feat(web): стабилизация UI, Gemini-скроллинг, роутеры контекста/снапшотов и актуализация роадмапа

modules/web_api/static/js/chat/core.js

@@ -1,67 +1,586 @@
 /**
  * ===============================================================================
- * FILE: static/js/chat/core.js
- * ROLE: Отправка сообщений в API с токеном и обработка ошибок.
+ * FILE: modules/web_api/static/js/chat/core.js
+ * ROLE: Ядро чата: полноэкранный Drag-and-Drop оверлей, авто-высота инпута (24px),
+ *       надежный расчет скролла вопроса к верху окна, крупный шрифт text-sm.
  * ===============================================================================
  */
 
-async function sendMessage(userMessageText) {
-    const chatInput = document.getElementById("chat-input");
-    const message = userMessageText || (chatInput ? chatInput.value.trim() : "");
-    if (!message) return;
+let currentAttachedFile = null;
 
-    if (chatInput && !userMessageText) {
-        chatInput.value = "";
+const CHAT_INPUT_STORAGE_KEY = "scud_chat_input_history";
+let chatInputHistory = JSON.parse(localStorage.getItem(CHAT_INPUT_STORAGE_KEY) || "[]");
+let chatHistoryIndex = -1;
+let temporaryCurrentInput = "";
+
+function saveCommandToHistory(commandText) {
+    if (!commandText || !commandText.trim()) return;
+    const cleanCmd = commandText.trim();
+    if (cleanCmd.startsWith("action:save_draft_")) return;
+
+    chatInputHistory = chatInputHistory.filter(item => item !== cleanCmd);
+    chatInputHistory.push(cleanCmd);
+    if (chatInputHistory.length > 50) chatInputHistory.shift();
+    localStorage.setItem(CHAT_INPUT_STORAGE_KEY, JSON.stringify(chatInputHistory));
+    chatHistoryIndex = -1;
+}
+
+// ⭐️ ЕДИНАЯ ФУНКЦИЯ СКРОЛЛА: плавное выравнивание вопроса к верхней границе
+function scrollToUserMessageTop() {
+    const container = document.getElementById("chat-messages-container");
+    if (!container) return;
+
+    const userBubbles = container.querySelectorAll(".user-chat-bubble");
+    const targetEl = userBubbles[userBubbles.length - 1] || container.lastElementChild;
+    if (!targetEl) return;
+
+    requestAnimationFrame(() => {
+        setTimeout(() => {
+            const containerTop = container.getBoundingClientRect().top;
+            const targetTop = targetEl.getBoundingClientRect().top;
+            
+            const targetScroll = container.scrollTop + (targetTop - containerTop) - 16;
+
+            container.scrollTo({
+                top: Math.max(0, targetScroll),
+                behavior: 'smooth'
+            });
+        }, 50);
+    });
+}
+
+function updateInputHeightAndFade(textarea) {
+    if (!textarea) return;
+
+    if (!textarea.value || textarea.value.trim() === '') {
+        textarea.style.height = '24px';
+        textarea.style.overflowY = 'hidden';
+        textarea.style.maskImage = 'none';
+        textarea.style.webkitMaskImage = 'none';
+        return;
     }
 
-    // Отображаем сообщение пользователя в чате
-    if (typeof appendMessageToUI === "function") {
-        appendMessageToUI("user", message);
+    textarea.style.height = 'auto';
+    const minHeight = 24;
+    const maxHeight = 120;
+    const currentScrollHeight = textarea.scrollHeight;
+
+    if (currentScrollHeight <= minHeight + 2) {
+        textarea.style.height = minHeight + 'px';
+        textarea.style.overflowY = 'hidden';
+        textarea.style.maskImage = 'none';
+        textarea.style.webkitMaskImage = 'none';
+    } else if (currentScrollHeight > maxHeight) {
+        textarea.style.height = maxHeight + 'px';
+        textarea.style.overflowY = 'auto';
+        textarea.style.maskImage = 'linear-gradient(to bottom, transparent 0%, black 14px, black 100%)';
+        textarea.style.webkitMaskImage = 'linear-gradient(to bottom, transparent 0%, black 14px, black 100%)';
