use std::time::Duration;

use anyhow::{anyhow, Result};

use crate::config::{
  ConfigOpts, ConfigOptsAcme, ConfigOptsConsul, ConfigOptsFirewall, ConfigOptsIgd,
};

// This code is inspired by the Trunk crate (https://github.com/thedodd/trunk)

// In this file, we take ConfigOpts and transform them into ready-to-use RuntimeConfig.
// We apply default values and business logic.

// Consul config is mandatory, all the others are optional.

#[derive(Debug)]
pub struct RuntimeConfigConsul {
  pub node_name: String,
  pub url: String,
}

#[derive(Debug)]
pub struct RuntimeConfigAcme {
  pub email: String,
}

#[derive(Debug)]
pub struct RuntimeConfigFirewall {
  pub refresh_time: Duration,
}

#[derive(Debug)]
pub struct RuntimeConfigIgd {
  pub private_ip: String,
  pub expiration_time: Duration,
  pub refresh_time: Duration,
}

#[derive(Debug)]
pub struct RuntimeConfig {
  pub consul: RuntimeConfigConsul,
  pub acme: Option<RuntimeConfigAcme>,
  pub firewall: Option<RuntimeConfigFirewall>,
  pub igd: Option<RuntimeConfigIgd>,
}

impl RuntimeConfig {
  pub fn new(opts: ConfigOpts) -> Result<Self> {
    let consul = RuntimeConfigConsul::new(opts.consul.clone())?;
    let acme = RuntimeConfigAcme::new(opts.acme.clone())?;
    let firewall = RuntimeConfigFirewall::new(opts.firewall.clone())?;
    let igd = RuntimeConfigIgd::new(opts.igd.clone())?;

    Ok(Self {
      acme,
      consul,
      firewall,
      igd,
    })
  }
}

impl RuntimeConfigConsul {
  pub(super) fn new(opts: ConfigOptsConsul) -> Result<Self> {
    let node_name = opts
      .node_name
      .expect("'DIPLONAT_CONSUL_NODE_NAME' is required");
    let url = opts.url.unwrap_or(super::CONSUL_URL.to_string());

    Ok(Self { node_name, url })
  }
}

impl RuntimeConfigAcme {
  pub fn new(opts: ConfigOptsAcme) -> Result<Option<Self>> {
    if !opts.enable {
      return Ok(None);
    }

    let email = opts
      .email
      .expect("'DIPLONAT_ACME_EMAIL' is required if ACME is enabled");

    Ok(Some(Self { email }))
  }
}

impl RuntimeConfigFirewall {
  pub(super) fn new(opts: ConfigOptsFirewall) -> Result<Option<Self>> {
    if !opts.enable {
      return Ok(None);
    }

    let refresh_time = Duration::from_secs(opts.refresh_time.unwrap_or(super::REFRESH_TIME).into());

    Ok(Some(Self { refresh_time }))
  }
}

impl RuntimeConfigIgd {
  pub(super) fn new(opts: ConfigOptsIgd) -> Result<Option<Self>> {
    if !opts.enable {
      return Ok(None);
    }

    let private_ip = opts
      .private_ip
      .expect("'DIPLONAT_IGD_PRIVATE_IP' is required if IGD is enabled");
    let expiration_time = Duration::from_secs(
      opts
        .expiration_time
        .unwrap_or(super::EXPIRATION_TIME)
        .into(),
    );
    let refresh_time = Duration::from_secs(opts.refresh_time.unwrap_or(super::REFRESH_TIME).into());

    if refresh_time.as_secs() * 2 > expiration_time.as_secs() {
      return Err(anyhow!(
	        "IGD expiration time (currently: {}s) must be at least twice bigger than refresh time (currently: {}s)", 
	        expiration_time.as_secs(),
	        refresh_time.as_secs()));
    }

    Ok(Some(Self {
      private_ip,
      expiration_time,
      refresh_time,
    }))
  }
}