<?php

namespace App\Services\FattureElettroniche;

use App\Models\FeXsdCode;
use App\Models\FeXsdCodeDomain;
use App\Models\FeXsdVersion;

class FeXsdCodesDiff
{
    /**
     * @return array{
     *   old_version_id:int|null,
     *   new_version_id:int,
     *   domains_added:int,
     *   domains_removed:int,
     *   domains_changed:int,
     *   codes_added:int,
     *   codes_removed:int,
     *   codes_changed:int,
     *   per_domain: array<int, array{type_name:string, added:int, removed:int, changed:int}>
     * }
     */
    public function diff(?FeXsdVersion $old, FeXsdVersion $new): array
    {
        $oldDomains = $old
            ? FeXsdCodeDomain::query()->where('version_id', $old->id)->get(['id', 'type_name'])->keyBy('type_name')
            : collect();

        $newDomains = FeXsdCodeDomain::query()->where('version_id', $new->id)->get(['id', 'type_name'])->keyBy('type_name');

        $domainsAdded = 0;
        $domainsRemoved = 0;
        $domainsChanged = 0;
        $codesAdded = 0;
        $codesRemoved = 0;
        $codesChanged = 0;
        $perDomain = [];

        $allDomainNames = $oldDomains->keys()->merge($newDomains->keys())->unique()->sort()->values();

        foreach ($allDomainNames as $typeName) {
            $oldDomain = $oldDomains->get($typeName);
            $newDomain = $newDomains->get($typeName);

            if (!$oldDomain && $newDomain) {
                $domainsAdded++;
                $count = FeXsdCode::query()->where('domain_id', $newDomain->id)->count();
                $codesAdded += $count;
                $perDomain[] = ['type_name' => $typeName, 'added' => $count, 'removed' => 0, 'changed' => 0];
                continue;
            }

            if ($oldDomain && !$newDomain) {
                $domainsRemoved++;
                $count = FeXsdCode::query()->where('domain_id', $oldDomain->id)->count();
                $codesRemoved += $count;
                $perDomain[] = ['type_name' => $typeName, 'added' => 0, 'removed' => $count, 'changed' => 0];
                continue;
            }

            if (!$oldDomain || !$newDomain) {
                continue;
            }

            // Confronto per code + documentation.
            $oldCodes = FeXsdCode::query()
                ->where('domain_id', $oldDomain->id)
                ->get(['code', 'documentation'])
                ->keyBy('code');

            $newCodes = FeXsdCode::query()
                ->where('domain_id', $newDomain->id)
                ->get(['code', 'documentation'])
                ->keyBy('code');

            $added = $newCodes->keys()->diff($oldCodes->keys())->count();
            $removed = $oldCodes->keys()->diff($newCodes->keys())->count();

            $changed = 0;
            foreach ($newCodes as $code => $row) {
                if (!$oldCodes->has($code)) {
                    continue;
                }
                $oldDoc = (string) ($oldCodes->get($code)?->documentation ?? '');
                $newDoc = (string) ($row->documentation ?? '');
                if (trim($oldDoc) !== trim($newDoc)) {
                    $changed++;
                }
            }

            if ($added + $removed + $changed > 0) {
                $domainsChanged++;
                $codesAdded += $added;
                $codesRemoved += $removed;
                $codesChanged += $changed;

                $perDomain[] = ['type_name' => $typeName, 'added' => $added, 'removed' => $removed, 'changed' => $changed];
            }
        }

        return [
            'old_version_id' => $old?->id,
            'new_version_id' => $new->id,
            'domains_added' => $domainsAdded,
            'domains_removed' => $domainsRemoved,
            'domains_changed' => $domainsChanged,
            'codes_added' => $codesAdded,
            'codes_removed' => $codesRemoved,
            'codes_changed' => $codesChanged,
            'per_domain' => $perDomain,
        ];
    }
}