use std::{
    io::{Cursor, Read},
    net::{IpAddr, SocketAddr},
};

use axum::{
    async_trait,
    body::HttpBody,
    extract::{ConnectInfo, FromRequest, FromRequestParts},
    http::{header::USER_AGENT, request::Parts, Request},
    response::Response,
    BoxError, RequestExt,
};
use bytes::Bytes;
use image::{io::Reader, DynamicImage, ImageFormat};
use serde::de::DeserializeOwned;
use tower_cookies::Cookies;

use crate::{
    public::admin,
    public::console,
    types::{
        http::{ResponseCode, Result},
        session::Session,
        user::User,
    },
};

pub struct RequestIp(pub IpAddr);

#[async_trait]
impl<S> FromRequestParts<S> for RequestIp
where
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self> {
        let headers = &parts.headers;

        let forwardedfor = headers
            .get("x-forwarded-for")
            .and_then(|h| h.to_str().ok())
            .and_then(|h| {
                h.split(',')
                    .rev()
                    .find_map(|s| s.trim().parse::<IpAddr>().ok())
            });

        if let Some(forwardedfor) = forwardedfor {
            return Ok(Self(forwardedfor));
        }

        let realip = headers
            .get("x-real-ip")
            .and_then(|hv| hv.to_str().ok())
            .and_then(|s| s.parse::<IpAddr>().ok());

        if let Some(realip) = realip {
            return Ok(Self(realip));
        }

        let realip = headers
            .get("x-real-ip")
            .and_then(|hv| hv.to_str().ok())
            .and_then(|s| s.parse::<IpAddr>().ok());

        if let Some(realip) = realip {
            return Ok(Self(realip));
        }

        let info = parts.extensions.get::<ConnectInfo<SocketAddr>>();

        if let Some(info) = info {
            return Ok(Self(info.0.ip()));
        }

        Err(ResponseCode::Forbidden.text("You have no ip"))
    }
}

pub struct AuthorizedUser(pub User);

#[async_trait]
impl<S> FromRequestParts<S> for AuthorizedUser
where
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self> {
        let Ok(Some(cookies)) = Option::<Cookies>::from_request_parts(parts, state).await else {
            return Err(ResponseCode::Forbidden.text("No cookies provided"))
        };

        let Some(token) = cookies.get("auth") else {
            return Err(ResponseCode::Forbidden.text("No auth token provided"))
        };

        let Ok(session) = Session::from_token(token.value()) else {
            return Err(ResponseCode::Unauthorized.text("Auth token invalid"))
        };

        let Ok(user) = User::from_user_id(session.user_id, true)  else {
            tracing::error!("Valid token but no valid user");
            return Err(ResponseCode::InternalServerError.text("Valid token but no valid user"))
        };

        Ok(Self(user))
    }
}

pub struct AdminUser;

#[async_trait]
impl<S> FromRequestParts<S> for AdminUser
where
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self> {
        let Ok(Some(cookies)) = Option::<Cookies>::from_request_parts(parts, state).await else {
            return Err(ResponseCode::Forbidden.text("No cookies provided"))
        };

        let Some(secret) = cookies.get("admin") else {
            return Err(ResponseCode::Forbidden.text("No admin secret provided"))
        };

        let check = admin::get_secret().await;

        if check != secret.value() {
            return Err(ResponseCode::Unauthorized.text("Auth token invalid"));
        }

        Ok(Self)
    }
}

pub struct Log;

#[async_trait]
impl<S, B> FromRequest<S, B> for Log
where
    B: HttpBody + Sync + Send + 'static,
    B::Data: Send,
    B::Error: Into<BoxError>,
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request(req: Request<B>, state: &S) -> Result<Self> {
        parse_body(req, state).await?;
        Ok(Self)
    }
}

pub struct Png(pub DynamicImage);

#[async_trait]
impl<S, B> FromRequest<S, B> for Png
where
    B: HttpBody + Sync + Send + 'static,
    B::Data: Send,
    B::Error: Into<BoxError>,
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request(req: Request<B>, state: &S) -> Result<Self> {
        let bytes = match read_body(req, state).await {
            Ok(body) => body,
            Err(err) => return Err(err),
        };

        let mut reader = Reader::new(Cursor::new(bytes));
        reader.set_format(ImageFormat::Png);

        let Ok(img) = reader.decode()  else {
            return Err(ResponseCode::BadRequest.text("Failed to decode png image"))
        };

