use crate::models::Mode;
use chrono::{DateTime, Utc};
use reqwest::{Client, RequestBuilder};

trait ToQuery {
    fn to_query(&self) -> Vec<(&'static str, String)>;
}

impl<T: ToQuery> ToQuery for Option<T> {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        match self {
            Some(ref v) => v.to_query(),
            None => vec![],
        }
    }
}

impl ToQuery for Mode {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        vec![("m", (*self as u8).to_string())]
    }
}

impl ToQuery for (Mode, bool) {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        vec![
            ("m", (self.0 as u8).to_string()),
            ("a", (self.1 as u8).to_string()),
        ]
    }
}

impl ToQuery for (&'static str, String) {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        vec![(self.0, self.1.clone())]
    }
}

impl ToQuery for (&'static str, DateTime<Utc>) {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        vec![(self.0, format!("{}", self.1.date().format("%Y-%m-%d")))]
    }
}

pub enum UserID {
    Username(String),
    ID(u64),
    Auto(String),
}

impl ToQuery for UserID {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        use UserID::*;
        match self {
            Username(ref s) => vec![("u", s.clone()), ("type", "string".to_owned())],
            ID(u) => vec![("u", u.to_string()), ("type", "id".to_owned())],
            Auto(ref s) => vec![("u", s.clone())],
        }
    }
}
pub enum BeatmapRequestKind {
    ByUser(UserID),
    Beatmap(u64),
    Beatmapset(u64),
    BeatmapHash(String),
}

impl ToQuery for BeatmapRequestKind {
    fn to_query(&self) -> Vec<(&'static str, String)> {
        use BeatmapRequestKind::*;
        match self {
            ByUser(ref u) => u.to_query(),
            Beatmap(b) => vec![("b", b.to_string())],
            Beatmapset(s) => vec![("s", s.to_string())],
            BeatmapHash(ref h) => vec![("h", h.clone())],
        }
    }
}

pub mod builders {
    use super::*;
    /// A builder for a Beatmap request.
    pub struct BeatmapRequestBuilder {
        kind: BeatmapRequestKind,
        since: Option<DateTime<Utc>>,
        mode: Option<(Mode, /* Converted */ bool)>,
    }
    impl BeatmapRequestBuilder {
        pub(crate) fn new(kind: BeatmapRequestKind) -> Self {
            BeatmapRequestBuilder {
                kind,
                since: None,
                mode: None,
            }
        }

        pub fn since(&mut self, since: DateTime<Utc>) -> &mut Self {
            self.since = Some(since);
            self
        }

        pub fn mode(&mut self, mode: Mode, converted: bool) -> &mut Self {
            self.mode = Some((mode, converted));
            self
        }

        pub(crate) fn build(self, client: &Client) -> RequestBuilder {
            client
                .get("https://osu.ppy.sh/api/get_beatmaps")
                .query(&self.kind.to_query())
                .query(&self.since.map(|v| ("since", v)).to_query())
                .query(&self.mode.to_query())
        }
    }

    pub struct UserRequestBuilder {
        user: UserID,
        mode: Option<Mode>,
        event_days: Option<u8>,
    }

    impl UserRequestBuilder {
        pub(crate) fn new(user: UserID) -> Self {
            UserRequestBuilder {
                user,
                mode: None,
                event_days: None,
            }
        }

        pub fn mode(&mut self, mode: Mode) -> &mut Self {
            self.mode = Some(mode);
            self
        }

        pub fn event_days(&mut self, event_days: u8) -> &mut Self {
            self.event_days = Some(event_days).filter(|&v| v <= 31).or(self.event_days);
            self
        }

        pub(crate) fn build(&self, client: &Client) -> RequestBuilder {
            client
                .get("https://osu.ppy.sh/api/get_user")
                .query(&self.user.to_query())
                .query(&self.mode.to_query())
                .query(
                    &self
                        .event_days
                        .map(|v| ("event_days", v.to_string()))
                        .to_query(),
                )
        }
    }
}

pub struct UserRequest {
    pub user: UserID,
    pub mode: Option<Mode>,
    pub event_days: Option<u8>,
}
pub struct ScoreRequest {
    pub beatmap_id: u64,
    pub user: Option<UserID>,
    pub mode: Option<Mode>,
    pub mods: u64, // Later
}
pub struct UserBestRequest {
    pub user: UserID,
    pub mode: Option<Mode>,
}
pub struct UserRecentRequest {
    pub user: UserID,
    pub mode: Option<Mode>,
}