use crate::app::AppState;
use crate::data::entities::{EntityHandle, WordData, WordGroup};
use crate::data::repositories::{Query, Repository};
use crate::data::Id;
use crate::data_provider::word_groups::{WordGroupDataLayer, WordGroupRepositoryInner};
use crate::data_provider::words::WordDataLayer;
use crate::data_provider::words::WordRepositoryInner;
use crate::navigation::Page::Import;
use crate::navigation::{KeyPressedPage, NavigatedPage, Page, RootMessage};
use crate::pages::dictionary::BasicWordFields::*;
use crate::pages::dictionary::DictionaryMessage::*;
use crate::pages::dictionary::SelectionChangeDirection::*;
use crate::pages::dictionary_quiz::DictionaryQuizState;
use crate::pages::import::ImportState;
use crate::pages::word::{WordEditor, WordMessage};
use crate::push_error_task;
use crate::styling::*;
use crate::widgets::hard_mouse_area::hard_mouse_area;
use crate::{jl_button, push_error};
use chrono::{DateTime, TimeDelta, Utc};
use hashbrown::{HashMap, HashSet};
use iced::alignment::Vertical::Center;
use iced::widget::button::Style;
use iced::widget::button::{danger, text};
use iced::widget::operation::focus;
use iced::widget::space::horizontal;
use iced::widget::text_input::default;
use iced::widget::text_input::Status::Active;
use iced::widget::*;
use iced::{Border, Color, Shadow, Task};
use iced_core::keyboard;
use iced_core::keyboard::key::Physical::Code;
use iced_core::keyboard::{Event, Modifiers};
use iced_core::keyboard::Key::Named;
use iced_core::Length::{Fill, FillPortion};
use log::info;
use rand::random_range;
use std::ops::Add;
use std::sync::Arc;
use std::time::{Duration, Instant};

pub struct DictionaryState {
    state: AppState,
    included: HashSet<EntityHandle<WordData>>,
    tag_map: HashMap<String, bool>,
    words_tags: Vec<(EntityHandle<WordData>, Vec<String>)>,
    reverse: bool,
    search: String,
    no_typing: bool,
    selected_group: EntityHandle<WordGroup>,
    reverse_list: bool,
    auto_save_queue: HashMap<EntityHandle<WordData>, DateTime<Utc>>,
    displayed_words_query: Query<WordData, WordRepositoryInner, WordDataLayer>,
    groups_query: Query<WordGroup, WordGroupRepositoryInner, WordGroupDataLayer>,
    selected_cell: Option<(EntityHandle<WordData>, BasicWordFields, usize)>,
    word_editor: Option<WordEditor<DictionaryMessage>>,
}

#[derive(Clone)]
pub enum DictionaryMessage {
    Back,
    ExtendedEdit(EntityHandle<WordData>),
    DeleteWord(EntityHandle<WordData>),
    NewWord,
    Include(EntityHandle<WordData>, bool),
    IncludeTag(String, bool),
    GotoTest,
    ResetTags,
    SetReverse(bool),
    Search(String),
    SetTyping(bool),
    CreateGroup,
    EditGroup(String),
    SaveGroup,
    SelectGroup(EntityHandle<WordGroup>),
    DeleteGroup,
    ChangeDirection,
    TrySave(EntityHandle<WordData>),
    GotoImport,
    SelectField(EntityHandle<WordData>, BasicWordFields, usize),
    EditField(String),
    ChangeSelectedField(SelectionChangeDirection),
    EditorAction(WordMessage),
    ExtendedWordEdited
}

#[derive(Clone, PartialEq, Eq, Hash, Copy)]
pub enum SelectionChangeDirection {
    Next,
    Previous,
    Forward,
    Backward,
}