+    } else {
+        textarea.style.height = currentScrollHeight + 'px';
+        textarea.style.overflowY = 'hidden';
+        textarea.style.maskImage = 'none';
+        textarea.style.webkitMaskImage = 'none';
+    }
+}
+
+function appendUserMessage(text, filename = null) {
+    const container = document.getElementById("chat-messages-container");
+    if (!container) return;
+
+    const msgId = 'user-msg-' + Date.now();
+    let fileBadge = '';
+    if (filename) {
+        fileBadge = `
+            <div class="inline-flex items-center gap-1.5 px-2.5 py-1 mb-2 bg-indigo-700/80 rounded-lg text-xs font-semibold text-white shadow-xs">
+                <i class="fa-solid fa-paperclip text-xs"></i>
+                <span class="truncate max-w-xs">${escapeHtml(filename)}</span>
+            </div>
+        `;
     }
 
-    // Подготовка заголовков с гарантированным токеном
-    const token = (typeof AuthManager !== "undefined") ? AuthManager.getToken() : (localStorage.getItem("auth_token") || "dev_token_1");
-    const userId = (typeof AuthManager !== "undefined") ? AuthManager.getUserId() : parseInt(localStorage.getItem("user_id") || "1", 10);
-    const sessionId = localStorage.getItem("chat_session_id") || "web_session_main";
+    const msgHtml = `
+        <div id="${msgId}" class="user-chat-bubble flex gap-3 max-w-4xl mx-auto w-full justify-end pt-3 scroll-mt-4">
+            <div class="flex-1 max-w-2xl bg-indigo-600 text-white rounded-2xl rounded-tr-none p-4 shadow-sm">
+                ${fileBadge}
+                <div class="text-sm leading-relaxed whitespace-pre-wrap">${escapeHtml(text)}</div>
+            </div>
+            <div class="w-8 h-8 rounded-lg bg-slate-200 text-slate-600 flex items-center justify-center shrink-0 shadow-sm mt-0.5 font-bold text-sm">
+                <i class="fa-solid fa-user"></i>
+            </div>
+        </div>
+    `;
+    container.insertAdjacentHTML("beforeend", msgHtml);
+}
+
+function appendAssistantLoading() {
+    const container = document.getElementById("chat-messages-container");
+    if (!container) return null;
+
+    const loadingId = 'loading-' + Date.now();
+    const html = `
+        <div id="${loadingId}" class="flex gap-3 max-w-4xl mx-auto w-full pt-1">
+            <div class="w-8 h-8 rounded-lg bg-indigo-600 text-white flex items-center justify-center shrink-0 shadow-sm mt-0.5">
+                <i class="fa-solid fa-robot text-sm"></i>
+            </div>
+            <div class="flex-1 bg-white border border-slate-200 rounded-2xl rounded-tl-none p-4 shadow-sm">
+                <div class="text-sm text-slate-500 flex items-center gap-2">
+                    <i class="fa-solid fa-spinner fa-spin text-indigo-600"></i>
+                    <span>ИИ обрабатывает запрос...</span>
+                </div>
+            </div>
+        </div>
+    `;
+    container.insertAdjacentHTML("beforeend", html);
+    return loadingId;
+}
+
+function appendAssistantMessage(text, buttons = [], actionPayload = null) {
+    const container = document.getElementById("chat-messages-container");
+    if (!container) return;
+
+    let payloadHtml = '';
+    let isHtmlBody = false;
+
+    if (actionPayload) {
+        if (actionPayload.type === 'SNAPSHOTS_CARD' && typeof renderSnapshotsCard === 'function') {
+            payloadHtml = renderSnapshotsCard(actionPayload.data);
+        } else if (actionPayload.type === 'TASK_INTERACTIVE_CARD' && typeof renderInteractiveTaskCard === 'function') {
+            payloadHtml = renderInteractiveTaskCard(actionPayload.tasks);
+        } else if (actionPayload.type === 'FILE_DOWNLOAD_CARD') {
+            const dlUrl = actionPayload.download_url || '#';
+            const fName = actionPayload.filename || 'ROADMAP.md';
