<?php

namespace App\Services;

use Opis\JsonSchema\Validator;

/** Transparent field completion, separate from validation, approval and external decisions. */
class OpportunityCompleteness
{
    /** @param array<string,mixed> $payload
     * @return array<string,mixed> */
    public function calculate(array $payload): array
    {
        $schema = app(OpportunityCanonicalContract::class)->schema(false, $payload);
        $validator = new Validator;
        $paths = [];
        $walk = function (mixed $value, array $node, string $path) use (&$walk, &$paths, $schema, $validator): void {
            if (isset($node['$ref'])) {
                $node = $schema['$defs'][basename($node['$ref'])] ?? $node;
            }
            $requirements = $node['required'] ?? [];
            foreach ($node['allOf'] ?? [] as $condition) {
                if (! isset($condition['if'])) {
                    $walk($value, $condition, $path);

                    continue;
                }
                $test = $condition['if'];
                if (str_contains(json_encode($test, JSON_THROW_ON_ERROR), '#/$defs/')) {
                    $test['$defs'] = $schema['$defs'];
                }
                $actual = json_decode(json_encode(is_array($value) && ! array_is_list($value) ? (object) $value : $value, JSON_THROW_ON_ERROR), false, 512, JSON_THROW_ON_ERROR);
                $yes = $validator->validate($actual, json_decode(json_encode($test, JSON_THROW_ON_ERROR), false, 512, JSON_THROW_ON_ERROR))->isValid();
                $walk($value, $condition[$yes ? 'then' : 'else'] ?? [], $path);
            }
            foreach ($requirements as $key) {
                $v = is_array($value) ? ($value[$key] ?? null) : null;
                $paths[ltrim($path.'.'.$key, '.')] = $v !== null && $v !== '' && $v !== [];
            }
            foreach ($node['properties'] ?? [] as $key => $child) {
                if (is_array($value) && array_key_exists($key, $value)) {
                    $walk($value[$key], $child, ltrim($path.'.'.$key, '.'));
                }
            }
            if (isset($node['items']) && is_array($value) && array_is_list($value)) {
                foreach ($value as $i => $child) {
                    $walk($child, $node['items'], $path.'.'.$i);
                }
            }
        };
        $walk($payload, ['$ref' => '#/$defs/opportunityCreate'], '');
        $filled = count(array_filter($paths));
        $total = count($paths);

        return ['percentage' => $total ? round(100 * $filled / $total, 2) : 0, 'filled' => $filled, 'applicable' => $total,
            'missing_paths' => array_keys(array_filter($paths, fn ($filled) => ! $filled)),
            'rule' => 'required-applicable-fields-v1', 'scope' => 'Required fields and activated schema conditions; optional/hidden modules excluded. Presence is not validation or approval.'];
    }
}