#[derive(Clone, PartialEq, Eq, Hash, Copy)]
pub enum BasicWordFields {
    Key,
    Value,
    Tags,
}

const FIELDS: &[BasicWordFields] = &[Key, Value, Tags];

impl NavigatedPage<DictionaryMessage> for DictionaryState {
    fn navigate(&mut self, message: &DictionaryMessage) -> Option<Page> {
        if let Back = message {
            return Some(Page::PreviousPage);
        }
        if let GotoTest = message
            && !self.included.is_empty()
        {
            let mut words = vec![];
            let dict = &self.state.dictionary.read();

            let query = dict.query(Arc::new(|_| true));
            let handles = query.handles();
            words = handles.filter(|h| self.included.contains(h)).collect();

            return Some(Page::DictionaryQuiz(DictionaryQuizState::new(
                words,
                self.reverse,
                self.no_typing,
                self.state.clone(),
            )));
        }

        if let GotoImport = message {
            return Some(Import(ImportState::new(self.state.clone())));
        }
        None
    }

    fn navigated(&mut self) {
        self.included = Default::default();
        self.tag_map = Default::default();
        let groups = self.state.word_groups.read();
        self.groups_query.load(&groups);
        drop(groups);
        self.update_tags();
    }

    fn update(&mut self, message: DictionaryMessage) -> Task<RootMessage> {
        match message {
            NewWord => {
                let mut dictionary = self.state.dictionary.write();
                let mut word = WordData::new();
                word.group_id = self.selected_group.id;
                dictionary.create(word);
                self.displayed_words_query.load(&dictionary);
            }
            ExtendedEdit(i) => {
                self.word_editor = Some(self.editor_for_word(i));
                if let Some((handle, cell, index)) = self.selected_cell.clone() {
                    self.selected_cell = Some((i, cell, index))
                }
            }
            Include(i, b) => {
                if b {
                    self.included.insert(i);
                } else {
                    self.included.remove(&i);
                }
            }
            IncludeTag(t, v) => {
                self.tag_map.insert(t, v);
                self.update_words_include(self.selected_group.id)
            }

            ResetTags => {
                self.tag_map.iter_mut().for_each(|(_, v)| *v = false);
                self.included.clear();
            }
            SetReverse(v) => self.reverse = v,
            Search(s) => {
                self.search = s;
            }
            SetTyping(b) => self.no_typing = b,
            Back => {}
            GotoTest => {}
            CreateGroup => {
                let mut groups = self.state.word_groups.write();
                groups.create(WordGroup {
                    id: 0.into(),
                    name: format!("Группа слов {}", random_range(100..1000)),
                });
                self.groups_query.load(&groups);
            }
            EditGroup(new) => {
                let mut groups = self.state.word_groups.write();

                let group = groups.get_mut(&mut self.selected_group);
                if let Some(group) = group {
                    group.name = new;
                }
            }
            SaveGroup => {
                {
                    let mut groups = self.state.word_groups.write();

                    if let Err(err) = groups.save(&mut self.selected_group) {
                        return push_error_task!(err);
                    }

                    self.groups_query.load(&groups);
                }

                self.setup_words_query();
            }
            SelectGroup(i) => {
                self.selected_group = i;
                self.setup_words_query();
                self.update_words_include(i.id)
            }
            DeleteGroup => {
                if self.selected_group.id.0 == 1 {
                    return Task::none();
                }
                {
                    let delete_group = self.selected_group;
                    self.selected_group = EntityHandle::from_id(1.into());
                    self.setup_words_query();
                    let mut groups = self.state.word_groups.write();

                    if let Err(err) = groups.delete(delete_group) {
                        return push_error_task!(err);
                    }

                    if let Err(err) = self.state.dictionary.write().reload() {
                        return push_error_task!(err);
                    }
                    self.groups_query.load(&groups);
                }

                self.update_tags()
            }
            ChangeDirection => {
                self.reverse_list = !self.reverse_list;
            }
            TrySave(mut handle) => {
                let original = handle;
                let now = Utc::now();
                if !self.auto_save_queue.contains_key(&handle) {
                    return Task::none();
                }
                if self.auto_save_queue[&handle] <= now {
                    self.update_tags();
                    self.auto_save_queue.remove(&handle);

                    let mut dictionary = self.state.dictionary.write();

