import tkinter as tk
from tkinter import ttk
import pyperclip
from tkinter import messagebox
import json

def create_ui(parent, run_callback):
    """创建前端界面：JSON 输入、字段选择、模板输入、输出显示"""
    frame = ttk.Frame(parent)
    frame.grid(row=0, column=0, sticky=(tk.W, tk.E, tk.N, tk.S))
    frame.columnconfigure(1, weight=1)
    frame.rowconfigure(1, weight=1)
    frame.rowconfigure(4, weight=1)

    # 描述
    ttk.Label(frame, text="解析 JSON 数组，按模板拼接指定字段（如 $field$:OJ:$field2$）").grid(
        row=0, column=0, columnspan=3, sticky=tk.W, pady=5
    )

    # JSON 输入
    ttk.Label(frame, text="输入 JSON：").grid(row=1, column=0, sticky=tk.NW, pady=2)
    input_text = tk.Text(frame, height=5, width=50)
    input_text.grid(row=1, column=1, columnspan=2, sticky=(tk.W, tk.E, tk.N, tk.S), pady=2)
    input_scroll = ttk.Scrollbar(frame, orient=tk.VERTICAL, command=input_text.yview)
    input_scroll.grid(row=1, column=3, sticky=(tk.N, tk.S))
    input_text["yscrollcommand"] = input_scroll.set

    # 字段选择
    ttk.Label(frame, text="可用字段：").grid(row=2, column=0, sticky=tk.NW, pady=2)
    field_listbox = tk.Listbox(frame, height=5, selectmode=tk.SINGLE)
    field_listbox.grid(row=2, column=1, sticky=(tk.W, tk.E, tk.N, tk.S), pady=2)
    field_scroll = ttk.Scrollbar(frame, orient=tk.VERTICAL, command=field_listbox.yview)
    field_scroll.grid(row=2, column=2, sticky=(tk.N, tk.S))
    field_listbox["yscrollcommand"] = field_scroll.set

    def detect_fields():
        """检测 JSON 中的字段"""
        field_listbox.delete(0, tk.END)
        json_str = input_text.get("1.0", tk.END).strip()
        try:
            data = json.loads(json_str)
            if isinstance(data, dict) and "data" in data and isinstance(data["data"], list) and data["data"]:
                fields = set(data["data"][0].keys())
                for field in sorted(fields):
                    field_listbox.insert(tk.END, field)
            else:
                messagebox.showerror("错误", "JSON 格式无效或缺少 'data' 数组")
        except json.JSONDecodeError:
            messagebox.showerror("错误", "无效的 JSON 字符串")
        except Exception as e:
            messagebox.showerror("错误", f"检测失败：{str(e)}")

    def add_to_template():
        """将选中的字段添加到模板"""
        selected = field_listbox.curselection()
        if not selected:
            messagebox.showwarning("警告", "请选择一个字段")
            return
        field = field_listbox.get(selected[0])
        template_entry.insert(tk.END, f"${field}$")

    ttk.Button(frame, text="检测字段", command=detect_fields).grid(row=3, column=1, sticky=tk.W, pady=2)
    ttk.Button(frame, text="添加到模板", command=add_to_template).grid(row=3, column=1, sticky=tk.E, pady=2)

    # 模板输入
    ttk.Label(frame, text="拼接模板：").grid(row=4, column=0, sticky=tk.NW, pady=2)
    template_entry = ttk.Entry(frame)
    template_entry.grid(row=4, column=1, columnspan=2, sticky=(tk.W, tk.E), pady=2)

    # 输出
    ttk.Label(frame, text="输出结果：").grid(row=5, column=0, sticky=tk.NW, pady=2)
    output_text = tk.Text(frame, height=5, width=50, state="disabled")
    output_text.grid(row=5, column=1, columnspan=2, sticky=(tk.W, tk.E, tk.N, tk.S), pady=2)
    output_scroll = ttk.Scrollbar(frame, orient=tk.VERTICAL, command=output_text.yview)
    output_scroll.grid(row=5, column=3, sticky=(tk.N, tk.S))
    output_text["yscrollcommand"] = output_scroll.set

    def copy_output(event):
        output = output_text.get("1.0", tk.END).strip()
        if output:
            pyperclip.copy(output)
            messagebox.showinfo("提示", "输出已复制到剪贴板")

    output_text.bind("<Button-1>", copy_output)

    # 运行按钮
    def run():
        json_str = input_text.get("1.0", tk.END).strip()
        template = template_entry.get().strip()
        if not json_str or not template:
            messagebox.showerror("错误", "请输入 JSON 和模板")
            return
        result = run_callback([json_str, template])
        output_text.configure(state="normal")
        output_text.delete("1.0", tk.END)
        output_text.insert("1.0", result[0] if result else "无结果")
        output_text.configure(state="disabled")

    # 清空按钮
    def clear():
        input_text.delete("1.0", tk.END)
        template_entry.delete(0, tk.END)
        field_listbox.delete(0, tk.END)
        output_text.configure(state="normal")
        output_text.delete("1.0", tk.END)
        output_text.configure(state="disabled")

    ttk.Button(frame, text="运行脚本", command=run).grid(row=6, column=0, pady=5)
    ttk.Button(frame, text="清空", command=clear).grid(row=6, column=1, sticky=tk.W, pady=5)

    return frame