use std::sync::Arc;

use askama::Template;
use axum::{
    body::Body,
    extract::{Form, FromRequest, Path, Query, RequestParts},
    http::{header, StatusCode},
    response::{Html, IntoResponse, Redirect, Response},
    routing::{get, get_service, post},
    Extension, Json,
};

use axum_extra::extract::{cookie::Cookie, CookieJar};
use db::{Database, Db, Party, Ticket, User};
use rand::Rng;
use serde::{Deserialize, Serialize};
use sqlx::postgres::PgPoolOptions;
use tower_http::services::ServeDir;

mod db;

#[axum::async_trait]
impl<B: Send> FromRequest<B> for User {
    /// If the extractor fails it'll use this "rejection" type. A rejection is
    /// a kind of error that can be converted into a response.
    type Rejection = Redirect;

    /// Perform the extraction.
    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
        let jar = req
            .extract::<CookieJar>()
            .await
            .or_else(|_| Err(Redirect::to("/login")))?;

        let token = jar.get("token").ok_or_else(|| Redirect::to("/login"))?;
        let db = req
            .extensions()
            .get::<Database>()
            .ok_or_else(|| Redirect::to("/login"))?
            .clone();
        if let Ok(uuid) = uuid::Uuid::parse_str(&token.value()) {
            let user = db.get_user_token_by_token(uuid).await;
            if let Some(user) = user {
                if let Some(user) = db.get_user_by_token(user).await {
                    Ok(user)
                } else {
                    Err(Redirect::to("/login"))
                }
            } else {
                Err(Redirect::to("/login"))
            }
        } else {
            Err(Redirect::to("/login"))
        }
    }
}

#[derive(Template)]
#[template(path = "index.html")]
struct IndexPage {
    user: User,
    parties: Vec<Party>,
}

async fn index(Extension(pool): Extension<Database>, user: User) -> impl IntoResponse {
    let parties = pool.get_all_parties().await;
    let page = IndexPage { user, parties };
    Html(page.render().unwrap())
}

#[derive(Template)]
#[template(path = "login.html")]
struct LoginPage {
    not_found: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct LoginQuery {
    not_found: Option<bool>,
}

async fn login_page(Query(query): Query<LoginQuery>) -> impl IntoResponse {
    Html(
        LoginPage {
            not_found: query.not_found.unwrap_or(false),
        }
        .render()
        .unwrap(),
    )
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct LoginForm {
    username: String,
    password: String,
}

async fn login(
    Form(user): Form<LoginForm>,
    Extension(pool): Extension<Database>,
    jar: CookieJar,
) -> impl IntoResponse {
    let u = pool.get_user_by_username(&user.username).await;
    if let Some(u) = u {
        if u.verify_password(&user.password) {
            let token = pool
                .add_new_user_token(&u, chrono::Utc::now() + chrono::Duration::weeks(5))
                .await;
            let cookie = token.to_cookie();
            (jar.add(cookie), Redirect::to("/"))
        } else {
            (jar, Redirect::to("/login?not_found=true"))
        }
    } else {
        (jar, Redirect::to("/login?not_found=true"))
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct ScanRequest {
    code: String,
    check: bool,
    party: i32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
enum ScanState {
    NotFound,
    Found,
    Added,
    AlreadyScanned,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct ScanResponse {
    code: String,
    state: ScanState,
}

async fn scan_card(
    _: User,
    Extension(pool): Extension<Database>,
    Json(scan): Json<ScanRequest>,
) -> impl IntoResponse {
    let scanned = pool.is_student_in_party(scan.party, &scan.code).await;
    if scan.check {
        if let Some(mut ticket) = scanned {
            if ticket.inside {
                Json(ScanResponse {
                    code: scan.code,
                    state: ScanState::AlreadyScanned,
                })
            } else {
                ticket.inside = true;
                pool.update_ticket(&ticket).await;
                Json(ScanResponse {
                    code: scan.code,
                    state: ScanState::Found,
                })
            }
        } else {
            Json(ScanResponse {
                code: scan.code,
                state: ScanState::NotFound,
            })
        }
    } else {
        if let Some(_) = scanned {
            Json(ScanResponse {
                code: scan.code,
                state: ScanState::AlreadyScanned,
            })
        } else {
            pool.add_ticket(scan.party, &scan.code).await;
            Json(ScanResponse {
                code: scan.code,
                state: ScanState::Added,
            })
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct TicketsQuery {
    party: i32,
}

async fn get_tickets(
    _: User,
    Extension(pool): Extension<Database>,
    Query(q): Query<TicketsQuery>,
) -> impl IntoResponse {
    let tickets = pool.get_all_tickets_for_party(q.party).await;
    Json(tickets)
}

async fn get_parties(_: User, Extension(pool): Extension<Database>) -> impl IntoResponse {
    let parties = pool.get_all_parties().await;
    Json(parties)
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct CreatePartyParams {
    name: String,
}

async fn create_party(
    _: User,
    Extension(pool): Extension<Database>,
    Json(party): Json<CreatePartyParams>,
) -> impl IntoResponse {
    let party = pool.add_party(&party.name).await;
    Json(party)
}

async fn get_party_by_name(
    _: User,
    Extension(pool): Extension<Database>,
    Json(party): Json<CreatePartyParams>,
) -> impl IntoResponse {
    let party = pool.get_party_by_name(&party.name).await;
    Json(party)
}

