from os import remove
from tkinter import Tk, Label, Menu, filedialog, SUNKEN, Frame, Text, Entry, Button, END, messagebox
from PIL import  Image, ImageTk, ImageFile, UnidentifiedImageError
from encode import encode_bmp, save_encode_img
from decode import extract
ImageFile.LOAD_TRUNCATED_IMAGES = True

class PlaceholderEntry(Entry):
    def __init__(self, master=None, placeholder="Enter text here...", **kwargs):
        super().__init__(master, **kwargs)
        self.placeholder = placeholder
        self.insert("0", self.placeholder)
        self.bind("<FocusIn>", self._clear_placeholder)
        self.bind("<FocusOut>", self._restore_placeholder)

    def _clear_placeholder(self, event):
        if self.get() == self.placeholder:
            self.delete("0", "end")

    def _restore_placeholder(self, event):
        if not self.get():
            self.insert("0", self.placeholder)

class bmp_transfer:
    def __init__(self):
        self.original_file_path= "" # 原图的路径/待解码的图的路径
        self.embedded_file_path = ""  # 嵌入图的路径
        self.embedded_info="" # 嵌入的信息
        self.embedded_img_header="" # 嵌入图片信息，包括header
        self.embedded_img_header_others = ""  # 嵌入图的其他信息
        self.embedded_img_data="" # 嵌入图片信息，包括data
        self.extract_info="" # 提取的图片信息
        self.max_embed_length_bits=0 # 可嵌入信息的最大长度(bit)
        self.max_embed_length_bytes=0 # 可嵌入信息的最大长度(byte)

        # 创建一个Tkinter窗口
        self.root = Tk()
        self.root.geometry("1300x800")  # 设置窗口大小

        # 按钮组件
        self.button_frame = Frame(self.root, width=400, height=300)
        self.button_frame.pack_propagate(0)
        self.button_frame.grid(row=0, column=0)

        self.button_frame.grid_columnconfigure(0, weight=1)
        self.button_frame.grid_columnconfigure(1, weight=1)
        self.button_frame.grid_rowconfigure(0, weight=1)
        self.button_frame.grid_rowconfigure(1, weight=1)

        self.read_img_button = Button(self.button_frame, text="读取图片", command=self.open_img)
        self.read_img_button.grid(row=0, column=0)

        self.embed_button = Button(self.button_frame, text="嵌入", command=self.embed_info)
        self.embed_button.grid(row=0, column=1)

        self.save_img_button = Button(self.button_frame, text="存储图片", command=self.save_embed_img)
        self.save_img_button.grid(row=1, column=0)

        self.extract_button = Button(self.button_frame, text="提取", command=self.extract_embed_info)
        self.extract_button.grid(row=1, column=1)

        # 图片展示组件
        self.original_frame=Frame(self.root, width=400, height=300)
        self.encoded_frame=Frame(self.root, width=400, height=300)
        self.original_frame.pack_propagate(0)
        self.encoded_frame.pack_propagate(0)

        self.original_label = Label(self.original_frame, text='原图', borderwidth=2, relief=SUNKEN)
        self.encoded_label = Label(self.encoded_frame, text='嵌入信息后的图', borderwidth=2, relief=SUNKEN)

        self.original_label.pack(fill='both', expand=True)
        self.encoded_label.pack(fill='both', expand=True)
        self.original_frame.grid(row=1, column=0)
        self.encoded_frame.grid(row=1, column=2)

        #对话框展示组件
        self.text_frame = Frame(self.root, width=400, height=300)
        self.text_frame.pack_propagate(0)
        self.text_frame.grid(row=1, column=1)

        self.upper_text = Text(self.text_frame, height=15, font=("Arial", 20))
        self.lower_text = PlaceholderEntry(self.text_frame, placeholder="输入要嵌入的信息/显示提取出的信息", font=("Arial", 20))
        self.upper_text.pack(fill='both', expand=True)
        self.lower_text.pack(fill='both', expand=True)
        self.upper_text.place(x=0, y=0, width=400, height=150)
        self.lower_text.place(x=0, y=150, width=400, height=150)
        self.upper_text.insert('1.0', '这是要显示计算出来的可嵌入信息的最大长度')
        self.upper_text.configure(state='disabled')

        # 创建菜单栏
        menubar = Menu(self.root)
        # 创建菜单选项
        file_menu = Menu(menubar, tearoff=0)
        file_menu.add_command(label="读取图片", command=self.open_img)  # 将open_img函数绑定到菜单项
        file_menu.add_command(label="存储图片", command=self.save_embed_img)
        file_menu.add_separator()
        file_menu.add_command(label="嵌入", command=self.embed_info)
        file_menu.add_command(label="提取", command=self.extract_embed_info)
        file_menu.add_separator()
        file_menu.add_command(label="退出", command=self.root.quit)
        menubar.add_cascade(label="菜单", menu=file_menu)  # 将菜单选项添加到menubar

