<?php

namespace App\Services;

use App\Models\Opportunity;
use Carbon\CarbonImmutable;

/** Read-time exclusion never depends on the scheduler or the NDA. */
final class OfferAvailability
{
    /** @return array{state:string,expires_at:?string,policy_pending:bool} */
    public function view(mixed $operation, mixed $publication): array
    {
        // Legacy public snapshots without an editorial hash retain their first frozen policy.
        $key = is_array($publication) ? ($publication['editorial_hash'] ?? '') : null;
        $key ??= is_array($operation) ? ($operation['last_approval_hash'] ?? '') : '';
        if (! is_string($key)) {
            return ['state' => 'unavailable', 'expires_at' => null, 'policy_pending' => true];
        }
        $policy = is_array($operation) ? ($operation['validity_policies'][$key] ?? $operation['validity'] ?? null) : null;
        $pending = ! is_array($policy) || ($policy['days'] ?? null) === null;
        $result = ['state' => 'available', 'expires_at' => null, 'policy_pending' => $pending];
        if ($operation !== null && ! is_array($operation)) {
            return [...$result, 'state' => 'unavailable'];
        }
        $state = $operation['status'] ?? 'available';
        if (! is_int($operation['cycle'] ?? 0) || ($operation['cycle'] ?? 0) < 0) {
            return [...$result, 'state' => 'unavailable'];
        }
        if (! in_array($state, ['available', 'withdrawn', 'expired', 'revalidation'], true)) {
            return [...$result, 'state' => 'unavailable'];
        }
        if ($state !== 'available') {
            return [...$result, 'state' => $state];
        }
        $days = $policy['days'] ?? null;
        if (($operation['cycle'] ?? 0) > 0 && ($publication['offer_cycle'] ?? null) !== $operation['cycle']) {
            return $result;
        }
        if ($days === null || ! is_array($publication) || ($publication['publication']['state'] ?? null) !== 'published') {
            return $result;
        }
        if (! is_int($days) || $days < 1 || $days > 36500) {
            return [...$result, 'state' => 'unavailable'];
        }
        try {
            $at = $publication['publication']['at'] ?? null;
            if (! is_string($at) || ! preg_match('/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d{1,6})?(?:Z|[+-]\d{2}:\d{2})$/D', $at)) {
                return [...$result, 'state' => 'unavailable'];
            }
            $start = CarbonImmutable::parse($at);
            $end = $start->addDays($days)->utc();
        } catch (\Throwable) {
            return [...$result, 'state' => 'unavailable'];
        }

        return [...$result, 'expires_at' => $end->toIso8601String(), 'state' => $end->lte(CarbonImmutable::now()) ? 'expired' : 'available'];
    }

    /** @return array{state:string,expires_at:?string,policy_pending:bool} */
    public function record(Opportunity $record): array
    {
        return $this->view($record->workflow_context['offer_operation'] ?? null, $record->workflow_context['offer_publication'] ?? null);
    }

    public function publicAllowed(mixed $operation, mixed $publication): bool
    {
        if ($this->view($operation, $publication)['state'] !== 'available') {
            return false;
        }
        $cycle = $operation['cycle'] ?? 0;
        if (! is_int($cycle) || $cycle < 0) {
            return false;
        }

        // A new validation must never resurrect the previous public snapshot.
        return $cycle === 0 || (is_array($publication) && ($publication['offer_cycle'] ?? null) === $cycle
            && is_string($operation['activated_hash'] ?? null) && ($publication['editorial_hash'] ?? null) === $operation['activated_hash']);
    }
}