import gradio as gr
import json
import os
from datetime import datetime
from typing import List, Dict

# File to persist todos
TODO_FILE = "todos.json"

def load_todos() -> List[Dict]:
    """Load todos from JSON file"""
    if os.path.exists(TODO_FILE):
        try:
            with open(TODO_FILE, 'r') as f:
                return json.load(f)
        except:
            return []
    return []

def save_todos(todos: List[Dict]):
    """Save todos to JSON file"""
    try:
        with open(TODO_FILE, 'w') as f:
            json.dump(todos, f, indent=2)
    except Exception as e:
        print(f"Error saving todos: {e}")

def add_todo(task: str, priority: int) -> tuple[List[Dict], str]:
    """Add a new todo item"""
    if not task.strip():
        return load_todos(), "Task cannot be empty!"
    
    todos = load_todos()
    new_todo = {
        "id": len(todos) + 1,
        "task": task.strip(),
        "priority": priority,
        "completed": False,
        "created": datetime.now().isoformat()
    }
    todos.append(new_todo)
    save_todos(todos)
    return todos, f"Added: '{task}' (Priority: {priority})"

def toggle_todo(todo_id: int) -> List[Dict]:
    """Toggle todo completion status"""
    todos = load_todos()
    for todo in todos:
        if todo["id"] == todo_id:
            todo["completed"] = not todo["completed"]
            break
    save_todos(todos)
    return todos

def delete_todo(todo_id: int) -> List[Dict]:
    """Delete a todo item"""
    todos = load_todos()
    todos = [todo for todo in todos if todo["id"] != todo_id]
    # Update IDs to maintain sequential order
    for i, todo in enumerate(todos):
        todo["id"] = i + 1
    save_todos(todos)
    return todos

def get_todos_display(todos: List[Dict]) -> str:
    """Format todos for display"""
    if not todos:
        return "🎉 No todos! Great job!"
    
    lines = []
    sorted_todos = sorted(todos, key=lambda x: (x["priority"], x["id"]))
    
    for todo in sorted_todos:
        status = "✅" if todo["completed"] else "⏳"
        priority_emoji = {1: "🔥", 2: "⚡", 3: "📋"}.get(todo["priority"], "📌")
        line = f"{status} [{priority_emoji} P{todo['priority']}] {todo['task']}"
        lines.append(line)
    
    return "\n".join(lines)

def clear_completed() -> List[Dict]:
    """Remove all completed todos"""
    todos = load_todos()
    todos = [todo for todo in todos if not todo["completed"]]
    # Update IDs
    for i, todo in enumerate(todos):
        todo["id"] = i + 1
    save_todos(todos)
    return todos

# Initialize app with current todos
initial_todos = load_todos()

with gr.Blocks(
    title="🚀 Todo App",
    theme=gr.themes.Soft(),
    css="""
    .todo-header { font-size: 2em; margin-bottom: 1em; }
    .priority-selector { display: flex; gap: 1em; align-items: center; }
    .todo-list { background: white; border-radius: 10px; padding: 1.5em; min-height: 200px; }
    .action-buttons { display: flex; gap: 1em; flex-wrap: wrap; }
    """
) as demo:
    
    gr.HTML(
        """
        <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 2em;">
            <h1 class="todo-header">🚀 My Todo App</h1>
            <a href="https://huggingface.co/spaces/akhaliq/anycoder" target="_blank" 
               style="color: #666; text-decoration: none; font-size: 0.9em;">
                Built with <b>anycoder</b>
            </a>
        </div>
        """
    )
    
    with gr.Row():
        with gr.Column(scale=1):
            task_input = gr.Textbox(
                label="New Task",
                placeholder="What needs to be done?",
                lines=2
            )
            
            priority_input = gr.Slider(
                minimum=1,
                maximum=3,
                value=2,
                step=1,
                label="Priority",
                info="1 = Urgent 🔥 | 2 = Important ⚡ | 3 = Normal 📋"
            )
            
            add_btn = gr.Button("➕ Add Todo", variant="primary", size="lg")
        
        with gr.Column(scale=2):
            todos_display = gr.Markdown(
                get_todos_display(initial_todos),
                label="Your Todos",
                elem_classes=["todo-list"]
            )
    
    with gr.Row():
        clear_btn = gr.Button("🗑️ Clear Completed", variant="secondary")
        delete_btn = gr.Button("🗑️ Delete Selected", interactive=False, visible=False)
    
    # Status message
    status_msg = gr.Textbox(
        label="Status",
        interactive=False,
        visible=False
    )
    
    # Event handlers
    add_btn.click(
        add_todo,
        inputs=[task_input, priority_input],
        outputs=[todos_display, status_msg]
    ).then(
        lambda: gr.update(visible=True),
        outputs=[status_msg]
    ).then(
        gr.update(value=""),
        outputs=[task_input]
    )
    
    clear_btn.click(
        clear_completed,
        outputs=[todos_display]
    )
    
    # Update display when todos change
    demo.load(
        fn=lambda: get_todos_display(load_todos()),
        outputs=todos_display
    )

if __name__ == "__main__":
    demo.launch()