<?php
/**
 * Check Duplicate Invoices
 * POST /v1/invoices/check-duplicate
 * Checks if similar invoice exists before processing
 */

use App\Core\Database;
use App\Core\Encryption;
use App\Middleware\AuthMiddleware;

$decoded = AuthMiddleware::check();
$data = input();
$db = Database::getInstance();

$tenantId = $decoded['tenant_id'];
$invoiceNumber = $data['invoice_number'] ?? null;
$supplierTin = $data['supplier_tin'] ?? null;
$grandTotal = $data['grand_total'] ?? null;
$invoiceDate = $data['invoice_date'] ?? null;
$excludeId = $data['exclude_id'] ?? null;

$duplicates = [];

// 1. Exact match on invoice number
if ($invoiceNumber) {
    $sql = "SELECT id, invoice_number, invoice_date, grand_total, status, supplier_name
            FROM invoices WHERE invoice_number = ? AND tenant_id = ?";
    $params = [$invoiceNumber, $tenantId];
    
    if ($excludeId) {
        $sql .= " AND id != ?";
        $params[] = $excludeId;
    }
    
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    $matches = $stmt->fetchAll();
    
    foreach ($matches as $m) {
        $decName = Encryption::decrypt($m['supplier_name']);
        $duplicates[] = [
            'id' => $m['id'],
            'invoice_number' => $m['invoice_number'],
            'invoice_date' => $m['invoice_date'],
            'grand_total' => $m['grand_total'],
            'status' => $m['status'],
            'supplier_name' => ($decName !== false && $decName !== null) ? $decName : $m['supplier_name'],
            'match_type' => 'exact_number',
            'confidence' => 100,
        ];
    }
}

// 2. Fuzzy match: same supplier TIN + same total + same date
if ($supplierTin && $grandTotal && $invoiceDate && empty($duplicates)) {
    $sql = "SELECT id, invoice_number, invoice_date, grand_total, status, supplier_name, supplier_tin
            FROM invoices 
            WHERE tenant_id = ? 
            AND invoice_date = ? 
            AND ABS(grand_total - ?) < 0.01";
    $params = [$tenantId, $invoiceDate, $grandTotal];
    
    if ($excludeId) {
        $sql .= " AND id != ?";
        $params[] = $excludeId;
    }
    
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    $matches = $stmt->fetchAll();
    
    foreach ($matches as $m) {
        $decTin = Encryption::decrypt($m['supplier_tin']);
        $decName = Encryption::decrypt($m['supplier_name']);
        
        if ($decTin === $supplierTin || $m['supplier_tin'] === $supplierTin) {
            $duplicates[] = [
                'id' => $m['id'],
                'invoice_number' => $m['invoice_number'],
                'invoice_date' => $m['invoice_date'],
                'grand_total' => $m['grand_total'],
                'status' => $m['status'],
                'supplier_name' => ($decName !== false && $decName !== null) ? $decName : $m['supplier_name'],
                'match_type' => 'fuzzy_tin_total_date',
                'confidence' => 90,
            ];
        }
    }
}

// 3. Near match: same total + near date (±3 days)
if ($grandTotal && $invoiceDate && empty($duplicates)) {
    $sql = "SELECT id, invoice_number, invoice_date, grand_total, status, supplier_name
            FROM invoices 
            WHERE tenant_id = ? 
            AND ABS(grand_total - ?) < 0.01
            AND ABS(DATEDIFF(invoice_date, ?)) <= 3";
    $params = [$tenantId, $grandTotal, $invoiceDate];
    
    if ($excludeId) {
        $sql .= " AND id != ?";
        $params[] = $excludeId;
    }
    $sql .= " LIMIT 5";
    
    $stmt = $db->prepare($sql);
    $stmt->execute($params);
    $matches = $stmt->fetchAll();
    
    foreach ($matches as $m) {
        $decName = Encryption::decrypt($m['supplier_name']);
        $duplicates[] = [
            'id' => $m['id'],
            'invoice_number' => $m['invoice_number'],
            'invoice_date' => $m['invoice_date'],
            'grand_total' => $m['grand_total'],
            'status' => $m['status'],
            'supplier_name' => ($decName !== false && $decName !== null) ? $decName : $m['supplier_name'],
            'match_type' => 'near_total_date',
            'confidence' => 60,
        ];
    }
}

json_success([
    'is_duplicate' => !empty($duplicates),
    'matches' => $duplicates,
    'count' => count($duplicates),
], empty($duplicates) ? 'لا توجد فواتير مكررة' : 'تم العثور على فواتير مشابهة');