<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\{GatewayUser, ApiKey, GatewayUserCredential, Budget, LlmRequest};
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Validator;

class AccountController extends Controller
{
    /**
     * Get account information
     * 
     * Returns comprehensive information about the authenticated gateway user,
     * including API keys, provider configuration, budget, and statistics.
     * 
     * ## Example Response
     * 
     * ```json
     * {
     *   "data": {
     *     "user_id": "usr_xyz789",
     *     "name": "API Client App",
     *     "email": "api@example.com",
     *     "status": "active",
     *     "created_at": "2025-11-01T08:00:00Z",
     *     "last_login": "2025-11-19T11:45:00Z",
     *     "api_keys": [...],
     *     "providers_configured": 3,
     *     "budget": {...},
     *     "statistics": {...},
     *     "rate_limits": {...}
     *   }
     * }
     * ```
     * 
     * @tags Account
     * 
     * @param Request $request
     * @return JsonResponse
     */
    public function index(Request $request): JsonResponse
    {
        $user = $request->user();
        
        // Get API keys
        $apiKeys = ApiKey::where('gateway_user_id', $user->user_id)
            ->orderByDesc('created_at')
            ->get()
            ->map(function ($key) {
                return [
                    'id' => $key->id,
                    'name' => $key->name ?? 'Default Key',
                    'key_preview' => substr($key->api_key, 0, 8) . '...' . substr($key->api_key, -4),
                    'created_at' => $key->created_at->toIso8601String(),
                    'last_used' => $key->last_used_at?->toIso8601String(),
                    'expires_at' => $key->expires_at?->toIso8601String(),
                ];
            });
        
        // Count configured providers
        $providersConfigured = GatewayUserCredential::where('gateway_user_id', $user->user_id)
            ->where('is_active', true)
            ->count();
        
        // Get budget info
        $budget = Budget::where('gateway_user_id', $user->user_id)->first();
        $monthlySpending = LlmRequest::where('gateway_user_id', $user->user_id)
            ->whereYear('created_at', now()->year)
            ->whereMonth('created_at', now()->month)
            ->where('status', 'success')
            ->sum('total_cost') ?? 0;
        
        $budgetInfo = $budget ? [
            'total' => round($budget->monthly_limit, 2),
            'used' => round($monthlySpending, 4),
            'remaining' => round($budget->monthly_limit - $monthlySpending, 4),
            'currency' => 'USD',
        ] : null;
        
        // Get statistics
        $stats = LlmRequest::where('gateway_user_id', $user->user_id)
            ->where('status', 'success')
            ->selectRaw('
                COUNT(*) as total_requests,
                SUM(total_tokens) as total_tokens,
                SUM(total_cost) as total_cost,
                MIN(created_at) as first_request
            ')
            ->first();
        
        return response()->json([
            'data' => [
                'user_id' => $user->user_id,
                'name' => $user->name,
                'email' => $user->email,
                'status' => $user->is_active ? 'active' : 'inactive',
                'created_at' => $user->created_at->toIso8601String(),
                'last_login' => $user->last_login_at?->toIso8601String(),
                'api_keys' => $apiKeys,
                'providers_configured' => $providersConfigured,
                'budget' => $budgetInfo,
                'statistics' => [
                    'total_requests' => $stats->total_requests ?? 0,
                    'total_tokens' => $stats->total_tokens ?? 0,
                    'total_cost' => round($stats->total_cost ?? 0, 4),
                    'first_request' => $stats->first_request?->toIso8601String(),
                ],
                'rate_limits' => [
                    'requests_per_minute' => 100, // TODO: Get from rate_limits table
                    'tokens_per_request' => 10000,
                    'daily_budget_limit' => $budget ? round($budget->monthly_limit / 30, 2) : null,
                ],
            ],
        ]);
    }
    
    /**
     * Get recent activity log
     * 
     * Returns recent activity including requests, credential changes,
     * budget alerts, and other account events.
     * 
     * ## Query Parameters
     * 
     * - `limit` (optional) - Number of items (default: 20, max: 100)
     * - `type` (optional) - Activity type: request, credential_change, budget_alert, all (default: all)
     * 
     * ## Example Response
     * 
     * ```json
     * {
     *   "data": [
     *     {
     *       "id": 1,
     *       "type": "request",
     *       "action": "chat_completion",
     *       "details": {
     *         "provider": "openai",
     *         "model": "gpt-4-turbo",
     *         "cost": 0.00405,
     *         "status": "success"
     *       },
     *       "timestamp": "2025-11-19T11:45:00Z"
     *     }
     *   ],
     *   "meta": {
     *     "total": 156,
     *     "limit": 20,
     *     "has_more": true
     *   }
     * }
     * ```
     * 
     * @tags Account
     * 
     * @param Request $request
     * @return JsonResponse
     */
    public function activity(Request $request): JsonResponse
    {
        $validator = Validator::make($request->all(), [
            'limit' => 'sometimes|integer|min:1|max:100',
            'type' => 'sometimes|string|in:request,credential_change,budget_alert,all',
        ]);
        
        if ($validator->fails()) {
            return response()->json([
                'error' => [
                    'code' => 'validation_error',
                    'message' => 'Invalid query parameters',
                    'status' => 422,
                    'details' => $validator->errors(),
                ],
            ], 422);
        }
        
        $user = $request->user();
        $limit = $request->input('limit', 20);
        $type = $request->input('type', 'all');
        
        $activities = collect();
        
        // Get recent requests
        if ($type === 'all' || $type === 'request') {
            $recentRequests = LlmRequest::where('gateway_user_id', $user->user_id)
                ->orderByDesc('created_at')
                ->limit($limit)
                ->get()
                ->map(function ($req) {
                    return [
                        'id' => $req->id,
                        'type' => 'request',
                        'action' => 'chat_completion',
                        'details' => [
                            'provider' => $req->provider,
                            'model' => $req->model,
                            'cost' => round($req->total_cost, 6),
                            'status' => $req->status,
                        ],
                        'timestamp' => $req->created_at->toIso8601String(),
                        'sort_timestamp' => $req->created_at,
                    ];
                });
            
            $activities = $activities->merge($recentRequests);
        }
        
        // Get credential changes
        if ($type === 'all' || $type === 'credential_change') {
            $credentialChanges = GatewayUserCredential::where('gateway_user_id', $user->user_id)
                ->orderByDesc('created_at')
                ->limit($limit)
                ->get()
                ->map(function ($cred) {
                    return [
                        'id' => $cred->id,
                        'type' => 'credential_change',
                        'action' => 'credentials_updated',
                        'details' => [
                            'provider' => $cred->provider,
                            'status' => $cred->is_active ? 'active' : 'inactive',
                        ],
                        'timestamp' => $cred->updated_at->toIso8601String(),
                        'sort_timestamp' => $cred->updated_at,
                    ];
                });
            
            $activities = $activities->merge($credentialChanges);
        }
        
        // Sort by timestamp and limit
        $activities = $activities->sortByDesc('sort_timestamp')
            ->take($limit)
            ->values()
            ->map(function ($activity) {
                unset($activity['sort_timestamp']);
                return $activity;
            });
        
        // Count total activities (approximate)
        $totalCount = LlmRequest::where('gateway_user_id', $user->user_id)->count();
        
        return response()->json([
            'data' => $activities,
            'meta' => [
                'total' => $totalCount,
                'limit' => $limit,
                'has_more' => $totalCount > $limit,
            ],
        ]);
    }
}