#![allow(clippy::unused_unit)]

use crate::db_conn::Db;
use crate::models::User;
use crate::random_hasher::RandomHasher;
use rocket::request::{FromRequest, Outcome, Request};
use rocket::response::Redirect;
use rocket::serde::Deserialize;
use rocket::State;
use std::env;
use url::Url;

#[derive(Debug)]
pub struct FrontendAddr(pub String);

#[rocket::async_trait]
impl<'r> FromRequest<'r> for FrontendAddr {
    type Error = ();
    async fn from_request(request: &'r Request<'_>) -> Outcome<Self, Self::Error> {
        Outcome::Success(Self(
            request
                .headers()
                .get_one("Referer")
                .map(|s| s.to_string())
                .unwrap_or_else(|| env::var("DEFAULT_FRONTEND").unwrap()),
        ))
    }
}

#[derive(Debug)]
pub struct BackendAddr(pub String);

#[rocket::async_trait]
impl<'r> FromRequest<'r> for BackendAddr {
    type Error = ();
    async fn from_request(request: &'r Request<'_>) -> Outcome<Self, Self::Error> {
        Outcome::Success(Self(
            request
                .headers()
                .get_one("Host")
                .map(|s| format!("https://{}", s))
                .unwrap_or_else(|| env::var("DEFAULT_BACKEND").unwrap()),
        ))
    }
}

#[get("/?p=cs")]
pub fn cs_login(r: FrontendAddr, h: BackendAddr) -> Redirect {
    let mast_url = env::var("MAST_BASE_URL").unwrap();
    let mast_cli = env::var("MAST_CLIENT").unwrap();
    let mast_scope = env::var("MAST_SCOPE").unwrap();

    let jump_to_url = Url::parse(&r.0).unwrap();
    let mut redirect_url = Url::parse(&h.0).unwrap();
    redirect_url.set_path("/_login/cs/auth");

    redirect_url = Url::parse_with_params(
        redirect_url.as_str(),
        &[
            ("redirect_url", redirect_url.as_str()),
            ("jump_to_url", jump_to_url.as_str()),
        ],
    )
    .unwrap();

    let url = Url::parse_with_params(
        &format!("{}oauth/authorize", mast_url),
        &[
            ("redirect_uri", redirect_url.as_str()),
            ("client_id", &mast_cli),
            ("scope", &mast_scope),
            ("response_type", "code"),
        ],
    )
    .unwrap();

    Redirect::to(url.to_string())
}

#[derive(Deserialize, Debug)]
#[serde(crate = "rocket::serde")]
struct Token {
    pub access_token: String,
}

#[derive(Deserialize, Debug)]
#[serde(crate = "rocket::serde")]
struct Account {
    pub id: String,
}
#[get("/cs/auth?<code>&<redirect_url>&<jump_to_url>")]
pub async fn cs_auth(
    code: String,
    redirect_url: String,
    jump_to_url: String,
    db: Db,
    rh: &State<RandomHasher>,
) -> Result<Redirect, &'static str> {
    if !env::var("FRONTEND_WHITELIST")
        .unwrap_or_default()
        .split(',')
        .any(|url| jump_to_url.starts_with(url))
    {
        return Err("前端地址不在白名单内");
    }

    let mast_url = env::var("MAST_BASE_URL").unwrap();
    let mast_cli = env::var("MAST_CLIENT").unwrap();
    let mast_sec = env::var("MAST_SECRET").unwrap();
    let mast_scope = env::var("MAST_SCOPE").unwrap();

    // to keep same
    let redirect_url = Url::parse_with_params(
        redirect_url.as_str(),
        &[
            ("redirect_url", redirect_url.as_str()),
            ("jump_to_url", jump_to_url.as_str()),
        ],
    )
    .unwrap();

    let client = reqwest::Client::new();
    let r = client
        .post(format!("{}oauth/token", &mast_url))
        .form(&[
            ("client_id", mast_cli.as_str()),
            ("client_secret", mast_sec.as_str()),
            ("scope", mast_scope.as_str()),
            ("redirect_uri", redirect_url.as_str()),
            ("grant_type", "authorization_code"),
            ("code", code.as_str()),
        ])
        .send()
        .await
        .unwrap();
    //dbg!(&r);

    let token: Token = r.json().await.unwrap();
    //dbg!(&token);

    let client = reqwest::Client::new();
    let account = client
        .get(format!("{}api/v1/accounts/verify_credentials", &mast_url))
        .bearer_auth(token.access_token)
        .send()
        .await
        .unwrap()
        .json::<Account>()
        .await
        .unwrap();

