use anyhow::Context;
use serde::{Deserialize, Serialize};
use std::{collections::HashMap, fs::read_to_string, net::SocketAddr, path::PathBuf};

#[derive(Debug, Serialize, Deserialize)]
pub struct Config {
    pub http: Option<HttpConfig>,
    pub https: Option<HttpsConfig>,
    #[serde(default)]
    pub limits: Limits,
    #[serde(default)]
    pub hosts: HashMap<String, HostConfig>,
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(default)]
pub struct Limits {
    pub max_incoming_connections: usize,
    pub max_outgoing_connections: usize,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct HttpConfig {
    pub bind: SocketAddr,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct HttpsConfig {
    pub bind: SocketAddr,
    pub tls_cert: PathBuf,
    pub tls_key: PathBuf,
}

#[derive(Debug, Serialize, Deserialize)]
#[serde(untagged)]
pub enum HostConfig {
    Backend { backend: SocketAddr },
    Files { files: FileserverConfig },
}

#[derive(Debug, Serialize, Deserialize)]
pub struct FileserverConfig {
    pub root: PathBuf,
    #[serde(default)]
    pub index: bool,
}

impl Config {
    pub fn load(path: &str) -> anyhow::Result<Config> {
        let raw = read_to_string(path).context("reading config file")?;
        let config: Config = toml::from_str(&raw).context("parsing config")?;
        Ok(config)
    }
}

impl Default for Limits {
    fn default() -> Self {
        Self {
            max_incoming_connections: 1024,
            max_outgoing_connections: usize::MAX,
        }
    }
}