use crate::constants;
use crate::libvirt_lib_structures::XMLUuid;
use crate::libvirt_rest_structures::net::NetworkName;
use crate::libvirt_rest_structures::nw_filter::NetworkFilterName;
use clap::Parser;
use std::net::IpAddr;
use std::path::{Path, PathBuf};
use std::str::FromStr;

/// VirtWeb backend API
#[derive(Parser, Debug, Clone)]
#[clap(author, version, about, long_about = None)]
pub struct AppConfig {
    /// Read arguments from env file
    #[clap(short, long, env)]
    pub config: Option<String>,

    /// Listen address
    #[clap(short, long, env, default_value = "0.0.0.0:8000")]
    pub listen_address: String,

    /// Website main origin
    #[clap(short, long, env, default_value = "http://localhost:3000")]
    pub website_origin: String,

    /// Additional allowed website origin
    ///
    /// Warning! These origins won't be usable for OpenID authentication,
    /// only for local auth
    #[clap(short = 'o', long, env)]
    pub additional_origins: Vec<String>,

    /// Proxy IP, might end with a star "*"
    #[clap(short, long, env)]
    pub proxy_ip: Option<String>,

    /// Secret key, used to sign some resources. Must be randomly generated
    #[clap(short = 'S', long, env, default_value = "")]
    secret: String,

    /// Specify whether the cookie should be transmitted only over secure connections
    #[clap(long, env)]
    pub cookie_secure: bool,

    /// Auth username
    #[arg(short = 'u', long, env, default_value = "admin")]
    pub auth_username: String,

    /// Auth password
    #[arg(short = 'P', long, env, default_value = "admin")]
    pub auth_password: String,

    /// Disable authentication WARNING! THIS IS UNSECURE, it was designed only for development
    /// purpose, it should NEVER be used in production
    #[arg(long, env)]
    pub unsecure_disable_auth: bool,

    /// Disable local auth
    #[arg(long, env)]
    pub disable_local_auth: bool,

    /// Request header that can be added by a reverse proxy to disable local authentication
    #[arg(long, env, default_value = "X-Disable-Local-Auth")]
    pub disable_auth_header_token: String,

    /// URL where the OpenID configuration can be found
    #[arg(
        long,
        env,
        default_value = "http://localhost:9001/.well-known/openid-configuration"
    )]
    pub oidc_configuration_url: String,

    /// Disable OpenID authentication
    #[arg(long, env)]
    pub disable_oidc: bool,

    /// OpenID client ID
    #[arg(long, env, default_value = "foo")]
    pub oidc_client_id: String,

    /// OpenID client secret
    #[arg(long, env, default_value = "bar")]
    pub oidc_client_secret: String,

    /// OpenID login redirect URL
    #[arg(long, env, default_value = "APP_ORIGIN/oidc_cb")]
    oidc_redirect_url: String,

    /// Storage directory
    #[arg(short, long, env, default_value = "storage")]
    pub storage: String,

    /// Directory where temporary files are stored
    ///
    /// Warning! This directory MUST be changed if `/tmp` is not in the same disk as the storage
    /// directory!
    #[arg(short, long, env, default_value = "/tmp")]
    pub temp_dir: String,

    /// Hypervisor URI. If not specified, "" will be used instead
    #[arg(short = 'H', long, env)]
    pub hypervisor_uri: Option<String>,

    /// Trusted network. If set, a client from a different will not be able to perform request other
    /// than those with GET verb (aside for login)
    #[arg(short = 'T', long, env)]
    pub trusted_network: Vec<String>,
}

lazy_static::lazy_static! {
    static ref ARGS: AppConfig = {
        AppConfig::parse()
    };
}

impl AppConfig {
    /// Parse environment variables from file, if requedst
    pub fn parse_env_file() -> anyhow::Result<()> {
        if let Some(c) = Self::parse().config {
            log::info!("Load additional environment variables from {c}");
            let conf_file = Path::new(&c);

            if !conf_file.is_file() {
                panic!("Specified configuration is not a file!");
            }
            dotenvy::from_path(conf_file)?;
        }

        Ok(())
    }

    /// Get parsed command line arguments
    pub fn get() -> &'static AppConfig {
        &ARGS
    }