+            const count = actionPayload.tasks_count || '';
+            payloadHtml = `
+                <div class="mt-3 p-3.5 bg-indigo-50/80 border border-indigo-200 rounded-xl flex items-center justify-between gap-3 shadow-sm">
+                    <div class="flex items-center gap-3 min-w-0">
+                        <div class="w-9 h-9 rounded-lg bg-indigo-600 text-white flex items-center justify-center shrink-0 shadow-sm">
+                            <i class="fa-solid fa-file-lines text-base"></i>
+                        </div>
+                        <div class="min-w-0">
+                            <div class="text-sm font-bold text-slate-800 truncate">${escapeHtml(fName)}</div>
+                            <div class="text-xs text-slate-500">Задач выгружено: ${count} шт. · Markdown</div>
+                        </div>
+                    </div>
+                    <a href="${dlUrl}" download="${escapeHtml(fName)}" target="_blank"
+                       class="px-4 py-2 bg-indigo-600 hover:bg-indigo-700 active:bg-indigo-800 text-white rounded-lg text-xs font-bold shadow-sm transition flex items-center gap-1.5 shrink-0">
+                        <i class="fa-solid fa-download text-xs"></i>
+                        <span>Скачать файл</span>
+                    </a>
+                </div>
+            `;
+        } else if (actionPayload.type === 'SNAPSHOT_INSPECT_CARD') {
+            const records = actionPayload.records || [];
+            const inspectTableId = 'inspect-table-' + Date.now();
+            const searchInputId = 'inspect-search-' + Date.now();
+
+            const rowsHtml = records.map((r, idx) => `
+                <tr class="inspect-row border-b border-slate-100 text-xs ${r.is_present ? 'bg-white' : 'bg-slate-50/60'} hover:bg-indigo-50/40"
+                    data-fio="${escapeHtml(r.fio).toLowerCase()}" data-dept="${escapeHtml(r.department).toLowerCase()}">
+                    <td class="p-2.5 text-slate-400 text-center font-mono w-10">${idx + 1}</td>
+                    <td class="p-2.5 font-medium text-slate-800">${escapeHtml(r.fio)}</td>
+                    <td class="p-2.5 text-slate-500 text-center">${escapeHtml(r.department)}</td>
+                    <td class="p-2.5 text-center ${r.time_in !== 'Нет входа' ? 'font-bold text-emerald-700' : 'text-slate-400'}">${escapeHtml(r.time_in)}</td>
+                    <td class="p-2.5 text-center text-slate-500">${escapeHtml(r.first_activity)}</td>
+                    <td class="p-2.5 text-center ${r.time_out !== 'Нет выхода' ? 'font-bold text-slate-800' : 'text-slate-400'}">${escapeHtml(r.time_out)}</td>
+                    <td class="p-2.5 text-center font-mono text-slate-600">${escapeHtml(r.in_building)}</td>
+                    <td class="p-2.5 text-center font-bold">${r.is_present ? '<span class="text-emerald-600">✓ Да</span>' : '<span class="text-slate-400">Нет</span>'}</td>
+                </tr>
+            `).join('');
+
+            payloadHtml = `
+                <div class="mt-3 bg-white border border-slate-200 rounded-xl overflow-hidden shadow-sm flex flex-col">
+                    <div class="px-4 py-3 bg-slate-100/90 border-b border-slate-200 flex items-center justify-between gap-2 flex-wrap">
+                        <div class="flex items-center gap-2">
+                            <span class="text-sm font-bold text-slate-800">Срез #${escapeHtml(actionPayload.snapshot_id)}</span>
+                            <span class="text-xs text-slate-500">· Всего: ${records.length} чел. (Присутствуют: ${actionPayload.present_count || 0})</span>
+                        </div>
+                        <div class="flex items-center gap-2">
+                            <input type="text" id="${searchInputId}" placeholder="Поиск в срезе (ФИО / отдел)..." 
