<?php
declare(strict_types=1);

require_once __DIR__ . '/../../includes/bootstrap.php';
require_once __DIR__ . '/../../includes/FreeTier.php';
require_once __DIR__ . '/../../includes/CaseStore.php';

dbnToolsRequireMethod('POST');
dbnToolsRequireAuth();

$userId = (int)($_SESSION['dbn_tools_sso_uid'] ?? 0);
if ($userId <= 0) {
    dbnToolsError('Auth required.', 401, 'auth_required');
}

if (empty($_FILES['file']) || ($_FILES['file']['error'] ?? UPLOAD_ERR_NO_FILE) !== UPLOAD_ERR_OK) {
    dbnToolsError('No file uploaded or upload error.', 400, 'no_file');
}

$file = $_FILES['file'];
$size = (int)$file['size'];
$tmp  = (string)$file['tmp_name'];
$name = (string)$file['name'];

if ($size <= 0 || $size > 25 * 1024 * 1024) {
    dbnToolsError('Filen må være mellom 1 byte og 25 MB.', 413, 'bad_size');
}

// Validate it's actually a PDF (magic number check)
$fh = @fopen($tmp, 'rb');
if ($fh === false) {
    dbnToolsError('Kunne ikke lese filen.', 500, 'read_fail');
}
$head = (string)fread($fh, 5);
fclose($fh);
if (strncmp($head, '%PDF-', 5) !== 0) {
    dbnToolsError('Filen er ikke en gyldig PDF.', 415, 'not_pdf');
}

try {
    $doc = CaseStore::registerUpload($userId, $name, $tmp, $size);
    CaseStore::caseEnqueueIngest((int)$doc['doc_id'], $userId);
} catch (Throwable $e) {
    dbnToolsError($e->getMessage(), 400, 'upload_failed');
}

// Dual-write to CaveauAI corpus (best-effort — never fails the upload)
$caveauDocId = null;
$clientId = (int)($_SESSION['dbn_tools_client_id'] ?? 0);
if ($clientId > 0 && !empty($doc['storage_path'])) {
    try {
        dbnToolsBootCaveau();
        $aiPortalRoot = dbnToolsAiPortalRoot();
        $textExtractFile = $aiPortalRoot . '/platform/includes/text_extract.php';
        if (is_file($textExtractFile)) {
            require_once $textExtractFile;
            $content = extractPdfText($doc['storage_path']);
            if ($content !== '' && strlen($content) > 30) {
                $caveauDb = getDb();
                $corpusSt = $caveauDb->prepare(
                    'SELECT id FROM client_corpora WHERE client_id = ? AND is_default = 1 LIMIT 1'
                );
                $corpusSt->execute([$clientId]);
                $corpusId = (int)($corpusSt->fetchColumn() ?: 0);
                if ($corpusId > 0) {
                    $title = pathinfo($doc['filename'], PATHINFO_FILENAME);
                    $caveauDb->prepare("
                        INSERT INTO client_documents
                          (client_id, corpus_id, title, source_type, content, category,
                           import_method, word_count, status)
                        VALUES (?, ?, ?, 'pdf', ?, 'user-upload', 'dbn_upload', ?, 'pending')
                    ")->execute([$clientId, $corpusId, $title, $content, str_word_count($content)]);
                    $caveauDocId = (int)$caveauDb->lastInsertId();
                    $rag = new ClientRagPipeline($clientId);
                    $rag->ingestDocument($caveauDocId);
                }
            }
        }
    } catch (Throwable $e) {
        // Non-fatal: log and continue
        error_log('[upload] CaveauAI dual-write failed for doc ' . ($doc['doc_id'] ?? '?') . ': ' . $e->getMessage());
    }
}

dbnToolsRespond([
    'ok' => true,
    'doc_id' => $doc['doc_id'],
    'filename' => $doc['filename'],
    'caveau_doc_id' => $caveauDocId,
]);