    //dbg!(&account);

    let tk = User::find_or_create_token(
        &db,
        &rh.hash_with_salt(&format!("cs_{}", &account.id)),
        false,
    )
    .await
    .unwrap();

    Ok(Redirect::to(format!("{}?token={}", &jump_to_url, &tk)))
}

#[get("/gh")]
pub fn gh_login(r: FrontendAddr, h: BackendAddr) -> Redirect {
    let gh_url = "https://github.com/login/oauth/authorize";
    let gh_cli = env::var("GH_CLIENT").unwrap();
    let gh_scope = "user:email";

    let jump_to_url = Url::parse(&r.0).unwrap();
    let mut redirect_url = Url::parse(&h.0).unwrap();
    redirect_url.set_path("/_login/gh/auth");

    redirect_url = Url::parse_with_params(
        redirect_url.as_str(),
        &[("jump_to_url", jump_to_url.as_str())],
    )
    .unwrap();

    let url = Url::parse_with_params(
        gh_url,
        &[
            ("redirect_uri", redirect_url.as_str()),
            ("client_id", &gh_cli),
            ("scope", gh_scope),
        ],
    )
    .unwrap();

    Redirect::to(url.to_string())
}

#[derive(Deserialize, Debug)]
#[serde(crate = "rocket::serde")]
struct GithubEmail {
    pub email: String,
    pub verified: bool,
}

#[get("/gh/auth?<code>&<jump_to_url>")]
pub async fn gh_auth(
    code: String,
    jump_to_url: String,
    db: Db,
    rh: &State<RandomHasher>,
) -> Result<Redirect, &'static str> {
    if !env::var("FRONTEND_WHITELIST")
        .unwrap_or_default()
        .split(',')
        .any(|url| jump_to_url.starts_with(url))
    {
        return Err("前端地址不在白名单内");
    }

    let gh_cli = env::var("GH_CLIENT").unwrap();
    let gh_sec = env::var("GH_SECRET").unwrap();

    let client = reqwest::Client::new();
    let r = client
        .post("https://github.com/login/oauth/access_token")
        .header(reqwest::header::ACCEPT, "application/json")
        .form(&[
            ("client_id", gh_cli.as_str()),
            ("client_secret", gh_sec.as_str()),
            ("code", code.as_str()),
        ])
        .send()
        .await
        .unwrap();

    //let token: rocket::serde::json::Value = r.json().await.unwrap();
    let token: Token = r.json().await.unwrap();

    dbg!(&token);

    let client = reqwest::Client::new();
    let r = client
        .get("https://api.github.com/user/emails")
        .bearer_auth(token.access_token)
        .header(reqwest::header::USER_AGENT, "hole_thu LoginBot")
        .send()
        .await
        .unwrap();
    // dbg!(&r);
    let emails = r
        .json::<Vec<GithubEmail>>()
        //.json::<rocket::serde::json::Value>()
        .await
        .unwrap();

    //dbg!(&emails);

    let name = emails
        .iter()
        .filter(|email| email.verified)
        .find_map(
            |email| match email.email.split('@').collect::<Vec<&str>>()[..] {
                [name, "mails.tsinghua.edu.cn"] | [name, "tsinghua.org.cn"] => Some(name),
                _ => None,
            },
        );

    if let Some(name) = name {
        let tk =
            User::find_or_create_token(&db, &rh.hash_with_salt(&format!("email_{}", name)), false)
                .await
                .unwrap();

        Ok(Redirect::to(format!("{}?token={}", &jump_to_url, &tk)))
    } else {
        Err("没有找到已验证的清华邮箱/校友邮箱")
    }
}