//! # Windows for Matrix rooms and spaces
use matrix_sdk::{
    room::Room as MatrixRoom,
    ruma::{
        events::{
            room::{name::RoomNameEventContent, topic::RoomTopicEventContent},
            tag::{TagInfo, Tags},
        },
        RoomId,
    },
    DisplayName,
    RoomState as MatrixRoomState,
};

use ratatui::{
    buffer::Buffer,
    layout::{Alignment, Rect},
    style::{Modifier as StyleModifier, Style},
    text::{Line, Span, Text},
    widgets::{Paragraph, StatefulWidget, Widget},
};

use modalkit::actions::{
    Action,
    Editable,
    EditorAction,
    Jumpable,
    PromptAction,
    Promptable,
    Scrollable,
};
use modalkit::errors::{EditResult, UIError};
use modalkit::prelude::*;
use modalkit::{editing::completion::CompletionList, keybindings::dialog::PromptYesNo};
use modalkit_ratatui::{TermOffset, TerminalCursor, WindowOps};

use crate::base::{
    IambAction,
    IambError,
    IambId,
    IambInfo,
    IambResult,
    MessageAction,
    ProgramAction,
    ProgramContext,
    ProgramStore,
    RoomAction,
    RoomField,
    SendAction,
};

use self::chat::ChatState;
use self::space::{Space, SpaceState};

mod chat;
mod scrollback;
mod space;

macro_rules! delegate {
    ($s: expr, $id: ident => $e: expr) => {
        match $s {
            RoomState::Chat($id) => $e,
            RoomState::Space($id) => $e,
        }
    };
}

/// State for a Matrix room or space.
///
/// Since spaces function as special rooms within Matrix, we wrap their window state together, so
/// that operations like sending and accepting invites, opening the members window, etc., all work
/// similarly.
pub enum RoomState {
    Chat(ChatState),
    Space(SpaceState),
}

impl From<ChatState> for RoomState {
    fn from(chat: ChatState) -> Self {
        RoomState::Chat(chat)
    }
}

impl From<SpaceState> for RoomState {
    fn from(space: SpaceState) -> Self {
        RoomState::Space(space)
    }
}

impl RoomState {
    pub fn new(
        room: MatrixRoom,
        name: DisplayName,
        tags: Option<Tags>,
        store: &mut ProgramStore,
    ) -> Self {
        let room_id = room.room_id().to_owned();
        let info = store.application.get_room_info(room_id);
        info.name = name.to_string().into();
        info.tags = tags;

        if room.is_space() {
            SpaceState::new(room).into()
        } else {
            ChatState::new(room, store).into()
        }
    }

    pub fn refresh_room(&mut self, store: &mut ProgramStore) {
        match self {
            RoomState::Chat(chat) => chat.refresh_room(store),
            RoomState::Space(space) => space.refresh_room(store),
        }
    }

    fn draw_invite(
        &self,
        invited: MatrixRoom,
        area: Rect,
        buf: &mut Buffer,
        store: &mut ProgramStore,
    ) {
        let inviter = store.application.worker.get_inviter(invited.clone());

        let name = match invited.canonical_alias() {
            Some(alias) => alias.to_string(),
            None => format!("{:?}", store.application.get_room_title(self.id())),
        };

        let mut invited = vec![Span::from(format!("You have been invited to join {name}"))];

        if let Ok(Some(inviter)) = &inviter {
            let info = store.application.rooms.get_or_default(self.id().to_owned());
            invited.push(Span::from(" by "));
            invited.push(store.application.settings.get_user_span(inviter.user_id(), info));
        }

        let l1 = Line::from(invited);
        let l2 = Line::from(
            "You can run `:invite accept` or `:invite reject` to accept or reject this invitation.",
        );
        let text = Text { lines: vec![l1, l2] };

