use crate::app::AppState;
use crate::data::entities::DeckSettings;
use crate::data_provider::card_sets::{delete_set, update_deck};
use crate::data_provider::card_stats::{delete_stats, load_stats_of_deck};
use crate::navigation::Page::PreviousPage;
use crate::navigation::{NavigatedPage, Page, RootMessage};
use crate::notification::MaybeError;
use crate::pages::repetition_settings::RepetitionSettingsMessage::*;
use crate::styling::*;
use crate::{push_error, push_error_task};
use iced::widget::button::danger;
use iced::widget::text_input::Catalog;
use iced::widget::{button, column, row, scrollable, space, text, text_input};
use iced::{Element, Task};
use iced_core::Length::Fill;
use iced_core::{Padding, Theme, color};
use parking_lot::Mutex;
use std::sync::Arc;
use std::time::Duration;

pub struct RepetitionSettingsState {
    set: DeckSettings,
    index: usize,
    state: Arc<Mutex<AppState>>,
    real_delete: bool,
    correct_filter: bool,
    filter_changed: bool,
}

impl RepetitionSettingsState {
    pub(crate) fn new(index: usize, state: Arc<Mutex<AppState>>) -> RepetitionSettingsState {
        let set;
        {
            let local_state = state.lock();
            set = local_state.decks[index].clone();
        }
        let filter_state = set.check_filter();

        RepetitionSettingsState {
            index,
            set,
            state,
            real_delete: false,
            correct_filter: filter_state,
            filter_changed: false,
        }
    }
}

impl NavigatedPage<RepetitionSettingsMessage> for RepetitionSettingsState {
    fn navigate(&mut self, message: &RepetitionSettingsMessage) -> Option<Page> {
        if let Back = message {
            Some(PreviousPage)
        } else {
            None
        }
    }

    fn navigated(&mut self) {}
    fn update(&mut self, message: RepetitionSettingsMessage) -> Task<RootMessage> {
        match message {
            Back => {}
            Save => {
                let mut state = self.state.lock();
                if let Err(e) = update_deck(&mut self.set, &state.connection) {
                    return push_error_task!(e);
                }
                if self.filter_changed
                    && let Err(e) = update_deck_stats(&self.set, &state)
                {
                    return push_error_task!(e);
                }
                state.decks[self.index] = self.set.clone();
            }
            SetName(new) => {
                self.set.name = new;
            }
            SetForward(new) => {
                self.set.forward = new;
            }
            SetBackward(backward) => {
                self.set.backward = backward;
            }
            SetFilter(new) => {
                self.set.filter = new;
                self.correct_filter = self.set.check_filter();
                self.filter_changed = true;
            }
            TryFilter => {
                let state = self.state.lock();
                let count = self.set.get_word_list(&state).len();
                self.set.count = Some(count);
            }
            DeleteSet => {
                if !self.real_delete {
                    self.real_delete = true;
                    return Task::future(async {
                        tokio::time::sleep(Duration::from_millis(3000)).await;
                        RootMessage::RepetitionSettings(RevertDeleteSet)
                    });
                }
                let mut state = self.state.lock();
                if let Err(e) = delete_set(&self.set, &state.connection) {
                    return push_error_task!(e);
                }

                state.decks.remove(self.index);
                return Task::done(RootMessage::RepetitionSettings(Back));
            }
            RevertDeleteSet => self.real_delete = false,
        }
        Task::none()
    }

    fn view(&self) -> Element<'_, RepetitionSettingsMessage> {
        back_overlay(
            iced::widget::column![
                scrollable(
                    column![
                        column![
                            text!("Название набора"),
                            text_input("", &self.set.name).on_input(SetName),
                        ]
                        .spacing(QUARTER_SPACING),
                        column![
                            text!("Передняя сторона"),
                            text_input("", &self.set.forward).on_input(SetForward),
                        ]
                        .spacing(QUARTER_SPACING),
                        column![
                            text!("Задняя сторона"),
                            text_input("", &self.set.backward).on_input(SetBackward),
                        ]
                        .spacing(QUARTER_SPACING),
                        column![
                            text!("Фильтр"),
                            text_input("", &self.set.filter)
                                .style(|x, status| {
                                    let mut primary = Theme::default()(x, status);
                                    if !self.correct_filter {
                                        primary.border.color = color!(255, 255, 0);
                                    }
                                    primary
                                })
                                .on_input(SetFilter),
                            button("Проверить фильтр")
                                .style(jl_button)
                                .on_press(TryFilter),
                            self.count_view(&self.set),
                        ]
                        .spacing(QUARTER_SPACING),
                    ]
                    .spacing(DEFAULT_SPACING)
                    .padding(Padding {
                        top: 0.0,
                        right: DEFAULT_SPACING,
                        bottom: 0.0,
                        left: 0.0,
                    })
                )
                .height(Fill),
                row![
                    button("Сохранить").style(jl_button).on_press(Save),
                    button(if self.real_delete {
                        "Вы уверены?"
                    } else {
                        "Удалить"
                    })
                    .style(danger)
                    .on_press(DeleteSet),
                    space().width(Fill),
                ]
                .spacing(DEFAULT_SPACING),
            ]
            .spacing(DEFAULT_SPACING)
            .into(),
            Back,
        )
    }
}

fn update_deck_stats(deck: &DeckSettings, state: &AppState) -> MaybeError {
    let mut db_stats = load_stats_of_deck(deck, &state.connection).expect("Wrong db operation");
    let filtered_words = deck.get_word_list(state);
    filtered_words.iter().for_each(|word| {
        let word_id = state.dictionary[*word].id;
        if let Some(index) = db_stats.iter().position(|stat| stat.word_id == word_id) {
            db_stats.remove(index);
        }
    });

    delete_stats(db_stats.as_slice(), &state.connection)?;
    Ok(())
}

impl RepetitionSettingsState {
    fn count_view(&self, set: &DeckSettings) -> Element<'_, RepetitionSettingsMessage> {
        if let Some(count) = set.count {
            return text!("Количество слов: {}", count).into();
        }
        space().into()
    }
}

#[derive(Clone)]
pub enum RepetitionSettingsMessage {
    Back,
    Save,
    SetName(String),
    SetForward(String),
    SetBackward(String),
    SetFilter(String),
    TryFilter,
    DeleteSet,
    RevertDeleteSet,
}