Code Editor for app.py

import streamlit as st
from sqlalchemy import create_engine, Column, Integer, String, Boolean, DateTime
from sqlalchemy.orm import Session, DeclarativeBase
from datetime import datetime
import time

# Page configuration
st.set_page_config(
    page_title="To-Do App",
    page_icon="✅",
    layout="centered"
)

# Define database models
class Base(DeclarativeBase):
    pass

class Todo(Base):
    __tablename__ = "todos"
    
    id = Column(Integer, primary_key=True)
    title = Column(String, nullable=False)
    description = Column(String, nullable=True)
    completed = Column(Boolean, default=False)
    created_at = Column(DateTime, default=datetime.now)
    priority = Column(String, default="Medium")

# Create database engine and tables
engine = create_engine("sqlite:///todos.sqlite")
Base.metadata.create_all(bind=engine)

# App header
st.title("✅ To-Do App")
st.markdown("Manage your tasks efficiently with this simple to-do app.")

# Sidebar for adding new tasks
with st.sidebar:
    st.header("Add New Task")
    
    # Task input form
    with st.form(key="add_task_form"):
        task_title = st.text_input("Task Title", max_chars=100)
        task_description = st.text_area("Description (Optional)", max_chars=500)
        task_priority = st.selectbox("Priority", ["Low", "Medium", "High"])
        
        submit_button = st.form_submit_button(label="Add Task")
        
        if submit_button and task_title:
            with Session(engine) as session:
                new_todo = Todo(
                    title=task_title,
                    description=task_description,
                    priority=task_priority
                )
                session.add(new_todo)
                session.commit()
                
            st.success("Task added successfully!")
            time.sleep(1)
            st.rerun()

# Main content - Display tasks
task_tabs = st.tabs(["All Tasks", "Active", "Completed"])

# Function to display tasks in a tab
def display_tasks(tasks):
    if not tasks:
        st.info("No tasks to display.")
        return
    
    for task in tasks:
        col1, col2, col3 = st.columns([0.05, 0.8, 0.15])
        
        with col1:
            checked = st.checkbox("", task.completed, key=f"check_{task.id}")
            if checked != task.completed:
                with Session(engine) as session:
                    todo = session.get(Todo, task.id)
                    todo.completed = checked
                    session.commit()
                st.rerun()
        
        with col2:
            expander_label = task.title
            if task.completed:
                expander_label = f"~~{expander_label}~~"
            
            # Add priority indicator
            priority_color = {"Low": "🔵", "Medium": "🟢", "High": "🔴"}
            expander_label = f"{priority_color.get(task.priority, '⚪')} {expander_label}"
            
            with st.expander(expander_label):
                if task.description:
                    st.write(task.description)
                st.caption(f"Created: {task.created_at.strftime('%Y-%m-%d %H:%M')}")
                st.caption(f"Priority: {task.priority}")
        
        with col3:
            if st.button("Delete", key=f"delete_{task.id}"):
                with Session(engine) as session:
                    todo = session.get(Todo, task.id)
                    session.delete(todo)
                    session.commit()
                st.rerun()

# Load and display tasks in tabs
with Session(engine) as session:
    all_tasks = session.query(Todo).order_by(Todo.created_at.desc()).all()
    active_tasks = [task for task in all_tasks if not task.completed]
    completed_tasks = [task for task in all_tasks if task.completed]

with task_tabs[0]:
    display_tasks(all_tasks)

with task_tabs[1]:
    display_tasks(active_tasks)

with task_tabs[2]:
    display_tasks(completed_tasks)

# Clear completed tasks button
if completed_tasks:
    if st.button("Clear Completed Tasks"):
        with Session(engine) as session:
            session.query(Todo).filter(Todo.completed == True).delete()
            session.commit()
        st.success("Completed tasks cleared successfully!")
        time.sleep(1)
        st.rerun()