        Paragraph::new(text).alignment(Alignment::Center).render(area, buf);

        return;
    }

    pub async fn message_command(
        &mut self,
        act: MessageAction,
        ctx: ProgramContext,
        store: &mut ProgramStore,
    ) -> IambResult<EditInfo> {
        match self {
            RoomState::Chat(chat) => chat.message_command(act, ctx, store).await,
            RoomState::Space(_) => Err(IambError::NoSelectedMessage.into()),
        }
    }

    pub async fn send_command(
        &mut self,
        act: SendAction,
        ctx: ProgramContext,
        store: &mut ProgramStore,
    ) -> IambResult<EditInfo> {
        match self {
            RoomState::Chat(chat) => chat.send_command(act, ctx, store).await,
            RoomState::Space(_) => Err(IambError::NoSelectedRoom.into()),
        }
    }

    pub async fn room_command(
        &mut self,
        act: RoomAction,
        _: ProgramContext,
        store: &mut ProgramStore,
    ) -> IambResult<Vec<(Action<IambInfo>, ProgramContext)>> {
        match act {
            RoomAction::InviteAccept => {
                if let Some(room) = store.application.worker.client.get_room(self.id()) {
                    let details = room.invite_details().await.map_err(IambError::from)?;
                    let details = details.invitee.event().original_content();
                    let is_direct = details.and_then(|ev| ev.is_direct).unwrap_or_default();

                    room.join().await.map_err(IambError::from)?;

                    if is_direct {
                        room.set_is_direct(true).await.map_err(IambError::from)?;
                    }

                    Ok(vec![])
                } else {
                    Err(IambError::NotInvited.into())
                }
            },
            RoomAction::InviteReject => {
                if let Some(room) = store.application.worker.client.get_room(self.id()) {
                    room.leave().await.map_err(IambError::from)?;

                    Ok(vec![])
                } else {
                    Err(IambError::NotInvited.into())
                }
            },
            RoomAction::InviteSend(user) => {
                if let Some(room) = store.application.worker.client.get_room(self.id()) {
                    room.invite_user_by_id(user.as_ref()).await.map_err(IambError::from)?;

                    Ok(vec![])
                } else {
                    Err(IambError::NotJoined.into())
                }
            },
            RoomAction::Leave(skip_confirm) => {
                if let Some(room) = store.application.worker.client.get_room(self.id()) {
                    if skip_confirm {
                        room.leave().await.map_err(IambError::from)?;

                        Ok(vec![])
                    } else {
                        let msg = "Do you really want to leave this room?";
                        let leave = IambAction::Room(RoomAction::Leave(true));
                        let prompt = PromptYesNo::new(msg, vec![Action::from(leave)]);
                        let prompt = Box::new(prompt);

                        Err(UIError::NeedConfirm(prompt))
                    }
                } else {
                    Err(IambError::NotJoined.into())
                }
            },
            RoomAction::Members(mut cmd) => {
                let width = Count::Exact(30);
                let act =
                    cmd.default_axis(Axis::Vertical).default_relation(MoveDir1D::Next).window(
                        OpenTarget::Application(IambId::MemberList(self.id().to_owned())),
                        width.into(),
                    );

                Ok(vec![(act, cmd.context.clone())])
            },
            RoomAction::Set(field, value) => {
                let room = store
                    .application
                    .get_joined_room(self.id())
                    .ok_or(UIError::Application(IambError::NotJoined))?;

                match field {
                    RoomField::Name => {
                        let ev = RoomNameEventContent::new(value);
                        let _ = room.send_state_event(ev).await.map_err(IambError::from)?;
                    },
                    RoomField::Tag(tag) => {
                        let mut info = TagInfo::new();
                        info.order = Some(1.0);

                        let _ = room.set_tag(tag, info).await.map_err(IambError::from)?;
                    },
                    RoomField::Topic => {
                        let ev = RoomTopicEventContent::new(value);
                        let _ = room.send_state_event(ev).await.map_err(IambError::from)?;
                    },
                }

                Ok(vec![])
            },
            RoomAction::Unset(field) => {
                let room = store
                    .application
                    .get_joined_room(self.id())
                    .ok_or(UIError::Application(IambError::NotJoined))?;

                match field {
                    RoomField::Name => {
                        let ev = RoomNameEventContent::new("".into());
                        let _ = room.send_state_event(ev).await.map_err(IambError::from)?;
                    },
                    RoomField::Tag(tag) => {
                        let _ = room.remove_tag(tag).await.map_err(IambError::from)?;
                    },
                    RoomField::Topic => {
                        let ev = RoomTopicEventContent::new("".into());
                        let _ = room.send_state_event(ev).await.map_err(IambError::from)?;
                    },
                }

                Ok(vec![])
            },
        }
    }

    pub fn get_title(&self, store: &mut ProgramStore) -> Line {
        let title = store.application.get_room_title(self.id());
        let style = Style::default().add_modifier(StyleModifier::BOLD);
        let mut spans = vec![Span::styled(title, style)];

        match self.room().topic() {
            Some(desc) if !desc.is_empty() => {
                spans.push(" (".into());
                spans.push(desc.into());
                spans.push(")".into());
            },
            _ => {},
        }

