use crate::blobs::{Blob, BlobState};
use crate::engine::structs::LuaMap;
use crate::errors::*;
use crate::hlua::AnyLuaValue;
use crate::json::LuaJsonValue;
use chrootable_https::http::request::Builder;
use chrootable_https::http::uri::Parts;
use chrootable_https::http::HttpTryFrom;
use chrootable_https::{Body, Request, Uri};
pub use chrootable_https::{Client, HttpClient, Resolver, Response};
use data_encoding::BASE64;
use rand::distributions::Alphanumeric;
use rand::{thread_rng, Rng};
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet};
use std::fmt;
use std::fmt::Write;
use std::iter;
use std::net::SocketAddr;
use std::ops::Deref;
use std::sync::Arc;
use std::time::Duration;
use url::Url;

pub fn url_set_qs<S: Serialize + fmt::Debug>(url: Uri, query: &S) -> Result<Uri> {
    let mut parts = Parts::from(url);

    let query = serde_urlencoded::to_string(query)?;

    parts.path_and_query = Some(
        match parts.path_and_query {
            Some(pq) => {
                format!("{}?{}", pq.path(), query)
            }
            None => format!("/?{}", query),
        }
        .parse()?,
    );

    Uri::from_parts(parts).map_err(Error::from)
}

pub trait WebState {
    fn http(&self, proxy: &Option<SocketAddr>) -> Result<Arc<chrootable_https::Client<Resolver>>>;

    fn register_in_jar(&self, session: &str, key: String, value: String);
}

#[derive(Debug)]
pub struct HttpSession {
    id: String,
    pub cookies: CookieJar,
}

impl HttpSession {
    pub fn new() -> (String, HttpSession) {
        let mut rng = thread_rng();
        let id: String = iter::repeat(())
            .map(|()| rng.sample(Alphanumeric))
            .map(char::from)
            .take(16)
            .collect();
        (
            id.clone(),
            HttpSession {
                id,
                cookies: CookieJar::default(),
            },
        )
    }
}

#[derive(Debug, Default, Deserialize)]
pub struct RequestOptions {
    pub query: Option<HashMap<String, String>>,
    pub headers: Option<HashMap<String, String>>,
    pub basic_auth: Option<(String, String)>,
    pub user_agent: Option<String>,
    pub json: Option<serde_json::Value>,
    pub form: Option<serde_json::Value>,
    #[serde(default)]
    pub follow_redirects: usize,
    pub body: Option<String>,
    pub timeout: Option<u64>,
    #[serde(default)]
    pub into_blob: bool,
    pub proxy: Option<SocketAddr>,
    #[serde(default)]
    pub binary: bool,
}

impl RequestOptions {
    pub fn try_from(x: AnyLuaValue) -> Result<RequestOptions> {
        let x = LuaJsonValue::from(x);
        let x = serde_json::from_value(x.into())?;
        Ok(x)
    }
}

#[derive(Debug, Default, Serialize, Deserialize)]
pub struct HttpRequest {
    // reference to the HttpSession
    session: String,
    cookies: CookieJar,
    method: String,
    url: String,
    query: Option<HashMap<String, String>>,
    headers: Option<HashMap<String, String>>,
    basic_auth: Option<(String, String)>,
    user_agent: String,
    follow_redirects: usize,
    body: Option<ReqBody>,
    timeout: Option<Duration>,
    into_blob: bool,
    proxy: Option<SocketAddr>,
    binary: bool,
}

impl HttpRequest {
    pub fn new(
        session: &HttpSession,
        method: String,
        url: String,
        user_agent: String,
        options: RequestOptions,
    ) -> HttpRequest {
        let cookies = session.cookies.clone();
        let timeout = options.timeout.map(Duration::from_millis);

        let mut request = HttpRequest {
            session: session.id.clone(),
            cookies,
            method,
            url,
            query: options.query,
            headers: options.headers,
            basic_auth: options.basic_auth,
            user_agent,
            follow_redirects: options.follow_redirects,
            body: None,
            timeout,
            into_blob: options.into_blob,
            proxy: options.proxy,
            binary: options.binary,
        };

        if let Some(json) = options.json {
            request.body = Some(ReqBody::Json(json));
        }

        if let Some(form) = options.form {
            request.body = Some(ReqBody::Form(form));
        }

        if let Some(text) = options.body {
            request.body = Some(ReqBody::Raw(text));
        }

        request
    }

    pub fn send(&mut self, state: &dyn WebState) -> Result<Response> {
        let mut url = self.url.parse::<Uri>()?;

        // set query string
        if let Some(query) = &self.query {
            url = url_set_qs(url, query)?;
        }

        // start setting up request
        let mut req = self.mkrequest(self.method.as_str(), &url);

        // add headers
        if let Some(ref auth) = self.basic_auth {
            use chrootable_https::header::AUTHORIZATION;
            let (user, password) = auth;

            let auth = BASE64.encode(format!("{}:{}", user, password).as_bytes());
            let auth = format!("Basic {}", auth);
            req.header(AUTHORIZATION, auth.as_str());
        }

        let mut observed_headers = HashSet::new();
        if let Some(ref headers) = self.headers {
            for (k, v) in headers {
                req.header(k.as_str(), v.as_str());
                observed_headers.insert(k.to_lowercase());
            }
        }

