use std::{
    borrow::Cow,
    collections::{HashMap, HashSet},
};

use crossbeam_channel::Receiver;
use eframe::egui::{self, Color32, Label, RichText, ScrollArea, Sense};
use matrix_sdk::{
    deserialized_responses::SyncResponse,
    encryption::verification::{SasVerification, Verification, VerificationRequest},
    room::{Joined, Room},
    ruma::{
        events::{
            key::verification::VerificationMethod,
            room::{create::RoomType as CreateRoomType, message::MessageType},
            AnyMessageEvent, AnyRoomEvent, AnyToDeviceEvent,
        },
        RoomId, UserId,
    },
    Client, RoomMember,
};
use serde::{Deserialize, Serialize};
use tokio::sync::mpsc::UnboundedSender;

use crate::sync;

use super::Id;

/// Logged in application state
#[derive(Debug)]
pub struct App {
    pub client: matrix_sdk::Client,
    /// Request sender.
    pub request: RequestSender,
    /// Response receiver.
    pub response: Receiver<sync::Response>,
    /// Handle to the sync loop thread.
    pub sync_handle: Option<std::thread::JoinHandle<()>>,
    /// Error message.
    pub error: Option<String>,
    /// State of an active verification request.
    pub verify_req: Option<VerificationRequest>,
    /// State of a started verification session.
    pub verify: Option<Verification>,

    /// Data for the room list
    pub room_list: RoomList,
    /// Data for storing a timeline
    pub timelines: HashMap<RoomId, Timeline>,
    /// Message entry
    pub entry: MessageEntry,
}

#[derive(Debug, Default, Clone, Serialize, Deserialize)]
pub struct RoomList {
    pub selected_room: Option<matrix_sdk::ruma::identifiers::RoomId>,
    pub room_name: HashMap<RoomId, String>,
}

#[derive(Debug, Default, Clone, Serialize, Deserialize)]
pub struct Timeline {
    messages: Vec<AnyRoomEvent>,
    #[serde(skip)]
    member: HashMap<UserId, RoomMember>,
    #[serde(skip)]
    member_pending: HashSet<UserId>,
}

#[derive(Debug, Default, Clone, Serialize, Deserialize)]
pub struct MessageEntry {
    text: HashMap<RoomId, String>,
}

impl MessageEntry {
    pub fn get(&mut self, room: &RoomId) -> &mut String {
        self.text.entry(room.clone()).or_default()
    }
}

impl RoomList {
    fn room_name<'a>(&'a self, room: &matrix_sdk::BaseRoom) -> Cow<'a, str> {
        if let Some(name) = self.room_name.get(room.room_id()) {
            name.into()
        } else if let Some(name) = room.name() {
            name.into()
        } else if let Some(alias) = room.canonical_alias() {
            String::from(alias).into()
        } else {
            room.room_id().to_string().into()
        }
    }

    fn is_selected(&self, room_id: &RoomId) -> bool {
        self.selected_room
            .as_ref()
            .map_or(false, |id| id == room_id)
    }

    fn selected_room(&self, client: &Client) -> Option<matrix_sdk::room::Room> {
        match self.selected_room {
            Some(ref selected) => client.get_room(selected),
            None => None,
        }
    }
}

impl App {
    pub fn new(
        client: Client,
        request: UnboundedSender<sync::Request>,
        response: Receiver<sync::Response>,
        sync_handle: std::thread::JoinHandle<()>,
    ) -> Self {
        Self {
            client,
            request: RequestSender(request),
            response,

            sync_handle: Some(sync_handle),
            room_list: RoomList::default(),
            timelines: HashMap::new(),
            verify_req: None,
            verify: None,
            error: None,
            entry: MessageEntry::default(),
        }
    }

    pub fn update(&mut self, ctx: &egui::CtxRef) {
        if let Ok(response) = self.response.try_recv() {
            self.handle_response(response);
        }

        egui::SidePanel::left(Id::RoomPanel)
            .max_width(400.0)
            .default_width(400.0)
            .show(ctx, |ui| {
                ui.add(Label::new(RichText::new("Joined").strong()));

                let mut joined = self.client.joined_rooms();
                joined.sort_by_key(|room| self.room_list.room_name(&room).to_uppercase());
                joined.retain(|room| {
                    room.create_content()
                        .and_then(|c| c.room_type)
                        .map_or(true, |t| t != CreateRoomType::Space)
                });

                for room in joined {
                    let group = if self.room_list.is_selected(room.room_id()) {
                        egui::Frame::group(&Default::default())
                    } else {
                        egui::Frame::group(&Default::default()).fill(Color32::from_rgb(0, 0, 0))
                    };
                    let response = group.show(ui, |ui| {
                        ui.set_width(ui.available_width());
                        let name = self.room_list.room_name(&*room);
                        ui.label(&*name);
                    });
                    let response = response.response.interact(Sense::click());
                    if response.clicked() {
                        self.room_list.selected_room = Some(room.room_id().clone());
                    }
                }
            });

