use super::*;
use std::{
    fmt::Write,
};

#[derive(Debug)]
pub struct Bar
{
    width: usize,
    max_width: usize,
    progress: f64,
    buffer: String,
    title: String,
}

/*
#[cfg(test)]
mod tests
{
    #[test]
    fn display()
    {
	
	let mut bar = Bar::new(50);
	bar.set_title("hello world");
	bar.progress = 0.455456749849;
	bar.update();
	bar.refresh();
	bar.progress = 0.8;
	bar.update();
	bar.refresh();
	bar.progress = 0.88;
	bar.update();
	bar.refresh();
	bar.set_title("almost AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA");
	bar.progress = 0.99554;
	bar.update();
	bar.refresh();

	println!("\nuhh");
	panic!("h");
    }
}*/

impl Bar
{
    /// Create a new bar `width` long with a title.
    pub fn with_title(width: usize, title: impl AsRef<str>) -> Self
    {
	let mut this = Self::new(width);
	this.set_title(title.as_ref());
	this
    }
    /// Create a new bar with max display width of our terminal
    pub fn new(width: usize) -> Self
    {
	if let Some((terminal_size::Width(tw), _)) = terminal_size::terminal_size() {
	    let tw = usize::from(tw);
	    Self::with_max(if width < tw {width} else {tw}, tw)
	} else {
	    Self::with_max(width, width +20)
	}
    }
    /// Create a bar with a max display width
    ///
    /// # Panics
    /// If `width` is larger than or equal to `max_width`.
    pub fn with_max(width: usize, max_width: usize) -> Self
    {
	Self {
	    width,
	    max_width,
	    progress: 0.0,
	    buffer: String::with_capacity(width),
	    title: String::with_capacity(max_width - width),
	}
    }

    /// Fit to terminal's width if possible.
    pub fn fit(&mut self) -> bool
    {
	
	if let Some((terminal_size::Width(tw), _)) = terminal_size::terminal_size() {
	    let tw = usize::from(tw);
	    self.width = if self.width < tw {self.width} else {tw};
	    self.update_dimensions(tw);
	    return true;
	}
	false
    }
    
    /// Update the buffer.
    pub fn update(&mut self)
    {
	self.buffer.clear();

	let pct = (self.progress * (self.width as f64)) as usize;
	for i in 0..self.width
	{
	    if i >= pct {
		write!(self.buffer, " ").unwrap();
	    } else {
		write!(self.buffer, "=").unwrap();
	    }
	}
    }

    /// Consume the bar and complete it, regardless of progress.
    pub fn complete(self)
    {
	println!("");
    }
}

fn ensure_eq(input: String, to: usize) -> String
{
    let  chars = input.chars();
    if chars.count() != to {
	let mut chars = input.chars();
	let mut output = String::with_capacity(to);
	for _ in 0..to
	{
	    if let Some(c) = chars.next() {
		write!(output, "{}", c).unwrap();
	    } else {
		write!(output, " ").unwrap();
	    }
	}
	output
    } else {
	input
    }
}


fn ensure_lower(input: String, to: usize) -> String
{
    let chars = input.chars();
    if chars.count() > to
    {
	let chars = input.chars();
	let mut output = String::with_capacity(to);
	for (i,c) in (0..).zip(chars)
	{
	    write!(output, "{}", c).unwrap();
	    if to>3 && i == to-3 {
		write!(output, "...").unwrap();
		break;
	    } else if i==to {
		break;
	    }
	}

	output
    } else {
	input
    }
}

impl Display for Bar
{
    fn refresh(&self)
    {
	let temp = format!("[{}]: {:.2}%", self.buffer, self.progress * 100.00);
	let title = ensure_lower(format!(" {}", self.title), self.max_width - temp.chars().count());

	let temp = ensure_eq(format!("{}{}", temp, title), self.max_width);
	print!("\x1B[0m\x1B[K{}", temp);
	print!("\n\x1B[1A");
    }

    fn blank(&self)
    {
	print!("\r{}\r", " ".repeat(self.max_width));
    }

    fn get_title(&self) -> &str
    {
	&self.title
    }

    fn set_title(&mut self, from: &str)
    {
	self.title = from.to_string();
    }

    fn update_dimensions(&mut self, to: usize)
    {
	self.max_width = to;
	self.refresh();
    }
}

impl ProgressBar for Bar
{
    fn get_progress(&self) -> f64
    {
	self.progress
    }
    fn set_progress(&mut self, value: f64)
    {
	if self.progress != value {
	    self.progress = value;
	    self.update();
	}
	self.refresh();
    }
}