use crate::*;
use tek_tui::ratatui::{style::{Color, Style}, prelude::Stylize};
use pad::PadStr;
use std::fmt::Display;

pub struct Column<T> {
    title: Arc<str>,
    width: usize,
    value: Box<dyn Fn(&T)->Option<Arc<str>> + Send + Sync>,
}

impl<T> Column<T> {
    pub fn new (
        title: &impl AsRef<str>,
        width: usize,
        value: impl Fn(&T)->Option<Arc<str>> + Send + Sync + 'static
    ) -> Self {
        Self { width, value: Box::new(value), title: title.as_ref().into() }
    }
}

pub struct Columns<T>(pub Vec<Column<T>>);

impl Default for Columns<Entry> {
    fn default () -> Self {
        Self(vec![
            Column::new(&"HASH",    16, |entry: &Entry|entry.hash()),
            Column::new(&"FILE",    80, |entry: &Entry|entry.name()),
            Column::new(&"ARTIST",  30, |entry: &Entry|entry.artist()),
            Column::new(&"RELEASE", 30, |entry: &Entry|entry.album()),
            Column::new(&"TRACK",   5,  |entry: &Entry|entry.track()),
            Column::new(&"TITLE",   80, |entry: &Entry|entry.title()),
        ])
    }
}

impl<T> Columns<T> {
    pub fn header (&self) -> Arc<str> {
        let mut output = String::new();
        for Column { width, value, title } in self.0.iter() {
            let cell = title.pad_to_width(*width);
            output = format!("{output}{cell}│");
        }
        output.into()
    }
    pub fn row (&self, entry: &T) -> Arc<str> {
        let mut output = String::new();
        for Column { width, value, .. } in self.0.iter() {
            let cell = value(entry).unwrap_or_default().pad_to_width(*width);
            output = format!("{output}{cell}│");
        }
        output.into()
    }
}

impl Content<TuiOut> for Taggart {
    fn content (&self) -> impl Render<TuiOut> {
        let sizer    = Fill::xy(&self.size);
        let size     = format!("{}x{}", self.size.w(), self.size.h());
        let size_bar = status_bar(Align::e(size));
        let titlebar = status_bar(Align::w(self.columns.header()));
        Bsp::n(size_bar, Bsp::s(titlebar, Bsp::b(sizer, Fill::xy(TreeTable(self)))))
    }
}

struct TreeTable<'a>(&'a Taggart);

impl<'a> Content<TuiOut> for TreeTable<'a> {
    fn render (&self, to: &mut TuiOut) {
        let area = to.area();
        let Taggart { offset, paths, cursor, column, .. } = self.0;
        let mut x = 0;
        for (index, Column { width, .. }) in self.0.columns.0.iter().enumerate() {
            let w = *width as u16 + 1;
            if index == *column {
                to.fill_bg([area.x() + x, area.y(), w, area.h()], Color::Rgb(0, 0, 0));
                break
            } else {
                x += w;
            }
        }
        for (i, y) in area.iter_y().enumerate() {
            let i_offset = i + offset;
            let selected = *cursor == i_offset;
            if let Some(entry) = paths.get(i_offset) {
                for (index, fragment) in entry.path.iter().enumerate() {
                    if index == entry.depth - 1 {
                        let cursor = if selected { ">" } else { " " };
                        let label  = self.0.columns.row(&entry);
                        to.blit(&label, area.x(), y, entry.style());
                        if selected {
                            let fill = [area.x(), y, area.w(), 1];
                            to.fill_fg(fill, Color::Rgb(0, 0, 0));
                            to.fill_bg(fill, Color::Rgb(224, 192, 0));
                        }
                    }
                }
            } else {
                break
            }
        }
    }
}

impl Entry {
    pub fn name (&self) -> Option<Arc<str>> {
        let indent = "".pad_to_width((self.depth - 1) * 2);
        let icon   = self.icon();
        let name   = self.path.iter().last().expect("empty path").display();
        Some(format!("{indent}{icon} {name}").into())
    }
    fn icon (&self) -> &'static str {
        if self.is_dir() {
            "" //"+"
        } else if self.is_img() {
            ""
        } else if self.is_mus() {
            ""
        } else {
            " "
        }
    }
    fn style (&self) -> Option<Style> {
        if self.is_dir() {
            None
        } else {
            Some(Style::default().bold())
        }
    }
}

fn status_bar (content: impl Content<TuiOut>) -> impl Content<TuiOut> {
    Fixed::y(1, Fill::x(Tui::bold(true, Tui::fg_bg(Color::Rgb(0,0,0), Color::Rgb(255,255,255), content))))
}