<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use App\Models\AuditLog;
use Illuminate\Support\Facades\Auth;

class AuditLogMiddleware
{
    /**
     * Handle an incoming request and log mutating actions to the audit log.
     *
     * Automatically logs all POST, PUT, PATCH, DELETE requests with
     * user_id, tenant_id, model info, action, old/new values, and request metadata.
     */
    public function handle(Request $request, Closure $next)
    {
        $method = $request->method();
        $isMutating = in_array($method, ['POST', 'PUT', 'PATCH', 'DELETE']);

        // For PUT/PATCH/DELETE, capture the current state before the request runs
        $oldValues = null;
        $modelType = null;
        $modelId = null;

        if ($isMutating && in_array($method, ['PUT', 'PATCH', 'DELETE'])) {
            $resolvedModel = $this->resolveRouteModel($request);

            if ($resolvedModel) {
                $modelType = get_class($resolvedModel);
                $modelId = $resolvedModel->getKey();

                if ($method !== 'POST') {
                    $oldValues = $resolvedModel->toArray();
                }
            }
        }

        // Execute the request
        $response = $next($request);

        // Only log if the request was successful (2xx status)
        if ($isMutating && $response->getStatusCode() >= 200 && $response->getStatusCode() < 300) {
            $action = $this->determineAction($method, $request);
            $newValues = null;

            // For POST/PUT/PATCH, capture new values from the model
            if (in_array($method, ['POST', 'PUT', 'PATCH'])) {
                $resolvedModel = $this->resolveRouteModel($request);

                if ($resolvedModel) {
                    $modelType = get_class($resolvedModel);
                    $modelId = $resolvedModel->getKey();
                    $newValues = $resolvedModel->toArray();
                } elseif ($method === 'POST') {
                    // For POST with resource creation, try to get the model from the response redirect
                    $createdModel = $this->extractCreatedModel($request, $response);
                    if ($createdModel) {
                        $modelType = get_class($createdModel);
                        $modelId = $createdModel->getKey();
                        $newValues = $createdModel->toArray();
                    }
                }
            }

            // Filter out sensitive fields from values
            $sensitiveFields = ['password', 'password_hash', 'remember_token', 'national_code', 'bank_account', 'base_salary'];
            $oldValues = $this->filterSensitiveFields($oldValues, $sensitiveFields);
            $newValues = $this->filterSensitiveFields($newValues, $sensitiveFields);

            try {
                AuditLog::create([
                    'user_id' => Auth::id(),
                    'tenant_id' => session('tenant_id'),
                    'model_type' => $modelType,
                    'model_id' => $modelId,
                    'action' => $action,
                    'old_values' => $oldValues,
                    'new_values' => $newValues,
                    'ip_address' => $request->ip(),
                    'user_agent' => $request->userAgent(),
                    'url' => $request->fullUrl(),
                    'method' => $method,
                ]);
            } catch (\Throwable $e) {
                // Silently fail — audit logging should never break the request
                logger()->error('Audit log failed: ' . $e->getMessage());
            }
        }

        return $response;
    }

    /**
     * Resolve the Eloquent model from the current route.
     */
    protected function resolveRouteModel(Request $request): ?\Illuminate\Database\Eloquent\Model
    {
        $route = $request->route();

        if (!$route) {
            return null;
        }

        foreach ($route->parameters() as $parameter) {
            if ($parameter instanceof \Illuminate\Database\Eloquent\Model) {
                return $parameter;
            }
        }

        return null;
    }

    /**
     * Determine the action label based on HTTP method.
     */
    protected function determineAction(string $method, Request $request): string
    {
        // Check if the route name suggests an approve/reject action
        $routeName = $request->route()?->getName() ?? '';

        if (str_contains($routeName, 'approve')) {
            return 'approve';
        }
        if (str_contains($routeName, 'reject')) {
            return 'reject';
        }
        if (str_contains($routeName, 'settle')) {
            return 'settle';
        }
        if (str_contains($routeName, 'status')) {
            return 'status_change';
        }

        return match ($method) {
            'POST' => 'create',
            'PUT', 'PATCH' => 'update',
            'DELETE' => 'delete',
            default => strtolower($method),
        };
    }

    /**
     * Try to extract a newly created model from a redirect response.
     */
    protected function extractCreatedModel(Request $request, $response): ?\Illuminate\Database\Eloquent\Model
    {
        // If the controller set a 'created_model' on the request, use it
        if ($request->attributes->has('_audit_created_model')) {
            return $request->attributes->get('_audit_created_model');
        }

        // If the response redirects to a show route, try to extract model from redirect target
        if ($response instanceof \Illuminate\Http\RedirectResponse) {
            $targetUrl = $response->getTargetUrl();
            $route = app('router')->getRoutes()->match(
                \Illuminate\Http\Request::create($targetUrl)
            );

            foreach ($route->parameters() as $parameter) {
                if ($parameter instanceof \Illuminate\Database\Eloquent\Model) {
                    return $parameter;
                }
            }
        }

        return null;
    }

    /**
     * Filter out sensitive fields from an array of values.
     */
    protected function filterSensitiveFields(?array $values, array $sensitiveFields): ?array
    {
        if ($values === null) {
            return null;
        }

        foreach ($sensitiveFields as $field) {
            unset($values[$field]);
        }

        return $values;
    }
}