from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from typing import List, Optional
import uvicorn
from datetime import datetime

app = FastAPI(
    title="API Demo Application",
    description="Demo API with Swagger documentation",
    version="1.0.0"
)

# Models
class Item(BaseModel):
    id: Optional[int] = None
    name: str
    description: Optional[str] = None
    price: float
    in_stock: bool = True

class User(BaseModel):
    id: Optional[int] = None
    username: str
    email: str
    active: bool = True

# In-memory storage
items_db = [
    {"id": 1, "name": "Laptop", "description": "High-performance laptop", "price": 999.99, "in_stock": True},
    {"id": 2, "name": "Mouse", "description": "Wireless mouse", "price": 29.99, "in_stock": True},
    {"id": 3, "name": "Keyboard", "description": "Mechanical keyboard", "price": 79.99, "in_stock": False},
]

users_db = [
    {"id": 1, "username": "john_doe", "email": "john@example.com", "active": True},
    {"id": 2, "username": "jane_smith", "email": "jane@example.com", "active": True},
]

# Root endpoint
@app.get("/")
async def root():
    """Root endpoint with API information"""
    return {
        "message": "Welcome to API Demo",
        "version": "1.0.0",
        "docs": "/docs",
        "timestamp": datetime.now().isoformat()
    }

# Health check
@app.get("/health")
async def health():
    """Health check endpoint"""
    return {"status": "healthy", "service": "api", "timestamp": datetime.now().isoformat()}

# Items endpoints
@app.get("/items", response_model=List[Item], tags=["Items"])
async def get_items():
    """Get all items"""
    return items_db

@app.get("/items/{item_id}", response_model=Item, tags=["Items"])
async def get_item(item_id: int):
    """Get a specific item by ID"""
    item = next((item for item in items_db if item["id"] == item_id), None)
    if item is None:
        raise HTTPException(status_code=404, detail="Item not found")
    return item

@app.post("/items", response_model=Item, tags=["Items"])
async def create_item(item: Item):
    """Create a new item"""
    new_id = max([i["id"] for i in items_db]) + 1 if items_db else 1
    item_dict = item.dict()
    item_dict["id"] = new_id
    items_db.append(item_dict)
    return item_dict

@app.put("/items/{item_id}", response_model=Item, tags=["Items"])
async def update_item(item_id: int, item: Item):
    """Update an existing item"""
    for idx, existing_item in enumerate(items_db):
        if existing_item["id"] == item_id:
            item_dict = item.dict()
            item_dict["id"] = item_id
            items_db[idx] = item_dict
            return item_dict
    raise HTTPException(status_code=404, detail="Item not found")

@app.delete("/items/{item_id}", tags=["Items"])
async def delete_item(item_id: int):
    """Delete an item"""
    for idx, item in enumerate(items_db):
        if item["id"] == item_id:
            items_db.pop(idx)
            return {"message": "Item deleted successfully"}
    raise HTTPException(status_code=404, detail="Item not found")

# Users endpoints
@app.get("/users", response_model=List[User], tags=["Users"])
async def get_users():
    """Get all users"""
    return users_db

@app.get("/users/{user_id}", response_model=User, tags=["Users"])
async def get_user(user_id: int):
    """Get a specific user by ID"""
    user = next((user for user in users_db if user["id"] == user_id), None)
    if user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return user

@app.post("/users", response_model=User, tags=["Users"])
async def create_user(user: User):
    """Create a new user"""
    new_id = max([u["id"] for u in users_db]) + 1 if users_db else 1
    user_dict = user.dict()
    user_dict["id"] = new_id
    users_db.append(user_dict)
    return user_dict

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8001)