#[allow(non_upper_case_globals)]

use crate::{
    MASTER_SERVER,
    MASTER_PORT,
    models::*,
    UResult,
    UError
};
use reqwest::{
    Client,
    Url,
    Response,
    RequestBuilder
};
use std::{
    net::Ipv4Addr,
    str::FromStr
};
use uuid::Uuid;

pub struct Paths;

#[macro_export]
macro_rules! get_result {
    ( () ) => ( |_| async Ok(()) );
    ( $result:ty ) => {
        |response: Response| async {
            response
                .json::<Message<$result>>()
                .await
                .map(|msg| msg.into_item())
                .map_err(|e| UError::from(e))
        }
    };
}

#[macro_export]
macro_rules! build_url_by_method {
    (
        POST $path:tt,
        pname = $($param_name:literal)?,
        ptype = $($param_type:ty)?,
        urlparam = $($url_param:ty)?
    ) => {
        |instance: &ClientHandler $(, param: &$param_type)?| {
            let request = ClientHandler::build_post(
                instance,
                &format!("{}/{}",
                    stringify!($path),
                    String::new() $(+ stringify!($url_param))?
                )
            );
            request
                $( .json::<Message<'_, $param_type>>(&param.as_message()) )?
        }
    };
    (
        GET $path:tt,
        pname = $($param_name:literal)?,
        ptype = $($param_type:ty)?,
        urlparam = $($url_param:ty)?
    ) => {
        |instance: &ClientHandler $(, param: &$param_type)?| {
            let request = ClientHandler::build_get(
                instance,
                &format!("{}/{}",
                    stringify!($path),
                    String::new() $(+ stringify!($url_param))?
                )
            );
            request
                $( .query(&[(stringify!($param_name), param.to_string())]) )?
        }
    };
}

// param_type and result must impl ToMsg
#[macro_export]
macro_rules! build_handler {
    (
        $method:tt
        $path:tt(
            $($param_name:literal:)?
            $($param_type:ty)?
            $(; $url_param:ty)?
        ) -> $result:ty 
    ) => {
        impl ClientHandler {
            pub async fn $path(
                &self $(, param: &$param_type)? $(, url_param: &$url_param)?
            ) -> UResult<$result> {
                let request = $crate::build_url_by_method!(
                    $method $path,
                    pname = $($param_name)?, ptype = $($param_type)?, urlparam = $($url_param)?
                )(self $(, param as &$param_type)? );
                let response = request.send().await?;
                ($crate::get_result!($result)(response)).await
            }
        }

        impl Paths {
            pub const $path: &'static str = stringify!($path);
        }
    };
}


pub struct ClientHandler {
    base_url: Url,
    client: Client,
    password: Option<String>
}

impl ClientHandler {
    pub fn new(server: Option<String>) -> Self {
        let master_server = server
            .map(|s| Ipv4Addr::from_str(&s).unwrap())
            .unwrap_or(MASTER_SERVER);
        Self {
            client: Client::new(),
            base_url: Url::parse(
                &format!("http://{}:{}", master_server, MASTER_PORT)
            ).unwrap(),
            password: None
        }
    }

    pub fn password(mut self, password: String) -> ClientHandler {
        self.password = Some(password);
        self
    }

    fn set_pwd(&self, rb: RequestBuilder) -> RequestBuilder {
        match &self.password {
            Some(p) => rb.bearer_auth(p),
            None => rb
        }
    }

    fn build_get(&self, url: &str) -> RequestBuilder {
        let rb = self.client.get(self.base_url.join(url).unwrap());
        self.set_pwd(rb)
    }

    fn build_post(&self, url: &str) -> RequestBuilder {
        let rb = self.client.post(self.base_url.join(url).unwrap());
        self.set_pwd(rb)
    }
}

// method basic_path(json/query param; additional_url_param) -> return value
// A - admin only
// client listing (A)
build_handler!(GET ls() -> ItemWrap<Vec<Agent>>);
// get jobs for client himself (A: id=client_id)
build_handler!(GET get_jobs() -> ItemWrap<Vec<JobMeta>>);
// add client to server's db
build_handler!(POST init(IAgent) -> RawMsg);
// create and upload job (A)
//build_handler!(POST upload_jobs)
// ???
/*build_handler!(POST del() -> ());
// set jobs for client (A)
// POST /set_jobs/Uuid json: JobMetaStorage
build_handler!(POST set_jobs(JobMetaStorage; Uuid) -> ());
// get results (A)
// GET /get_job_results?job_id=Uuid
build_handler!(GET get_job_results("job_id":Uuid) -> Vec<JobResult>);
// report job result
build_handler!(POST report(Vec<JobResult>) -> ());
*/