#[derive(Template)]
#[template(path = "party.html")]
struct PartyPage {
    name: String,
    id: i32,
}

async fn party_page(
    _: User,
    Extension(pool): Extension<Database>,
    Path(party): Path<i32>,
) -> impl IntoResponse {
    let party = pool.get_party(party).await;
    if let Some(party) = party {
        let page = PartyPage {
            name: party.name,
            id: party.id,
        };
        Html(page.render().unwrap()).into_response()
    } else {
        Redirect::to("/").into_response()
    }
}

async fn export_party(
    _: User,
    Extension(pool): Extension<Database>,
    Path(party): Path<i32>,
) -> impl IntoResponse {
    let tickets = pool.get_all_tickets_for_party(party).await;
    let mut csv = String::new();
    csv.push_str("leerlingnummer,binnen\n");
    for ticket in tickets {
        csv.push_str(&format!("{},{}\n", ticket.student, ticket.inside));
    }
    let mut resp = Response::new(Body::from(csv));
    resp.headers_mut().insert(
        header::CONTENT_DISPOSITION,
        header::HeaderValue::from_static("attachment; filename=tickets.csv"),
    );
    resp.headers_mut().insert(
        header::CONTENT_TYPE,
        header::HeaderValue::from_static("text/csv"),
    );
    resp
}

#[derive(Template)]
#[template(path = "party_goers.html")]
struct PartyGoersPage {
    id: i32,
    name: String,
    guests: Vec<Ticket>,
}

async fn party_goers(
    _: User,
    Extension(pool): Extension<Database>,
    Path(party): Path<i32>,
) -> impl IntoResponse {
    let party = pool.get_party(party).await;
    if let Some(party) = party {
        let guests = pool.get_all_tickets_for_party(party.id).await;
        let page = PartyGoersPage {
            id: party.id,
            name: party.name,
            guests,
        };
        Html(page.render().unwrap()).into_response()
    } else {
        Redirect::to("/").into_response()
    }
}

#[derive(Template)]
#[template(path = "password.html")]
struct PasswordPage {
    wrong_password: bool,
    wrong_dupe_password: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct PasswordParams {
    wrong: Option<bool>,
    dupe: Option<bool>,
}

async fn change_password(Query(params): Query<PasswordParams>) -> impl IntoResponse {
    let page = PasswordPage {
        wrong_password: params.wrong.unwrap_or(false),
        wrong_dupe_password: params.dupe.unwrap_or(false),
    };
    Html(page.render().unwrap()).into_response()
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct ChangePasswordForm {
    password: String,
    password_new: String,
    password_new_again: String,
}

async fn change_password_post(
    mut user: User,
    Extension(pool): Extension<Database>,
    Form(form): Form<ChangePasswordForm>,
) -> impl IntoResponse {
    if !user.verify_password(&form.password) {
        return Redirect::to("/password?wrong=true").into_response();
    }
    if form.password_new != form.password_new_again {
        return Redirect::to("/password?dupe=true").into_response();
    }

    user.update_password(&form.password_new);
    pool.save_user(&user).await;
    Redirect::to("/").into_response()
}

async fn logout(_: User, jar: CookieJar) -> impl IntoResponse {
    (jar.remove(Cookie::named("token")), Redirect::to("/"))
}

#[derive(Template)]
#[template(path = "add_user.html")]
struct AddUserPage {}

async fn add_user_page(_: User) -> impl IntoResponse {
    Html(AddUserPage {}.render().unwrap())
}

async fn add_user(
    _: User,
    Extension(pool): Extension<Database>,
    Form(form): Form<LoginForm>,
) -> impl IntoResponse {
    pool.add_new_user(&form.username, &form.password).await;
    Redirect::to("/")
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct TicketDeleteRequest {
    ticket_id: i32,
}

async fn remove_ticket(
    _: User,
    Extension(pool): Extension<Database>,
    Json(ticket): Json<TicketDeleteRequest>,
) -> impl IntoResponse {
    pool.remove_ticket(ticket.ticket_id).await;
    "OK"
}

#[tokio::main]
async fn main() {
    let url = if let Some(url) = std::env::var("DATABASE_URL").ok() {
        url
    } else {
        "postgres://postgres:postgres@localhost:5432/postgres".to_string()
    };
    let pool = PgPoolOptions::new()
        .connect(&url)
        .await
        .unwrap();
    db::setup_db(&pool).await;
    let pool = Arc::new(Db::new(pool));
    if let None = pool.get_user_by_username("admin").await {
        let password = if let Some(pass) = std::env::var("ADMIN_PASSWORD").ok() {
            pass
        } else {
            rand::thread_rng()
                .sample_iter(rand::distributions::Alphanumeric)
                .take(32)
                .map(char::from)
                .collect::<String>()
        };
        println!("User admin was created with password {{{password}}}! Save it somewhere!");
        pool.add_new_user("admin", &password).await;
    }
    let router = axum::Router::new()
        .route("/", get(index))
        .route("/login", get(login_page).post(login))
        .route("/logout", get(logout))
        .route("/password", get(change_password).post(change_password_post))
        .route("/add_user", get(add_user_page).post(add_user))
        .route("/party/:id", get(party_page))
        .route("/party/:id/export", get(export_party))
        .route("/party/:id/lijst", get(party_goers))
        .route("/api/ticket", get(get_tickets).post(scan_card))
        .route("/api/ticket/delete", post(remove_ticket))
        .route("/api/party", get(get_party_by_name).post(create_party))
        .route("/api/party/list", get(get_parties))
        .nest(
            "/static",
            get_service(ServeDir::new("static")).handle_error(handle_error),
        )
        .layer(Extension(pool));

    axum::Server::bind(&"0.0.0.0:8080".parse().unwrap())
        .serve(router.into_make_service())
        .await
        .unwrap();
}

async fn handle_error(_err: std::io::Error) -> impl IntoResponse {
    (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong...")
}