        // finalize request
        let body = match self.body {
            Some(ReqBody::Raw(ref x)) => Body::from(x.clone()),
            Some(ReqBody::Form(ref x)) => {
                // if Content-Type is not set, set header
                if !observed_headers.contains("content-type") {
                    req.header("Content-Type", "application/x-www-form-urlencoded");
                }
                Body::from(serde_urlencoded::to_string(x)?)
            }
            Some(ReqBody::Json(ref x)) => {
                // if Content-Type is not set, set header
                if !observed_headers.contains("content-type") {
                    req.header("Content-Type", "application/json");
                }
                Body::from(serde_json::to_string(x)?)
            }
            None => Body::empty(),
        };
        let mut req = req.body(body)?;

        debug!("Getting http client");
        let client = state.http(&self.proxy)?;

        let res = loop {
            // send request
            debug!("Sending http request: {:?}", req);
            let res = client
                .request(req)
                .with_timeout(self.timeout)
                .wait_for_response()?;

            for cookie in &res.cookies {
                HttpRequest::register_cookies_on_state(&self.session, state, cookie);
            }

            if self.follow_redirects > 0 && res.status >= 300 && res.status < 400 {
                if let Some(location) = res.headers.get("location") {
                    let base = Url::parse(&url.to_string())?;
                    let joined = base.join(location)?;
                    url = joined.to_string().parse()?;

                    req = self.mkrequest("GET", &url).body(Body::empty())?;
                    self.follow_redirects -= 1;
                    continue;
                }
            }

            break res;
        };

        Ok(res)
    }

    /// create a basic request, reusable when following redirects
    fn mkrequest<T>(&self, method: &str, url: T) -> Builder
    where
        Uri: HttpTryFrom<T>,
    {
        let mut req = Request::builder();
        req.method(method);
        req.uri(url);
        self.attach_cookies(&mut req);

        use chrootable_https::header::USER_AGENT;
        req.header(USER_AGENT, self.user_agent.as_str());

        req
    }

    fn attach_cookies(&self, req: &mut Builder) {
        use chrootable_https::header::COOKIE;
        let mut cookies = String::new();

        for (key, value) in self.cookies.iter() {
            if !cookies.is_empty() {
                cookies += "; ";
            }
            // it's a write to a String, so panic if re-allocation fails is fine
            write!(cookies, "{}={}", key, value).expect("out of memory");
        }

        if !cookies.is_empty() {
            req.header(COOKIE, cookies.as_str());
        }
    }

    pub fn response_to_lua<S>(&self, state: &S, res: Response) -> Result<LuaMap>
    where
        S: WebState + BlobState,
    {
        // map result to LuaMap
        let mut resp = LuaMap::new();
        resp.insert_num("status", f64::from(res.status));

        let mut headers = LuaMap::new();
        for (key, value) in res.headers {
            headers.insert_str(key.to_lowercase(), value);
        }
        resp.insert("headers", headers);

        if let Some(ipaddr) = res.ipaddr {
            resp.insert_str("ipaddr", ipaddr.to_string());
        }

        if self.into_blob {
            let blob = Blob::create(res.body);
            let id = state.register_blob(blob);
            resp.insert_str("blob", id);
        } else if self.binary {
            resp.insert_serde("binary", &res.body[..])?;
        } else {
            resp.insert_str("text", String::from_utf8_lossy(&res.body));
        }

        Ok(resp)
    }

    fn register_cookies_on_state(session: &str, state: &dyn WebState, cookie: &str) {
        let mut key = String::new();
        let mut value = String::new();
        let mut in_key = true;

        for c in cookie.as_bytes() {
            match *c as char {
                '=' if in_key => in_key = false,
                ';' => break,
                c if in_key => key.push(c),
                c => value.push(c),
            }
        }

        state.register_in_jar(session, key, value);
    }
}

impl HttpRequest {
    pub fn try_from(x: AnyLuaValue) -> Result<HttpRequest> {
        let x = LuaJsonValue::from(x);
        let x = serde_json::from_value(x.into())?;
        Ok(x)
    }
}

impl From<HttpRequest> for AnyLuaValue {
    fn from(req: HttpRequest) -> AnyLuaValue {
        let v = serde_json::to_value(req).unwrap();
        LuaJsonValue::from(v).into()
    }
}

// see https://github.com/seanmonstar/reqwest/issues/14 for proper cookie jars
// maybe change this to reqwest::header::Cookie
#[derive(Debug, Default, Clone, Serialize, Deserialize)]
pub struct CookieJar(HashMap<String, String>);

impl CookieJar {
    #[inline(always)]
    pub fn register_in_jar(&mut self, key: String, value: String) {
        self.0.insert(key, value);
    }
}

impl Deref for CookieJar {
    type Target = HashMap<String, String>;

    #[inline(always)]
    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub enum ReqBody {
    Raw(String), // TODO: maybe Vec<u8>
    Form(serde_json::Value),
    Json(serde_json::Value),
}