    /// Get auth cookie domain
    pub fn cookie_domain(&self) -> Option<String> {
        if cfg!(debug_assertions) {
            let domain = self.website_origin.split_once("://")?.1;
            Some(
                domain
                    .split_once(':')
                    .map(|s| s.0)
                    .unwrap_or(domain)
                    .to_string(),
            )
        } else {
            // In release mode, the web app is hosted on the same origin as the API
            None
        }
    }

    /// Get app secret
    pub fn secret(&self) -> &str {
        let mut secret = self.secret.as_str();

        if cfg!(debug_assertions) && secret.is_empty() {
            secret = "DEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEY";
        }

        if secret.is_empty() {
            panic!("SECRET is undefined or too short (min 64 chars)!")
        }

        secret
    }

    /// Check out whether provided credentials are valid or not for local authentication
    pub fn check_local_login(&self, user: &str, pass: &str) -> bool {
        self.auth_username == user && self.auth_password == pass
    }

    /// Check if an IP belongs to a trusted network or not
    pub fn is_trusted_ip(&self, ip: IpAddr) -> bool {
        if self.trusted_network.is_empty() {
            return true;
        }

        for i in &self.trusted_network {
            let net = ipnetwork::IpNetwork::from_str(i).expect("Trusted network is invalid!");

            if net.contains(ip) {
                return true;
            }
        }

        false
    }

    /// Get OpenID providers configuration
    pub fn openid_provider(&self) -> Option<OIDCProvider<'_>> {
        if self.disable_oidc {
            return None;
        }

        Some(OIDCProvider {
            client_id: self.oidc_client_id.as_str(),
            client_secret: self.oidc_client_secret.as_str(),
            configuration_url: self.oidc_configuration_url.as_str(),
        })
    }

    /// Get OIDC callback URL
    pub fn oidc_redirect_url(&self) -> String {
        self.oidc_redirect_url
            .replace("APP_ORIGIN", &self.website_origin)
    }

    /// Get root storage directory
    pub fn storage_path(&self) -> PathBuf {
        let storage_path = Path::new(&self.storage);
        if !storage_path.is_dir() {
            panic!(
                "Specified storage path ({}) is not a directory!",
                self.storage
            );
        }
        storage_path.canonicalize().unwrap()
    }

    /// Get iso storage directory
    pub fn iso_storage_path(&self) -> PathBuf {
        self.storage_path().join("iso")
    }

    /// Get VM vnc sockets directory
    pub fn vnc_sockets_path(&self) -> PathBuf {
        self.storage_path().join("vnc")
    }

    /// Get VM vnc sockets path for domain
    pub fn vnc_socket_for_domain(&self, name: &str) -> PathBuf {
        self.vnc_sockets_path().join(format!("vnc-{}", name))
    }

    /// Get VM vnc sockets directory
    pub fn disks_storage_path(&self) -> PathBuf {
        self.storage_path().join("disks")
    }

    pub fn vm_storage_path(&self, id: XMLUuid) -> PathBuf {
        self.disks_storage_path().join(id.as_string())
    }

    pub fn definitions_path(&self) -> PathBuf {
        self.storage_path().join("definitions")
    }

    pub fn vm_definition_path(&self, name: &str) -> PathBuf {
        self.definitions_path().join(format!("vm-{name}.json"))
    }

    pub fn net_definition_path(&self, name: &NetworkName) -> PathBuf {
        self.definitions_path().join(format!("net-{}.json", name.0))
    }

    pub fn nat_path(&self) -> PathBuf {
        self.storage_path().join(constants::STORAGE_NAT_DIR)
    }

    pub fn net_nat_path(&self, name: &NetworkName) -> PathBuf {
        self.nat_path().join(format!("nat-{}.json", name.0))
    }

    pub fn net_filter_definition_path(&self, name: &NetworkFilterName) -> PathBuf {
        self.definitions_path()
            .join(format!("nwfilter-{}.json", name.0))
    }
}

#[derive(Debug, Clone, serde::Serialize)]
pub struct OIDCProvider<'a> {
    #[serde(skip_serializing)]
    pub client_id: &'a str,
    #[serde(skip_serializing)]
    pub client_secret: &'a str,
    #[serde(skip_serializing)]
    pub configuration_url: &'a str,
}

#[cfg(test)]
mod test {
    use crate::app_config::AppConfig;

    #[test]
    fn verify_cli() {
        use clap::CommandFactory;
        AppConfig::command().debug_assert()
    }
}