// This file is part of Germ <https://github.com/gemrest/sydney>.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Copyright (C) 2022-2022 Fuwn <contact@fuwn.me>
// SPDX-License-Identifier: GPL-3.0-only

use tui::{
  layout::{Constraint, Direction, Layout, Rect},
  style::{Color, Style},
  widgets,
  widgets::{ListItem, Paragraph},
};

pub fn ui<B: tui::backend::Backend>(
  f: &mut tui::Frame<'_, B>,
  app: &mut crate::App,
) {
  let chunks = Layout::default()
    .direction(Direction::Vertical)
    .constraints(
      [
        Constraint::Percentage(95),
        Constraint::Percentage(4),
        Constraint::Percentage(1),
      ]
      .as_ref(),
    )
    .split(f.size());

  let items: Vec<ListItem<'_>> = app
    .items
    .items
    .iter()
    .map(|(text_lines, _link)| {
      let mut spans = vec![];

      for line in text_lines {
        spans.push(tui::text::Spans::from(line.as_str()));
      }

      ListItem::new(spans)
    })
    .collect();

  let items = widgets::List::new(items).highlight_style(
    Style::default()
      .bg(Color::White)
      .fg(Color::Black)
      .add_modifier(tui::style::Modifier::BOLD),
  );

  f.render_stateful_widget(items, chunks[0], &mut app.items.state);
  f.render_widget(
    Paragraph::new(app.url.to_string())
      .style(Style::default().bg(Color::White).fg(Color::Black)),
    chunks[1],
  );

  if let Some(error) = app.error.as_ref() {
    f.render_widget(
      Paragraph::new(&**error).style(Style::default().bg(Color::Red)),
      chunks[2],
    );
  } else if !app.input.is_empty()
    || app.input_mode == crate::input::Mode::Editing
  {
    f.render_widget(Paragraph::new(format!(":{}", app.input)), chunks[2]);
  }

  if app.accept_response_input {
    let block = widgets::Block::default()
      .title(app.url.to_string())
      .borders(widgets::Borders::ALL);
    let area = centered_rect(60, 20, f.size());

    f.render_widget(widgets::Clear, area);
    f.render_widget(block.clone(), area);
    f.render_widget(
      Paragraph::new(format!(
        "{} {}",
        app.response_input_text.trim(),
        app.response_input
      ))
      .wrap(widgets::Wrap {
        trim: false
      }),
      block.inner(area),
    );
  }

  if let Some(error) = &app.error {
    let block = widgets::Block::default()
      .title("Sydney")
      .borders(widgets::Borders::ALL)
      .style(Style::default().bg(Color::Cyan));
    let area = centered_rect(60, 20, f.size());

    f.render_widget(widgets::Clear, area);
    f.render_widget(block.clone(), area);
    f.render_widget(
      Paragraph::new(error.to_string()).wrap(widgets::Wrap {
        trim: false
      }),
      block.inner(area),
    );
  }
}

fn centered_rect(percent_x: u16, percent_y: u16, r: Rect) -> Rect {
  let popup_layout = Layout::default()
    .direction(Direction::Vertical)
    .constraints(
      [
        Constraint::Percentage((100 - percent_y) / 2),
        Constraint::Percentage(percent_y),
        Constraint::Percentage((100 - percent_y) / 2),
      ]
      .as_ref(),
    )
    .split(r);

  Layout::default()
    .direction(Direction::Horizontal)
    .constraints(
      [
        Constraint::Percentage((100 - percent_x) / 2),
        Constraint::Percentage(percent_x),
        Constraint::Percentage((100 - percent_x) / 2),
      ]
      .as_ref(),
    )
    .split(popup_layout[1])[1]
}