/** The parsers for the chat and multiplayer protocol. The main parser is `message`.

 * # Protocol

 * All messages consist of `\n`-separated strings. The end of a message is

 * indicated by a double newline - `\n\n`.

 *

 * For example, a nullary command like PING will be actually sent as `PING\n\n`.

 * A unary command, such as `START_GAME nick` will be actually sent as `START_GAME\nnick\n\n`.

 */

use std::{

    num::ParseIntError,

    ops::Range,

    str,

    str::{FromStr, Utf8Error},

};

use super::messages::{HwProtocolMessage, HwProtocolMessage::*};

use crate::core::types::{

    GameCfg, HedgehogInfo, ServerVar, TeamInfo, VoteType, MAX_HEDGEHOGS_PER_TEAM,

};

#[derive(Debug, PartialEq)]

pub struct HwProtocolError {}

impl HwProtocolError {

    fn new() -> Self {

        HwProtocolError {}

    }

}

impl<I> ParseError<I> for HwProtocolError {

    fn from_error_kind(input: I, kind: ErrorKind) -> Self {

        HwProtocolError::new()

    }

    fn append(input: I, kind: ErrorKind, other: Self) -> Self {

        HwProtocolError::new()

    }

}

impl From<Utf8Error> for HwProtocolError {

    fn from(_: Utf8Error) -> Self {

        HwProtocolError::new()

    }

}

impl From<ParseIntError> for HwProtocolError {

    fn from(_: ParseIntError) -> Self {

        HwProtocolError::new()

    }

}

pub type HwResult<'a, O> = IResult<&'a [u8], O, HwProtocolError>;

fn end_of_message(input: &[u8]) -> HwResult<&[u8]> {

    tag("\n\n")(input)

}

fn convert_utf8(input: &[u8]) -> HwResult<&str> {

    match str::from_utf8(input) {

        Ok(str) => Ok((b"", str)),

        Err(utf_err) => Result::Err(Err::Failure(utf_err.into())),

    }

}

fn convert_from_str<T>(str: &str) -> HwResult<T>

where

    T: FromStr<Err = ParseIntError>,

{

    match T::from_str(str) {

        Ok(x) => Ok((b"", x)),

        Err(format_err) => Result::Err(Err::Failure(format_err.into())),

    }

}

fn str_line(input: &[u8]) -> HwResult<&str> {

    let (i, text) = not_line_ending(input)?;

    Ok((i, convert_utf8(text)?.1))

}

fn a_line(input: &[u8]) -> HwResult<String> {

    let (i, str) = str_line(input)?;

    Ok((i, str.to_string()))

}

fn hw_tag<'a>(tag_str: &'a str) -> impl Fn(&'a [u8]) -> HwResult<'a, ()> {

    move |i| tag(tag_str)(i).map(|(i, _)| (i, ()))

}

fn hw_tag_no_case<'a>(tag_str: &'a str) -> impl Fn(&'a [u8]) -> HwResult<'a, ()> {

    move |i| tag_no_case(tag_str)(i).map(|(i, _)| (i, ()))

}

fn cmd_arg(input: &[u8]) -> HwResult<String> {

    let delimiters = b" \n";

    let (i, str) = take_while(move |c| !delimiters.contains(&c))(input)?;

    Ok((i, convert_utf8(str)?.1.to_string()))

}

fn u8_line(input: &[u8]) -> HwResult<u8> {

    let (i, str) = str_line(input)?;

    Ok((i, convert_from_str(str)?.1))

}

fn u16_line(input: &[u8]) -> HwResult<u16> {

    let (i, str) = str_line(input)?;

    Ok((i, convert_from_str(str)?.1))

}

fn u32_line(input: &[u8]) -> HwResult<u32> {

    let (i, str) = str_line(input)?;

    Ok((i, convert_from_str(str)?.1))

}

fn yes_no_line(input: &[u8]) -> HwResult<bool> {

    alt((

        |i| tag_no_case(b"YES")(i).map(|(i, _)| (i, true)),

        |i| tag_no_case(b"NO")(i).map(|(i, _)| (i, false)),

    ))(input)

