-lms' ), 'destructive', array( 'size' => 'sm', 'data-rl-asg-rec' => 'stop', 'hidden' => true ) )
				. ' <span class="rooster-lms-assignment__rectime" data-rl-asg-rectime aria-live="polite"></span>'
				. ( 'video' === $kind ? '<video class="rooster-lms-assignment__preview" muted playsinline hidden data-rl-asg-preview></video>' : '' )
				. '<label class="rooster-lms-assignment__fallback" hidden data-rl-asg-fallback><span>' . esc_html( 'audio' === $kind ? __( 'Your browser cannot record here: choose or capture an audio file.', 'rooster-lms' ) : __( 'Your browser cannot record here: choose or capture a video file.', 'rooster-lms' ) ) . '</span> '
				. '<input type="file" accept="' . esc_attr( $kind . '/*' ) . '" capture data-rl-asg-upload /></label>'
				. '</div>';
		}
		$html .= '</fieldset>';
		$html .= '<p class="rooster-lms-assignment__actions">'
			. Ui::button( __( 'Save draft', 'rooster-lms' ), 'outline', array( 'data-rl-asg' => 'save' ) ) . ' '
			. Ui::button( __( 'Hand in', 'rooster-lms' ), 'primary', array( 'type' => 'submit' ) ) . '</p>'
			. '<p class="rooster-lms-message" role="alert" data-rl-asg-msg></p></form>';
		return $html;
	}

	private static function result( array $try ): string {
		$passed = 'passed' === $try['status'];
		$html   = Ui::notice( $passed ? __( 'Your assignment has passed.', 'rooster-lms' ) : __( 'Your assignment did not pass.', 'rooster-lms' ), $passed ? 'success' : 'warning' );
		if ( null !== $try['score'] ) {
			/* translators: %s: a percentage. */
			$html .= '<p class="rooster-lms-assignment__score">' . esc_html( sprintf( __( 'Score: %s', 'rooster-lms' ), Format::percent( (int) round( (float) $try['score'] ) ) ) ) . '</p>';
		}
		if ( '' !== trim( (string) $try['feedback'] ) ) {
			$html .= '<div class="rooster-lms-assignment__feedback"><h3>' . esc_html__( 'Feedback', 'rooster-lms' ) . '</h3>' . wpautop( esc_html( (string) $try['feedback'] ) ) . '</div>';
		}
		if ( array() !== $try['staff_files'] ) {
			$html .= '<h3>' . esc_html__( 'Files from your trainer', 'rooster-lms' ) . '</h3><ul class="rooster-lms-assignment__filelist">' . self::file_items( (int) $try['id'], $try['staff_files'], false ) . '</ul>';
		}
		return $html . self::answer( $try );
	}

	private static function answer( array $try ): string {
		$html = '<details class="rooster-lms-assignment__answer"><summary>' . esc_html__( 'Your answer', 'rooster-lms' ) . '</summary>' . wp_kses_post( wpautop( (string) $try['body'] ) );
		if ( array() !== $try['files'] ) {
			$html .= '<ul class="rooster-lms-assignment__filelist">' . self::file_items( (int) $try['id'], $try['files'], false ) . '</ul>';
		}
		return $html . '</details>';
	}

	private static function history( array $tries ): string {
		$html = '<details class="rooster-lms-assignment__history"><summary>' . esc_html__( 'Earlier tries', 'rooster-lms' ) . '</summary><ol>';
		foreach ( $tries as $t ) {
			$status = self::status_of( (string) $t['status'] );
			/* translators: 1: try number, 2: the try's state. */
			$html .= '<li>' . esc_html( sprintf( __( 'Try %1$s: %2$s', 'rooster-lms' ), Format::number( (int) $t['try_no'] ), null === $status ? '' : $status->label() ) );
			if ( '' !== trim( (string) $t['feedback'] ) ) {
				$html .= '<div class="rooster-lms-assignment__feedback">' . wpautop( esc_html( (string) $t['feedback'] ) ) . '</div>';
			}
			$html .= '</li>';
		}
		return $html . '</ol></details>';
	}

