<?php

namespace App\Services;

use Illuminate\Support\Facades\DB;
use stdClass;

/** Formats an already-authorized instrument; callers retain their own access checks. */
class PartnershipAgreementProjection
{
    /** @var array<int,string|null> */
    private array $people = [];

    public function current(?string $json): stdClass|string|null
    {
        $value = $json === null ? null : json_decode($json, false, 512, JSON_THROW_ON_ERROR);
        if ($value === null) {
            return null;
        }
        if (! $value instanceof stdClass) {
            return 'unrecognized';
        }

        return (object) $this->fields((array) $value);
    }

    /** @param array<string,mixed> $instrument
     * @return array<string,mixed>
     */
    public function fields(array $instrument, bool $names = false): array
    {
        $fields = [];
        foreach (['title', 'terms', 'legal_signature_status'] as $key) {
            if (is_string($instrument[$key] ?? null)) {
                $fields[$key] = $instrument[$key];
            }
        }
        if (array_key_exists('confirmations', $instrument)) {
            $fields['confirmations'] = $this->confirmations($instrument['confirmations'], $names);
        }

        return $fields;
    }

    /** @return array<string,mixed>|stdClass|string|null */
    private function confirmations(mixed $value, bool $names): array|stdClass|string|null
    {
        if ($value === null) {
            return null;
        }
        if ($value instanceof stdClass) {
            $value = (array) $value;
        }
        if (! is_array($value) || $value !== [] && array_is_list($value)) {
            return 'unrecognized';
        }
        $result = [];
        foreach (['proponent', 'candidate'] as $party) {
            if (! array_key_exists($party, $value)) {
                continue;
            }
            $stamp = $value[$party] instanceof stdClass ? (array) $value[$party] : (is_array($value[$party]) ? $value[$party] : []);
            $id = is_int($stamp['actor_id'] ?? null) && $stamp['actor_id'] > 0 ? $stamp['actor_id'] : null;
            $result[$party] = ['actor_id' => $id, 'date' => is_string($stamp['date'] ?? null) ? $stamp['date'] : null, 'reason' => is_string($stamp['reason'] ?? null) ? $stamp['reason'] : null];
            if ($names) {
                $result[$party]['actor_name'] = $id ? $this->person($id) : null;
            }
        }
        if (array_diff(array_keys($value), ['proponent', 'candidate']) !== []) {
            $result['_unrecognized_references'] = true;
        }

        return $result === [] ? (object) [] : $result;
    }

    private function person(int $id): ?string
    {
        if (! array_key_exists($id, $this->people)) {
            $this->people[$id] = DB::table('users')->where('id', $id)->value('name');
        }

        return $this->people[$id];
    }
}