use std::{collections::HashMap, net::IpAddr};

use x25519_dalek::PublicKey;

#[derive(Debug, Clone, PartialEq, Eq, Hash, Copy)]
pub struct SourceKey {
    pub prefix: IpAddr,
    pub plen: u8,
    pub router_id: PublicKey, 
}

#[derive(Debug, Clone, Copy)]
pub struct FeasibilityDistance {
    pub metric: u16,
    pub seqno: u16,
}

impl FeasibilityDistance {
    pub fn new(metric: u16, seqno: u16) -> Self {
        FeasibilityDistance { metric, seqno }
    }
}

// Store (prefix, plen, router_id) -> feasibility distance mapping
#[derive(Debug)]
pub struct SourceTable {
    pub table: HashMap<SourceKey, FeasibilityDistance>,
}

impl SourceTable {
    pub fn new() -> Self {
        Self {
            table: HashMap::new(),
        }
    }

    pub fn insert(&mut self, key: SourceKey, feas_dist: FeasibilityDistance) {
        self.table.insert(key, feas_dist);
    }

    pub fn remove(&mut self, key: &SourceKey) {
        self.table.remove(key);
    }

    pub fn get(&self, key: &SourceKey) -> Option<&FeasibilityDistance> {
        self.table.get(key)
    }

    // pub fn update(&mut self, update: &ControlStruct) {
    //     match update.control_packet.body.tlv {
    //         BabelTLV::Update {
    //             plen,
    //             interval,
    //             seqno,
    //             metric,
    //             prefix,
    //             router_id,
    //         } => {
    //             // first check if the update is feasible
    //             if !self.is_feasible(update) {
    //                 return;
    //             }

    //             let key = SourceKey {
    //                 prefix: prefix,
    //                 plen: plen,
    //                 router_id: router_id,
    //             };

    //             let new_distance = FeasibilityDistance(metric, seqno);
    //             let old_distance = self.table.get(&key).cloned();
    //             match old_distance {
    //                 Some(old_distance) => {
    //                     if new_distance.0 < old_distance.0 {
    //                         self.table
    //                             .insert(key, FeasibilityDistance(new_distance.0, new_distance.1));
    //                     }
    //                 }
    //                 None => {
    //                     self.table
    //                         .insert(key, FeasibilityDistance(new_distance.0, new_distance.1));
    //                 }
    //             }
    //         }
    //         _ => {
    //             panic!("not an update");
    //         }
    //     }
    // }

    // pub fn is_feasible(&self, update: &ControlStruct) -> bool {
    //     match update.control_packet.body.tlv {
    //         BabelTLV::Update {
    //             plen,
    //             interval: _,
    //             seqno,
    //             metric,
    //             prefix,
    //             router_id,
    //         } => {
    //             let key = SourceKey {
    //                 prefix: prefix,
    //                 plen: plen,
    //                 router_id: router_id,
    //             };

    //             match self.table.get(&key) {
    //                 Some(&source_entry) => {
    //                     let metric_2 = source_entry.0;
    //                     let seqno_2 = source_entry.1;

    //                     seqno > seqno_2 || (seqno == seqno_2 && metric < metric_2)
    //                 }
    //                 None => true,
    //             }
    //         }
    //         _ => {
    //             panic!("not an update");
    //         }
    //     }
    // }
}