use std::result::Result;

use syntect::html::{ClassedHTMLGenerator, ClassStyle, css_for_theme_with_class_style};
use syntect::parsing::SyntaxSet;
use syntect::highlighting::ThemeSet;
use syntect::util::LinesWithEndings;

pub fn highlight(syntax_name: &str, source: &str) -> Result<String, String> {
    let syntax_set = SyntaxSet::load_defaults_newlines();
    let syntax = syntax_set.find_syntax_by_token(syntax_name)
        .ok_or(format!("couldn't find syntax {}", syntax_name))?;
    let mut html_generator =
        ClassedHTMLGenerator::new_with_class_style(&syntax, &syntax_set, ClassStyle::Spaced);
    for line in LinesWithEndings::from(source) {
        html_generator.parse_html_for_line_which_includes_newline(&line);
    }

    let result = html_generator.finalize();
    Ok(format!("<pre class=\"code\">{}</pre>", result))
}

// const ONEDARK_THEME: &'static str = include_str!("../assets/One_Dark.tmTheme");

pub fn get_css() -> String {
    // let mut reader = std::io::Cursor::new(ONEDARK_THEME);
    // let theme = ThemeSet::load_from_reader(&mut reader).unwrap();
    let theme = &ThemeSet::load_defaults().themes["base16-ocean.dark"];
    css_for_theme_with_class_style(&theme, ClassStyle::Spaced)
}