                    let reload_query = !handle.real();
                    let _ = dictionary.save(&mut handle);
                    if reload_query {
                        self.displayed_words_query.load(&dictionary);
                        if let Some(selected) = self.selected_cell && selected.0 == original {
                            self.selected_cell = Some((handle, selected.1, selected.2));
                            if self.word_editor.is_some() {
                                self.word_editor = Some(self.editor_for_word(handle));
                            }
                        }
                    }
                    info!("Saved word");
                    return Task::none();
                }
            }
            GotoImport => {}
            SelectField(e, f, index) => {
                info!("Editing word {}", e.id);
                if self.word_editor.is_some() && let Some(selected) = &self.selected_cell && selected.0 != e {
                    self.word_editor = Some(self.editor_for_word(e));
                }
                self.selected_cell = Some((e, f, index));

                return focus(iced::widget::Id::new("editor"));
            }
            EditField(value) => {
                if let Some(selected) = self.selected_cell.as_ref() {
                    {
                        let mut dictionary = self.state.dictionary.write();
                        let word = dictionary.get_mut_static(selected.0).unwrap();
                        match selected.1 {
                            Key => {
                                word.key = value;
                            }
                            Value => {
                                word.value = value;
                            }
                            Tags => {
                                word.tags = value;
                            }
                        }
                    }

                    return self.launch_auto_save_offset(selected.0);
                }
            }
            ChangeSelectedField(change) => {
                return if let Some(selected) = self.selected_cell {
                    let update_vertical = move |mut dir: bool| {
                        if self.reverse_list {
                            dir = !dir;
                        }
                        let new_index = if dir {
                            selected.2.saturating_add(1)
                        } else {
                            selected.2.saturating_sub(1)
                        };
                        if new_index < self.displayed_words_query.len() {
                            return SelectField(
                                self.displayed_words_query.get(new_index).unwrap(),
                                selected.1,
                                new_index,
                            );
                        }

                        SelectField(selected.0, selected.1, selected.2)
                    };

                    let update_horizontal = move |dir: bool| {
                        let current = selected.1;
                        let delta = if dir { 1 } else { -1 };
                        let mut index =
                            FIELDS.iter().position(|&f| f == current).unwrap() as i8 + delta;
                        if index < 0 {
                            index = (FIELDS.len() - 1) as i8;
                        }
                        if index >= FIELDS.len() as i8 {
                            index = 0;
                        }
                        SelectField(selected.0, FIELDS[index as usize], selected.2)
                    };

                    Task::done(RootMessage::Dictionary(match change {
                        Next => update_vertical(true),
                        Previous => update_vertical(false),
                        Forward => update_horizontal(true),
                        Backward => update_horizontal(false),
                    }))
                } else {
                    Task::none()
                };
            }
            DeleteWord(i) => {
                let mut dictionary = self.state.dictionary.write();

                if let Err(err) = dictionary.delete(i) {
                    return push_error_task!(err);
                }

                self.displayed_words_query.load(&dictionary);
                   self.selected_cell = None;
                   self.word_editor = None;

            }
            EditorAction(action) => {
                let result = self.word_editor.as_mut().unwrap().update(action);
                if let Some(result) = result {
                    match result {
                        DeleteWord(_) |
                            ExtendedWordEdited => {
                            return Task::done(RootMessage::Dictionary(result));
                        },

                        _ => {}
                    }
                }
            }
            ExtendedWordEdited => {
                return self.launch_auto_save_offset(self.selected_cell.unwrap().0);
            }
        }

        Task::none()
    }

    fn view(&self) -> iced::Element<'_, DictionaryMessage> {
        back_overlay(
            row![
                iced::widget::column![
                    self.groups_panel(),
                    row![horizontal().width(8), self.words_list(),],
                    self.selection_editor(),
                    row![
                        self.add_word_button(),
                        horizontal().width(Fill),
                        button("Импорт").style(text).on_press(GotoImport),
                    ]
                ]
                .spacing(5).width(FillPortion(4)),
                self.right_panel(),
            ]
            .spacing(DEFAULT_SPACING)
            .into(),
            Back,
        )
    }
}

impl DictionaryState {
    pub fn new(state: AppState) -> Self {
        let words_query = state.dictionary.read().empty_query_par();
        let groups_query = state.word_groups.read().query(Arc::new(|_| true));
        let mut result = DictionaryState {
            included: Default::default(),
            selected_group: EntityHandle::new(Id(1), 0, true),
            state,
            tag_map: HashMap::new(),
            words_tags: vec![],
            reverse: false,
            search: "".to_string(),
            no_typing: true,
            reverse_list: true,
            auto_save_queue: HashMap::new(),
            displayed_words_query: words_query,
            groups_query,
            selected_cell: None,
            word_editor: None,
        };

