<?php

declare(strict_types=1);

namespace App\Http\Controllers;

use App\Http\Validation\ContentFilterRule;
use App\Models\ChatMessage;
use App\Models\TokenUsage;
use App\Services\AIService;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
use Illuminate\Validation\Rule as ValidationRule;
use Illuminate\View\View;

/**
 * Controller for the AI Chat feature.
 * Allows users to chat with registered AI models.
 */
class ChatController extends Controller
{
    /**
     * Display the AI chat interface.
     */
    public function index(): View
    {
        /** @var \App\Models\User $user */
        $user = Auth::user();

        // Get available AI providers from config
        $providers = config('services.ai.providers', []);

        // Get user's chat history
        $chatHistory = ChatMessage::where('user_id', $user->id)
            ->orderBy('created_at', 'asc')
            ->take(50)
            ->get();

        // Get chat default provider/model from DB, fallback to config
        $defaultProvider = \App\Models\Setting::where('key', 'chat_default_provider')->value('value');
        $defaultModel = \App\Models\Setting::where('key', 'chat_default_model')->value('value');

        if (!$defaultProvider) {
            $defaultProvider = config('services.ai.default_provider', 'openrouter');
        }

        if (!$defaultModel) {
            $defaultModel = config('services.ai.providers.'.$defaultProvider.'.model', 'inclusionai/ling-3.0-tiny:free');
        }

        return view('dashboard.chat', compact(
            'providers',
            'chatHistory',
            'defaultProvider',
            'defaultModel'
        ));
    }

    /**
     * Send a message to the AI and get a response.
     */
    public function store(Request $request): \Illuminate\Http\RedirectResponse
    {
        /** @var \App\Models\User $user */
        $user = Auth::user();

        $validated = $request->validate([
            'message' => ['required', 'string', 'max:4000', new ContentFilterRule()],
        ]);

        $message = trim($validated['message']);

        // Use chat default provider/model from DB
        $defaultProvider = \App\Models\Setting::where('key', 'chat_default_provider')->value('value');
        $defaultModel = \App\Models\Setting::where('key', 'chat_default_model')->value('value');

        if (!$defaultProvider) {
            $defaultProvider = config('services.ai.default_provider', 'openrouter');
        }

        if (!$defaultModel) {
            $defaultModel = config('services.ai.providers.'.$defaultProvider.'.model', 'inclusionai/ling-3.0-tiny:free');
        }

        // Build conversation history for context
        $recentMessages = ChatMessage::where('user_id', $user->id)
            ->orderByDesc('created_at')
            ->take(10)
            ->get()
            ->reverse()
            ->values();

        $messages = [];
        foreach ($recentMessages as $chat) {
            $messages[] = ['role' => 'user', 'content' => $chat->message];
            if ($chat->response) {
                $messages[] = ['role' => 'assistant', 'content' => $chat->response];
            }
        }
        $messages[] = ['role' => 'user', 'content' => $message];

        // Initialize AI service with selected provider and model
        $aiService = new AIService($defaultProvider, $defaultModel);

        // Use the chat completion endpoint directly
        $result = $aiService->chat($messages);

        if (!$result['success']) {
            return back()->with('error', __('Failed to get response: :error', [
                'error' => $result['error'] ?? __('Unknown error'),
            ]));
        }

        $response = $result['content'];
        $inputTokens = $result['input_tokens'] ?? 0;
        $outputTokens = $result['output_tokens'] ?? 0;
        $model = $defaultModel;
        $provider = $defaultProvider;

        // Save chat message
        ChatMessage::create([
            'user_id' => $user->id,
            'message' => $message,
            'response' => $response,
            'provider' => $provider,
            'model' => $model,
            'input_tokens' => $inputTokens,
            'output_tokens' => $outputTokens,
            'sent_at' => now(),
        ]);

        // Track token usage
        if ($inputTokens > 0 || $outputTokens > 0) {
            TokenUsage::create([
                'user_id' => $user->id,
                'input_tokens' => $inputTokens,
                'output_tokens' => $outputTokens,
                'total_tokens' => $inputTokens + $outputTokens,
                'model' => $model,
                'provider' => $provider,
            ]);
        }

        return back()->with('success', __('Message sent successfully!'));
    }

    /**
     * Clear chat history.
     */
    public function destroy(Request $request): \Illuminate\Http\RedirectResponse
    {
        /** @var \App\Models\User $user */
        $user = Auth::user();

        ChatMessage::where('user_id', $user->id)->delete();

        return back()->with('success', __('Chat history cleared.'));
    }
}