        Ok(Self(img))
    }
}

pub struct Json<T>(pub T);

#[async_trait]
impl<T, S, B> FromRequest<S, B> for Json<T>
where
    T: DeserializeOwned + Check,
    B: HttpBody + Sync + Send + 'static,
    B::Data: Send,
    B::Error: Into<BoxError>,
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request(req: Request<B>, state: &S) -> Result<Self> {
        let body = match parse_body(req, state).await {
            Ok(body) => body,
            Err(err) => return Err(err),
        };

        let Ok(value) = serde_json::from_str::<T>(&body) else {
            return Err(ResponseCode::BadRequest.text("Body does not match paramaters"))
        };

        if let Err(msg) = value.check() {
            return Err(ResponseCode::BadRequest.text(&msg));
        }

        Ok(Self(value))
    }
}

pub type CheckResult = std::result::Result<(), String>;

pub trait Check {
    fn check(&self) -> CheckResult;

    fn assert_length(string: &str, min: usize, max: usize, message: &str) -> CheckResult {
        if string.len() < min || string.len() > max {
            return Err(message.to_string());
        }
        Ok(())
    }

    fn assert_range(number: u64, min: u64, max: u64, message: &str) -> CheckResult {
        if number < min || number > max {
            return Err(message.to_string());
        }
        Ok(())
    }
}

pub struct UserAgent(pub String);

#[async_trait]
impl<S> FromRequestParts<S> for UserAgent
where
    S: Send + Sync,
{
    type Rejection = Response;

    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self> {
        let agent = parts.headers.get(USER_AGENT);

        let Some(agent) = agent else {
            return Err(ResponseCode::BadRequest.text("Bad Request"));
        };

        let Ok(agent) = agent.to_str() else {
            return Err(ResponseCode::BadRequest.text("Bad Request"));
        };

        Ok(Self(agent.to_string()))
    }
}

async fn read_body<S, B>(mut req: Request<B>, state: &S) -> Result<Vec<u8>>
where
    B: HttpBody + Sync + Send + 'static,
    B::Data: Send,
    B::Error: Into<BoxError>,
    S: Send + Sync,
{
    let Ok(RequestIp(ip)) = req.extract_parts::<RequestIp>().await else {
        tracing::error!("Failed to read client ip");
        return Err(ResponseCode::InternalServerError.text("Failed to read client ip"));
    };

    let method = req.method().clone();
    let uri = req.uri().clone();
    let path = req
        .extensions()
        .get::<RouterURI>()
        .map_or("", |path| path.0);

    let Ok(bytes) = Bytes::from_request(req, state).await else {
        return Err(ResponseCode::BadRequest.text("Request can be at most 512kb"));
    };

    console::log(ip, method, uri, Some(path.to_string()), None).await;

    Ok(bytes.bytes().flatten().collect())
}

async fn parse_body<S, B>(mut req: Request<B>, state: &S) -> Result<String>
where
    B: HttpBody + Sync + Send + 'static,
    B::Data: Send,
    B::Error: Into<BoxError>,
    S: Send + Sync,
{
    let Ok(RequestIp(ip)) = req.extract_parts::<RequestIp>().await else {
        tracing::error!("Failed to read client ip");
        return Err(ResponseCode::InternalServerError.text("Failed to read client ip"));
    };

    let method = req.method().clone();
    let uri = req.uri().clone();
    let path = req
        .extensions()
        .get::<RouterURI>()
        .map_or("", |path| path.0);

    let Ok(bytes) = Bytes::from_request(req, state).await else {
        return Err(ResponseCode::BadRequest.text("Request can be at most 512kb"));
    };

    let Ok(body) = String::from_utf8(bytes.bytes().flatten().collect()) else {
        return Err(ResponseCode::BadRequest.text("Invalid utf8 body"))
    };

    console::log(
        ip,
        method,
        uri,
        Some(path.to_string()),
        Some(body.to_string()),
    )
    .await;

    Ok(body)
}

#[derive(Clone)]
pub struct RouterURI(pub &'static str);