        result.init();
        result.update_tags();

        result
    }

    fn editor_for_word(&self, handle: EntityHandle<WordData>) -> WordEditor<DictionaryMessage> {
        WordEditor::new(handle, self.state.clone()).on_delete(DeleteWord(handle)).on_edit(ExtendedWordEdited)
    }

    fn init(&mut self) {
        self.displayed_words_query = self
            .state
            .dictionary
            .read()
            .query(Arc::new(|word| word.group_id == Id(1)));
    }

    fn setup_words_query(&mut self) {
        let id = self.selected_group.id;
        self.displayed_words_query = self
            .state
            .dictionary
            .read()
            .query(Arc::new(move |word| word.group_id == id));
    }

    fn launch_auto_save_offset(&mut self, handle: EntityHandle<WordData>) -> Task<RootMessage> {
        let save_time = Utc::now().add(TimeDelta::milliseconds(500));
        self.auto_save_queue.insert(handle, save_time);
        let message = RootMessage::Dictionary(TrySave(handle));
        Task::perform(
            async { tokio::time::sleep(Duration::from_millis(520)).await },
            |_| message,
        )
    }

    fn words_list(&self) -> iced::Element<'_, DictionaryMessage> {
        let time = Instant::now();
        let mut col = Column::new().width(Fill);

        let query = &self.displayed_words_query;
        let dictionary = self.state.dictionary.read();

        for access_index in 0..query.len() {
            let mut i = access_index;
            if self.reverse_list {
                i = query.len() - access_index - 1;
            }
            let word_handle = &query[i];
            let word = dictionary.get_ref_static(*word_handle).unwrap();

            if !self.search.is_empty()
                && !word.key.contains(&self.search)
                && !word.value.contains(&self.search)
                && !word.tags.contains(&self.search)
            {
                continue;
            }

            let mut selection = None;

            if let Some(cell) = self.selected_cell.as_ref()
                && cell.0 == *word_handle
            {
                selection = Some(cell.1);
            }

            let word_line_data = WordLineState {
                is_included: self.included.contains(word_handle),
                key: word.key.clone().into(),
                value: word.value.clone().into(),
                tags: word.tags.clone().into(),
                handle: *word_handle,
                selection,
                number: i,
            };

            let lazy_line = lazy(word_line_data, Self::word_line);

            col = col.push(lazy_line);
        }

        info!("Words rendering time: {:?}", time.elapsed());
        scrollable(col).height(Fill).into()
    }

    fn word_line<'a>(data: &WordLineState) -> Row<'a, DictionaryMessage> {
        let mut line = Row::new().width(Fill).align_y(Center);
        let handle = data.handle;
        line = line.push(
            checkbox(data.is_included)
                .label("")
                .spacing(15)
                .on_toggle(move |b| Include(handle, b)),
        );

        let field = |placeholder: &str, data: &str, selected: bool| {
            text_input(placeholder, data)
                .size(ACCENT_FONT_SIZE)
                .width(Fill)
                .style(move |x, _| {
                    let mut default_style = default(x, Active);
                    default_style.border.radius = 0.0.into();
                    if selected {
                        default_style.border.color = x.extended_palette().secondary.base.color;
                        default_style.border.width = 3.0_f32;
                    }
                    default_style
                })
        };

        line = line.push(
            hard_mouse_area(field(
                "Слово",
                &data.key,
                data.selection.is_some() && data.selection.unwrap() == Key,
            ))
            .on_press(SelectField(data.handle, Key, data.number)),
        );
        line = line.push(
            hard_mouse_area(field(
                "Перевод",
                &data.value,
                data.selection.is_some() && data.selection.unwrap() == Value,
            ))
            .on_press(SelectField(data.handle, Value, data.number)),
        );

        line = line.push(
            hard_mouse_area(field(
                "Теги",
                &data.tags,
                data.selection.is_some() && data.selection.unwrap() == Tags,
            ))
            .on_press(SelectField(data.handle, Tags, data.number)),
        );

