"""
聊天视图组件
处理普通对话的 UI 展示 - 支持流式消息和加载动画
"""

import tkinter as tk
from tkinter import scrolledtext
from typing import Callable, Optional


class LoadingIndicator:
    """加载动画指示器"""
    
    FRAMES = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"]
    
    def __init__(self, parent: tk.Widget, text: str = "处理中"):
        self.parent = parent
        self.text = text
        self.frame_index = 0
        self.running = False
        self.after_id = None
        
        # 创建标签
        self.label = tk.Label(
            parent,
            text="",
            font=('Microsoft YaHei UI', 10),
            fg='#ffd54f',
            bg='#1e1e1e'
        )
    
    def start(self, text: str = None):
        """开始动画"""
        if text:
            self.text = text
        self.running = True
        self.label.pack(pady=5)
        self._animate()
    
    def stop(self):
        """停止动画"""
        self.running = False
        if self.after_id:
            self.parent.after_cancel(self.after_id)
            self.after_id = None
        self.label.pack_forget()
    
    def update_text(self, text: str):
        """更新提示文字"""
        self.text = text
    
    def _animate(self):
        """动画帧更新"""
        if not self.running:
            return
        
        frame = self.FRAMES[self.frame_index]
        self.label.config(text=f"{frame} {self.text}...")
        self.frame_index = (self.frame_index + 1) % len(self.FRAMES)
        self.after_id = self.parent.after(100, self._animate)


class ChatView:
    """
    聊天视图
    
    包含：
    - 消息显示区域
    - 输入框
    - 发送按钮
    - 流式消息支持
    """
    
    def __init__(
        self,
        parent: tk.Widget,
        on_send: Callable[[str], None],
        on_show_history: Optional[Callable[[], None]] = None
    ):
        """
        初始化聊天视图
        
        Args:
            parent: 父容器
            on_send: 发送消息回调函数
            on_show_history: 显示历史记录回调函数
        """
        self.parent = parent
        self.on_send = on_send
        self.on_show_history = on_show_history
        
        # 流式消息状态
        self._stream_active = False
        self._stream_tag = None
        
        # 加载指示器
        self.loading: Optional[LoadingIndicator] = None
        
        self._create_widgets()
    
    def _create_widgets(self):
        """创建 UI 组件"""
        # 主框架
        self.frame = tk.Frame(self.parent, bg='#1e1e1e')
        self.frame.pack(fill=tk.BOTH, expand=True, padx=10, pady=10)
        
        # 标题栏（包含标题和历史按钮）
        title_frame = tk.Frame(self.frame, bg='#1e1e1e')
        title_frame.pack(fill=tk.X, pady=(0, 10))
        
        # 标题
        title_label = tk.Label(
            title_frame,
            text="LocalAgent - 本地 AI 助手",
            font=('Microsoft YaHei UI', 16, 'bold'),
            fg='#61dafb',
            bg='#1e1e1e'
        )
        title_label.pack(side=tk.LEFT, expand=True)
        
        # 历史记录按钮
        if self.on_show_history:
            self.history_btn = tk.Button(
                title_frame,
                text="📜 历史",
                font=('Microsoft YaHei UI', 10),
                bg='#424242',
                fg='#ce93d8',
                activebackground='#616161',
                activeforeground='#ce93d8',
                relief=tk.FLAT,
                padx=10,
                pady=3,
                cursor='hand2',
                command=self.on_show_history
            )
            self.history_btn.pack(side=tk.RIGHT)
        
        # 消息显示区域
        self.message_area = scrolledtext.ScrolledText(
            self.frame,
            wrap=tk.WORD,
            font=('Microsoft YaHei UI', 11),
            bg='#2d2d2d',
            fg='#d4d4d4',
            insertbackground='white',
            relief=tk.FLAT,
            padx=10,
            pady=10,
            state=tk.DISABLED
        )
        self.message_area.pack(fill=tk.BOTH, expand=True, pady=(0, 10))
        
        # 配置消息标签样式
        self.message_area.tag_configure('user', foreground='#4fc3f7', font=('Microsoft YaHei UI', 11, 'bold'))
        self.message_area.tag_configure('assistant', foreground='#81c784', font=('Microsoft YaHei UI', 11))
        self.message_area.tag_configure('system', foreground='#ffb74d', font=('Microsoft YaHei UI', 10, 'italic'))
        self.message_area.tag_configure('error', foreground='#ef5350', font=('Microsoft YaHei UI', 10))
        self.message_area.tag_configure('streaming', foreground='#81c784', font=('Microsoft YaHei UI', 11))
        