+                                   oninput="window.filterInspectTable('${inspectTableId}', this.value)"
+                                   class="text-xs px-3 py-1.5 bg-white border border-slate-300 rounded-lg focus:outline-none focus:border-indigo-500 w-60" />
+                            <button onclick="window.sendChatAction('покажи срезы')" class="text-xs text-indigo-600 hover:underline font-semibold">Все срезы</button>
+                        </div>
+                    </div>
+                    <div class="max-h-96 overflow-y-auto">
+                        <table id="${inspectTableId}" class="w-full text-left border-collapse">
+                            <thead class="bg-slate-50 text-[11px] uppercase text-slate-500 sticky top-0 border-b border-slate-200 shadow-xs">
+                                <tr>
+                                    <th class="p-2.5 text-center w-10">№</th>
+                                    <th class="p-2.5">Сотрудник</th>
+                                    <th class="p-2.5 text-center">Отдел</th>
+                                    <th class="p-2.5 text-center">Вход</th>
+                                    <th class="p-2.5 text-center">Активность</th>
+                                    <th class="p-2.5 text-center">Выход</th>
+                                    <th class="p-2.5 text-center">В здании</th>
+                                    <th class="p-2.5 text-center">Статус</th>
+                                </tr>
+                            </thead>
+                            <tbody>${rowsHtml}</tbody>
+                        </table>
+                    </div>
+                </div>
+            `;
+        } else if (actionPayload.type === 'PROMPT_EDITOR') {
+            const draftText = actionPayload.raw_draft || actionPayload.baseline_prompt || '';
+            const editorId = 'prompt-editor-' + Date.now();
+            payloadHtml = `
+                <div class="mt-3 p-3.5 bg-slate-50 border border-slate-300 rounded-xl flex flex-col gap-2 shadow-inner">
+                    <div class="flex items-center justify-between text-xs font-bold text-slate-700">
+                        <span><i class="fa-solid fa-pen-to-square text-indigo-600 mr-1"></i> Инлайн-редактор системного промпта:</span>
+                        <span class="text-[11px] text-slate-400 font-normal">Прямое редактирование текста</span>
+                    </div>
+                    <textarea id="${editorId}" rows="14" 
+                              class="w-full text-xs font-mono p-3 border border-slate-300 rounded-lg focus:outline-none focus:border-indigo-500 bg-white leading-relaxed resize-y">${escapeHtml(draftText)}</textarea>
+                    <div class="flex items-center justify-end gap-2 pt-1">
+                        <button type="button" onclick="window.sendChatAction('отмена')" class="px-3.5 py-1.5 text-xs text-slate-600 hover:bg-slate-200 rounded-lg transition font-medium">Отменить</button>
+                        <button type="button" onclick="window.submitPromptDraftToDiff('${editorId}')" class="px-4 py-1.5 bg-indigo-600 hover:bg-indigo-700 text-white rounded-lg text-xs font-bold shadow transition flex items-center gap-1.5">
+                            <i class="fa-solid fa-eye text-xs"></i>
+                            <span>Показать превью изменений</span>
+                        </button>
+                    </div>
+                </div>
+            `;
+        } else if (actionPayload.type === 'RULES_EDITOR') {
+            const draftText = actionPayload.raw_draft || actionPayload.baseline_prompt || '';
+            const editorId = 'rules-editor-' + Date.now();
+            payloadHtml = `
+                <div class="mt-3 p-3.5 bg-slate-50 border border-slate-300 rounded-xl flex flex-col gap-2 shadow-inner">
+                    <div class="flex items-center justify-between text-xs font-bold text-slate-700">
+                        <span><i class="fa-solid fa-book-bookmark text-emerald-600 mr-1"></i> Редактор базы знаний и правил компании:</span>
+                        <span class="text-[11px] text-slate-400 font-normal">Прямое изменение правил кадрового арбитража</span>
+                    </div>
+                    <textarea id="${editorId}" rows="12" 
+                              class="w-full text-xs font-mono p-3 border border-slate-300 rounded-lg focus:outline-none focus:border-emerald-500 bg-white leading-relaxed resize-y">${escapeHtml(draftText)}</textarea>
+                    <div class="flex items-center justify-end gap-2 pt-1">
