use std::collections::{HashMap, HashSet};

use peanuts::element::{Content, ElementBuilder, FromElement, IntoElement, NamespaceDeclaration};
use peanuts::XML_NS;
use peanuts::{element::Name, Element};
use tracing::debug;

use crate::{Error, JID};

use super::sasl::{self, Mechanisms};
use super::starttls::{self, StartTls};

pub const XMLNS: &str = "http://etherx.jabber.org/streams";
pub const XMLNS_CLIENT: &str = "jabber:client";

// MUST be qualified by stream namespace
// #[derive(XmlSerialize, XmlDeserialize)]
// #[peanuts(xmlns = XMLNS)]
#[derive(Debug)]
pub struct Stream {
    pub from: Option<JID>,
    to: Option<JID>,
    id: Option<String>,
    version: Option<String>,
    // TODO: lang enum
    lang: Option<String>,
    // #[peanuts(content)]
    // content: Message,
}

impl FromElement for Stream {
    fn from_element(mut element: Element) -> std::result::Result<Self, peanuts::DeserializeError> {
        element.check_namespace(XMLNS)?;
        element.check_name("stream")?;

        let from = element.attribute_opt("from")?;
        let to = element.attribute_opt("to")?;
        let id = element.attribute_opt("id")?;
        let version = element.attribute_opt("version")?;
        let lang = element.attribute_opt_namespaced("lang", peanuts::XML_NS)?;

        Ok(Stream {
            from,
            to,
            id,
            version,
            lang,
        })
    }
}

impl IntoElement for Stream {
    fn builder(&self) -> ElementBuilder {
        Element::builder("stream", Some(XMLNS.to_string()))
            .push_namespace_declaration_override(Some("stream"), XMLNS)
            .push_namespace_declaration_override(None::<&str>, XMLNS_CLIENT)
            .push_attribute_opt("to", self.to.clone())
            .push_attribute_opt("from", self.from.clone())
            .push_attribute_opt("id", self.id.clone())
            .push_attribute_opt("version", self.version.clone())
            .push_attribute_opt_namespaced(peanuts::XML_NS, "to", self.lang.clone())
    }
}

impl<'s> Stream {
    pub fn new(
        from: Option<JID>,
        to: Option<JID>,
        id: Option<String>,
        version: Option<String>,
        lang: Option<String>,
    ) -> Self {
        Self {
            from,
            to,
            id,
            version,
            lang,
        }
    }

    /// For initial stream headers, the initiating entity SHOULD include the 'xml:lang' attribute.
    /// For privacy, it is better to not set `from` when sending a client stanza over an unencrypted connection.
    pub fn new_client(from: Option<JID>, to: JID, id: Option<String>, lang: String) -> Self {
        Self {
            from,
            to: Some(to),
            id,
            version: Some("1.0".to_string()),
            lang: Some(lang),
        }
    }
}

#[derive(Debug)]
pub struct Features {
    pub features: Vec<Feature>,
}

impl IntoElement for Features {
    fn builder(&self) -> ElementBuilder {
        Element::builder("features", Some(XMLNS)).push_children(self.features.clone())
    }
}

impl FromElement for Features {
    fn from_element(
        mut element: Element,
    ) -> std::result::Result<Features, peanuts::DeserializeError> {
        element.check_namespace(XMLNS)?;
        element.check_name("features")?;

        debug!("got features stanza");
        let features = element.children()?;
        debug!("got features period");

        Ok(Features { features })
    }
}

#[derive(Debug, Clone)]
pub enum Feature {
    StartTls(StartTls),
    Sasl(Mechanisms),
    Bind,
    Unknown,
}

impl IntoElement for Feature {
    fn builder(&self) -> ElementBuilder {
        match self {
            Feature::StartTls(start_tls) => start_tls.builder(),
            Feature::Sasl(mechanisms) => mechanisms.builder(),
            Feature::Bind => todo!(),
            Feature::Unknown => todo!(),
        }
    }
}

impl FromElement for Feature {
    fn from_element(element: Element) -> peanuts::element::DeserializeResult<Self> {
        let identity = element.identify();
        debug!("identity: {:?}", identity);
        match element.identify() {
            (Some(starttls::XMLNS), "starttls") => {
                debug!("identified starttls");
                Ok(Feature::StartTls(StartTls::from_element(element)?))
            }
            (Some(sasl::XMLNS), "mechanisms") => {
                debug!("identified mechanisms");
                Ok(Feature::Sasl(Mechanisms::from_element(element)?))
            }
            _ => {
                debug!("identified unknown feature");
                Ok(Feature::Unknown)
            }
        }
    }
}