// ===== index.js (Redis 存储版) =====
const chatArea = document.getElementById('chatArea');
const messageInput = document.getElementById('messageInput');
const submitBtn = document.getElementById('submitBtn');
const newChatBtn = document.getElementById('newChatBtn');
const chatList = document.getElementById('chatList');
const welcomeMessage = document.getElementById('welcomeMessage');
const toggleSidebarBtn = document.getElementById('toggleSidebar');
const sidebar = document.getElementById('sidebar');

// RAG 相关 DOM
const ragSelect = document.getElementById('ragSelect');
const deleteRagBtn = document.getElementById('deleteRagBtn');
const refreshRagBtn = document.getElementById('refreshRagBtn');

let currentEventSource = null;
let currentChatId = localStorage.getItem('currentChatId') || null;

// ==================== Redis 存储相关函数 ====================

/**
 * 获取所有聊天会话及其标题
 */
async function getAllChats() {
    try {
        const response = await fetch('http://localhost:8095/api/v1/chat');
        const chatIds = await response.json();

        return Promise.all(chatIds.map(async chatId => {
            const nameResponse = await fetch(`http://localhost:8095/api/v1/chat/${chatId}/name`);
            const name = await nameResponse.text();
            return { chatId, name };
        }));
    } catch (error) {
        console.error('获取聊天列表失败:', error);
        return [];
    }
}

/**
 * 创建新聊天会话
 */
async function createNewChat() {
    const chatId = Date.now().toString();

    try {
        // 设置默认名称
        await fetch(`http://localhost:8095/api/v1/chat/${chatId}/rename`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ name: '新聊天' })
        });

        currentChatId = chatId;
        localStorage.setItem('currentChatId', chatId);

        updateChatList();
        clearChatArea();
        return chatId;
    } catch (error) {
        console.error('创建聊天失败:', error);
        throw error;
    }
}

/**
 * 删除聊天会话
 */
async function deleteChat(chatId) {
    if (!confirm('确定要删除这个聊天记录吗？')) return;

    try {
        const response = await fetch(`http://localhost:8095/api/v1/chat/${chatId}`, {
            method: 'DELETE'
        });

        if (response.ok) {
            if (currentChatId === chatId) {
                await createNewChat();
            }
            updateChatList();
        } else {
            throw new Error(`HTTP ${response.status}`);
        }
    } catch (error) {
        console.error('删除聊天失败:', error);
        alert('删除失败: ' + error.message);
    }
}

/**
 * 重命名聊天会话
 */
async function renameChat(chatId) {
    const currentName = await (await fetch(`http://localhost:8095/api/v1/chat/${chatId}/name`)).text();
    const newName = prompt('请输入新的聊天名称', currentName);

    if (newName) {
        try {
            await fetch(`http://localhost:8095/api/v1/chat/${chatId}/rename`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ name: newName })
            });
            updateChatList();
        } catch (error) {
            console.error('重命名失败:', error);
            alert('重命名失败: ' + error.message);
        }
    }
}

/**
 * 加载聊天历史
 */
async function loadChat(chatId) {
    try {
        const response = await fetch(`http://localhost:8095/chat/${chatId}`);
        const messages = await response.json();

        currentChatId = chatId;
        localStorage.setItem('currentChatId', chatId);
        clearChatArea();

        messages.forEach(msg => {
            appendMessage(msg.content, msg.role === 'assistant', false);
        });
    } catch (error) {
        console.error('加载聊天失败:', error);
        alert('加载聊天失败: ' + error.message);
    }
}

/**
 * 保存消息到 Redis
 */
async function saveMessage(chatId, content, isAssistant) {
    const msg = {
        role: isAssistant ? "assistant" : "user",
        content: content,
        ts: Date.now()
    };

    try {
        await fetch(`http://localhost:8095/api/v1/chat/${chatId}/message`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(msg)
        });
    } catch (error) {
        console.error('保存消息失败:', error);
    }
}

/**
 * 更新聊天列表 UI
 */
async function updateChatList() {
    chatList.innerHTML = '';
    const chats = await getAllChats();