        self.root.config(menu=menubar)  # 添加菜单栏

    # 交互函数
    def open_img(self):
        self.original_file_path = filedialog.askopenfilename()  # 打开文件选择对话框
        if self.original_file_path:  # 确保文件路径不为空
            try:
                img = Image.open(self.original_file_path)
            except UnidentifiedImageError:
                messagebox.showwarning('警告', "选择的文件不是图片")
                self.original_file_path=""
                return
            if img.format =='BMP' and img.mode == 'RGB':
                width, height = img.size
                self.max_embed_length_bits = width * height * 3  # 总共可以嵌入的bit数，每个像素可以嵌入3bits
                self.max_embed_length_bytes = self.max_embed_length_bits // 8  # 总共可以嵌入的字节数
            elif img.format =='BMP' and img.mode == 'L':
                width, height = img.size
                self.max_embed_length_bits = width * height  # 总共可以嵌入的bit数，每个像素可以嵌入3bits
                self.max_embed_length_bytes = self.max_embed_length_bits // 8  # 总共可以嵌入的字节数
            else:
                messagebox.showerror('错误', "嵌入图像必须是BMP图片的256灰度图或者24位真彩图，当前图片格式为：{}, {}".format(img.format, img.mode))
                # print("嵌入图像必须是BMP图片的256灰度图或者24位真彩图，当前图片格式为：{}, {}".format(img.format, img.mode))
                return
            if img.size[0]>512 or img.size[1]>512:
                messagebox.showerror('错误', "嵌入图像大小不超过512*512，当前图片大小为：{}*{}".format(img.size[0], img.size[1]))
                # print("嵌入图像大小不超过512*512，当前图片大小为：{}*{}".format(img.size[0], img.size[1]))
                return
            if img.size[0]%4 !=0 :
                messagebox.showerror('错误', "嵌入图像的宽度必须是4的倍数，当前图片宽度为：{}".format(img.size[0]))
                # print("嵌入图像的宽度必须是4的倍数，当前图片宽度为：{}".format(img.size[0]))
                return
            self.upper_text.configure(state='normal')
            self.upper_text.delete('1.0', 'end')
            self.upper_text.insert('1.0', '当前图像可嵌入信息最大字节数为：{}'.format(self.max_embed_length_bytes))
            self.upper_text.configure(state='disabled')
            max_size=(400, 300)
            #将大图按比例缩小
            if img.size[0]>400 or img.size[1]>300:
                img.thumbnail(max_size, Image.LANCZOS)
            #将小图按比例放大
            else:
                max_size = (400, 300)
                aspect_ratio = img.size[0] / img.size[1]
                new_width = min(max_size[0], max_size[1] * aspect_ratio)
                new_height = min(max_size[1], max_size[0] / aspect_ratio)
                img = img.resize((int(new_width), int(new_height)), Image.LANCZOS)
            img_tk = ImageTk.PhotoImage(img)
            self.original_label.config(image=img_tk)
            self.original_label.image = img_tk  # 保持对图像的引用

    def embed_info(self):
        if self.original_file_path:
            self.embedded_info=self.lower_text.get()
            if len(self.embedded_info.encode('utf-8'))>self.max_embed_length_bytes:
                messagebox.showerror('错误', '信息过长，无法嵌入')
                # print('信息过长，无法嵌入')
            else:
                # print('嵌入信息中')
                #调用encode.py中的嵌入函数将信息嵌入，结果先显示在嵌入信息后的图片中
                (self.embedded_img_header, self.embedded_img_header_others, self.embedded_img_data)=encode_bmp(self.original_file_path, self.embedded_info)
                self.embedded_file_path=self.original_file_path[:-4]+"_embeded"+self.original_file_path[-4:]
                save_encode_img(self.embedded_file_path, self.embedded_img_data, self.embedded_img_header, self.embedded_img_header_others)
                # 将这个新的bmp文件读取进来，转换成PhotoImage
                img = Image.open(self.embedded_file_path)
                max_size = (400, 300)
                # 将大图按比例缩小
                if img.size[0] > 400 or img.size[1] > 300:
                    img.thumbnail(max_size, Image.LANCZOS)
                # 将小图按比例放大
                else:
                    max_size = (400, 300)
                    aspect_ratio = img.size[0] / img.size[1]
                    new_width = min(max_size[0], max_size[1] * aspect_ratio)
                    new_height = min(max_size[1], max_size[0] / aspect_ratio)
                    img = img.resize((int(new_width), int(new_height)), Image.LANCZOS)
                img_tk = ImageTk.PhotoImage(img)
                self.encoded_label.config(image=img_tk)
                self.encoded_label.image = img_tk  # 保持对图像的引用
                #删除临时bmp文件
                try:
                    remove(self.embedded_file_path)
                    messagebox.showinfo('提示', "嵌入成功")
                    print("移除成功")
                except FileNotFoundError:
                    messagebox.showwarning('警告', "文件 {} 不存在.".format(self.embedded_file_path))
                    return
                    # print("文件 {} 不存在.".format(self.embedded_file_path))
        else:
            messagebox.showerror('错误', "必须选择图片才能嵌入哦～")
            # print("必须选择图片才能嵌入哦～")
    def save_embed_img(self):
        if self.embedded_file_path:
            save_encode_img(self.embedded_file_path, self.embedded_img_data, self.embedded_img_header, self.embedded_img_header_others)
            messagebox.showinfo('提示',"保存成功，文件位置为：{}".format(self.embedded_file_path))
        else:
            messagebox.showerror('错误', "还没嵌入图像呢～")
    def extract_embed_info(self):
        if self.original_file_path:
            self.extract_info=extract(self.original_file_path)
            self.lower_text.delete(0, END)
            self.lower_text.insert(0, self.extract_info)
            messagebox.showinfo('提示', "提取成功～，信息已经显示到上面的框框中了～")
        else:
            messagebox.showerror('错误', "必须选择图片才能提取哦～")
    def run(self):
        # 启动窗口
        self.root.mainloop()

def main():
    app = bmp_transfer()
    app.run()

if __name__ == "__main__":
    main()