        let line_button = || {
            if !data.handle.real() {
                return button("-")
                    .on_press(DeleteWord(data.handle))
                    .style(|_x: &Theme, _status: button::Status| Style {
                        background: None,
                        text_color: Color::BLACK,
                        border: Border::default(),
                        shadow: Shadow::default(),
                        snap: false,
                    })
                    .width(15);
            }

            button("")
                .on_press(ExtendedEdit(data.handle))
                .style(button::primary)
                .width(15)
        };
        line.push(line_button()).push(space().width(10))
    }

    fn right_panel(&self) -> iced::Element<'_, DictionaryMessage> {
        if let Some(editor) = &self.word_editor {
            container(editor.view().map(EditorAction)).width(FillPortion(3)).into()
        } else {
            self.filters()
        }
    }

    fn filters(&self) -> iced::Element<'_, DictionaryMessage> {
        let dict = &self.state.dictionary.read();

        iced::widget::column![
            text_input("Поиск", &self.search)
                .on_input(Search)
                .width(Fill),
            text!("Всего слов: {}", dict.len()),
            text!("Выбрано слов: {}", self.included.iter().count()),
            self.tags_selector(),
            toggler(self.no_typing)
                .label("Без набора")
                .on_toggle(SetTyping),
            toggler(self.reverse)
                .label("Обратный тест")
                .on_toggle(SetReverse),
            button(text!("Тест").center().width(Fill))
                .style(cta_button)
                .on_press(GotoTest)
                .width(Fill),
        ]
        .width(FillPortion(1))
        .spacing(DEFAULT_SPACING)
        .into()
    }

    fn tags_selector(&self) -> iced::Element<'_, DictionaryMessage> {
        let mut col = Column::new().width(Fill);
        col = col.push(
            button("Сбросить")
                .on_press(ResetTags)
                .style(|x: &Theme, _status| Style {
                    background: None,
                    text_color: x.palette().primary,
                    border: Border::default(),
                    shadow: Shadow::default(),
                    snap: false,
                }),
        );
        let mut sorted_tags = self.tag_map.iter().collect::<Vec<_>>();
        sorted_tags.sort();
        for tag in sorted_tags {
            col = col.push(
                checkbox(*tag.1)
                    .label(tag.0)
                    .on_toggle(|x1| IncludeTag(tag.0.clone(), x1)),
            )
        }

        container(scrollable(col)).height(Fill).into()
    }

    fn update_tags(&mut self) {
        self.words_tags.clear();
        let mut tags_list: HashSet<String> = HashSet::new();
        let dict = &self.state.dictionary.write();
        let mut words_query = dict.full_query();
        let handles = words_query.handles().collect::<Vec<_>>();
        words_query
            .iter(dict)
            .zip(handles)
            .for_each(|(element, handle)| {
                let tags = split_with_coma(element.tags.as_str());
                tags.iter().for_each(|tag| {
                    tags_list.insert(tag.clone());
                });
                self.words_tags.push((handle, tags))
            });

        let current_tags = self
            .tag_map
            .keys()
            .map(|k| k.clone().to_string())
            .collect::<Vec<String>>();

        current_tags
            .iter()
            .filter(|tag| !tags_list.contains(*tag))
            .for_each(|tag| {
                self.tag_map.remove(tag);
            });

        tags_list.iter().for_each(|tag| {
            self.tag_map.insert(tag.clone(), false);
        });
    }

    fn update_words_include(&mut self, group_id: Id) {
        let include_tags = self
            .tag_map
            .iter()
            .filter(|(_, value)| **value)
            .map(|(t, _)| t.clone())
            .collect::<Vec<String>>();

        if include_tags.is_empty() {
            self.included.clear();
            return;
        }

        let dict = &self.state.dictionary.read();
        let time = Instant::now();

        self.included.clear();
        for (handle, tags) in &mut self.words_tags {
            if let Some(word) = dict.get_ref(handle) {
                if word.group_id != group_id {
                    continue;
                }

                if !tags.is_empty() && tags.iter().all(|t| include_tags.contains(t)) {
                    self.included.insert(*handle);
                }
            } else {
                continue;
            }
        }

