use std::path::PathBuf;

use figment::{
    providers::{Env, Format, Json, Toml},
    Figment, Metadata, Provider,
};
use hickory_proto::rr::Name;
use serde::{Deserialize, Serialize};

/// libvirt storage pool configuration
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct StorageConfig {
    /// The primary storage pool, allocated to all VMs.
    pub primary_pool: String,
    /// The secondary storage pool, allocated to any VMs that require slower storage.
    pub secondary_pool: String,
    /// Pool containing cloud-init base images.
    pub base_image_pool: String,
}

/// Provides the basic SOA (Start-of-Authority) for the internal DNS zone.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct SOAConfig {
    pub nzr_domain: Name,
    pub contact: Name,
    pub refresh: i32,
    pub retry: i32,
    pub expire: i32,
}

/// DNS server configuration.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct DNSConfig {
    pub listen_addr: String,
    pub port: u16,
    pub default_zone: Name,
    pub soa: SOAConfig,
}

/// DHCP server configuration.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct DHCPConfig {
    pub listen_addr: String,
    pub port: u16,
}

/// Cloud-init configuration, used by omyacid.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct CloudConfig {
    pub listen_addr: String,
    pub port: u16,
    pub http_addr: Option<String>,
    pub admin_user: String,
}

impl CloudConfig {
    pub fn http_addr(&self) -> String {
        if let Some(http_addr) = &self.http_addr {
            if http_addr.ends_with('/') {
                http_addr.clone()
            } else {
                format!("{}/", http_addr)
            }
        } else {
            format!("http://{}:{}/", self.listen_addr, self.port)
        }
    }
}

/// Server<->Client RPC configuration.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct RPCConfig {
    pub socket_path: PathBuf,
    pub admin_group: Option<String>,
}

/// The root configuration struct.
#[derive(Debug, Serialize, Deserialize)]
pub struct Config {
    pub rpc: RPCConfig,
    pub log_level: String,
    /// Where database information should be stored.
    pub db_uri: String,
    pub qemu_img_path: Option<PathBuf>,
    /// The libvirt URI to use for connections; e.g. `qemu:///system`.
    pub libvirt_uri: String,
    pub storage: StorageConfig,
    pub dns: DNSConfig,
    pub dhcp: DHCPConfig,
    pub cloud: CloudConfig,
}

impl Default for Config {
    fn default() -> Self {
        Self {
            log_level: "WARN".to_owned(),
            qemu_img_path: None,
            rpc: RPCConfig {
                socket_path: PathBuf::from("/var/run/nazrin/nzrd.sock"),
                admin_group: None,
            },
            db_uri: "sqlite:/var/lib/nazrin/main_sql.db".to_owned(),
            libvirt_uri: match std::env::var("LIBVIRT_URI") {
                Ok(v) => v,
                Err(_) => String::from("qemu:///system"),
            },
            storage: StorageConfig {
                primary_pool: "pri".to_owned(),
                secondary_pool: "data".to_owned(),
                base_image_pool: "images".to_owned(),
            },
            dns: DNSConfig {
                listen_addr: "127.0.0.1".to_owned(),
                port: 5353,
                default_zone: Name::from_utf8("servers.local").unwrap(),
                soa: SOAConfig {
                    nzr_domain: Name::from_utf8("nzr.local").unwrap(),
                    contact: Name::from_utf8("admin.nzr.local").unwrap(),
                    refresh: 86400,
                    retry: 7200,
                    expire: 3_600_000,
                },
            },
            dhcp: DHCPConfig {
                listen_addr: "127.0.0.1".to_owned(),
                port: 67,
            },
            cloud: CloudConfig {
                listen_addr: "0.0.0.0".to_owned(),
                port: 80,
                http_addr: None,
                admin_user: "admin".to_owned(),
            },
        }
    }
}

impl Provider for Config {
    fn metadata(&self) -> figment::Metadata {
        Metadata::named("Nazrin config")
    }

    fn data(
        &self,
    ) -> Result<figment::value::Map<figment::Profile, figment::value::Dict>, figment::Error> {
        figment::providers::Serialized::defaults(Config::default()).data()
    }

    fn profile(&self) -> Option<figment::Profile> {
        None
    }
}

impl Config {
    pub fn figment() -> Figment {
        let mut fig = Figment::from(Config::default()).merge(Toml::file("/etc/nazrin.conf"));

        #[allow(deprecated)]
        if let Some(mut home) = std::env::home_dir() {
            home.push(".nazrin.conf");
            fig = fig.merge(Json::file(home));
        }

        fig.merge(Env::prefixed("NZR_"))
    }
}