<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Booking;

use Unsupervised\Schedular\Auth\RoleManager;
use Unsupervised\Schedular\Availability\AvailabilityRepository;
use Unsupervised\Schedular\Availability\AvailabilitySlot;
use Unsupervised\Schedular\Availability\WeekCalendar;
use Unsupervised\Schedular\Offering\OfferingRepository;
use Unsupervised\Schedular\Payment\Payment;
use Unsupervised\Schedular\Payment\PaymentRepository;
use Unsupervised\Schedular\Registration\IntakeAudit;
use Unsupervised\Schedular\Registration\IntakeProvenance;
use Unsupervised\Schedular\Registration\IntakeRecording;
use Unsupervised\Schedular\Val;

class LessonController {

	public function __construct(
		private BookingRepository $repository,
		private PaymentRepository $payments,
		private AvailabilityRepository $availability,
		private OfferingRepository $offerings,
		private IntakeAudit $detail,
		private AdminBooking $adminBooking,
		private IntakeRecording $intake,
	) {}

	public function renderAdminDashboard(): void {
		if ( ! current_user_can( RoleManager::CAP_VIEW_ALL_LESSONS ) ) {
			wp_die( esc_html__( 'You do not have permission to view this page.', 'unsupervised-schedular' ) );
		}

		if ( $this->maybeRenderDetail( 'us-scheduler', false ) ) {
			return;
		}

		[ $notice, $error ] = $this->handleFormAction( false, 0 );

		$rows = array_map( fn( Lesson $lesson ): array => $this->row( $lesson ), $this->repository->findAllUpcoming() );

		$this->renderLessonsPage( $rows, 'us-scheduler', 0, $notice, $error );
	}

	public function renderInstructorLessons(): void {
		if ( ! current_user_can( RoleManager::CAP_VIEW_LESSONS ) ) {
			wp_die( esc_html__( 'You do not have permission to view lessons.', 'unsupervised-schedular' ) );
		}

		if ( $this->maybeRenderDetail( 'us-my-lessons', true ) ) {
			return;
		}

		$instructorId = get_current_user_id();

		[ $notice, $error ] = $this->handleFormAction( true, $instructorId );

		$rows = array_map( fn( Lesson $lesson ): array => $this->row( $lesson ), $this->repository->findUpcomingForInstructor( $instructorId ) );

		$this->renderLessonsPage( $rows, 'us-my-lessons', $instructorId, $notice, $error );
	}

	/**
	 * When the request targets a single lesson (`?lesson_id=`), render its detail
	 * view and report that the page has been handled. Instructors may only open
	 * their own lessons; the studio dashboard ($onlyOwn = false) may open any.
	 */
	private function maybeRenderDetail( string $pageSlug, bool $onlyOwn ): bool {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only lesson selector.
		$lessonId = absint( Val::int( $_GET['lesson_id'] ?? 0 ) );
		if ( $lessonId <= 0 ) {
			return false;
		}

		$lesson  = $this->repository->findById( $lessonId );
		$backUrl = admin_url( 'admin.php?page=' . $pageSlug );
		$notice  = '';
		$error   = '';

		if ( null === $lesson || ( $onlyOwn && get_current_user_id() !== $lesson->instructorId ) ) {
			$row     = null;
			$answers = [];
			$accepts = [];
			$intake  = $this->emptyIntake();
		} else {
			// Recorded before the tables are read, so what was just entered appears
			// on the page that reports it.
			[ $notice, $error ] = $this->recordIntake( $lesson );

			$row     = $this->row( $lesson );
			$answers = $this->detail->answers( $lesson );
			$accepts = $this->detail->acceptances( $lesson );
			$intake  = $this->intakeForm( $lesson );
		}

		include USC_PLUGIN_DIR . 'templates/admin/lesson-detail.php';

		return true;
	}

	/**
	 * Handle a submitted "record intake collected elsewhere" form.
	 *
	 * @return array{string, string} Success notice and error message.
	 */
	private function recordIntake( Lesson $lesson ): array {
		if ( ! isset( $_POST['usc_action'] ) || ! check_admin_referer( 'usc_lesson_action' ) ) {
			return [ '', '' ];
		}