+                        <button type="button" onclick="window.sendChatAction('отмена')" class="px-3.5 py-1.5 text-xs text-slate-600 hover:bg-slate-200 rounded-lg transition font-medium">Отменить</button>
+                        <button type="button" onclick="window.submitRulesDraftToDiff('${editorId}')" class="px-4 py-1.5 bg-emerald-600 hover:bg-emerald-700 text-white rounded-lg text-xs font-bold shadow transition flex items-center gap-1.5">
+                            <i class="fa-solid fa-eye text-xs"></i>
+                            <span>Показать превью изменений</span>
+                        </button>
+                    </div>
+                </div>
+            `;
+        } else if (actionPayload.type === 'PROMPT_PREVIEW') {
+            isHtmlBody = true;
+        }
+    }
+
+    let buttonsHtml = '';
+    if (!actionPayload || (actionPayload.type !== 'PROMPT_EDITOR' && actionPayload.type !== 'RULES_EDITOR')) {
+        const allButtons = (buttons && buttons.length > 0) ? buttons : (actionPayload && actionPayload.buttons ? actionPayload.buttons : []);
+        if (allButtons && Array.isArray(allButtons) && allButtons.length > 0) {
+            buttonsHtml = `
+                <div class="flex flex-wrap gap-2 mt-3.5 pt-2.5 border-t border-slate-100">
+                    ${allButtons.map(b => `
+                        <button onclick="window.sendChatAction('${escapeHtml(b.value || b.action || b.title || '')}')" 
+                                class="px-3 py-1.5 bg-indigo-50 hover:bg-indigo-100 text-indigo-700 rounded-lg text-xs font-semibold border border-indigo-200 transition">
+                            ${escapeHtml(b.label || b.title || b.action)}
+                        </button>
+                    `).join('')}
+                </div>
+            `;
+        }
+    }
+
+    const bodyContent = isHtmlBody ? text : escapeHtml(text);
+
+    const html = `
+        <div class="flex gap-3 max-w-4xl mx-auto w-full pt-1">
+            <div class="w-8 h-8 rounded-lg bg-indigo-600 text-white flex items-center justify-center shrink-0 shadow-sm mt-0.5">
+                <i class="fa-solid fa-robot text-sm"></i>
+            </div>
+            <div class="flex-1 bg-white border border-slate-200 rounded-2xl rounded-tl-none p-4 shadow-sm min-w-0">
+                <div class="text-[11px] font-bold text-indigo-600 uppercase tracking-wider mb-1.5">ИИ-ассистент SCUD Orion AI</div>
+                <div class="text-sm text-slate-800 leading-relaxed whitespace-pre-wrap">${bodyContent}</div>
+                ${payloadHtml}
+                ${buttonsHtml}
+            </div>
+        </div>
+    `;
+    container.insertAdjacentHTML("beforeend", html);
+}
+
+window.filterInspectTable = function(tableId, query) {
+    const table = document.getElementById(tableId);
+    if (!table) return;
+    const q = (query || '').trim().toLowerCase();
+    const rows = table.querySelectorAll('.inspect-row');
+    rows.forEach(r => {
+        const fio = r.getAttribute('data-fio') || '';
+        const dept = r.getAttribute('data-dept') || '';
+        if (!q || fio.includes(q) || dept.includes(q)) {
+            r.classList.remove('hidden');
+        } else {
+            r.classList.add('hidden');
+        }
+    });
+};
+
+window.sendChatAction = function(actionText) {
+    if (!actionText || !actionText.trim()) return;
+    const input = document.getElementById("user-input");
+    if (input) {
+        input.value = actionText.trim();
+        updateInputHeightAndFade(input);
+    }
+    window.sendMessage();
+};
+
+window.submitPromptDraftToDiff = function(editorId) {
+    const textarea = document.getElementById(editorId);
+    if (!textarea) return;
+    const newText = textarea.value.trim();
+    if (!newText) {
+        alert("Текст системного промпта не может быть пустым");
+        return;
+    }
+
+    const command = `action:save_draft_prompt:::${newText}`;
+    const input = document.getElementById("user-input");
+    if (input) input.value = command;
+    window.sendMessage();
+};
+
+window.submitRulesDraftToDiff = function(editorId) {
+    const textarea = document.getElementById(editorId);
+    if (!textarea) return;
+    const newText = textarea.value.trim();
+    if (!newText) {
+        alert("Правила не могут быть пустыми");
+        return;
+    }
+
+    const command = `action:save_draft_rules:::${newText}`;
+    const input = document.getElementById("user-input");
+    if (input) input.value = command;
+    window.sendMessage();
+};
+
+window.sendMessage = async function() {
+    const input = document.getElementById("user-input");
+    if (!input) return;
+
+    const messageText = input.value.trim();
+    const fileToSend = currentAttachedFile;
