<?php

namespace Tests\Unit\Schedule\UseCases;

use App\Exceptions\BadRequestException;
use App\Exceptions\NotFoundException;
use App\Schedule\CreateScheduleAssignmentDto;
use App\Schedule\CreateScheduleDto;
use App\Schedule\EvenDistributionScheduler;
use App\Schedule\ScheduleAssignment;
use App\Schedule\UseCases\RescheduleSchedule\RescheduleSchedule;
use App\Schedule\UseCases\RescheduleSchedule\RescheduleScheduleRequest;
use App\Shared\ValueObject\EmailAddress;
use App\User\User;
use DateTimeImmutable;
use DateTimeZone;
use PHPUnit\Framework\TestCase;
use Tests\Fakes\FakeScheduleRepository;

class RescheduleScheduleTest extends TestCase
{
    public function test_it_redistributes_only_unfinished_assignments(): void
    {
        $user = $this->user(1, 'reader@example.com');
        $repository = new FakeScheduleRepository;
        $schedule = $repository->create($this->schedule($user));
        $assignments = $schedule->getAssignments();
        $firstCompletion = $this->utc('2026-08-15T10:00:00');
        $secondCompletion = $this->utc('2026-08-16T11:00:00');
        $assignments[1]->complete($firstCompletion);
        $assignments[3]->complete($secondCompletion);
        $repository->updateAssignment($assignments[1]);
        $repository->updateAssignment($assignments[3]);

        $rescheduled = $this->useCase($repository)->execute(
            new RescheduleScheduleRequest(
                scheduleId: $schedule->getId(),
                user: $user,
                startDate: '2026-08-20',
                targetDate: '2026-08-21',
                workloadPlacement: 'end',
            ),
        );

        $this->assertSame('2026-08-20', $rescheduled->getStartDate()
            ->format('Y-m-d'));
        $this->assertSame('2026-08-21', $rescheduled->getTargetDate()
            ->format('Y-m-d'));
        $this->assertSame(
            [
                '2026-08-20',
                '2026-08-12',
                '2026-08-21',
                '2026-08-14',
                '2026-08-21',
            ],
            array_map(function (ScheduleAssignment $assignment): string {
                return $assignment->getScheduledDate()->format('Y-m-d');
            }, $rescheduled->getAssignments()),
        );
        $this->assertSame(
            [null, $firstCompletion, null, $secondCompletion, null],
            array_map(function (
                ScheduleAssignment $assignment,
            ): ?DateTimeImmutable {
                return $assignment->getCompletedAt();
            }, $rescheduled->getAssignments()),
        );
        $this->assertSame(
            [1, 2, 3, 4, 5],
            array_map(function (ScheduleAssignment $assignment): int {
                return $assignment->getId();
            }, $rescheduled->getAssignments()),
        );
        $this->assertSame(
            ['Lesson 1', 'Lesson 2', 'Lesson 3', 'Lesson 4', 'Lesson 5'],
            array_map(function (ScheduleAssignment $assignment): string {
                return $assignment->getName();
            }, $rescheduled->getAssignments()),
        );
    }

    public function test_it_rejects_a_target_before_the_start(): void
    {
        $user = $this->user(1, 'reader@example.com');
        $repository = new FakeScheduleRepository;
        $schedule = $repository->create($this->schedule($user));

        $this->expectException(BadRequestException::class);
        $this->expectExceptionMessage(
            'targetDate must not be before startDate',
        );

        $this->useCase($repository)->execute(
            new RescheduleScheduleRequest(
                scheduleId: $schedule->getId(),
                user: $user,
                startDate: '2026-08-21',
                targetDate: '2026-08-20',
                workloadPlacement: 'middle',
            ),
        );
    }

    public function test_it_rejects_an_unknown_workload_placement(): void
    {
        $user = $this->user(1, 'reader@example.com');
        $repository = new FakeScheduleRepository;
        $schedule = $repository->create($this->schedule($user));

        $this->expectException(BadRequestException::class);
        $this->expectExceptionMessage(
            'workloadPlacement must be start, middle, or end',
        );

        $this->useCase($repository)->execute(
            new RescheduleScheduleRequest(
                scheduleId: $schedule->getId(),
                user: $user,
                startDate: '2026-08-20',
                targetDate: '2026-08-21',
                workloadPlacement: 'sideways',
            ),
        );
    }

    public function test_it_rejects_a_schedule_without_unfinished_work(): void
    {
        $user = $this->user(1, 'reader@example.com');
        $repository = new FakeScheduleRepository;
        $schedule = $repository->create($this->schedule($user));
        foreach ($schedule->getAssignments() as $assignment) {
            $assignment->complete($this->utc('2026-08-15T10:00:00'));
            $repository->updateAssignment($assignment);
        }

        $this->expectException(BadRequestException::class);
        $this->expectExceptionMessage(
            'schedule has no unfinished assignments',
        );

        $this->useCase($repository)->execute(
            new RescheduleScheduleRequest(
                scheduleId: $schedule->getId(),
                user: $user,
                startDate: '2026-08-20',
                targetDate: '2026-08-21',
                workloadPlacement: 'middle',
            ),
        );
    }

    public function test_it_hides_another_users_schedule(): void
    {
        $repository = new FakeScheduleRepository;
        $owner = $this->user(1, 'owner@example.com');
        $schedule = $repository->create($this->schedule($owner));

        $this->expectException(NotFoundException::class);
        $this->expectExceptionMessage('schedule not found');

        $this->useCase($repository)->execute(
            new RescheduleScheduleRequest(
                scheduleId: $schedule->getId(),
                user: $this->user(2, 'viewer@example.com'),
                startDate: '2026-08-20',
                targetDate: '2026-08-21',
                workloadPlacement: 'middle',
            ),
        );
    }

    private function useCase(
        FakeScheduleRepository $repository,
    ): RescheduleSchedule {
        return new RescheduleSchedule(
            $repository,
            new EvenDistributionScheduler,
        );
    }

    private function schedule(User $user): CreateScheduleDto
    {
        $assignments = [];
        foreach (range(1, 5) as $number) {
            $assignments[] = new CreateScheduleAssignmentDto(
                name: "Lesson {$number}",
                kind: 'lesson',
                path: ['Course', "Lesson {$number}"],
                scheduledDate: $this->utc("2026-08-1{$number}"),
                position: $number,
            );
        }

        return new CreateScheduleDto(
            user: $user,
            setName: 'Course',
            elementKind: 'lesson',
            startDate: $this->utc('2026-08-10'),
            targetDate: $this->utc('2026-08-15'),
            assignments: $assignments,
        );
    }

    private function user(int $id, string $email): User
    {
        return new User(
            id: $id,
            email: new EmailAddress($email),
            passwordHash: 'hashed-password',
        );
    }

    private function utc(string $value): DateTimeImmutable
    {
        return new DateTimeImmutable($value, new DateTimeZone('UTC'));
    }
}