use axum::{
    http::HeaderMap, http::StatusCode, routing::get, routing::post, routing::put, Json, Router,
};

use serde::Deserialize;

use redis::Commands;

use std::time::{SystemTime, UNIX_EPOCH};

#[derive(Deserialize)]
pub struct User {
    username: String,
    password: String,
}

#[derive(Deserialize)]
pub struct Progress {
    document: String,
    progress: String,
    percentage: String,
    device: String,
    device_id: String,
}

#[tokio::main]
async fn main() {
    // build our application with a single route
    let app = Router::new()
        .route("/", get(root))
        .route("/users/create", post(create_user))
        .route("/users/auth", get(auth_user))
        .route("/syncs/progress", put(update_progress))
        .route("/syncs/progress/:document", get(get_progress))
        .route("/healthcheck", get(healthcheck));

    // run it with hyper on localhost:3000
    axum::Server::bind(&"0.0.0.0:3003".parse().unwrap())
        .serve(app.into_make_service())
        .await
        .unwrap();
}

async fn root() -> &'static str {
    "KOreader sync server"
}

async fn create_user(Json(payload): Json<User>) -> (StatusCode, String) {
    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
    let mut con = client.get_connection().unwrap();

    let username = payload.username;
    let password = payload.password;

    let user_key = format!("user:{username}:key");

    let does_exist: bool = con.exists(&user_key).unwrap();

    if does_exist == false {
        let _: () = con.set(&user_key, password).unwrap();
    } else {
        return (
            StatusCode::PAYMENT_REQUIRED,
            "Username is already registered.".to_owned(),
        );
    }

    (StatusCode::CREATED, format!("username = {username}"))
}

fn authorize(username: &str, password: &str) -> bool {
    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
    let mut con = client.get_connection().unwrap();

    if username.is_empty() || password.is_empty() {
        return false;
    }

    let user_key = format!("user:{username}:key");

    let redis_pw: String = con.get(&user_key).unwrap();

    if password != redis_pw {
        return false;
    }

    true
}

async fn auth_user(headers: HeaderMap) -> StatusCode {
    let username = headers["x-auth-user"].to_str().unwrap_or("");
    let password = headers["x-auth-key"].to_str().unwrap_or("");

    if authorize(&username, &password) == false {
        return StatusCode::UNAUTHORIZED;
    }

    StatusCode::OK
}

async fn update_progress(headers: HeaderMap, Json(payload): Json<Progress>) -> StatusCode {
    let username = headers["x-auth-user"].to_str().unwrap_or("");
    let password = headers["x-auth-key"].to_str().unwrap_or("");

    if authorize(username, password) == false {
        return StatusCode::UNAUTHORIZED;
    }

    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
    let mut con = client.get_connection().unwrap();

    let timestamp = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_secs();
    let document = payload.document;

    let doc_key = format!("user:{username}:document:{document}");
    let _: () = con
        .hset_multiple(
            &doc_key,
            &[
                ("percentage", &payload.percentage),
                ("progress", &payload.progress),
                ("device", &payload.device),
                ("device_id", &payload.device_id),
                ("timestamp", &timestamp.to_string()),
            ],
        )
        .unwrap();

    StatusCode::OK
}

async fn get_progress() {}

async fn healthcheck() -> (StatusCode, String) {
    (StatusCode::OK, "{ \"state\" : \"OK\" }".to_owned())
}