+
+    if (!messageText && !fileToSend) return;
+
+    saveCommandToHistory(messageText);
+
+    input.value = "";
+    input.style.height = '24px';
+    input.style.overflowY = 'hidden';
+    input.style.maskImage = 'none';
+    input.style.webkitMaskImage = 'none';
+    window.clearAttachedFile();
+
+    // 1. Отрисовка сообщения пользователя в ленте
+    if (!messageText.startsWith("action:save_draft_prompt:::") && !messageText.startsWith("action:save_draft_rules:::")) {
+        appendUserMessage(
+            messageText || (fileToSend ? `Прикреплен файл: ${fileToSend.name}` : ''), 
+            fileToSend ? fileToSend.name : null
+        );
+    } else {
+        appendUserMessage("Сформировать предпросмотр изменений");
+    }
+
+    // 2. Вставка лоадера
+    const loadingId = appendAssistantLoading();
+
+    // 3. Вызов точного скролла
+    scrollToUserMessageTop();
 
     try {
-        const response = await fetch("/api/v1/chat", {
-            method: "POST",
-            headers: {
-                "Content-Type": "application/json",
-                "Authorization": `Bearer ${token}`
-            },
-            body: JSON.stringify({
-                message: message,
-                session_id: sessionId,
-                user_id: userId
-            })
+        let res;
+        if (fileToSend) {
+            const formData = new FormData();
+            formData.append("file", fileToSend);
+            formData.append("message", messageText);
+            formData.append("session_id", "web_session_main");
+
+            res = await fetch("/api/v1/chat/upload", {
+                method: "POST",
+                headers: {
+                    "Authorization": AuthManager.getAuthHeaders()["Authorization"]
+                },
+                body: formData
+            });
+
+            if (res.status === 404) {
+                res = await fetch("/api/v1/chat", {
+                    method: "POST",
+                    headers: AuthManager.getAuthHeaders(),
+                    body: JSON.stringify({
+                        message: messageText || `Загружен файл: ${fileToSend.name}`,
+                        session_id: "web_session_main"
+                    })
+                });
+            }
+        } else {
+            res = await fetch("/api/v1/chat", {
+                method: "POST",
+                headers: AuthManager.getAuthHeaders(),
+                body: JSON.stringify({
+                    message: messageText,
+                    session_id: "web_session_main"
+                })
+            });
+        }
+
+        const loaderEl = document.getElementById(loadingId);
+        if (loaderEl) loaderEl.remove();
+
+        if (res.ok) {
+            const data = await res.json();
+            const replyText = data.response || data.text || data.message || "Запрос выполнен.";
+            const buttons = data.buttons || [];
+            const actionPayload = data.action_payload || null;
+
+            appendAssistantMessage(replyText, buttons, actionPayload);
+
+            if (window.SidebarManager) {
+                SidebarManager.renderContent();
+            }
+        } else {
+            const err = await res.json().catch(() => ({}));
+            appendAssistantMessage(`⚠️ Ошибка сервера (${res.status}): ${err.detail || "Не удалось получить ответ"}`);
+        }
+    } catch (err) {
+        console.error("Ошибка отправки сообщения:", err);
+        const loaderEl = document.getElementById(loadingId);
+        if (loaderEl) loaderEl.remove();
+        appendAssistantMessage("⚠️ Ошибка соединения с сервером при отправке сообщения.");
+    }
+};
+
+window.clearAttachedFile = function() {
+    currentAttachedFile = null;
+    const preview = document.getElementById("file-attachment-preview");
+    const nameEl = document.getElementById("file-attachment-name");
+    const fileInput = document.getElementById("file-upload-input");
+
+    if (preview) preview.classList.add("hidden");
+    if (nameEl) nameEl.innerText = "";
+    if (fileInput) fileInput.value = "";
+};
+
+function handleFileSelected(file) {
+    if (!file) return;
+    currentAttachedFile = file;
+    const preview = document.getElementById("file-attachment-preview");
+    const nameEl = document.getElementById("file-attachment-name");
+
+    if (preview && nameEl) {
+        nameEl.innerText = file.name;
+        preview.classList.remove("hidden");
+    }
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+    const input = document.getElementById("user-input");
+    const fileInput = document.getElementById("file-upload-input");
