use serde::{Deserialize, Serialize};
use serde_big_array::BigArray;
use ssz_derive::{Decode, Encode};
use std::fmt;
use tree_hash::{PackedEncoding, TreeHash};

const KZG_PROOF_BYTES_LEN: usize = 48;

#[derive(Debug, PartialEq, Hash, Clone, Copy, Encode, Decode, Serialize, Deserialize)]
#[serde(transparent)]
#[ssz(struct_behaviour = "transparent")]
pub struct KzgProof(#[serde(with = "BigArray")] pub [u8; KZG_PROOF_BYTES_LEN]);

impl fmt::Display for KzgProof {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", eth2_serde_utils::hex::encode(self.0))
    }
}

impl Default for KzgProof {
    fn default() -> Self {
        KzgProof([0; 48])
    }
}

impl From<[u8; KZG_PROOF_BYTES_LEN]> for KzgProof {
    fn from(bytes: [u8; KZG_PROOF_BYTES_LEN]) -> Self {
        Self(bytes)
    }
}

impl Into<[u8; KZG_PROOF_BYTES_LEN]> for KzgProof {
    fn into(self) -> [u8; KZG_PROOF_BYTES_LEN] {
        self.0
    }
}

impl TreeHash for KzgProof {
    fn tree_hash_type() -> tree_hash::TreeHashType {
        <[u8; KZG_PROOF_BYTES_LEN]>::tree_hash_type()
    }

    fn tree_hash_packed_encoding(&self) -> PackedEncoding {
        self.0.tree_hash_packed_encoding()
    }

    fn tree_hash_packing_factor() -> usize {
        <[u8; KZG_PROOF_BYTES_LEN]>::tree_hash_packing_factor()
    }

    fn tree_hash_root(&self) -> tree_hash::Hash256 {
        self.0.tree_hash_root()
    }
}