water_http 4.0.3

mod xwwwformurlencoded;
mod multipartformdata;
mod multer;
mod bytes_puller;
mod stream_holders;
mod chunked;

use std::borrow::Cow;
use std::collections::HashMap;
pub (crate) use stream_holders::*;

pub use multer::*;
pub use bytes_puller::*;
use std::future::Future;
use std::pin::Pin;
use bytes::Bytes;
pub use multipartformdata::MultiPartFormDataField;
pub use crate::http::request::body::xwwwformurlencoded::*;
pub use chunked::*;
use crate::http::request::header::KeyValueMap;
use crate::server::errors::WaterErrors;

/// indicates the incoming body
/// as each request has it`s own body
#[derive(Debug)]
pub enum IBody<'a> {
    /// when body type of request should be handled as
    /// general bytes or manually handled
    Bytes(&'a [u8]),
    /// handling multipart-form-data within request
    MultiPartFormData(FormDataAll),
    /// handling x-www-form-data within request
    XWWWFormUrlEncoded(XWWWFormUrlEncoded<'a>)
}
/// if the incoming body need to be handled as chunks
pub enum IBodyChunks<'a> {
    /// handling incoming body bytes as chunked
    Bytes(
       BytesPuller<'a>
    ),
    /// parsing incoming bytes to [MultiPartFormDataField] Fields
    /// so each field would be given to callback function as single field handler
    FormData(
        MultipartData<'a>
    ),
    #[cfg(feature = "accept_transfer_chunked")]
    /// handling incoming body as chunked body
    Chunked(BodyChunkedReader<'a>)
}




/// telling the context how we would like to handle incoming body
 pub enum ParsingBodyMechanism {
    /// letting the context chose how to handle the incoming body bytes depending on
    /// Content-Type header value
    Default,
    /// handling the incoming bytes manually
    JustBytes,
    /// parsing incoming bytes to [MultiPartFormDataField] Fields
    FormData,
    /// parse incoming body bytes to [XWWWFormUrlEncoded] struct
    XWWWFormData,
    #[cfg(feature = "accept_transfer_chunked")]
    /// when body is chunked transfer-encoding
    ChunkedTransferEncoding
 }

/// parsing body mechanism results
pub enum  ParsingBodyResults<'a> {
    /// handling the incoming body as chunks because of the size
    /// # why we need to handle body using chunks ?
    ///
    /// well the incoming body could be very long data size for examples ( 4GB )
    /// and you are running your framework on a vps or low server resources
    /// so if your server ram size lower than the incoming data size you would face
    /// stack overflow error or your server would be panicked or encounter kill lag
    /// or even facing hacking attacks ( examples : if the hacker sent 4 request with 4gb on ram )
    /// this would make your server down
    ///
    /// so we need to handle data as chunks to load small chunks one the context reading buffer,
    /// and then we could handle this chunks on server slightly  like saving incoming data on hard
    /// disk synchronously
    Chunked(IBodyChunks<'a>),

    /// handling the incoming data as full body bytes which is the common use case
    FullBody(IBody<'a>),

    /// when request is get for examples and it`s not having any payload
    None,
    /// when could not handle body
    Err(WaterErrors<'a>)
}


impl <'a> ParsingBodyResults<'a> {

    pub async fn on_multipart_form_data_detect(
        payload:&'a [u8],
        mut on_detect: impl FnMut(
        Result<MultiPartFormDataField<'a>,&str>
    ) -> Pin<Box<dyn Future<Output=HandlingFormDataResult> + Send>>
    )->Result<(),&'a str>{
        let mut index:usize = 0;
        loop {
            match MultiPartFormDataField::new(&payload[index..]) {
                None => { break;}
                Some(data) => {
                    index = index + data.field_header_length;
                    let res = on_detect(Ok(data)).await;
                    match res {
                        HandlingFormDataResult::Pass => { continue;}
                        HandlingFormDataResult::Stop => { break; }
                        HandlingFormDataResult::Shutdown => { return Err("shutdown connection")}
                    }
                }
            }
        }
        Ok(())
    }

    /// checking if parsing body has error
    pub fn is_err(&self)->bool {
        if let ParsingBodyResults::Err(_) = self { return  true}
        false
    }

    /// checking if parsing body returns a [None] Value
    pub fn is_none(&self)->bool {
        if let ParsingBodyResults::None = self { return  true}
        false
    }
}

/// telling the framework to stop handling incoming data or resume
 pub enum HandlingFormDataResult {
    /// to continue reading and parsing new form-data field
     Pass,
    /// to stop  parsing new form-data field but continue reading
     Stop,
    /// to stop reading and parsing new data
     Shutdown
 }



/// generated multipart form data field on heap
/// keep in mind that this approach will allocate new space on heap portion of ram
/// which take a little much time and considering less efficient than calling chunks function
#[derive(Debug)]
pub struct HeapFormField {
    pub multipart:KeyValueMap,
    pub data:Vec<u8>
}

impl  HeapFormField {
    fn from(value: &MultiPartFormDataField,data:&[u8]) -> Self {
        let map = KeyValueMap::from(&value.headers);
        HeapFormField {
            multipart:map,
            data:data.to_vec()
        }
    }


    /// getting the data of this field
    pub fn data(&self)->&[u8]{
        self.data.as_ref()
    }