        # 输入区域框架
        input_frame = tk.Frame(self.frame, bg='#1e1e1e')
        input_frame.pack(fill=tk.X)
        
        # 输入框
        self.input_entry = tk.Entry(
            input_frame,
            font=('Microsoft YaHei UI', 12),
            bg='#3c3c3c',
            fg='#ffffff',
            insertbackground='white',
            relief=tk.FLAT
        )
        self.input_entry.pack(side=tk.LEFT, fill=tk.X, expand=True, ipady=8, padx=(0, 10))
        self.input_entry.bind('<Return>', self._on_enter_pressed)
        
        # 发送按钮
        self.send_button = tk.Button(
            input_frame,
            text="发送",
            font=('Microsoft YaHei UI', 11, 'bold'),
            bg='#0078d4',
            fg='white',
            activebackground='#106ebe',
            activeforeground='white',
            relief=tk.FLAT,
            padx=20,
            pady=5,
            cursor='hand2',
            command=self._on_send_clicked
        )
        self.send_button.pack(side=tk.RIGHT)
        
        # 显示欢迎消息
        welcome_msg = (
            "欢迎使用 LocalAgent!\n"
            "- 输入问题进行对话\n"
            "- 输入文件处理需求（如\"复制文件\"、\"整理图片\"）将触发执行模式"
        )
        self.add_message(welcome_msg, 'system')
        
        # 创建加载指示器（放在消息区域下方）
        self.loading = LoadingIndicator(self.frame)
    
    def _on_enter_pressed(self, event):
        """回车键处理"""
        self._on_send_clicked()
    
    def _on_send_clicked(self):
        """发送按钮点击处理"""
        text = self.input_entry.get().strip()
        if text:
            self.input_entry.delete(0, tk.END)
            self.on_send(text)
    
    def add_message(self, message: str, tag: str = 'assistant'):
        """
        添加消息到显示区域
        
        Args:
            message: 消息内容
            tag: 消息类型 (user/assistant/system/error)
        """
        self.message_area.config(state=tk.NORMAL)
        
        # 添加前缀
        prefix_map = {
            'user': '[你] ',
            'assistant': '[助手] ',
            'system': '[系统] ',
            'error': '[错误] '
        }
        prefix = prefix_map.get(tag, '')
        
        self.message_area.insert(tk.END, "\n" + prefix + message + "\n", tag)
        self.message_area.see(tk.END)
        self.message_area.config(state=tk.DISABLED)
    
    def start_stream_message(self, tag: str = 'assistant'):
        """
        开始流式消息
        
        Args:
            tag: 消息类型
        """
        self._stream_active = True
        self._stream_tag = tag
        
        self.message_area.config(state=tk.NORMAL)
        
        # 添加前缀
        prefix_map = {
            'user': '[你] ',
            'assistant': '[助手] ',
            'system': '[系统] ',
            'error': '[错误] '
        }
        prefix = prefix_map.get(tag, '')
        
        self.message_area.insert(tk.END, "\n" + prefix, tag)
        self.message_area.see(tk.END)
        # 保持 NORMAL 状态以便追加内容
    
    def append_stream_chunk(self, chunk: str):
        """
        追加流式消息片段
        
        Args:
            chunk: 消息片段
        """
        if not self._stream_active:
            return
        
        self.message_area.insert(tk.END, chunk, self._stream_tag)
        self.message_area.see(tk.END)
        # 强制更新 UI
        self.message_area.update_idletasks()
    
    def end_stream_message(self):
        """结束流式消息"""
        if self._stream_active:
            self.message_area.insert(tk.END, "\n")
            self.message_area.see(tk.END)
            self.message_area.config(state=tk.DISABLED)
            self._stream_active = False
            self._stream_tag = None
    
    def clear_messages(self):
        """清空消息区域"""
        self.message_area.config(state=tk.NORMAL)
        self.message_area.delete(1.0, tk.END)
        self.message_area.config(state=tk.DISABLED)
    
    def set_input_enabled(self, enabled: bool):
        """设置输入区域是否可用"""
        state = tk.NORMAL if enabled else tk.DISABLED
        self.input_entry.config(state=state)
        self.send_button.config(state=state)
    
    def show_loading(self, text: str = "处理中"):
        """显示加载动画"""
        if self.loading:
            self.loading.start(text)
    
    def hide_loading(self):
        """隐藏加载动画"""
        if self.loading:
            self.loading.stop()
    
    def update_loading_text(self, text: str):
        """更新加载提示文字"""
        if self.loading:
            self.loading.update_text(text)
    
    def get_frame(self) -> tk.Frame:
        """获取主框架"""
        return self.frame