}

fn opt_arg<'a>(input: &'a [u8]) -> HwResult<'a, Option<String>> {

    alt((

        |i| precededc(i, hw_tag("\n"), a_line).map(|(i, v)| (i, Some(v))),

    ))(input)

}

fn spaces(input: &[u8]) -> HwResult<&[u8]> {

    precededc(input, hw_tag(" "), |i| take_while(|c| c == b' ')(i))

}

fn opt_space_arg<'a>(input: &'a [u8]) -> HwResult<'a, Option<String>> {

    alt((

        |i| precededc(i, spaces, a_line).map(|(i, v)| (i, Some(v))),

    ))(input)

}

fn hedgehog_array(input: &[u8]) -> HwResult<[HedgehogInfo; 8]> {

    fn hedgehog_line(input: &[u8]) -> HwResult<HedgehogInfo> {

        let (i, hat) = a_line(i)?;

        Ok((i, HedgehogInfo { name, hat }))

    }

    let (i, h8) = hedgehog_line(i)?;

    Ok((i, [h1, h2, h3, h4, h5, h6, h7, h8]))

}

fn voting(input: &[u8]) -> HwResult<VoteType> {

    alt((

        |i| tag_no_case("PAUSE")(i).map(|(i, _)| (i, VoteType::Pause)),

        |i| tag_no_case("NEWSEED")(i).map(|(i, _)| (i, VoteType::NewSeed)),

        |i| {

            precededc(i, |i| precededc(i, hw_tag_no_case("KICK"), spaces), a_line)

                .map(|(i, s)| (i, VoteType::Kick(s)))

        },

        |i| {

            precededc(

                i,

                |i| precededc(i, hw_tag_no_case("HEDGEHOGS"), spaces),

                u8_line,

            )

            .map(|(i, n)| (i, VoteType::HedgehogsPerTeam(n)))

        },

        |i| precededc(i, hw_tag_no_case("MAP"), opt_space_arg).map(|(i, v)| (i, VoteType::Map(v))),

    ))(input)

}

fn no_arg_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

    fn messagec<'a>(

        input: &'a [u8],

        name: &'a str,

        msg: HwProtocolMessage,

    ) -> HwResult<'a, HwProtocolMessage> {

        tag(name)(input).map(|(i, _)| (i, msg.clone()))

    }

    alt((

        |i| messagec(i, "PING", Ping),

        |i| messagec(i, "PONG", Pong),

        |i| messagec(i, "LIST", List),

        |i| messagec(i, "BANLIST", BanList),

        |i| messagec(i, "GET_SERVER_VAR", GetServerVar),

        |i| messagec(i, "TOGGLE_READY", ToggleReady),

        |i| messagec(i, "START_GAME", StartGame),

        |i| messagec(i, "TOGGLE_RESTRICT_JOINS", ToggleRestrictJoin),

        |i| messagec(i, "TOGGLE_RESTRICT_TEAMS", ToggleRestrictTeams),

        |i| messagec(i, "TOGGLE_REGISTERED_ONLY", ToggleRegisteredOnly),

    ))(input)

}

fn single_arg_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

    fn messagec<'a, T, F, G>(

        input: &'a [u8],

        name: &'a str,

        parser: F,

        constructor: G,

    ) -> HwResult<'a, HwProtocolMessage>

    where

        F: Fn(&[u8]) -> HwResult<T>,

        G: Fn(T) -> HwProtocolMessage,

    {

        precededc(input, hw_tag(name), parser).map(|(i, v)| (i, constructor(v)))

    }

    alt((

        |i| messagec(i, "NICK\n", a_line, Nick),

        |i| messagec(i, "INFO\n", a_line, Info),

        |i| messagec(i, "CHAT\n", a_line, Chat),

        |i| messagec(i, "PART", opt_arg, Part),

        |i| messagec(i, "FOLLOW\n", a_line, Follow),

        |i| messagec(i, "KICK\n", a_line, Kick),

        |i| messagec(i, "UNBAN\n", a_line, Unban),

        |i| messagec(i, "EM\n", a_line, EngineMessage),

        |i| messagec(i, "TEAMCHAT\n", a_line, TeamChat),

        |i| messagec(i, "ROOM_NAME\n", a_line, RoomName),

        |i| messagec(i, "REMOVE_TEAM\n", a_line, RemoveTeam),

        |i| messagec(i, "ROUNDFINISHED", opt_arg, |_| RoundFinished),

        |i| messagec(i, "PROTO\n", u16_line, Proto),

        |i| messagec(i, "QUIT", opt_arg, Quit),

    ))(input)

