azure-iot-rs 0.2.0

use azure_iot_rs_sys::*;
use std::ffi::{CStr};

/// Enum to return the type of an IOT hub message.
#[derive(Debug)]
pub enum MessageBody<'b> {
    Unknown,
    Text(&'b str),
    Binary(&'b [u8])
}

/// A struct to represet an IOT hub message.
#[derive(Debug)]
pub struct IotHubMessage {
    pub(crate) handle: IOTHUB_MESSAGE_HANDLE,
    own: bool
}

impl Drop for IotHubMessage {
    fn drop(&mut self) {
        if self.own {
            unsafe {
                IoTHubMessage_Destroy(self.handle);
            }    
        }
    }
}

impl Clone for IotHubMessage {
    fn clone(&self) -> Self {
        let handle = unsafe { IoTHubMessage_Clone(self.handle) };
        if handle == std::ptr::null_mut() {
            panic!("Failed to allocate message");
        }
        return IotHubMessage {
            handle, 
            own: true
        }
    }
}

impl IotHubMessage {
    fn get_array<'a>(&self) -> &'a [u8] {
        let buffer: *mut *const ::std::os::raw::c_uchar = std::ptr::null_mut();
        let size: *mut size_t  = std::ptr::null_mut();
        unsafe { 
            IoTHubMessage_GetByteArray(self.handle, buffer, size); 
            std::slice::from_raw_parts(*buffer, *size as usize)
        }
    }

    fn get_text(&self) -> &'static str {
        let ptr = unsafe { IoTHubMessage_GetString(self.handle) };
        if ptr  ==  std::ptr::null() {
            return "";
        }
        match unsafe { CStr::from_ptr(ptr).to_str() } {
             Ok(string) => string,
             _ => ""
        }
    }

    pub fn content_type(&self) -> IOTHUBMESSAGE_CONTENT_TYPE {
        unsafe { IoTHubMessage_GetContentType(self.handle) }
    }

    pub fn from_handle(handle: *mut IOTHUB_MESSAGE_HANDLE_DATA_TAG) -> Self {
        return IotHubMessage {
            handle,
            own: false
        }
    }

    pub fn body<'a>(&self) -> MessageBody<'a> {
        let content_type = self.content_type();
        return match content_type {
            IOTHUBMESSAGE_CONTENT_TYPE_TAG_IOTHUBMESSAGE_STRING => MessageBody::Text(self.get_text()),
            IOTHUBMESSAGE_CONTENT_TYPE_TAG_IOTHUBMESSAGE_BYTEARRAY => MessageBody::Binary(self.get_array()),
            _ => MessageBody::Unknown
        }
    }
}