use std::collections::HashMap;

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

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

#[derive(Clone, Debug)]
pub struct TransactionsView {
    navigation: Navigation<AccountNavigationEntry>,
    transactions_by_account_id: HashMap<i32, Vec<Transaction>>,
}

#[derive(Clone, Debug)]
pub enum Message {
    NavigationMessage(navigation::Message<AccountNavigationEntry>),
    SelectNextAccount,
    SelectPrevAccount,
    SetAccounts(Vec<Account>),
    SetTransactions(Vec<Transaction>),
}

pub enum Action {
    None,
}

impl TransactionsView {
    pub fn new(accounts: Vec<Account>, transactions: Vec<Transaction>) -> Self {
        let account_navigation_entries: Vec<AccountNavigationEntry> = accounts
            .into_iter()
            .map(AccountNavigationEntry::new)
            .collect();
        let navigation = Navigation::new(
            account_navigation_entries.first().cloned(),
            account_navigation_entries,
        );
        Self {
            navigation: navigation,
            transactions_by_account_id: transactions
                .into_iter()
                .into_group_map_by(|t| t.account_id),
        }
    }
}

impl<'a> Viewable<'a, Message> for TransactionsView {
    fn view(&'a self) -> Element<'a, Message> {
        let navigation = self.navigation.view().map(Message::NavigationMessage);
        let main_content = column![
            Text::default("Hello, transactions!").as_element(),
            Text::default(&format!(
                "{} transactions in this account.",
                self.navigation.active_option.clone().map_or(
                    0,
                    |AccountNavigationEntry { account, .. }| self
                        .transactions_by_account_id
                        .get(&account.id)
                        .map_or(0, |transactions| transactions.len())
                )
            ))
            .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 TransactionsView {
    fn update(&mut self, message: Message) -> Action {
        match message {
            Message::NavigationMessage(message) => {
                self.navigation.update(message);
                Action::None
            }

            Message::SetAccounts(accounts) => {
                let account_navigation_entries: Vec<AccountNavigationEntry> = accounts
                    .into_iter()
                    .map(AccountNavigationEntry::new)
                    .collect();
                self.navigation
                    .update(navigation::Message::SetOptions(account_navigation_entries));
                Action::None
            }

            Message::SetTransactions(transactions) => {
                self.transactions_by_account_id =
                    transactions.into_iter().into_group_map_by(|t| t.account_id);
                Action::None
            }

            Message::SelectNextAccount => {
                self.navigation.update(navigation::Message::SelectNext);
                Action::None
            }

            Message::SelectPrevAccount => {
                self.navigation.update(navigation::Message::SelectPrev);
                Action::None
            }
        }
    }
}