use crate::tui::component::{Action, Component, ComponentState};
use ratatui::buffer::Buffer;
use ratatui::crossterm::event::{KeyCode, KeyEvent};
use ratatui::layout::Rect;
use ratatui::style::{Color, Style};
use ratatui::text::Line;
use ratatui::widgets::{Block, Borders, Tabs, Widget};
use strum::{EnumIter, FromRepr, IntoEnumIterator};

#[derive(Debug, Clone, Copy, PartialEq, Eq, FromRepr, EnumIter)]
enum TitleBarItem {
    File,
    Edit,
    View,
    Help,
}

impl TitleBarItem {
    pub fn next(mut self) -> Self {
        let cur = self as usize;
        let next = cur.saturating_add(1);
        Self::from_repr(next).unwrap_or(self)
    }

    pub fn prev(self) -> Self {
        let cur = self as usize;
        let prev = cur.saturating_sub(1);
        Self::from_repr(prev).unwrap_or(self)
    }

    pub fn id(&self) -> &str {
        match self {
            TitleBarItem::File => "File",
            TitleBarItem::Edit => "Edit",
            TitleBarItem::View => "View",
            TitleBarItem::Help => "Help",
        }
    }
}

pub struct TitleBar {
    selected: TitleBarItem,
    opened: Option<TitleBarItem>,
    pub(crate) component_state: ComponentState,
}

impl TitleBar {
    pub fn new() -> Self {
        Self {
            selected: TitleBarItem::File,
            opened: None,
            component_state: ComponentState::default()
                .with_help_text(concat!("TODO: Title bar help text.").as_ref()),
        }
    }

    fn render_title_bar(&self, area: Rect, buf: &mut Buffer) {
        let titles: Vec<Line> = TitleBarItem::iter()
            .map(|item| Line::from(item.id().to_owned()))
            .collect();
        let tabs_style = Style::default();
        let highlight_style = if self.opened.is_some() {
            Style::default().bg(Color::Blue).fg(Color::White)
        } else {
            Style::default().bg(Color::Cyan).fg(Color::Black)
        };
        Tabs::new(titles)
            .style(tabs_style)
            .block(Block::default().borders(Borders::ALL))
            .highlight_style(highlight_style)
            .select(self.selected as usize)
            .render(area, buf);
    }
}

impl Widget for &TitleBar {
    fn render(self, area: Rect, buf: &mut Buffer)
    where
        Self: Sized,
    {
        let title_bar_area = Rect {
            x: area.x,
            y: area.y,
            width: area.width,
            height: 3,
        };
        self.render_title_bar(title_bar_area, buf);
    }
}

impl Component for TitleBar {
    fn handle_key_events(&mut self, key: KeyEvent) -> anyhow::Result<Action> {
        match key.code {
            // KeyCode::Up | KeyCode::Char('k') => self.selected.key_up(),
            // KeyCode::Down | KeyCode::Char('j') => self.selected.key_down(),
            KeyCode::Left | KeyCode::Char('h') => {
                self.selected = self.selected.prev();
                Ok(Action::Handled)
            }
            KeyCode::Right | KeyCode::Char('l') => {
                self.selected = self.selected.next();
                Ok(Action::Handled)
            }
            KeyCode::Enter => {
                self.opened = Some(self.selected);
                Ok(Action::Handled)
            }
            _ => Ok(Action::Noop),
        }
    }
}