        let room = match self.room_list.selected_room(&self.client) {
            Some(room) => room,
            _ => return,
        };
        egui::TopBottomPanel::top(Id::RoomSummary).show(ctx, |ui| {
            ui.horizontal(|ui| {
                ui.set_width(ui.available_width());
                ui.heading(&*self.room_list.room_name(&room));
                if let Some(ref target) = room.direct_target() {
                    ui.label(target.as_str());
                } else if let Some(ref alias) = room.canonical_alias() {
                    ui.label(alias.as_str());
                }
                if let Some(ref topic) = room.topic() {
                    ui.label(topic);
                }
            })
        });

        egui::SidePanel::right(Id::MemberList).show(ctx, |ui| {
            ui.heading("Members");
            let timeline = self.timelines.entry(room.room_id().clone()).or_default();
            for member in timeline.member.values() {
                ui.group(|ui| {
                    ui.set_width(ui.available_width());
                    ui.label(member.name());
                });
            }
        });

        if self.error.is_some() {
            egui::TopBottomPanel::top(Id::ErrorPanel).show(ctx, |ui| {
                if ui.button("x").clicked() {
                    self.error = None;
                    return;
                }
                ui.label(self.error.as_ref().unwrap());
            });
        }

        if let Some(ref verify_req) = self.verify_req {
            egui::TopBottomPanel::top(Id::VerificationPanel).show(ctx, |ui| {
                ui.label(format!(
                    "Verification request for {}",
                    verify_req.other_user_id(),
                ));
                if !verify_req.is_ready() {
                    if verify_req.is_cancelled() {
                        ui.label("Verification attempt canceled");
                        return;
                    }
                    if verify_req.we_started() {
                        ui.label("Waiting for other user to accept verification.");
                    } else {
                        if ui.button("Accept").clicked() {
                            self.request.verify_accept(verify_req.clone())
                        }
                    }
                    if verify_req.is_ready() {
                        let methods = verify_req.their_supported_methods().unwrap();
                        for method in methods {
                            if method == VerificationMethod::SasV1 {
                                if ui.button("Verify with emoji").clicked() {
                                    self.request.verify_start_sas(verify_req.clone());
                                }
                            }
                        }
                    }
                    if ui.button("Cancel").clicked() {
                        self.request.verify_cancel(verify_req.clone())
                    }
                }
            });
        }
        if let Some(verify) = self.verify.clone() {
            match verify {
                Verification::SasV1(sas) => {
                    egui::Window::new("Emoji verification")
                        .id(egui::Id::new(Id::SasVerification))
                        .fixed_size([500.0, 300.0])
                        .show(ctx, |ui| {
                            if let Some(cancel) = sas.cancel_info() {
                                ui.label("Verification cancelled");
                                ui.label(cancel.reason());
                            }
                            ui.horizontal_wrapped(|ui| {
                                if let Some(emojis) = sas.emoji() {
                                    for emoji in emojis {
                                        ui.vertical_centered(|ui| {
                                            ui.set_max_width(50.0);
                                            ui.heading(emoji.symbol);
                                            ui.label(emoji.description);
                                        });
                                    }
                                }
                            });
                            ui.horizontal(|ui| {
                                if ui.button("Confirm").clicked() {
                                    self.request.verify_sas_confirm(sas);
                                }
                                if ui.button("Close").clicked() {
                                    self.verify = None;
                                }
                            })
                        });
                }
                Verification::QrV1(_qr) => {
                    egui::Window::new("QR code verification")
                        .id(egui::Id::new(Id::QrVerification))
                        .auto_sized()
                        .show(ctx, |ui| {
                            ui.label("Not implemented yet oops");
                        });
                }
            }
        }

        let joined = match room {
            Room::Joined(ref room) => room,
            _ => return,
        };