		// phpcs:disable WordPress.Security.NonceVerification.Missing -- nonce checked above.
		if ( 'record_intake' !== sanitize_key( Val::string( wp_unslash( $_POST['usc_action'] ) ) ) ) {
			return [ '', '' ];
		}

		$answers = [];
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized, WordPress.Security.ValidatedSanitizedInput.MissingUnslash -- each value is unslashed and sanitized below.
		foreach ( (array) ( $_POST['answers'] ?? [] ) as $questionId => $value ) {
			$answers[ absint( Val::int( $questionId ) ) ] = sanitize_textarea_field( Val::string( wp_unslash( $value ) ) );
		}

		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized, WordPress.Security.ValidatedSanitizedInput.MissingUnslash -- each element is coerced to a positive int; slashes cannot survive integer coercion.
		$rawVersionIds = (array) ( $_POST['accepted_policy_version_ids'] ?? [] );
		$versionIds    = array_values( array_filter( array_map( static fn( mixed $v ): int => absint( Val::int( $v ) ), $rawVersionIds ) ) );

		$result = $this->intake->record(
			$lesson,
			$answers,
			$versionIds,
			sanitize_key( Val::string( wp_unslash( $_POST['collected_via'] ?? '' ) ) ),
			sanitize_text_field( Val::string( wp_unslash( $_POST['collected_note'] ?? '' ) ) ),
			get_current_user_id()
		);
		// phpcs:enable WordPress.Security.NonceVerification.Missing

		return $result instanceof \WP_Error
			? [ '', $result->get_error_message() ]
			: [ $result, '' ];
	}

	/**
	 * What the detail template needs to offer the recording form: whether this
	 * lesson qualifies at all, what is still missing, and the collection methods
	 * to choose between.
	 *
	 * @return array{recordable: bool, questions: list<array{id: int, label: string, required: bool}>, policies: list<array{version_id: int, policy: string, version: string}>, methods: array<string, string>}
	 */
	private function intakeForm( Lesson $lesson ): array {
		if ( ! $lesson->isStaffRegistered() ) {
			return $this->emptyIntake();
		}

		return [ 'recordable' => true ] + $this->intake->pending( $lesson ) + [ 'methods' => IntakeProvenance::choices() ];
	}

	/**
	 * The form data for a lesson that cannot be recorded against — one the student
	 * booked, or one that could not be opened at all.
	 *
	 * @return array{recordable: bool, questions: list<array{id: int, label: string, required: bool}>, policies: list<array{version_id: int, policy: string, version: string}>, methods: array<string, string>}
	 */
	private function emptyIntake(): array {
		return [
			'recordable' => false,
			'questions'  => [],
			'policies'   => [],
			'methods'    => [],
		];
	}

	/**
	 * Render the lessons template with its calendar view state: week (default)
	 * or list, plus which week the week view shows, and the choices the
	 * book-for-a-student form offers — scoped to one instructor's own schedule on
	 * **My Lessons**, studio-wide (0) on the **Scheduler**.
	 *
	 * @param list<array<string, mixed>> $rows
	 */
	// phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter -- $notice is read by the included template.
	private function renderLessonsPage( array $rows, string $pageSlug, int $onlyInstructorId, string $notice, string $error ): void {
		// View-state query params only (which view, which week) — nothing is
		// mutated from them, so no nonce applies.
		// phpcs:disable WordPress.Security.NonceVerification.Recommended
		$view          = 'list' === sanitize_key( Val::string( wp_unslash( $_GET['usc_view'] ?? '' ) ) ) ? 'list' : 'week';
		$requestedWeek = sanitize_text_field( Val::string( wp_unslash( $_GET['usc_week'] ?? '' ) ) );
		// phpcs:enable WordPress.Security.NonceVerification.Recommended

