use pulldown_cmark::{html, Parser};
use std::error::Error;
use std::path::Path;

pub struct Theme {
    root_path: String,
    parser_options: pulldown_cmark::Options,
}

impl Theme {
    pub fn new(root_path: String) -> Self {
        let mut parser_options = pulldown_cmark::Options::empty();
        parser_options.insert(pulldown_cmark::Options::ENABLE_STRIKETHROUGH);

        Theme {
            root_path,
            parser_options,
        }
    }

    // Renders markdown as html
    pub fn markdown_as_html(&self, path: &String) -> Result<String, String> {
        log::trace!("Rendering file '{}'", path);

        let path = format!("{}.md", path);
        let file = std::fs::read_to_string(&path);

        match file {
            Ok(content) => {
                let parser = Parser::new_ext(content.as_str(), self.parser_options);
                let mut html_output = String::new();
                html::push_html(&mut html_output, parser);

                let mut buf = String::new();
                buf.push_str(self.get_fragment("header").as_str());
                buf.push_str(html_output.as_str());
                buf.push_str(self.get_fragment("footer").as_str());

                Ok(buf)
            }
            Err(error) => {
                log::error!("File located at path {} was not found.", path);
                Err(error.to_string())
            }
        }
    }

    // TODO: Cache
    fn get_fragment(&self, fragment_name: &str) -> String {
        let path = format!("{}/{}.html.tpl", self.root_path, fragment_name);
        log::trace!("Loading fragment file '{}'", path);
        std::fs::read_to_string(path).unwrap_or("".to_owned())
    }
}