use std::default::Default;
use std::path::{Path, PathBuf};
use std::collections::HashMap;

use serde::{Serialize, Deserialize, Deserializer, Serializer};

use std::fmt::Formatter;
use std::net::{SocketAddr, IpAddr, ToSocketAddrs};
use std::str::FromStr;
use serde::de::Error;
use crate::authorization::permissions::PermRule;
use crate::authorization::roles::RoleIdentifier;

type Result<T> = std::result::Result<T, serde_dhall::Error>;

pub fn read(path: &Path) -> Result<Config> {
    serde_dhall::from_file(path)
        .parse()
        .map_err(Into::into)
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Config {
    /// A list of address/port pairs to listen on.
    // TODO: This should really be a variant type; that is something that can figure out itself if
    // it contains enough information to open a socket (i.e. it checks if it's a valid path (=>
    // Unix socket) or IPv4/v6 address)
    pub listens: Vec<Listen>,

    /// Machine descriptions to load
    //pub machines: HashMap<MachineIdentifier, MachineDescription>,

    /// Actors to load and their configuration options
    pub actors: HashMap<String, ModuleConfig>,

    /// Initiators to load and their configuration options
    pub initiators: HashMap<String, ModuleConfig>,

    pub mqtt_url: String,

    pub actor_connections: Vec<(String, String)>,
    pub init_connections: Vec<(String, String)>,

    pub db_path: PathBuf,
    pub auditlog_path: PathBuf,

    pub roles: HashMap<RoleIdentifier, RoleConfig>,

    #[serde(flatten)]
    pub tlsconfig: TlsListen,

    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub tlskeylog: Option<PathBuf>,

    #[serde(default, skip)]
    pub verbosity: isize,

    #[serde(default, skip)]
    pub log_format: String,
}

impl Config {
    pub fn is_quiet(&self) -> bool {
        self.verbosity < 0
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RoleConfig {
    #[serde(default = "Vec::new")]
    pub parents: Vec<RoleIdentifier>,
    #[serde(default = "Vec::new")]
    pub permissions: Vec<PermRule>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ModuleConfig {
    pub module: String,
    pub params: HashMap<String, String>
}

pub struct ListenSock {
    listen: Listen,
    tls_config: TlsListen,
}


pub(crate) fn deser_option<'de, D, T>(d: D) -> std::result::Result<Option<T>, D::Error>
    where D: serde::Deserializer<'de>, T: serde::Deserialize<'de>,
{
    Ok(T::deserialize(d).ok())
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Listen {
    address: String,
    #[serde(default, skip_serializing_if = "Option::is_none", deserialize_with = "deser_option")]
    port: Option<u16>,
}

#[derive(Debug, Clone, Serialize, Deserialize, Default)]
pub struct TlsListen {
    pub certfile: PathBuf,
    pub keyfile: PathBuf,

    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub ciphers: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub tls_min_version: Option<String>,
    #[serde(default = "Vec::new", skip_serializing_if = "Vec::is_empty")]
    pub protocols: Vec<String>,
}

impl Listen {
    pub fn to_tuple(&self) -> (&str, u16) {
        (self.address.as_str(), self.port.unwrap_or(DEFAULT_PORT))
    }
}

impl std::fmt::Display for Listen {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}:{}", &self.address, self.port.unwrap_or(DEFAULT_PORT))
    }
}

impl ToSocketAddrs for Listen {
    type Iter = <(String, u16) as ToSocketAddrs>::Iter;

    fn to_socket_addrs(&self) -> std::io::Result<Self::Iter> {
        if let Some(port) = self.port {
            (self.address.as_str(), port).to_socket_addrs()
        } else {
            (self.address.as_str(), DEFAULT_PORT).to_socket_addrs()
        }
    }
}

impl Default for Config {
    fn default() -> Self {
        let mut actors: HashMap::<String, ModuleConfig> = HashMap::new();
        let mut initiators: HashMap::<String, ModuleConfig> = HashMap::new();

        actors.insert("Actor".to_string(), ModuleConfig {
            module: "Shelly".to_string(),
            params: HashMap::new(),
        });
        initiators.insert("Initiator".to_string(), ModuleConfig {
            module: "TCP-Listen".to_string(),
            params: HashMap::new(),
        });

        Config {
            listens: vec![
                Listen {
                    address: "127.0.0.1".to_string(),
                    port: None,
                }
            ],
            actors,
            initiators,
            mqtt_url: "tcp://localhost:1883".to_string(),
            actor_connections: vec![
                ("Testmachine".to_string(), "Actor".to_string()),
            ],
            init_connections: vec![
                ("Initiator".to_string(), "Testmachine".to_string()),
            ],

            db_path: PathBuf::from("/run/bffh/database"),
            auditlog_path: PathBuf::from("/var/log/bffh/audit.log"),
            roles: HashMap::new(),

            tlsconfig: TlsListen {
                certfile: PathBuf::from("./bffh.crt"),
                keyfile: PathBuf::from("./bffh.key"),
                .. Default::default()
            },

            tlskeylog: None,
            verbosity: 0,
            log_format: "Full".to_string(),
        }
    }
}

// The default port in the non-assignable i.e. free-use area
pub const DEFAULT_PORT: u16 = 59661;