<?php

declare(strict_types=1);

namespace Controller;

// @responsibility: HTTP-Endpunkte für KI-Chat (Sessions, Nachrichten, Export)

use Domain\Factory\ChatSessionFactory;
use Domain\Service\ModelRegistryInterface;
use Framework\Controller;
use Infrastructure\Formatting\ChatMessageFormatter;
use UseCases\Chat\CreateChatSessionUseCaseInterface;
use UseCases\Chat\DeleteChatSessionUseCaseInterface;
use UseCases\Chat\ExportChatSessionUseCase;
use UseCases\Chat\GetChatSessionUseCaseInterface;
use UseCases\Chat\SendChatMessageUseCase;
use UseCases\Chat\UpdateChatSessionUseCaseInterface;

class ChatController extends Controller
{
    public function __construct(
        private CreateChatSessionUseCaseInterface $createSessionUseCase,
        private GetChatSessionUseCaseInterface $getSessionUseCase,
        private UpdateChatSessionUseCaseInterface $updateSessionUseCase,
        private DeleteChatSessionUseCaseInterface $deleteSessionUseCase,
        private SendChatMessageUseCase $messageUseCase,
        private ChatMessageFormatter $formatter,
        private ExportChatSessionUseCase $exportUseCase,
        private ModelRegistryInterface $modelRegistry
    ) {
    }

    public function index(): void
    {
        $uuid = $this->createSessionUseCase->createSession();
        header('Location: /chat/' . $uuid);
        exit;
    }

    public function show(string $uuid): void
    {
        $session = $this->getSessionUseCase->getSession($uuid);

        if ($session === null) {
            header('Location: /chat');
            exit;
        }

        // Convert entities to arrays for views
        $messages = $this->getSessionUseCase->getMessages($session->getId() ?? 0);
        $messagesArray = array_map(fn ($m) => $m->toArray(), $messages);

        $this->view('chat.index', [
            'title' => $session->getTitle() ?? 'KI-Chat',
            'session' => ChatSessionFactory::toArray($session),
            'messages' => $messagesArray,
            'sessions' => $this->getSessionUseCase->getAllSessionsWithStats(),
            'authorProfiles' => $this->getSessionUseCase->getAuthorProfiles(),
            'systemPrompts' => $this->getSessionUseCase->getSystemPrompts(),
            'outputStructures' => $this->getSessionUseCase->getOutputStructures(),
            'collections' => $this->getSessionUseCase->getAvailableCollections(),
            'models' => $this->modelRegistry->getChatModels(),
            'defaultModel' => $this->modelRegistry->getDefaultChatModel(),
        ]);
    }

    public function sessionList(): void
    {
        $this->view('chat.partials.session-list', [
            'sessions' => $this->getSessionUseCase->getAllSessionsWithStats(),
            'currentUuid' => $this->getString('current') ?: null,
        ]);
    }

    public function message(string $uuid): void
    {
        $session = $this->getSessionUseCase->getSession($uuid);

        if ($session === null) {
            $this->view('chat.partials.error', ['error' => 'Session nicht gefunden.']);

            return;
        }

        $sessionId = $session->getId() ?? 0;
        $question = trim($_POST['message'] ?? '');
        $requestedModel = $_POST['model'] ?? $session->getModel();
        $model = $this->modelRegistry->isValid($requestedModel)
            ? $requestedModel
            : $this->modelRegistry->getDefaultChatModel();
        $sessionCollections = $session->getCollections();
        $collections = $_POST['collections'] ?? $sessionCollections;
        $contextLimit = (int) ($_POST['context_limit'] ?? $session->getContextLimit());
        $authorProfileId = (int) ($_POST['author_profile_id'] ?? $session->getAuthorProfileId() ?? 0);
        $systemPromptId = (int) ($_POST['system_prompt_id'] ?? $session->getSystemPromptId() ?? 1);
        $structureId = (int) ($_POST['structure_id'] ?? 0);
        $temperature = (float) ($_POST['temperature'] ?? $session->getTemperature());
        $maxTokens = (int) ($_POST['max_tokens'] ?? $session->getMaxTokens());