    // 当前聊天置顶
    chats.sort((a, b) => {
        if (a.chatId === currentChatId) return -1;
        if (b.chatId === currentChatId) return 1;
        return parseInt(b.chatId) - parseInt(a.chatId); // 按时间倒序
    });

    chats.forEach(chat => {
        const li = document.createElement('li');
        li.className = `chat-item flex items-center justify-between p-2 hover:bg-gray-100 rounded-lg cursor-pointer transition-colors ${
            chat.chatId === currentChatId ? 'bg-blue-50' : ''
        }`;

        const date = new Date(parseInt(chat.chatId)).toLocaleDateString('zh-CN', {
            year: 'numeric',
            month: '2-digit',
            day: '2-digit'
        });

        li.innerHTML = `
            <div class="flex-1">
                <div class="text-sm font-medium">${chat.name}</div>
                <div class="text-xs text-gray-400">${date}</div>
            </div>
            <div class="chat-actions flex items-center gap-1 opacity-0 transition-opacity duration-200">
                <button class="p-1 hover:bg-gray-200 rounded text-gray-500">重命名</button>
                <button class="p-1 hover:bg-red-200 rounded text-red-500">删除</button>
            </div>
        `;

        // 事件绑定
        li.querySelectorAll('button')[0].addEventListener('click', (e) => {
            e.stopPropagation();
            renameChat(chat.chatId);
        });

        li.querySelectorAll('button')[1].addEventListener('click', (e) => {
            e.stopPropagation();
            deleteChat(chat.chatId);
        });

        li.addEventListener('click', () => loadChat(chat.chatId));
        li.addEventListener('mouseenter', () => {
            li.querySelector('.chat-actions').classList.remove('opacity-0');
        });
        li.addEventListener('mouseleave', () => {
            li.querySelector('.chat-actions').classList.add('opacity-0');
        });

        chatList.appendChild(li);
    });
}

// ==================== 消息显示相关函数 ====================

function clearChatArea() {
    chatArea.innerHTML = '';
    welcomeMessage.style.display = 'flex';
}

function appendMessage(content, isAssistant = false, saveToStorage = true) {
    welcomeMessage.style.display = 'none';
    const messageDiv = document.createElement('div');
    messageDiv.className = `max-w-4xl mx-auto mb-4 p-4 rounded-lg ${
        isAssistant ? 'bg-gray-100' : 'bg-white border'
    } markdown-body relative`;

    const renderedContent = DOMPurify.sanitize(marked.parse(content));
    messageDiv.innerHTML = renderedContent;

    const copyBtn = document.createElement('button');
    copyBtn.className = 'absolute top-2 right-2 p-1 bg-gray-200 rounded-md text-xs';
    copyBtn.textContent = '复制';
    copyBtn.onclick = () => {
        navigator.clipboard.writeText(content).then(() => {
            copyBtn.textContent = '已复制';
            setTimeout(() => (copyBtn.textContent = '复制'), 2000);
        });
    };
    messageDiv.appendChild(copyBtn);

    chatArea.appendChild(messageDiv);
    chatArea.scrollTop = chatArea.scrollHeight;

    if (saveToStorage && currentChatId) {
        saveMessage(currentChatId, content, isAssistant);
    }
}

// ==================== 事件流处理 ====================

function startEventStream(message) {
    if (currentEventSource) currentEventSource.close();

    const ragTag = ragSelect.value;
    const aiModelSelect = document.getElementById('aiModel');
    const aiModelValue = aiModelSelect.value;
    const aiModelModel = aiModelSelect.options[aiModelSelect.selectedIndex].getAttribute('model');

    let url;
    const base = `http://localhost:8095/api/v1/${aiModelValue}`;
    const params = new URLSearchParams({ message, model: aiModelModel });
    if (ragTag) {
        params.append('ragTag', ragTag);
        url = `${base}/generate_stream_rag?${params.toString()}`;
    } else {
        url = `${base}/generate_stream?${params.toString()}`;
    }

    currentEventSource = new EventSource(url);
    let accumulatedContent = '';
    let tempMessageDiv = null;

    currentEventSource.onmessage = function(event) {
        try {
            const data = JSON.parse(event.data);
            const content = data.result?.output?.content || data.content;

            if (content) {
                accumulatedContent += content;

                if (!tempMessageDiv) {
                    tempMessageDiv = document.createElement('div');
                    tempMessageDiv.className = 'max-w-4xl mx-auto mb-4 p-4 rounded-lg bg-gray-100 markdown-body relative';
                    chatArea.appendChild(tempMessageDiv);
                    welcomeMessage.style.display = 'none';
                }

                tempMessageDiv.textContent = accumulatedContent;
                chatArea.scrollTop = chatArea.scrollHeight;
            }