+    const overlay = document.getElementById("global-drag-overlay");
+
+    if (input) {
+        input.style.lineHeight = '24px';
+        input.style.height = '24px';
+
+        input.addEventListener("keydown", (e) => {
+            if (e.key === "Enter") {
+                if (e.shiftKey) return;
+                e.preventDefault();
+                window.sendMessage();
+                return;
+            }
+
+            if (e.key === "ArrowUp") {
+                const isSingleLine = !input.value.includes("\n");
+                const isAtBeginning = input.selectionStart === 0 && input.selectionEnd === 0;
+
+                if (isSingleLine || isAtBeginning) {
+                    if (chatInputHistory.length > 0) {
+                        e.preventDefault();
+                        if (chatHistoryIndex === -1) {
+                            temporaryCurrentInput = input.value;
+                            chatHistoryIndex = chatInputHistory.length - 1;
+                        } else if (chatHistoryIndex > 0) {
+                            chatHistoryIndex--;
+                        }
+                        input.value = chatInputHistory[chatHistoryIndex];
+                        updateInputHeightAndFade(input);
+                        input.setSelectionRange(input.value.length, input.value.length);
+                    }
+                }
+            } else if (e.key === "ArrowDown") {
+                const isSingleLine = !input.value.includes("\n");
+                const isAtEnd = input.selectionStart === input.value.length;
+
+                if (isSingleLine || isAtEnd) {
+                    if (chatHistoryIndex !== -1) {
+                        e.preventDefault();
+                        if (chatHistoryIndex < chatInputHistory.length - 1) {
+                            chatHistoryIndex++;
+                            input.value = chatInputHistory[chatHistoryIndex];
+                        } else {
+                            chatHistoryIndex = -1;
+                            input.value = temporaryCurrentInput;
+                        }
+                        updateInputHeightAndFade(input);
+                        input.setSelectionRange(input.value.length, input.value.length);
+                    }
+                }
+            }
         });
 
-        if (response.status === 403) {
-            console.warn("[Chat] Получен 403 Forbidden. Сбрасываем сессию и повторяем...");
-            localStorage.removeItem("auth_token");
-            if (typeof appendMessageToUI === "function") {
-                appendMessageToUI("assistant", "⚠️ Сессия была обновлена. Пожалуйста, отправьте сообщение повторно.");
-            }
-            return;
-        }
-
-        if (!response.ok) {
-            throw new Error(`Ошибка сервера (HTTP ${response.status})`);
-        }
-
-        const data = await response.json();
-        const reply = data.response || data.message || "Ответ получен без текста.";
-
-        if (typeof appendMessageToUI === "function") {
-            appendMessageToUI("assistant", reply);
-        }
-
-    } catch (err) {
-        console.error("[Chat Error]:", err);
-        if (typeof appendMessageToUI === "function") {
-            appendMessageToUI("assistant", `⚠️ Не удалось связаться с сервером: ${err.message}`);
-        }
+        input.addEventListener("input", function() {
+            updateInputHeightAndFade(this);
+            chatHistoryIndex = -1;
+        });
     }
-}
+
+    if (fileInput) {
+        fileInput.addEventListener("change", (e) => {
+            if (e.target.files && e.target.files[0]) {
+                handleFileSelected(e.target.files[0]);
+            }
+        });
+    }
+
+    let dragCounter = 0;
+
+    window.addEventListener('dragenter', (e) => {
+        e.preventDefault();
+        dragCounter++;
+        if (overlay) {
+            overlay.classList.remove('hidden');
+        }
+    }, false);
+
+    window.addEventListener('dragleave', (e) => {
+        e.preventDefault();
+        dragCounter--;
+        if (dragCounter <= 0) {
+            dragCounter = 0;
+            if (overlay) {
+                overlay.classList.add('hidden');
+            }
+        }
+    }, false);
+
+    window.addEventListener('dragover', (e) => {
+        e.preventDefault();
+    }, false);
+
+    window.addEventListener('drop', (e) => {
+        e.preventDefault();
+        dragCounter = 0;
+        if (overlay) {
+            overlay.classList.add('hidden');
+        }
+
+        const dt = e.dataTransfer;
+        if (dt && dt.files && dt.files[0]) {
+            handleFileSelected(dt.files[0]);
+        }
+    }, false);
+});