<?php

namespace App\Services\Ai;

use App\Models\User;
use App\Services\VirtualDesk;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;

class InvestorGuidanceEvidence
{
    public const FIELDS = ['market_evidence', 'location_evidence', 'resource_evidence', 'funding_evidence'];

    /** @return array<string,array<string,mixed>> */
    public function forCase(User $actor, \stdClass $case, VirtualDesk $desk): array
    {
        $privateScope = ! $desk->owns($actor, $case, false) && ! $actor->can('manage-portal');
        $documents = DB::table('desk_documents as l')->join('documents as d', 'd.id', '=', 'l.document_id')->where('l.case_id', $case->id)->whereNull('d.deleted_at')
            ->when($privateScope, fn ($q) => $q->where(fn ($p) => $p->whereNull('l.request_id')->orWhereIn('l.request_id', DB::table('desk_requests')->where('analyst_id', $actor->id)->select('id'))))
            ->get(['l.id as link_id', 'l.document_id', 'l.category', 'l.valid_until', 'd.file_name', 'd.version_no', 'd.sha256', 'd.status', 'd.malware_scan_status', 'd.malware_scanned_sha256', 'd.storage_key']);
        $reviews = DB::table('desk_events as e')->join('users as u', 'u.id', '=', 'e.actor_id')->where('e.case_id', $case->id)->where('e.action', 'document_reviewed')
            ->when($privateScope, fn ($q) => $q->where(fn ($p) => $p->whereNull('e.request_id')->orWhereIn('e.request_id', DB::table('desk_requests')->where('analyst_id', $actor->id)->select('id'))))
            ->orderByDesc('e.event_order')->get(['e.id', 'e.payload', 'e.created_at', 'e.actor_id', 'u.name']);
        $result = [];
        foreach (self::FIELDS as $field) {
            $records = [];
            foreach ($documents as $doc) {
                $latest = null;
                foreach ($reviews as $review) {
                    $payload = $desk->decode($review->payload);
                    if (($payload['link_id'] ?? null) === $doc->link_id) {
                        $latest = ['id' => $review->id, 'author_id' => $review->actor_id, 'author' => $review->name, 'date' => $review->created_at, 'payload' => $payload];
                        break;
                    }
                }
                if ($doc->category !== $field && ! ($latest && in_array($field, $latest['payload']['supports'] ?? [], true))) {
                    continue;
                }
                // A later review replaces the earlier scope. Merely choosing a
                // document category does not verify a preparation assumption.
                if ($latest && ! in_array($field, $latest['payload']['supports'] ?? [], true)) {
                    $latest = null;
                }
                $state = 'attached_unchecked';
                if ($doc->valid_until && $doc->valid_until < now()->toDateString()) {
                    $state = 'expired';
                } elseif ($latest && (($latest['payload']['sha256'] ?? null) !== trim($doc->sha256) || ($latest['payload']['document_version'] ?? null) !== (int) $doc->version_no)) {
                    $state = 'superseded';
                } elseif ($latest) {
                    $path = realpath(Storage::disk('local')->path($doc->storage_key));
                    $root = realpath(Storage::disk('local')->path(''));
                    if (! $path || ! $root || ! str_starts_with($path, $root.DIRECTORY_SEPARATOR) || ! is_file($path) || ! is_string($hash = hash_file('sha256', $path)) || ! hash_equals(trim($doc->sha256), $hash)) {
                        $state = 'superseded';
                    } elseif ($doc->status !== 'active' || $doc->malware_scan_status !== 'clean' || trim($doc->sha256) !== $doc->malware_scanned_sha256) {
                        $state = 'technical_unavailable';
                    } else {
                        $state = match ($latest['payload']['outcome'] ?? '') {
                            'internal_verified' => 'internally_verified',
                            'contradiction_identified' => 'contradiction',
                            default => 'issue_identified',
                        };
                    }
                }
                $records[] = ['document_id' => $doc->document_id, 'link_id' => $doc->link_id, 'name' => $doc->file_name, 'state' => $state, 'version' => (int) $doc->version_no, 'hash' => trim($doc->sha256), 'valid_until' => $doc->valid_until,
                    'review' => $latest ? ['event_id' => $latest['id'], 'author_id' => $latest['author_id'], 'author' => $latest['author'], 'date' => $latest['date'], 'what_checked' => $latest['payload']['what_checked'], 'evidence' => $latest['payload']['evidence'], 'scope' => $latest['payload']['scope']] : null];
            }
            if ($records) {
                // A specific current contradiction takes precedence; other valid evidence
                // remains visible instead of erasing expired or replaced originals.
                $states = array_column($records, 'state');
                $state = 'attached_unchecked';
                foreach (['contradiction', 'internally_verified', 'issue_identified', 'superseded', 'expired', 'technical_unavailable'] as $candidate) {
                    if (in_array($candidate, $states, true)) {
                        $state = $candidate;
                        break;
                    }
                }
                $result[$field] = ['state' => $state, 'documents' => $records];
            }
        }

        return $result;
    }
}