            if (data.result?.output?.properties?.finishReason === 'STOP') {
                currentEventSource.close();

                if (tempMessageDiv) {
                    tempMessageDiv.innerHTML = DOMPurify.sanitize(marked.parse(accumulatedContent));

                    const copyBtn = document.createElement('button');
                    copyBtn.className = 'absolute top-2 right-2 p-1 bg-gray-200 rounded-md text-xs';
                    copyBtn.textContent = '复制';
                    copyBtn.onclick = () => {
                        navigator.clipboard.writeText(accumulatedContent).then(() => {
                            copyBtn.textContent = '已复制';
                            setTimeout(() => (copyBtn.textContent = '复制'), 2000);
                        });
                    };
                    tempMessageDiv.appendChild(copyBtn);
                }

                if (currentChatId) {
                    saveMessage(currentChatId, accumulatedContent, true);
                }
            }
        } catch (e) {
            console.error('解析事件数据失败:', e);
        }
    };

    currentEventSource.onerror = function(error) {
        console.error('EventSource 错误:', error);
        currentEventSource.close();
    };
}

// ==================== 事件绑定 ====================

submitBtn.addEventListener('click', async () => {
    const message = messageInput.value.trim();
    if (!message) return;

    if (!currentChatId) {
        await createNewChat();
    }

    appendMessage(message, false);
    messageInput.value = '';
    startEventStream(message);
});

messageInput.addEventListener('keypress', (e) => {
    if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        submitBtn.click();
    }
});

newChatBtn.addEventListener('click', createNewChat);

toggleSidebarBtn.addEventListener('click', () => {
    sidebar.classList.toggle('-translate-x-full');
    updateSidebarIcon();
});

function updateSidebarIcon() {
    const iconPath = document.getElementById('sidebarIconPath');
    if (sidebar.classList.contains('-translate-x-full')) {
        iconPath.setAttribute('d', 'M4 6h16M4 12h4m12 0h-4M4 18h16');
    } else {
        iconPath.setAttribute('d', 'M4 6h16M4 12h16M4 18h16');
    }
}

// ==================== 初始化 ====================

// 初始化聊天列表
updateChatList();

// 加载当前聊天
if (currentChatId) {
    loadChat(currentChatId);
}

// 响应式处理
window.addEventListener('resize', () => {
    if (window.innerWidth > 768) {
        sidebar.classList.remove('-translate-x-full');
    } else {
        sidebar.classList.add('-translate-x-full');
    }
});

if (window.innerWidth <= 768) {
    sidebar.classList.add('-translate-x-full');
}

updateSidebarIcon();

/** -------------------------
 *  上传知识下拉菜单（保持你现有 HTML 结构）
 *  - 点击按钮展开/收起菜单
 *  - 点击外部区域/按下 Esc 关闭
 *  - 点击菜单项后自动关闭
 * ------------------------- */
(function initUploadMenu() {
    const uploadMenuButton = document.getElementById('uploadMenuButton');
    const uploadMenu = document.getElementById('uploadMenu');
    if (!uploadMenuButton || !uploadMenu) return;

    // 切换菜单显示/隐藏
    const toggleMenu = () => {
        uploadMenu.classList.toggle('hidden');
    };

    // 显示菜单
    const openMenu = () => {
        uploadMenu.classList.remove('hidden');
    };

    // 隐藏菜单
    const closeMenu = () => {
        uploadMenu.classList.add('hidden');
    };

    // 点击按钮展开/收起
    uploadMenuButton.addEventListener('click', (e) => {
        e.stopPropagation();
        toggleMenu();
    });

    // 键盘辅助：Enter/Space 展开，Esc 关闭
    uploadMenuButton.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' || e.key === ' ') {
            e.preventDefault();
            openMenu();
        } else if (e.key === 'Escape') {
            closeMenu();
        }
    });

    // 点击菜单项后自动关闭
    uploadMenu.querySelectorAll('a').forEach(a => {
        a.addEventListener('click', () => closeMenu());
    });

    // 点击外部任意区域关闭
    document.addEventListener('click', (e) => {
        if (!uploadMenu.classList.contains('hidden')) {
            if (!uploadMenu.contains(e.target) && e.target !== uploadMenuButton) {
                closeMenu();
            }
        }
    });

    // Esc 关闭（全局）
    document.addEventListener('keydown', (e) => {
        if (e.key === 'Escape') closeMenu();
    });
})();