    /// checking if incoming field is a file or not
    /// by checking file name property
    /// you could check also content-type manually by using [self.content_type]
    pub fn is_file(&self)->bool{
        self.multipart.get_as_bytes("filename").is_some()
    }

    /// for getting content type of field [MultiPartFormDataField]
    pub fn content_type(&self)->Option<&[u8]>{
        if let Some(value) = self.multipart.get_as_bytes("Content-Type") {
            return Some(value.as_ref())
        }
        None
    }

}



 /// for building incoming form data
 #[derive(Debug)]
 pub struct  FormDataAll {
     pub fields:Vec<HeapFormField>,
 }


impl DynamicBodyMapTrait for FormDataAll {
    fn get_as_bytes(&self, key: &str) -> Option<&[u8]> {
        if let Some(field) = self.get_field(key) {
            return Some(field.data.as_ref())
        }
        None
    }

    fn get(&self, key: &str) -> Option<Cow<'_,str>> {
        if let Some(data) = self.get_as_bytes(key){
           return Some(String::from_utf8_lossy(data))
        }
        None
    }

    fn all(&self) -> HashMap<String, Bytes> {
        let mut map = HashMap::new();
        for field in &self.fields {

            for  (key,value) in field.multipart.all_pairs() {

                map.insert(key.to_string(),value.clone());

            }
        }
        map
    }
}

impl  FormDataAll {
    /// for getting specific field form incoming multipart data
    pub fn get_field(&self,key:&str)->Option<&HeapFormField>{
        self.fields.iter().find(|c| {
            if let Some(f) = c.multipart.get_as_str("name") {
                return f == key || f.replace("\"","" ) == key
            }
                false
        })
    }
    /// for getting specific field form incoming multipart data
    pub fn get_mut(&mut self,mut key:&str)->Option<&mut HeapFormField>{
        if key.starts_with("\"") {
            key = &key[1..];
        }
        if key.ends_with("\""){
            key = &key[..key.len()-1];
        }
        let fields = &mut self.fields;
        for field in fields  {
            if let Some(name) = field.multipart.get_as_str("name") {
                if name == key || name.replace("\"","") == key {
                    return Some(field);
                }
            }
        }
        None
    }

    /// initiating new [FormDataAll]
    pub  fn new()->FormDataAll{
        FormDataAll {
            fields:Vec::new(),
        }
    }




    pub (crate) fn push(& mut self,field:&MultiPartFormDataField,data:&[u8]){

        if let Some(name) = field.content_disposition_name() {
            if let Some( field) = self.get_mut(name.as_ref()) {
                field.data.extend_from_slice(data);
                return;
            }
        }
        self.fields.push(
            HeapFormField::from(field,data)
        );
    }


}




/// telling context handler of request
/// if the body handling failed
/// so that context force stop handling request which cost resources
/// and continue handling another concurrent requests
pub enum  HandlingChunkResult<'a> {
    Consumed,
    Err(&'a str)
}

/// for creating dynamic memory safe body holder
/// functionalities
///
/// # Note
/// all of these function are to make some functionalities easy for you
/// , if you want blazingly efficient way just use getter function on main context
///  to get `HttpGetter`
/// ```rust,ignore
/// let context = todo!();
/// let mut getter = context.getter();
/// ```
/// ignore defining context because it would be ready for you by the framework
/// and this is the wright way to get `HttpGetter`
#[derive(Debug)]
pub enum  DynamicBodyMap{
    /// form field
    FormField(FormDataAll),
    /// x-www form field
    Xww(HeapXWWWFormUrlEncoded)
}
impl DynamicBodyMapTrait for DynamicBodyMap {
    fn get_as_bytes(&self, key: &str) -> Option<&[u8]> {
        match self {
            DynamicBodyMap::FormField(data) => { data.get_as_bytes(key)}
            DynamicBodyMap::Xww(data) => {data.get_as_bytes(key)}
        }
    }

    fn get(&self, key: &str) -> Option<Cow<'_,str>> {
        match self {
            DynamicBodyMap::FormField(data) => { data.get(key)}
            DynamicBodyMap::Xww(data) => {data.get(key)}
        }
    }

    fn all(&self) -> HashMap<String, Bytes> {
        match self {
            DynamicBodyMap::FormField(data) => { data.all()}
            DynamicBodyMap::Xww(data) => {data.all()}
        }
    }
}

/// for creating dynamic memory safe body holder
/// functionalities
///
/// # Note
/// all of these function are to make some functionalities easy for you
/// , if you want blazingly efficient way just use getter function on main context
///  to get `HttpGetter`
/// ```rust,ignore
/// let context = todo!();
/// let mut getter = context.getter();
/// ```
/// ignore defining context because it would be ready for you by the framework
/// and this is the wright way to get `HttpGetter`
pub trait DynamicBodyMapTrait{

    /// getting field or any data key value as bytes or [&[u8]]
    fn get_as_bytes(&self,key:&str)-> Option<&[u8]>;

    /// getting field or any data key value as [`Cow<'_,str>`]
    fn get (&self,key:&str)->Option<Cow<'_,str>>;

    /// getting all incoming keys and values as hashmap
    fn all(&self)-> HashMap<String,Bytes>;
}