        // Main panel with the timeline
        egui::CentralPanel::default().show(ctx, |ui| {
            ScrollArea::vertical().show(ui, |ui| {
                let timeline = self.timelines.entry(room.room_id().clone()).or_default();
                for event in timeline.messages.iter() {
                    let sender = event.sender();
                    let name = match timeline.member.get(sender) {
                        Some(member) => member.name(),
                        None => {
                            if !timeline.member_pending.contains(sender) {
                                self.request.joined_member(joined.clone(), sender.clone());
                            }
                            sender.localpart()
                        }
                    };
                    match event {
                        AnyRoomEvent::Message(AnyMessageEvent::RoomMessage(msg)) => {
                            match &msg.content.msgtype {
                                MessageType::Text(text) => {
                                    ui.horizontal_wrapped(|ui| {
                                        ui.add(Label::new(RichText::new(name).strong()))
                                            .on_hover_text(event.sender().as_str());
                                        ui.label(&text.body);
                                    });
                                }
                                MessageType::Notice(notice) => {
                                    ui.horizontal_wrapped(|ui| {
                                        ui.add(Label::new(RichText::new(name).strong()))
                                            .on_hover_text(event.sender().as_str());
                                        ui.add(egui::Label::new(
                                            RichText::new(&notice.body).weak(),
                                        ));
                                    });
                                }
                                MessageType::ServerNotice(notice) => {
                                    ui.add(Label::new(RichText::new(name).strong()))
                                        .on_hover_text(event.sender().as_str());
                                    ui.add(egui::Label::new(RichText::new(&notice.body).weak()));
                                }
                                MessageType::Emote(emote) => {
                                    ui.label(format!("* {} {}", name, emote.body));
                                }
                                _ => (),
                            };
                        }
                        _ => (),
                    }
                }
            });
        });
        egui::TopBottomPanel::bottom(Id::MessageEntry).show(ctx, |ui| {
            ui.add(
                egui::TextEdit::multiline(self.entry.get(joined.room_id()))
                    .desired_width(ui.available_width()),
            );
            if ui.button("Send").clicked() {
                self.send_message(joined.clone());
            }
        });
    }

    fn send_message(&mut self, room: Joined) {
        let entry = self.entry.get(room.room_id());
        self.request.message(room, std::mem::take(entry));
    }

    fn handle_response(&mut self, response: sync::Response) {
        use sync::Response;
        match response {
            Response::Sync(sync) => self.handle_sync(sync),
            Response::RoomName(room, name) => {
                self.room_list.room_name.insert(room, name);
            }
            Response::JoinedMember(room, member) => {
                self.timelines
                    .entry(room)
                    .or_default()
                    .member
                    .insert(member.user_id().clone(), member);
            }
            Response::VerifyRequest(verification) => {
                self.verify_req = Some(verification);
            }
            Response::VerifySas(sas) => {
                self.verify_req = None;
                self.verify = Some(Verification::SasV1(sas));
            }
            Response::VerifyQr(qr) => {
                self.verify_req = None;
                self.verify = Some(Verification::QrV1(qr));
            }
            Response::Error(e) => {
                self.error = Some(e.to_string());
            }
        };
    }

    fn handle_sync(&mut self, sync: SyncResponse) {
        dbg!(&sync);
        for (id, room) in sync.rooms.join {
            let timeline = self.timelines.entry(id.clone()).or_default();
            for event in room.timeline.events {
                let event = match event.event.deserialize() {
                    Ok(event) => event,
                    Err(_) => continue,
                };
                timeline.messages.push(event.into_full_event(id.clone()));
            }
        }
        for to_device in sync.to_device.events {
            let to_device = match to_device.deserialize() {
                Ok(to_device) => to_device,
                Err(_) => continue,
            };
            match to_device {
                AnyToDeviceEvent::KeyVerificationRequest(req) => {
                    self.request
                        .verify_request(req.sender, req.content.transaction_id);
                }
                AnyToDeviceEvent::KeyVerificationStart(start) => {
                    if self.verify_req.is_none() {
                        self.request
                            .verify_start(start.sender, start.content.transaction_id)
                    }
                }
                _ => (),
            }
        }
    }
}

#[derive(Debug)]
pub struct RequestSender(UnboundedSender<sync::Request>);

impl RequestSender {
    pub fn room_name(&self, name: RoomId) {
        self.0.send(sync::Request::RoomName(name)).ok();
    }

    pub fn joined_member(&self, room: Joined, id: UserId) {
        self.0.send(sync::Request::JoinedMember(room, id)).ok();
    }

    pub fn message(&self, room: Joined, message: String) {
        self.0.send(sync::Request::Message(room, message)).ok();
    }

    pub fn verify_request(&self, user: UserId, flow_id: String) {
        self.0
            .send(sync::Request::VerifyRequest(user, flow_id))
            .ok();
    }

    pub fn verify_cancel(&self, verify: VerificationRequest) {
        self.0.send(sync::Request::VerifyCancel(verify)).ok();
    }

    pub fn verify_accept(&self, verify: VerificationRequest) {
        self.0.send(sync::Request::VerifyAccept(verify)).ok();
    }

    pub fn verify_start(&self, user: UserId, flow_id: String) {
        self.0.send(sync::Request::VerifyStart(user, flow_id)).ok();
    }

    pub fn verify_start_sas(&self, verify: VerificationRequest) {
        self.0.send(sync::Request::VerifyStartSas(verify)).ok();
    }

    pub fn verify_sas_confirm(&self, sas: SasVerification) {
        self.0.send(sync::Request::VerifySasConfirm(sas)).ok();
    }

    pub fn verify_start_qr(&self, verify: VerificationRequest) {
        self.0.send(sync::Request::VerifyStartQr(verify)).ok();
    }

    pub fn quit(&self) {
        self.0.send(sync::Request::Quit).ok();
    }
}