		$weekStart = WeekCalendar::weekStart( $requestedWeek, Val::int( get_option( 'start_of_week', 1 ) ), current_time( 'Y-m-d' ) );
		$weekDays  = WeekCalendar::bucket( $weekStart, $rows, static fn( array $row ): string => Val::string( $row['day'] ) );
		$prevWeek  = ( new \DateTimeImmutable( $weekStart ) )->modify( '-7 days' )->format( 'Y-m-d' );
		$nextWeek  = ( new \DateTimeImmutable( $weekStart ) )->modify( '+7 days' )->format( 'Y-m-d' );
		$baseUrl   = admin_url( 'admin.php?page=' . $pageSlug );
		$bookForm  = $this->adminBooking->formData( $onlyInstructorId );

		// A refused booking is shown again as it was typed — losing five fields to a
		// single mistake is what made the panel infuriating to correct. A successful
		// one starts empty, so the next booking does not inherit the last one's.
		$bookValues = '' !== $error ? $this->submittedBooking() : $this->emptyBooking();

		include USC_PLUGIN_DIR . 'templates/admin/lessons.php';
	}

	/**
	 * Run the submitted action and report what happened: a per-lesson payment
	 * override (e-transfer email or HST rate), or a lesson booked for a student.
	 * When $onlyOwn, the payment or slot must belong to the current instructor.
	 *
	 * @return array{string, string} Success notice and error message; each is
	 *                               empty when it does not apply.
	 */
	private function handleFormAction( bool $onlyOwn, int $instructorId ): array {
		if ( ! isset( $_POST['usc_action'] ) || ! check_admin_referer( 'usc_lesson_action' ) ) {
			return [ '', '' ];
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- nonce checked above.
		$action = sanitize_key( Val::string( wp_unslash( $_POST['usc_action'] ) ) );

		if ( 'book_for_student' === $action ) {
			return $this->bookForStudent( $onlyOwn ? $instructorId : 0 );
		}

		$this->updatePayment( $action, $onlyOwn );

		return [ '', '' ];
	}

	/**
	 * Book a lesson on a student's behalf from the submitted form. The slot is
	 * scoped to the instructor's own schedule on **My Lessons** ($onlyInstructorId
	 * non-zero) and studio-wide on the **Scheduler**.
	 *
	 * @return array{string, string}
	 */
	private function bookForStudent( int $onlyInstructorId ): array {
		$submitted = $this->submittedBooking();

		$result = $this->adminBooking->book(
			$submitted['student_id'],
			$submitted['slot_id'],
			$submitted['offering_id'],
			$submitted['weekly'] ? Lesson::RECURRENCE_WEEKLY : Lesson::RECURRENCE_SINGLE,
			$submitted['no_charge'],
			$submitted['notes'],
			$onlyInstructorId
		);

		return $result instanceof \WP_Error
			? [ '', $result->get_error_message() ]
			: [ $result, '' ];
	}

	/**
	 * The book-for-a-student form exactly as submitted. Read in one place so what
	 * gets booked and what the form shows again after a refusal cannot drift apart
	 * on a field name.
	 *
	 * @return array{student_id: int, slot_id: int, offering_id: int, weekly: bool, no_charge: bool, notes: string}
	 */
	private function submittedBooking(): array {
		// phpcs:disable WordPress.Security.NonceVerification.Missing -- read only after handleFormAction() has verified the nonce: to book, or to re-render (escaped) a form it refused.
		return [
			'student_id'  => absint( Val::int( $_POST['student_id'] ?? 0 ) ),
			'slot_id'     => absint( Val::int( $_POST['slot_id'] ?? 0 ) ),
			'offering_id' => absint( Val::int( $_POST['offering_id'] ?? 0 ) ),
			'weekly'      => isset( $_POST['recurrence_weekly'] ),
			'no_charge'   => isset( $_POST['no_charge'] ),
			'notes'       => sanitize_text_field( Val::string( wp_unslash( $_POST['notes'] ?? '' ) ) ),
		];
		// phpcs:enable WordPress.Security.NonceVerification.Missing
	}

	/**
	 * An untouched book-for-a-student form.
	 *
	 * @return array{student_id: int, slot_id: int, offering_id: int, weekly: bool, no_charge: bool, notes: string}
	 */
	private function emptyBooking(): array {
		return [
			'student_id'  => 0,
			'slot_id'     => 0,
			'offering_id' => 0,
			'weekly'      => false,
			'no_charge'   => false,
			'notes'       => '',
		];
	}

