use iced::{
    alignment,
    widget::{column, row, Container},
    Length,
};
use itertools::Itertools;
use schist_models::Bucket;

use crate::{
    gui::components::{
        navigation::{self, InsertOptionResult},
        BucketNavigationEntry, Navigation, Text,
    },
    style::SPACING_LG,
    traits::{Component, Viewable},
};

#[derive(Clone, Debug)]
pub struct BucketsView {
    greeting: String,
    navigation: Navigation<BucketNavigationEntry>,
}

#[derive(Clone, Debug)]
pub enum Message {
    NavigationMessage(navigation::Message<BucketNavigationEntry>),
    SelectNext,
    SelectPrev,
    SetBuckets(Vec<Bucket>),
    ExpandGroup(String, Vec<Bucket>),
    CollapseGroup(String),
}

pub enum Action {
    None,
}

impl BucketsView {
    pub fn new(groups: Vec<String>, greeting: &str) -> Self {
        Self {
            greeting: greeting.to_owned(),
            navigation: Navigation::new(
                groups
                    .first()
                    .map(String::as_str)
                    .map(BucketNavigationEntry::from_group_closed),
                groups
                    .iter()
                    .map(String::as_str)
                    .map(BucketNavigationEntry::from_group_closed)
                    .collect(),
            ),
        }
    }

    pub fn active_group(&self) -> Option<String> {
        self.navigation
            .active_option
            .as_ref()
            .map(|active_option| active_option.group())
    }

    fn update_greeting(&mut self, active_entry: &str) {
        self.greeting = format!("Hello, {}!", active_entry);
    }

    fn expand_group(&mut self, group: String, buckets: Vec<Bucket>) -> Action {
        match self.navigation.insert_after_first(
            |bucket_navigation_entry| {
                bucket_navigation_entry.is_group_and(|bucket_group_name| {
                    !bucket_group_name.is_open && bucket_group_name.group.eq(group.as_str())
                })
            },
            &buckets
                .iter()
                .map(BucketNavigationEntry::from_bucket)
                .collect(),
        ) {
            InsertOptionResult::InsertedOptions => {
                self.navigation.replace_first(
                    |bucket_navigation_entry| {
                        bucket_navigation_entry.is_group_and(|g| g.group.eq(group.as_str()))
                    },
                    &vec![BucketNavigationEntry::from_group_open(&group)],
                );
                Action::None
            }
            InsertOptionResult::NoSuchOption => Action::None,
        }
    }

    fn collapse_group(&mut self, group: String) -> Action {
        self.navigation
            .remove_options_where(|bucket_navigation_entry| {
                bucket_navigation_entry.is_bucket_and(|bucket| bucket.group.eq(&group))
            });
        self.navigation.replace_first(
            |bucket_navigation_entry| bucket_navigation_entry.is_group_and(|g| g.group.eq(&group)),
            &vec![BucketNavigationEntry::from_group_closed(&group)],
        );
        Action::None
    }
}

impl<'a> Viewable<'a, Message> for BucketsView {
    fn view(&'a self) -> iced::Element<'a, Message>
    where
        Message: 'a,
    {
        let navigation = self.navigation.view().map(Message::NavigationMessage);
        let main_content = column![Text::default(&self.greeting).as_element()];
        row![
            Container::new(navigation).width(Length::FillPortion(1)),
            Container::new(main_content).width(Length::FillPortion(3)),
        ]
        .align_y(alignment::Vertical::Center)
        .height(Length::Fill)
        .spacing(SPACING_LG)
        .into()
    }
}

impl<'a> Component<'a, Message, Action> for BucketsView {
    fn update(&mut self, message: Message) -> Action {
        match message {
            Message::SetBuckets(buckets) => {
                let groups: Vec<BucketNavigationEntry> = buckets
                    .iter()
                    .map(|bucket| bucket.group.as_str())
                    .unique()
                    .map(BucketNavigationEntry::from_group_closed)
                    .collect();
                match self
                    .navigation
                    .update(navigation::Message::SetOptions(groups))
                {
                    navigation::Action::ActivateOption(bucket_navigation_entry)
                    | navigation::Action::SelectOption(bucket_navigation_entry) => {
                        self.update_greeting(&bucket_navigation_entry.to_string());
                        Action::None
                    }
                    navigation::Action::None => Action::None,
                }
            }

            Message::NavigationMessage(message) => match self.navigation.update(message) {
                navigation::Action::ActivateOption(bucket_navigation_entry)
                | navigation::Action::SelectOption(bucket_navigation_entry) => {
                    self.update_greeting(&bucket_navigation_entry.to_string());
                    Action::None
                }
                navigation::Action::None => Action::None,
            },

            Message::SelectNext => match self.navigation.update(navigation::Message::SelectNext) {
                navigation::Action::ActivateOption(bucket_navigation_entry)
                | navigation::Action::SelectOption(bucket_navigation_entry) => {
                    self.update_greeting(&bucket_navigation_entry.to_string());
                    Action::None
                }
                navigation::Action::None => Action::None,
            },

            Message::SelectPrev => match self.navigation.update(navigation::Message::SelectPrev) {
                navigation::Action::ActivateOption(bucket_navigation_entry)
                | navigation::Action::SelectOption(bucket_navigation_entry) => {
                    self.update_greeting(&bucket_navigation_entry.to_string());
                    Action::None
                }
                navigation::Action::None => Action::None,
            },

            Message::ExpandGroup(group, buckets) => self.expand_group(group, buckets),

            Message::CollapseGroup(group) => self.collapse_group(group),
        }
    }
}