}

fn cmd_message<'a>(input: &'a [u8]) -> HwResult<'a, HwProtocolMessage> {

    fn cmdc_no_arg<'a>(

        input: &'a [u8],

        name: &'a str,

        msg: HwProtocolMessage,

    ) -> HwResult<'a, HwProtocolMessage> {

        tag_no_case(name)(input).map(|(i, _)| (i, msg.clone()))

    }

    fn cmdc_single_arg<'a, T, F, G>(

        input: &'a [u8],

        name: &'a str,

        parser: F,

        constructor: G,

    ) -> HwResult<'a, HwProtocolMessage>

    where

        F: Fn(&'a [u8]) -> HwResult<'a, T>,

        G: Fn(T) -> HwProtocolMessage,

    {

        precededc(input, |i| pairc(i, hw_tag_no_case(name), spaces), parser)

            .map(|(i, v)| (i, constructor(v)))

    }

    fn cmd_no_arg_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

        alt((

            |i| cmdc_no_arg(i, "STATS", Stats),

            |i| cmdc_no_arg(i, "FIX", Fix),

            |i| cmdc_no_arg(i, "UNFIX", Unfix),

            |i| cmdc_no_arg(i, "REGISTERED_ONLY", ToggleServerRegisteredOnly),

            |i| cmdc_no_arg(i, "SUPER_POWER", SuperPower),

        ))(input)

    }

    fn cmd_single_arg_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

        alt((

            |i| cmdc_single_arg(i, "RESTART_SERVER", |i| tag("YES")(i), |_| RestartServer),

            |i| cmdc_single_arg(i, "DELEGATE", a_line, Delegate),

            |i| cmdc_single_arg(i, "DELETE", a_line, Delete),

            |i| cmdc_single_arg(i, "SAVEROOM", a_line, SaveRoom),

            |i| cmdc_single_arg(i, "LOADROOM", a_line, LoadRoom),

            |i| cmdc_single_arg(i, "GLOBAL", a_line, Global),

            |i| cmdc_single_arg(i, "WATCH", u32_line, Watch),

            |i| cmdc_single_arg(i, "VOTE", yes_no_line, Vote),

            |i| cmdc_single_arg(i, "FORCE", yes_no_line, ForceVote),

            |i| cmdc_single_arg(i, "INFO", a_line, Info),

            |i| cmdc_single_arg(i, "MAXTEAMS", u8_line, MaxTeams),

            |i| cmdc_single_arg(i, "CALLVOTE", voting, |v| CallVote(Some(v))),

        ))(input)

    }

    precededc(

        input,

        hw_tag("CMD\n"),

        alt((

            cmd_no_arg_message,

            cmd_single_arg_message,

            |i| tag_no_case("CALLVOTE")(i).map(|(i, _)| (i, CallVote(None))),

            |i| {

                precededc(i, hw_tag_no_case("GREETING"), opt_space_arg)

                    .map(|(i, s)| (i, Greeting(s)))

            },

            |i| precededc(i, hw_tag_no_case("PART"), opt_space_arg).map(|(i, s)| (i, Part(s))),

            |i| precededc(i, hw_tag_no_case("QUIT"), opt_space_arg).map(|(i, s)| (i, Quit(s))),

            |i| {

                precededc(i, hw_tag_no_case("SAVE"), |i| {

                    pairc(

                        i,

                        |i| precededc(i, spaces, cmd_arg),

                        |i| precededc(i, spaces, cmd_arg),

                    )

                })

                .map(|(i, (n, l))| (i, Save(n, l)))

            },

            |i| {

                let (i, _) = tag_no_case("RND")(i)?;

                let (i, v) = str_line(i)?;

                Ok((i, Rnd(v.split_whitespace().map(String::from).collect())))

            },

        )),

    )

