<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Tests\Unit\Offering;

use Brain\Monkey\Functions;
use Mockery;
use Unsupervised\Schedular\GroupClass\Enrollment;
use Unsupervised\Schedular\GroupClass\EnrollmentRepository;
use Unsupervised\Schedular\Offering\BillingModeReconciler;
use Unsupervised\Schedular\Offering\Offering;
use Unsupervised\Schedular\Payment\Payment;
use Unsupervised\Schedular\Payment\PaymentRepository;
use Unsupervised\Schedular\Tests\Unit\TestCase;

class BillingModeReconcilerTest extends TestCase
{
    private EnrollmentRepository&Mockery\MockInterface $enrollments;
    private PaymentRepository&Mockery\MockInterface $payments;
    private BillingModeReconciler $reconciler;

    protected function setUp(): void
    {
        parent::setUp();

        Functions\when('current_time')->justReturn('2026-09-15 09:00:00');

        $this->enrollments = Mockery::mock(EnrollmentRepository::class);
        $this->payments    = Mockery::mock(PaymentRepository::class);
        $this->reconciler  = new BillingModeReconciler($this->enrollments, $this->payments);
    }

    private function offering(string $billingMode, ?int $id = 9): Offering
    {
        return new Offering(
            instructorId: 3,
            kind:         Offering::KIND_GROUP_CLASS,
            title:        'Ensemble',
            price:        150.0,
            billingMode:  $billingMode,
            id:           $id,
        );
    }

    private function enrollment(int $id, int $studentId = 5): Enrollment
    {
        return new Enrollment(offeringId: 9, studentId: $studentId, instructorId: 3, id: $id);
    }

    public function testAdoptsUpfrontChargeIntoCurrentMonthWhenClassBecomesMonthly(): void
    {
        $this->enrollments->shouldReceive('findActiveByOffering')->with(9)->andReturn([$this->enrollment(7)]);

        $this->payments->shouldReceive('hasUnscheduledCharge')->with(Payment::REG_ENROLLMENT, 7)->andReturn(true);
        $this->payments->shouldReceive('existsForPeriod')->with(Payment::REG_ENROLLMENT, 7, '2026-09')->andReturn(false);

        // The up-front charge is stamped into 2026-09, due on the 1st, so the scan
        // treats September as already billed for this enrolment.
        $this->payments->shouldReceive('claimPeriodForUnscheduled')
            ->once()
            ->with(Payment::REG_ENROLLMENT, 7, '2026-09', '2026-09-01')
            ->andReturn(1);

        self::assertSame(1, $this->reconciler->reconcile($this->offering(Offering::BILLING_ONE_TIME), $this->offering(Offering::BILLING_MONTHLY)));
    }

    public function testDoesNothingWhenBillingModeDidNotChangeIntoMonthly(): void
    {
        $this->enrollments->shouldNotReceive('findActiveByOffering');
        $this->payments->shouldNotReceive('claimPeriodForUnscheduled');

        // Already monthly -> monthly (e.g. an unrelated title edit): no transition.
        self::assertSame(0, $this->reconciler->reconcile($this->offering(Offering::BILLING_MONTHLY), $this->offering(Offering::BILLING_MONTHLY)));
    }

    public function testDoesNothingWhenSwitchingToWeekly(): void
    {
        $this->enrollments->shouldNotReceive('findActiveByOffering');
        $this->payments->shouldNotReceive('claimPeriodForUnscheduled');

        // Weekly bills per session as sessions come due; there is no single upfront
        // period an enrolment charge maps onto, so it is left alone.
        self::assertSame(0, $this->reconciler->reconcile($this->offering(Offering::BILLING_ONE_TIME), $this->offering(Offering::BILLING_WEEKLY)));
    }

    public function testSkipsEnrolmentWithoutAnUpfrontCharge(): void
    {
        $this->enrollments->shouldReceive('findActiveByOffering')->with(9)->andReturn([$this->enrollment(7)]);

        // Enrolled after the class was already scheduled, or never charged upfront:
        // nothing to adopt.
        $this->payments->shouldReceive('hasUnscheduledCharge')->with(Payment::REG_ENROLLMENT, 7)->andReturn(false);
        $this->payments->shouldNotReceive('claimPeriodForUnscheduled');

        self::assertSame(0, $this->reconciler->reconcile($this->offering(Offering::BILLING_ONE_TIME), $this->offering(Offering::BILLING_MONTHLY)));
    }

    public function testSkipsEnrolmentAlreadyBilledForThisMonthByTheScan(): void
    {
        $this->enrollments->shouldReceive('findActiveByOffering')->with(9)->andReturn([$this->enrollment(7)]);

        $this->payments->shouldReceive('hasUnscheduledCharge')->with(Payment::REG_ENROLLMENT, 7)->andReturn(true);
        // The scan already made a 2026-09 charge: adopting the upfront one too would
        // leave two charges for the month — the very thing we are preventing.
        $this->payments->shouldReceive('existsForPeriod')->with(Payment::REG_ENROLLMENT, 7, '2026-09')->andReturn(true);
        $this->payments->shouldNotReceive('claimPeriodForUnscheduled');

        self::assertSame(0, $this->reconciler->reconcile($this->offering(Offering::BILLING_ONE_TIME), $this->offering(Offering::BILLING_MONTHLY)));
    }

    public function testReconcilesEveryActiveEnrolment(): void
    {
        $this->enrollments->shouldReceive('findActiveByOffering')->with(9)
            ->andReturn([$this->enrollment(7, 5), $this->enrollment(8, 6)]);

        $this->payments->shouldReceive('hasUnscheduledCharge')->with(Payment::REG_ENROLLMENT, 7)->andReturn(true);
        $this->payments->shouldReceive('existsForPeriod')->with(Payment::REG_ENROLLMENT, 7, '2026-09')->andReturn(false);
        $this->payments->shouldReceive('claimPeriodForUnscheduled')->with(Payment::REG_ENROLLMENT, 7, '2026-09', '2026-09-01')->andReturn(1);

        $this->payments->shouldReceive('hasUnscheduledCharge')->with(Payment::REG_ENROLLMENT, 8)->andReturn(true);
        $this->payments->shouldReceive('existsForPeriod')->with(Payment::REG_ENROLLMENT, 8, '2026-09')->andReturn(false);
        $this->payments->shouldReceive('claimPeriodForUnscheduled')->with(Payment::REG_ENROLLMENT, 8, '2026-09', '2026-09-01')->andReturn(1);

        self::assertSame(2, $this->reconciler->reconcile($this->offering(Offering::BILLING_ONE_TIME), $this->offering(Offering::BILLING_MONTHLY)));
    }

    public function testIgnoresNonGroupClassOfferings(): void
    {
        $before = new Offering(instructorId: 3, kind: Offering::KIND_PRIVATE_LESSON, title: 'Piano', billingMode: Offering::BILLING_ONE_TIME, id: 9);
        $after  = new Offering(instructorId: 3, kind: Offering::KIND_PRIVATE_LESSON, title: 'Piano', billingMode: Offering::BILLING_MONTHLY, id: 9);

        $this->enrollments->shouldNotReceive('findActiveByOffering');

        self::assertSame(0, $this->reconciler->reconcile($before, $after));
    }
}