	/**
	 * Apply a per-lesson payment override. When $onlyOwn, the payment must belong
	 * to the current instructor.
	 */
	private function updatePayment( string $action, bool $onlyOwn ): void {
		// phpcs:disable WordPress.Security.NonceVerification.Missing -- nonce checked by the caller.
		$paymentId = absint( Val::int( $_POST['payment_id'] ?? 0 ) );
		$email     = sanitize_email( Val::string( wp_unslash( $_POST['etransfer_email'] ?? '' ) ) );
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.MissingUnslash, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Val::float() coerces to float; slashes cannot survive numeric coercion.
		$taxRate = isset( $_POST['tax_rate'] ) ? max( 0.0, Val::float( $_POST['tax_rate'] ) ) : 0.0;
		// phpcs:enable WordPress.Security.NonceVerification.Missing

		if ( $paymentId <= 0 || ! in_array( $action, [ 'set_etransfer', 'set_tax' ], true ) ) {
			return;
		}

		$payment = $this->payments->findById( $paymentId );
		if ( null === $payment || ( $onlyOwn && get_current_user_id() !== $payment->instructorId ) ) {
			return;
		}

		if ( 'set_tax' === $action ) {
			$this->payments->updateTax( $paymentId, $taxRate );
			return;
		}

		$this->payments->updateEtransferEmail( $paymentId, '' !== $email ? $email : null );
	}

	/**
	 * Build a display row for a lesson, including its e-transfer and HST payment
	 * overrides.
	 *
	 * @return array<string, mixed>
	 */
	private function row( Lesson $lesson ): array {
		$student    = get_userdata( $lesson->studentId );
		$instructor = get_userdata( $lesson->instructorId );
		$payment    = null !== $lesson->paymentId ? $this->payments->findById( $lesson->paymentId ) : null;
		$slot       = $this->availability->findById( $lesson->slotId );
		$offering   = null !== $lesson->offeringId ? $this->offerings->findById( $lesson->offeringId ) : null;

		return [
			'lesson_id'          => (int) $lesson->id,
			'student'            => $student ? $student->display_name : (string) $lesson->studentId,
			'instructor'         => $instructor ? $instructor->display_name : (string) $lesson->instructorId,
			'offering'           => $offering ? $offering->title : '—',
			'duration'           => null !== $offering && null !== $offering->durationMinutes ? $offering->durationMinutes : 0,
			'recurrence'         => $lesson->recurrence,
			'time'               => $slot ? $this->formatSlotTime( $slot ) : '—',
			'day'                => $slot ? substr( $slot->startDt, 0, 10 ) : '',
			'time_short'         => $slot ? Val::string( mysql2date( 'g:i A', $slot->startDt ) ) : '—',
			'status'             => $lesson->status,
			'notes'              => $lesson->notes ?? '',
			'payment_id'         => $payment ? (int) $payment->id : 0,
			'currency'           => $payment ? (string) $payment->currency : '',
			'amount'             => $payment ? (float) $payment->amount : 0.0,
			'tax_rate'           => $payment ? (float) $payment->taxRate : 0.0,
			'tax_amount'         => $payment ? (float) $payment->taxAmount : 0.0,
			'total'              => $payment ? $payment->total() : 0.0,
			'etransfer_email'    => $payment ? (string) $payment->etransferEmail : '',
			'etransfer_editable' => null !== $payment && Payment::METHOD_ETRANSFER === $payment->method && ! $payment->isPaid(),
			'tax_editable'       => null !== $payment && ! $payment->isPaid(),
		];
	}

	/**
	 * Format a slot's window as e.g. "Jul 6, 2026 9:00 AM–10:00 AM", repeating the
	 * date on the end time only when the slot crosses midnight.
	 */
	private function formatSlotTime( AvailabilitySlot $slot ): string {
		$sameDay = substr( $slot->startDt, 0, 10 ) === substr( $slot->endDt, 0, 10 );

		return Val::string( mysql2date( 'M j, Y g:i A', $slot->startDt ) )
			. '–'
			. Val::string( mysql2date( $sameDay ? 'g:i A' : 'M j, Y g:i A', $slot->endDt ) );
	}
}