        Line::from(spans)
    }

    pub fn focus_toggle(&mut self) {
        match self {
            RoomState::Chat(chat) => chat.focus_toggle(),
            RoomState::Space(_) => return,
        }
    }

    pub fn room(&self) -> &MatrixRoom {
        match self {
            RoomState::Chat(chat) => chat.room(),
            RoomState::Space(space) => space.room(),
        }
    }

    pub fn id(&self) -> &RoomId {
        match self {
            RoomState::Chat(chat) => chat.id(),
            RoomState::Space(space) => space.id(),
        }
    }
}

impl Editable<ProgramContext, ProgramStore, IambInfo> for RoomState {
    fn editor_command(
        &mut self,
        act: &EditorAction,
        ctx: &ProgramContext,
        store: &mut ProgramStore,
    ) -> EditResult<EditInfo, IambInfo> {
        delegate!(self, w => w.editor_command(act, ctx, store))
    }
}

impl Jumpable<ProgramContext, IambInfo> for RoomState {
    fn jump(
        &mut self,
        list: PositionList,
        dir: MoveDir1D,
        count: usize,
        ctx: &ProgramContext,
    ) -> IambResult<usize> {
        delegate!(self, w => w.jump(list, dir, count, ctx))
    }
}

impl Scrollable<ProgramContext, ProgramStore, IambInfo> for RoomState {
    fn scroll(
        &mut self,
        style: &ScrollStyle,
        ctx: &ProgramContext,
        store: &mut ProgramStore,
    ) -> EditResult<EditInfo, IambInfo> {
        delegate!(self, w => w.scroll(style, ctx, store))
    }
}

impl Promptable<ProgramContext, ProgramStore, IambInfo> for RoomState {
    fn prompt(
        &mut self,
        act: &PromptAction,
        ctx: &ProgramContext,
        store: &mut ProgramStore,
    ) -> EditResult<Vec<(ProgramAction, ProgramContext)>, IambInfo> {
        delegate!(self, w => w.prompt(act, ctx, store))
    }
}

impl TerminalCursor for RoomState {
    fn get_term_cursor(&self) -> Option<TermOffset> {
        delegate!(self, w => w.get_term_cursor())
    }
}

impl WindowOps<IambInfo> for RoomState {
    fn draw(&mut self, area: Rect, buf: &mut Buffer, focused: bool, store: &mut ProgramStore) {
        if self.room().state() == MatrixRoomState::Invited {
            self.refresh_room(store);
        }

        if self.room().state() == MatrixRoomState::Invited {
            self.draw_invite(self.room().clone(), area, buf, store);
        }

        match self {
            RoomState::Chat(chat) => chat.draw(area, buf, focused, store),
            RoomState::Space(space) => {
                Space::new(store).focus(focused).render(area, buf, space);
            },
        }
    }

    fn dup(&self, store: &mut ProgramStore) -> Self {
        match self {
            RoomState::Chat(chat) => RoomState::Chat(chat.dup(store)),
            RoomState::Space(space) => RoomState::Space(space.dup(store)),
        }
    }

    fn close(&mut self, flags: CloseFlags, store: &mut ProgramStore) -> bool {
        match self {
            RoomState::Chat(chat) => chat.close(flags, store),
            RoomState::Space(space) => space.close(flags, store),
        }
    }

    fn write(
        &mut self,
        path: Option<&str>,
        flags: WriteFlags,
        store: &mut ProgramStore,
    ) -> IambResult<EditInfo> {
        match self {
            RoomState::Chat(chat) => chat.write(path, flags, store),
            RoomState::Space(space) => space.write(path, flags, store),
        }
    }

    fn get_completions(&self) -> Option<CompletionList> {
        match self {
            RoomState::Chat(chat) => chat.get_completions(),
            RoomState::Space(space) => space.get_completions(),
        }
    }

    fn get_cursor_word(&self, style: &WordStyle) -> Option<String> {
        match self {
            RoomState::Chat(chat) => chat.get_cursor_word(style),
            RoomState::Space(space) => space.get_cursor_word(style),
        }
    }

    fn get_selected_word(&self) -> Option<String> {
        match self {
            RoomState::Chat(chat) => chat.get_selected_word(),
            RoomState::Space(space) => space.get_selected_word(),
        }
    }
}