<?php
header('Content-Type: application/json');
require_once __DIR__ . '/../db/config.php';

$action = $_GET['action'] ?? 'list';

try {
    if ($action === 'list') {
        // Fetch last 20 chats
        $stmt = db()->query("SELECT id, title, mode, created_at FROM chats ORDER BY created_at DESC LIMIT 20");
        $chats = $stmt->fetchAll();
        echo json_encode(['success' => true, 'chats' => $chats]);
    } 
    elseif ($action === 'messages') {
        $chatId = $_GET['chat_id'] ?? null;
        if (!$chatId) {
            echo json_encode(['error' => 'Chat ID is required']);
            exit;
        }

        // Fetch all messages for this chat
        $stmt = db()->prepare("SELECT role, content, created_at FROM messages WHERE chat_id = ? ORDER BY id ASC");
        $stmt->execute([$chatId]);
        $messages = $stmt->fetchAll();

        // Also fetch chat details (to restore mode)
        $stmt = db()->prepare("SELECT mode FROM chats WHERE id = ?");
        $stmt->execute([$chatId]);
        $chat = $stmt->fetch();

        echo json_encode([
            'success' => true, 
            'messages' => $messages,
            'mode' => $chat['mode'] ?? 'regular'
        ]);
    }
    elseif ($action === 'delete') {
        $chatId = $_GET['chat_id'] ?? null;
        if (!$chatId) {
            echo json_encode(['error' => 'Chat ID is required']);
            exit;
        }

        $stmt = db()->prepare("DELETE FROM chats WHERE id = ?");
        $stmt->execute([$chatId]);
        echo json_encode(['success' => true]);
    }
    else {
        echo json_encode(['error' => 'Invalid action']);
    }
} catch (Exception $e) {
    echo json_encode(['error' => $e->getMessage()]);
}