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

impl Config {
    pub fn read_from_file() -> Result<Self, String> {
        let config_path = Self::get_location()?;
        let config_contents = fs::read_to_string(&config_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(
                PathBuf::from(&config_path)
                    .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,
        })
    }

    fn get_location() -> Result<String, String> {
        Ok(
            std::env::var("STORMSCRIBE_CONFIG_FILE").or_else(|_| -> Result<String, String> {
                Ok(std::path::Path::join(
                    &std::env::current_dir()
                        .map_err(|_| "Could not read current directory".to_string())?,
                    "config.toml",
                )
                .to_string_lossy()
                .to_string())
            })?,
        )
    }
}