use std::fs;
use std::path::{Path, PathBuf};

use serde::Deserialize;

#[derive(Deserialize)]
struct ConfigFile {
    site_title: Option<String>,
    data_dir: Option<PathBuf>,
    external_root: Option<String>,
    listen_port: Option<u16>,
    footer_copyright: Option<String>,
}

pub struct Config {
    site_title: String,
    data_dir: PathBuf,
    external_root: String,
    listen_port: u16,
    footer_copyright: Option<String>
}

impl Config {
    pub fn read_from_file<P: AsRef<Path>>(path: P) -> Result<Self, String> {
        let config_contents = fs::read_to_string(&path)
            .map_err(|_| "Unable to open config file".to_string())?;

        let file : ConfigFile = toml::from_str(&config_contents)
            .map_err(|err| err.to_string())?;

        let port = file.listen_port.unwrap_or(3000);

        Ok(Self {
            site_title: file.site_title
                .unwrap_or("Untitled StormScribe Site".to_string()),
            data_dir: file.data_dir.unwrap_or(path.as_ref()
                .canonicalize().map_err(|_| "Cannot resolve config file location".to_string())?
                .parent().ok_or("Cannot resolve data dir".to_string())?.to_path_buf()),
            external_root: file.external_root
                .unwrap_or(format!("http://localhost:{port}/")),
            listen_port: port,
            footer_copyright: file.footer_copyright,
        })
    }
}