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

app = FastAPI()

class ConversionData(BaseModel):
    input_value: str
    conversion_type: str

class LoginData(BaseModel):
    username: str
    password: str

class MeData(BaseModel):
    username: str
    email: str
    profile_picture: Optional[str] = None


@app.post("/convert")
async def convert_endpoint(data: ConversionData):
    """
    Converts an input value based on the specified conversion type.
    """
    # Dummy conversion logic
    if data.conversion_type == "uppercase":
        converted_value = data.input_value.upper()
    elif data.conversion_type == "lowercase":
        converted_value = data.input_value.lower()
    else:
        raise HTTPException(status_code=400, detail="Invalid conversion type")

    return {"converted_value": converted_value}


@app.post("/login")
async def login_endpoint(data: LoginData):
    """
    Verifies login credentials.
    """
    # Dummy verification logic
    if data.username == "user" and data.password == "password":
        return {"message": "Login successful"}
    else:
        raise HTTPException(status_code=401, detail="Invalid credentials")


@app.get("/me")
async def me_get_endpoint():
    """
    Retrieves user profile data.
    """
    # Dummy user data
    user_data = {
        "username": "example_user",
        "email": "user@example.com",
        "profile_picture": "https://example.com/profile.jpg"
    }
    return user_data

@app.post("/me")
async def me_post_endpoint(data: MeData):
    """
    Updates user profile data.
    """
    # Dummy update logic
    return {"message": "Profile updated successfully", **data.dict()}


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8000)