use crate::schema::gamenight::*;
use crate::schema::users::*;
use crate::schema::DatabaseError;
use crate::schema::DbConn;
use crate::AppConfig;
use chrono::Utc;
use futures::future::join_all;
use jsonwebtoken::{decode, encode, DecodingKey, EncodingKey, Header, Validation};
use rocket::http::Status;
use rocket::request::{FromRequest, Outcome, Request};
use rocket::serde::json::{json, Json, Value};
use rocket::State;
use serde::{Deserialize, Serialize};
use std::borrow::Cow;
use uuid::Uuid;
use validator::ValidateArgs;

#[derive(Debug, Responder)]
pub enum ApiResponseVariant {
    Status(Status),
    Value(Value),
}

#[derive(Serialize, Deserialize, Debug)]
struct ApiResponse {
    result: Cow<'static, str>,
    #[serde(skip_serializing_if = "Option::is_none")]
    message: Option<Cow<'static, str>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    user: Option<UserWithToken>,
    #[serde(skip_serializing_if = "Option::is_none")]
    gamenights: Option<Vec<GamenightOutput>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    games: Option<Vec<Game>>,
}

impl ApiResponse {
    const SUCCES_RESULT: Cow<'static, str> = Cow::Borrowed("Ok");
    const FAILURE_RESULT: Cow<'static, str> = Cow::Borrowed("Failure");

    const SUCCES: Self = Self {
        result: Self::SUCCES_RESULT,
        message: None,
        user: None,
        gamenights: None,
        games: None,
    };

    fn error(message: String) -> Self {
        Self {
            result: Self::FAILURE_RESULT,
            message: Some(Cow::Owned(message)),
            user: None,
            gamenights: None,
            games: None,
        }
    }

    fn login_response(user: User, jwt: String) -> Self {
        Self {
            result: Self::SUCCES_RESULT,
            message: None,
            user: Some(UserWithToken {
                user: user,
                jwt: jwt,
            }),
            gamenights: None,
            games: None,
        }
    }

    fn gamenight_response(gamenights: Vec<GamenightOutput>) -> Self {
        Self {
            result: Self::SUCCES_RESULT,
            message: None,
            user: None,
            gamenights: Some(gamenights),
            games: None,
        }
    }

    fn games_response(games: Vec<Game>) -> Self {
        Self {
            result: Self::SUCCES_RESULT,
            message: None,
            user: None,
            gamenights: None,
            games: Some(games),
        }
    }
}

#[derive(Debug)]
pub enum ApiError {
    RequestError(String),
}

const AUTH_HEADER: &str = "Authorization";
const BEARER: &str = "Bearer ";

#[rocket::async_trait]
impl<'r> FromRequest<'r> for User {
    type Error = ApiError;

    async fn from_request(req: &'r Request<'_>) -> Outcome<Self, Self::Error> {
        let header = match req.headers().get_one(AUTH_HEADER) {
            Some(header) => header,
            None => return Outcome::Forward(()),
        };

        if !header.starts_with(BEARER) {
            return Outcome::Forward(());
        };

        let app_config = req.guard::<&State<AppConfig>>().await.unwrap().inner();
        let jwt = header.trim_start_matches(BEARER).to_owned();
        let token = match decode::<Claims>(
            &jwt,
            &DecodingKey::from_secret(app_config.jwt_secret.as_bytes()),
            &Validation::default(),
        ) {
            Ok(token) => token,
            Err(_) => return Outcome::Forward(()),
        };
        let id = token.claims.uid;

        let conn = req.guard::<DbConn>().await.unwrap();
        return match get_user(conn, id).await {
            Ok(o) => Outcome::Success(o),
            Err(_) => Outcome::Forward(()),
        };
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub struct GamenightOutput {
    #[serde(flatten)]
    gamenight: Gamenight,
    game_list: Vec<Game>,
    participants: Vec<User>,
}

#[get("/gamenights")]
pub async fn gamenights(conn: DbConn, _user: User) -> ApiResponseVariant {
    let gamenights = match get_all_gamenights(&conn).await {
        Ok(result) => result,
        Err(err) => return ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    };

    let conn_ref = &conn;

    let game_results: Result<Vec<GamenightOutput>, DatabaseError> =
        join_all(gamenights.iter().map(|gn| async move {
            let games = get_games_of_gamenight(conn_ref, gn.id).await?;
            let participants = load_participants(conn_ref, gn.id).await?;
            Ok(GamenightOutput {
                gamenight: gn.clone(),
                game_list: games,
                participants: participants,
            })
        }))
        .await
        .into_iter()
        .collect();

    match game_results {
        Ok(result) => ApiResponseVariant::Value(json!(ApiResponse::gamenight_response(result))),
        Err(err) => ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    }
}

#[get("/gamenights", rank = 2)]
pub async fn gamenights_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct GamenightInput {
    pub name: String,
    pub datetime: String,
    pub owner_id: Option<Uuid>,
    pub game_list: Vec<Game>,
}

impl Into<Gamenight> for GamenightInput {
    fn into(self) -> Gamenight {
        Gamenight {
            id: Uuid::new_v4(),
            name: self.name,
            datetime: self.datetime,
            owner_id: self.owner_id.unwrap(),
        }
    }
}