        if ($this->updateSessionUseCase->settingsHaveChanged($session, $model, $collections, $contextLimit, $authorProfileId, $temperature, $maxTokens)) {
            $this->updateSessionUseCase->updateSettings($sessionId, $model, $collections, $contextLimit, $authorProfileId, $temperature, $maxTokens);
        }

        if ($question === '') {
            $this->view('chat.partials.error', ['error' => 'Bitte gib eine Frage ein.']);

            return;
        }

        if (!empty($collections)) {
            $compatibility = $this->updateSessionUseCase->validateCollectionCompatibility($collections);
            if (!$compatibility['valid']) {
                $this->view('chat.partials.error', [
                    'error' => 'Collection-Fehler: ' . $compatibility['error'],
                    'details' => 'Bitte wähle nur Collections mit gleichem Embedding-Modell.',
                ]);

                return;
            }
        }

        $qualityCheck = isset($_POST['quality_check']) && $_POST['quality_check'] === '1';

        $response = $this->messageUseCase->execute(
            sessionUuid: $uuid,
            message: $question,
            model: $model,
            collections: $collections,
            contextLimit: $contextLimit,
            authorProfileId: $authorProfileId,
            systemPromptId: $systemPromptId,
            temperature: $temperature,
            maxTokens: $maxTokens,
            structureId: $structureId,
            qualityCheck: $qualityCheck
        );

        if ($response->hasError()) {
            $this->view('chat.partials.error', ['error' => $response->getError()]);

            return;
        }

        $result = $response->toArray();
        $this->view('chat.partials.response', [
            'question' => $question,
            'result' => $result,
            'model' => $model,
            'formattedAnswer' => $this->formatter->formatAnswer($result['answer'] ?? ''),
        ]);
    }

    public function updateTitle(string $uuid): void
    {
        $session = $this->sessionsUseCase->getSession($uuid);

        if ($session === null) {
            $this->notFound('Session nicht gefunden');
        }

        $title = $this->sessionsUseCase->updateTitle($session->getId() ?? 0, $_POST['title'] ?? '');
        $this->html(htmlspecialchars($title));
    }

    public function systemPrompt(string $uuid): void
    {
        $session = $this->sessionsUseCase->getSession($uuid);

        if ($session === null) {
            $this->notFound('Session nicht gefunden');
        }

        $result = $this->sessionsUseCase->updateSystemPrompt($session->getId() ?? 0, $_POST['system_prompt'] ?? '');
        $this->view('chat.partials.success', ['message' => $result->message]);
    }

    public function getSystemPrompt(string $uuid): void
    {
        $session = $this->sessionsUseCase->getSession($uuid);

        if ($session === null) {
            $this->notFound('Session nicht gefunden');
        }

        $this->view('chat.partials.system-prompt-modal', [
            'session' => ChatSessionFactory::toArray($session),
            'currentPrompt' => $session->getSystemPrompt() ?? '',
            'defaultPrompt' => $this->sessionsUseCase->getDefaultSystemPrompt(),
        ]);
    }

    public function delete(string $uuid): void
    {
        $session = $this->sessionsUseCase->getSession($uuid);

        if ($session !== null) {
            $this->sessionsUseCase->deleteSession($session->getId() ?? 0);
        }

        $this->htmxRedirect('/chat');
    }

    public function export(string $uuid): void
    {
        $format = $this->getString('format') ?: 'markdown';
        $filename = $this->exportUseCase->generateFilename($uuid, $format);

        if ($format === 'json') {
            $data = $this->exportUseCase->exportAsJson($uuid);

            if ($data === null) {
                $this->notFound('Session nicht gefunden');
            }

            $content = json_encode($data, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
            $this->download($content, $filename, 'application/json');
        } else {
            $content = $this->exportUseCase->exportAsMarkdown($uuid);

            if ($content === null) {
                $this->notFound('Session nicht gefunden');
            }

            $this->download($content, $filename, 'text/markdown');
        }
    }
}