<?php

declare(strict_types=1);

namespace App\Http\Requests\Api\V1\Artist;

use App\Models\Stage;
use App\Models\StageDay;
use App\Rules\Artist\StageActiveOnEvent;
use App\Rules\Artist\WithinEventBounds;
use Carbon\CarbonImmutable;
use Illuminate\Contracts\Validation\Validator;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

/**
 * RFC v0.2 §10.4 — D18 transactional move endpoint.
 */
final class MoveTimetablePerformanceRequest extends FormRequest
{
    public function authorize(): bool
    {
        return true;
    }

    /**
     * @return array<string, mixed>
     */
    public function rules(): array
    {
        $event = $this->route('event');
        $resolvedEventId = $this->resolveTargetEventId();

        return [
            // performances has no organisation_id column (FK-chain via
            // engagement_id); cross-tenant is caught by the policy in
            // TimetableMoveController via Gate::authorize('move', ...).
            'performance_id' => [
                'required', 'string', 'max:30',
                Rule::exists('performances', 'id'),
            ],
            'target_stage_id' => [
                'nullable', 'string', 'max:30',
                Rule::exists('stages', 'id'),
                new StageActiveOnEvent($resolvedEventId),
            ],
            'target_start_at' => [
                'nullable', 'date_format:Y-m-d H:i:s',
                'required_unless:target_stage_id,null',
                new WithinEventBounds($resolvedEventId),
            ],
            'target_end_at' => [
                'nullable', 'date_format:Y-m-d H:i:s',
                'required_unless:target_stage_id,null',
                'after:target_start_at',
                new WithinEventBounds($resolvedEventId),
            ],
            'target_lane' => ['nullable', 'integer', 'min:0', 'max:9'],
            'version' => ['required', 'integer', 'min:0'],
        ];
    }

    public function withValidator(Validator $validator): void
    {
        $validator->after(function (Validator $validator): void {
            // When target_stage_id is non-null, target_lane must be set
            // (the move algorithm requires a definite lane).
            if ($this->input('target_stage_id') !== null && $this->input('target_lane') === null) {
                $validator->errors()->add('target_lane', 'target_lane is verplicht bij een niet-leeg target_stage_id.');
            }
        });
    }

    /**
     * Resolve the event_id the candidate move lands on so the
     * StageActiveOnEvent and WithinEventBounds rules can validate
     * against a concrete event window.
     *
     * For flat events: stage.event_id is the answer.
     * For festivals: walk stage_days for target_stage_id and find the
     * sub-event whose [start, end] contains target_start_at.
     */
    private function resolveTargetEventId(): ?string
    {
        $stageId = $this->input('target_stage_id');
        $startAt = $this->input('target_start_at');
        if (! is_string($stageId) || ! is_string($startAt)) {
            return null;
        }

        $start = CarbonImmutable::parse($startAt);
        $stage = Stage::query()->find($stageId);
        if ($stage === null) {
            return null;
        }

        $match = StageDay::query()
            ->where('stage_id', $stage->id)
            ->join('events', 'events.id', '=', 'stage_days.event_id')
            ->where('events.start_date', '<=', $start->toDateString())
            ->where('events.end_date', '>=', $start->toDateString())
            ->orderBy('events.start_date', 'desc')
            ->limit(1)
            ->value('stage_days.event_id');

        return is_string($match) ? $match : $stage->event_id;
    }
}