        info!("Time {}", time.elapsed().as_micros());
    }

    fn selection_editor(&self) -> iced::Element<'_, DictionaryMessage> {
        let mut display = "".to_string();
        if let Some(selected) = self.selected_cell.as_ref() {
            let mut dictionary = self.state.dictionary.write();
            let word = dictionary.get_mut_static(selected.0).unwrap();

            match selected.1 {
                Key => {
                    display = word.key.clone();
                }
                Value => {
                    display = word.value.clone();
                }
                Tags => {
                    display = word.tags.clone();
                }
            }
        }
        text_input("", display.as_str())
            .width(Fill)
            .id(iced::widget::Id::new("editor"))
            .on_input(EditField)
            .into()
    }

    fn groups_panel(&self) -> iced::Element<'_, DictionaryMessage> {
        let mut row = Row::new();
        row = row.push(button("+").style(text).on_press(CreateGroup));

        let groups = &self.state.word_groups.read();

        for mut group in self.groups_query.handles() {
            let group_name = groups.get(&mut group).unwrap().name.clone();
            row = row.push(
                button(text!("{}", group_name))
                    .style(text)
                    .on_press(SelectGroup(group)),
            );
        }

        let groups = self.state.word_groups.read();
        let group = groups.get_static(self.selected_group).unwrap();

        iced::widget::column![
            scrollable(row).width(Fill).horizontal(),
            row![
                jl_button!("⇳").on_press(ChangeDirection),
                text_input("Название группы слов", &group.name)
                    .on_input(EditGroup)
                    .width(250)
                    .on_submit(SaveGroup),
                horizontal(),
                self.group_delete_button(),
            ]
            .spacing(DEFAULT_SPACING / 2.0)
        ]
        .into()
    }

    fn group_delete_button(&self) -> iced::Element<'_, DictionaryMessage> {
        if self.selected_group.real() && self.selected_group.id != 1.into() {
            button("Удалить").style(danger).on_press(DeleteGroup).into()
        } else {
            space().into()
        }
    }

    fn add_word_button(&self) -> iced::Element<'_, DictionaryMessage> {
        let button = jl_button!("Добавить слово");

        if self.selected_group.real() {
            return button.on_press(NewWord).into();
        }

        button.into()
    }
}

impl KeyPressedPage for DictionaryState {
    fn press(&mut self, message: &Event) -> Task<RootMessage> {
        if let Event::KeyPressed {
            key: _,
            modified_key: modifier,
            physical_key: pk,
            location: _,
            modifiers: mods,
            text: _,
            repeat: _,
        } = message
            && let Code(code) = pk
        {
            return match code {
                keyboard::key::Code::ArrowDown => {
                    Task::done(RootMessage::Dictionary(ChangeSelectedField(Next)))
                }
                keyboard::key::Code::ArrowUp => {
                    Task::done(RootMessage::Dictionary(ChangeSelectedField(Previous)))
                }
                keyboard::key::Code::Tab => {
                    return if *mods == Modifiers::CTRL && let Some(selected) = self.selected_cell {
                        Task::done(RootMessage::Dictionary(ExtendedEdit(selected.0)))
                    } else if let Named(keyboard::key::Named::Alt) = modifier {
                        Task::done(RootMessage::Dictionary(ChangeSelectedField(Backward)))
                    } else {
                        Task::done(RootMessage::Dictionary(ChangeSelectedField(Forward)))
                    }
                }
                keyboard::key::Code::Escape => {
                    if self.word_editor.is_some() {
                        self.word_editor = None;
                    }else if self.selected_cell.is_some() {
                        self.selected_cell = None;
                    }

                    Task::none()
                }
                _ => Task::none(),
            };
        }

        Task::none()
    }
}

pub fn split_with_coma(ts: &str) -> Vec<String> {
    ts.split(',')
        .map(|ts| ts.to_lowercase().trim().to_string())
        .filter(|t| !t.is_empty())
        .collect::<Vec<String>>()
}

#[derive(Clone, Hash, PartialEq, Eq)]
struct WordLineState {
    is_included: bool,
    key: String,
    value: String,
    tags: String,
    handle: EntityHandle<WordData>,
    selection: Option<BasicWordFields>,
    number: usize,
}