use crate::app::Message;
use crate::app::Element;

use iced::widget::text_input::{self, TextInput};
use iced::widget::scrollable::{self, Scrollable};

#[derive(Clone, Debug)]
pub struct Lyrics {
	lines: Vec<Lyric>,
	scroll_state: scrollable::State,
}

impl Lyrics {
	pub fn new() -> Self {
		Lyrics {
			lines: vec![Lyric::new()],
			scroll_state: scrollable::State::new()
		}
	}

	pub fn update_line(&mut self, new_content: String, line_no: usize) {
		self.lines[line_no].set_content(new_content);
	}

	pub fn advance_line(&mut self, current_line: usize) {
		let new_line = current_line + 1;

		if new_line == self.lines.len() {
			self.lines.push(Lyric::new())
		}

		self.lines.get_mut(new_line)
			.expect("Unexpected .advance_line with index beyond # of lines")
			.select();
		self.lines.get_mut(current_line)
			.unwrap()
			.deselect();
	}

	pub fn view(&mut self) -> Element<Message> {
		self.lines.iter_mut()
			.enumerate()
			.map(|(i, l)| l.view(i))
			.fold(Scrollable::new(&mut self.scroll_state), |s, l| s.push(l))
			.into()
	}
}

#[derive(Clone, Debug)]
pub struct Lyric {
	state: text_input::State,
	value: String,
}

impl Lyric {
	pub fn new() -> Self {
		Lyric {
			state: text_input::State::new(),
			value: String::with_capacity(70),
		}
	}

	pub fn view(&mut self, line_no: usize) -> Element<Message> {
		TextInput::new(
			&mut self.state,
			"",
			&self.value,
			move|new_value| Message::LyricChanged { line_no, new_value },
		)
			.on_submit(Message::LineAdvanced(line_no))
			.into()
	}

	pub fn set_content(&mut self, content: String) {
		self.value = content;
	}

	pub fn select(&mut self) {
		self.state.focus();
	}

	pub fn deselect(&mut self) {
		self.state.unfocus();
	}
}