#[post("/gamenights", format = "application/json", data = "<gamenight_json>")]
pub async fn gamenights_post_json(
    conn: DbConn,
    user: User,
    gamenight_json: Json<GamenightInput>,
) -> ApiResponseVariant {
    let mut gamenight = gamenight_json.into_inner();
    gamenight.owner_id = Some(user.id);

    let mut mutable_game_list = gamenight.game_list.clone();

    match add_unknown_games(&conn, &mut mutable_game_list).await {
        Ok(_) => (),
        Err(err) => return ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    };

    let gamenight_id = match insert_gamenight(&conn, gamenight.clone().into(), mutable_game_list)
        .await
    {
        Ok(id) => id,
        Err(err) => return ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    };

    let participant = GamenightParticipantsEntry {
        gamenight_id: gamenight_id,
        user_id: user.id,
    };
    match insert_participant(&conn, participant).await {
        Ok(_) => ApiResponseVariant::Value(json!(ApiResponse::SUCCES)),
        Err(err) => ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    }
}

#[post("/gamenights", rank = 2)]
pub async fn gamenights_post_json_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[delete(
    "/gamenights",
    format = "application/json",
    data = "<delete_gamenight_json>"
)]
pub async fn gamenights_delete_json(
    conn: DbConn,
    user: User,
    delete_gamenight_json: Json<DeleteGamenight>,
) -> ApiResponseVariant {
    if user.role == Role::Admin {
        if let Err(error) = delete_gamenight(&conn, delete_gamenight_json.game_id).await {
            return ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string())));
        }
        return ApiResponseVariant::Value(json!(ApiResponse::SUCCES));
    }

    match get_gamenight(&conn, delete_gamenight_json.game_id).await {
        Ok(gamenight) => {
            if user.id == gamenight.owner_id {
                if let Err(error) = delete_gamenight(&conn, delete_gamenight_json.game_id).await {
                    return ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string())));
                }
                return ApiResponseVariant::Value(json!(ApiResponse::SUCCES));
            }
        }
        Err(error) => {
            return ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string())))
        }
    }
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[delete("/gamenights", rank = 2)]
pub async fn gamenights_delete_json_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[post("/register", format = "application/json", data = "<register_json>")]
pub async fn register_post_json(conn: DbConn, register_json: Json<Register>) -> ApiResponseVariant {
    let register = register_json.into_inner();
    let register_clone = register.clone();
    match conn
        .run(move |c| register_clone.validate_args((c, c)))
        .await
    {
        Ok(()) => (),
        Err(error) => {
            return ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string())))
        }
    }

    match insert_user(conn, register).await {
        Ok(_) => ApiResponseVariant::Value(json!(ApiResponse::SUCCES)),
        Err(err) => ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
    }
}

#[derive(Debug, Serialize, Deserialize)]
struct Claims {
    exp: i64,
    uid: Uuid,
    role: Role,
}

#[post("/login", format = "application/json", data = "<login_json>")]
pub async fn login_post_json(
    conn: DbConn,
    config: &State<AppConfig>,
    login_json: Json<Login>,
) -> ApiResponseVariant {
    match login(conn, login_json.into_inner()).await {
        Err(err) => ApiResponseVariant::Value(json!(ApiResponse::error(err.to_string()))),
        Ok(login_result) => {
            if !login_result.result {
                return ApiResponseVariant::Value(json!(ApiResponse::error(String::from(
                    "username and password didn't match"
                ))));
            }

            let user = login_result.user.unwrap();
            let my_claims = Claims {
                exp: Utc::now().timestamp() + chrono::Duration::days(7).num_seconds(),
                uid: user.id,
                role: user.role,
            };

            let secret = &config.inner().jwt_secret;
            match encode(
                &Header::default(),
                &my_claims,
                &EncodingKey::from_secret(secret.as_bytes()),
            ) {
                Ok(token) => {
                    ApiResponseVariant::Value(json!(ApiResponse::login_response(user, token)))
                }
                Err(error) => {
                    ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string())))
                }
            }
        }
    }
}

#[get("/games")]
pub async fn games(conn: DbConn, _user: User) -> ApiResponseVariant {
    match get_all_known_games(&conn).await {
        Ok(games) => ApiResponseVariant::Value(json!(ApiResponse::games_response(games))),
        Err(error) => ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string()))),
    }
}

#[get("/games", rank = 2)]
pub async fn games_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[get(
    "/participants",
    format = "application/json",
    data = "<gamenight_id_json>"
)]
pub async fn get_participants(
    conn: DbConn,
    _user: User,
    gamenight_id_json: Json<GamenightId>,
) -> ApiResponseVariant {
    match load_participants(&conn, gamenight_id_json.into_inner().gamenight_id).await {
        Ok(_) => ApiResponseVariant::Value(json!(ApiResponse::SUCCES)),
        Err(error) => ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string()))),
    }
}

#[get("/participants", rank = 2)]
pub async fn get_participants_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[post("/participants", format = "application/json", data = "<entry_json>")]
pub async fn post_participants(
    conn: DbConn,
    _user: User,
    entry_json: Json<GamenightParticipantsEntry>,
) -> ApiResponseVariant {
    match insert_participant(&conn, entry_json.into_inner()).await {
        Ok(_) => ApiResponseVariant::Value(json!(ApiResponse::SUCCES)),
        Err(error) => ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string()))),
    }
}

#[post("/participants", rank = 2)]
pub async fn post_participants_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}

#[delete("/participants", format = "application/json", data = "<entry_json>")]
pub async fn delete_participants(
    conn: DbConn,
    _user: User,
    entry_json: Json<GamenightParticipantsEntry>,
) -> ApiResponseVariant {
    match remove_participant(&conn, entry_json.into_inner()).await {
        Ok(_) => ApiResponseVariant::Value(json!(ApiResponse::SUCCES)),
        Err(error) => ApiResponseVariant::Value(json!(ApiResponse::error(error.to_string()))),
    }
}

#[delete("/participants", rank = 2)]
pub async fn delete_participants_unauthorized() -> ApiResponseVariant {
    ApiResponseVariant::Status(Status::Unauthorized)
}