}

fn config_message<'a>(input: &'a [u8]) -> HwResult<'a, HwProtocolMessage> {

    fn cfgc_single_arg<'a, T, F, G>(

        input: &'a [u8],

        name: &'a str,

        parser: F,

        constructor: G,

    ) -> HwResult<'a, GameCfg>

    where

        F: Fn(&[u8]) -> HwResult<T>,

        G: Fn(T) -> GameCfg,

    {

            .map(|(i, v)| (i, constructor(v)))

    }

    let (i, cfg) = precededc(

        input,

        hw_tag("CFG\n"),

        alt((

            |i| cfgc_single_arg(i, "THEME", a_line, GameCfg::Theme),

            |i| cfgc_single_arg(i, "SCRIPT", a_line, GameCfg::Script),

            |i| cfgc_single_arg(i, "MAP", a_line, GameCfg::MapType),

            |i| cfgc_single_arg(i, "MAPGEN", u32_line, GameCfg::MapGenerator),

            |i| cfgc_single_arg(i, "MAZE_SIZE", u32_line, GameCfg::MazeSize),

            |i| cfgc_single_arg(i, "TEMPLATE", u32_line, GameCfg::Template),

            |i| cfgc_single_arg(i, "FEATURE_SIZE", u32_line, GameCfg::FeatureSize),

            |i| cfgc_single_arg(i, "SEED", a_line, GameCfg::Seed),

            |i| cfgc_single_arg(i, "DRAWNMAP", a_line, GameCfg::DrawnMap),

            |i| {

                precededc(

                    i,

                    |i| {

                        let (i, name) = a_line(i)?;

                        let (i, value) = opt_arg(i)?;

                        Ok((i, GameCfg::Ammo(name, value)))

                    },

                )

            },

            |i| {

                precededc(

                    i,

                    |i| {

                        let (i, name) = a_line(i)?;

                        let (i, values) = alt((

                            |i| {

                                    .map(|(i, v)| (i, Some(v)))

                            },

                        ))(i)?;

                        Ok((i, GameCfg::Scheme(name, values.unwrap_or_default())))

                    },

                )

            },

        )),

    )?;

    Ok((i, Cfg(cfg)))

}

fn server_var_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

    precededc(

        input,

        hw_tag("SET_SERVER_VAR\n"),

        alt((

            |i| {

                precededc(i, hw_tag("MOTD_NEW\n"), a_line)

                    .map(|(i, s)| (i, SetServerVar(ServerVar::MOTDNew(s))))

            },

            |i| {

                precededc(i, hw_tag("MOTD_OLD\n"), a_line)

                    .map(|(i, s)| (i, SetServerVar(ServerVar::MOTDOld(s))))

            },

            |i| {

                precededc(i, hw_tag("LATEST_PROTO\n"), u16_line)

                    .map(|(i, n)| (i, SetServerVar(ServerVar::LatestProto(n))))

            },

        )),

    )

}

fn complex_message(input: &[u8]) -> HwResult<HwProtocolMessage> {

    alt((

        |i| {

            precededc(

                i,

                |i| {

                    let (i, salt) = a_line(i)?;

                    Ok((i, Password(pass, salt)))

                },

            )

        },

        |i| {

            precededc(

                i,

                |i| {

                    let (i, pass) = a_line(i)?;

                    Ok((i, Checker(protocol, name, pass)))

                },

            )

        },

        |i| {

            precededc(

                i,

                |i| {

                    let (i, name) = a_line(i)?;

                    let (i, pass) = opt_arg(i)?;

                    Ok((i, CreateRoom(name, pass)))

                },

            )

        },

        |i| {

            precededc(

                i,

                |i| {

                    let (i, name) = a_line(i)?;

                    let (i, pass) = opt_arg(i)?;

                    Ok((i, JoinRoom(name, pass)))

                },

            )

        },

        |i| {

            precededc(

                i,

                |i| {

                    let (i, hedgehogs) = hedgehog_array(i)?;

                    Ok((

                        i,

                        AddTeam(Box::new(TeamInfo {

                            owner: String::new(),

                            name,

                            color,

                            grave,

                            fort,

                            voice_pack,

                            flag,

                            difficulty,

                            hedgehogs,

                            hedgehogs_number: 0,

                        })),

                    ))

                },

            )

        },