#[macro_use]
extern crate serde_derive;
#[macro_use]
extern crate derive_error_chain;

extern crate serde_yaml;

use std::fs::File;
use std::path::Path;



fn main() {
    //read the files
    //let paths = [Path::new("test.yml")];
    let filenames: Vec<_> = std::env::args_os().skip(1).collect();
    let hosts: Vec<Host> = filenames.iter()
        .map(Path::new)
        .map(|path| Host::from_file(&path))
        .map(|result| match result {
            Ok(val) => val,
            Err(err) => panic!("{:#}", err),
        })
        .collect();

    //build dot-graph
    let nodes = hosts.iter().map(Host::to_dot_node);
    let edges = hosts.iter().flat_map(Host::to_dot_edge);

    // let edges = ..

    //render it

    println!("digraph antennen {{");
    
    for node in nodes {
        println!("{}", node);
    }
    for edge in edges {
        println!("{}", edge);
    }
    println!("}}");
}

#[derive(Debug, ErrorChain)]
pub enum ParseError {
    #[error_chain(foreign)]
    IO(std::io::Error),


    #[error_chain(custom)]
    #[error_chain(description = r#"|_| "File invalid/incomplete yaml""#)]
    #[error_chain(display = r#"|&(ref path, ref err)| write!(f, "failed at file {:?} with {}", path, err)"#)]
    Yaml((std::ffi::OsString, serde_yaml::Error)),

    #[error_chain(custom)]
    #[error_chain(description = r#"|_| "Host file structure broken""#)]
    #[error_chain(display = r#"|t| write!(f, "the antenna config is wrong: {}", t)"#)]
    Structure(String),
}

#[derive(Debug)]
struct Host {
    name: String,
    ip: String,
    mac: String,
    kind: HostKind,
}
impl Host {
    fn from_file(path: &Path) -> Result<Self> {
        RawHost::from_file(path)?.parse()
    }
    fn to_dot_node(&self) -> String {
        let mut attributes = vec!
            [ "shape=record".to_string()
            , format!("label=\"{{\'{name}\'|{typ}|{{{ip}|{mac}}}|{{{ipv6}}}}}\""
                , name = self.name, typ=self.kind.name(), ip=self.ip, mac=self.mac, ipv6="no ipv6")
            , "style=filled".into()
            ];

        // type-specific handling
        match self.kind {
            HostKind::Client {coordinates, ref subnet, .. } => attributes.extend_from_slice(
                &[ format!("pos=\"{breitengrad},{längengrad}\""
                    , längengrad=coordinates[0], breitengrad=coordinates[1])
                , "fillcolor=lightgray".into()
                ]),
            _ => (),
        };

        let attributes = attributes.join(", ");

        format!("\"{name}\" [{attributes}]", name=self.name, attributes=attributes)
    }
    fn to_dot_edge(&self) -> Option<String> {
        match self.kind {
            HostKind::Client { ref parent, .. } =>
                format!("\"{name}\" -> \"{parent}\"", name=self.name, parent=parent).into(),
            _ => None,
        }
    }
}

#[derive(Debug)]
enum HostKind {
    Client { subnet: String, coordinates: [f64;2], parent: String },
    AccessPoint,
    Other,
}

impl HostKind {
    fn name(&self) -> &'static str {
        use HostKind::*;
        match *self {
            Client { .. } => "Client",
            AccessPoint => "AccessPoint",
            Other => "Other",
        }
    }
}


#[derive(Deserialize,Debug)]
struct RawHost {
    #[serde(skip)]
    name: Option<std::ffi::OsString>,
    ansible_host: String,
    #[serde(rename = "type")]
    kind: String,
    mac: String,
    client_of: Option<String>,
    coordinate: Option<[f64;2]>,
    subnet: Option<String>,
}

impl RawHost {
    fn parse(self) -> Result<Host> {
        let name = self.name
            .ok_or(ParseError::Structure("got no file name? weird.".into()))?
            .into_string().unwrap()
            .split('.')
            .next().unwrap().into();
        Ok(Host
            { name: name
            , ip: self.ansible_host
            , mac: self.mac
            , kind: match self.kind.as_ref()
                { "wlan-ap" => HostKind::AccessPoint
                , "client" => HostKind::Client
                    { subnet: self.subnet.ok_or(ParseError::Structure("is client, has no subnet".into()))?
                    , coordinates: self.coordinate.ok_or(ParseError::Structure("is client, has no coordinates".into()))?
                    , parent: self.client_of.ok_or(ParseError::Structure("is client, has no client_of".into()))?
                    }
                , _ => HostKind::Other
                }
            })
    }
    fn from_file(path: &Path) -> Result<Self> {
        let fd = File::open(path)?;
        let mut antenna : Self = match serde_yaml::from_reader(&fd) {
            Ok(val) => val,
            Err(err) => return Err(ParseError::Yaml((path.as_os_str().to_owned(), err)).into()),
        };
        antenna.name = path.file_name().map(|a|a.to_owned());
        Ok(antenna)
    }
}