	public static function file_items( int $submission, array $files, bool $removable ): string {
		$ids = array_map( static fn( array $f ): int => (int) $f['id'], $files );
		if ( array() !== $ids ) {
			_prime_post_caches( $ids, false, false );
		}
		$html = '';
		foreach ( $files as $f ) {
			$name  = self::file_name( (int) $f['id'] );
			$html .= '<li data-rl-asg-file="' . esc_attr( (string) $f['id'] ) . '" data-kind="' . esc_attr( (string) $f['kind'] ) . '"><a href="' . esc_url( self::file_url( $submission, (int) $f['id'] ) ) . '">' . esc_html( $name ) . '</a>'
				. ( $removable ? ' ' . Ui::button( __( 'Remove', 'rooster-lms' ), 'ghost', array( 'size' => 'sm', 'data-rl-asg-remove' => (string) $f['id'], 'aria-label' => sprintf( /* translators: %s: file name. */ __( 'Remove %s', 'rooster-lms' ), $name ) ) ) : '' )
				. '</li>';
		}
		return $html;
	}

	public static function file_name( int $attachment ): string {
		$file  = (string) get_attached_file( $attachment, true );
		$ext   = strtolower( (string) pathinfo( $file, PATHINFO_EXTENSION ) );
		$title = trim( (string) get_post_field( 'post_title', $attachment, 'raw' ) );
		$name = '' !== $title ? $title . ( '' !== $ext ? '.' . $ext : '' ) : ( '' !== $file ? wp_basename( $file ) : '' );
		return '' !== $name ? $name : __( 'File', 'rooster-lms' );
	}

	public static function file_url( int $submission, int $attachment ): string {
		return \RoosterLMS\Live\Lesson\Links::submission_file( $submission, $attachment );
	}

	private static function status_of( string $slug ): ?SubmissionStatus {
		foreach ( SubmissionStatus::cases() as $case ) {
			if ( $case->slug() === $slug ) {
				return $case;
			}
		}
		return null;
	}

	public static function duration( int $sec ): string {
		$h     = intdiv( $sec, 3600 );
		$m     = intdiv( $sec % 3600, 60 );
		$parts = array();
		if ( $h > 0 ) {
			/* translators: %s: number of hours. */
			$parts[] = sprintf( _n( '%s hour', '%s hours', $h, 'rooster-lms' ), Format::number( $h ) );
		}
		if ( $m > 0 || array() === $parts ) {
			/* translators: %s: number of minutes. */
			$parts[] = sprintf( _n( '%s minute', '%s minutes', max( 1, $m ), 'rooster-lms' ), Format::number( max( 1, $m ) ) );
		}
		return implode( ' ', $parts );
	}

	public static function clock( int $sec ): string {
		$h = intdiv( $sec, 3600 );
		$m = intdiv( $sec % 3600, 60 );
		$s = $sec % 60;
		return $h > 0 ? sprintf( '%d:%02d:%02d', $h, $m, $s ) : sprintf( '%d:%02d', $m, $s );
	}

	private static function wrap( ?\WP_Block $block, string $state, string $body, array $extra = array() ): string {
		return '<section ' . Markup::wrapper( self::NAME, $block, array( 'data-state' => $state, 'aria-label' => __( 'Assignment', 'rooster-lms' ) ) + $extra ) . '>' . $body . '</section>';
	}

	public static function texts(): array {
		return array(
			'confirm'    => __( 'Hand in your answer? You cannot change it afterwards.', 'rooster-lms' ),
			'handIn'     => __( 'Hand in', 'rooster-lms' ),
			'keepEdit'   => __( 'Keep editing', 'rooster-lms' ),
			'saved'      => __( 'Draft saved.', 'rooster-lms' ),
			'empty'      => __( 'Write an answer or add a file before you hand in.', 'rooster-lms' ),
			'uploading'  => __( 'Uploading…', 'rooster-lms' ),
			'uploaded'   => __( 'File added.', 'rooster-lms' ),
			'tooBig'     => __( 'This file is too large.', 'rooster-lms' ),
			'badType'    => __( 'This type of file is not allowed.', 'rooster-lms' ),
			'tooMany'    => __( 'You cannot add more files.', 'rooster-lms' ),
			'removed'    => __( 'File removed.', 'rooster-lms' ),
			'recording'  => __( 'Recording…', 'rooster-lms' ),
			'noDevice'   => __( 'The microphone or camera could not be used. Choose a file instead.', 'rooster-lms' ),
			'timeUp'     => __( 'Time is up: your answer is being handed in.', 'rooster-lms' ),
			'failed'     => __( 'Something went wrong. Please try again.', 'rooster-lms' ),
			'remove'     => __( 'Remove', 'rooster-lms' ),
			'recordName' => __( 'Recording', 'rooster-lms' ),
		);
	}
}