// Bitcoin protocol primitives library.
//
// SPDX-License-Identifier: Apache-2.0
//
// Written in 2019-2023 by
//     Dr Maxim Orlovsky <orlovsky@lnp-bp.org>
//
// Copyright (C) 2019-2023 LNP/BP Standards Association. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use amplify::hex::{self, FromHex};
use amplify::{Bytes32, Bytes32StrRev, Wrapper};

use crate::LIB_NAME_BITCOIN;

#[derive(Wrapper, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, From)]
#[derive(StrictType, StrictDumb, StrictEncode, StrictDecode)]
#[strict_type(lib = LIB_NAME_BITCOIN)]
#[cfg_attr(
    feature = "serde",
    derive(Serialize, Deserialize),
    serde(crate = "serde_crate", transparent)
)]
#[wrapper(BorrowSlice, Index, RangeOps, Debug, LowerHex, UpperHex, Display, FromStr)]
pub struct BlockHash(
    #[from]
    #[from([u8; 32])]
    Bytes32StrRev,
);

impl FromHex for BlockHash {
    fn from_byte_iter<I>(iter: I) -> Result<Self, hex::Error>
    where I: Iterator<Item = Result<u8, hex::Error>> + ExactSizeIterator + DoubleEndedIterator {
        Bytes32StrRev::from_byte_iter(iter).map(Self)
    }
}

#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
#[derive(StrictType, StrictEncode, StrictDecode, StrictDumb)]
#[strict_type(lib = LIB_NAME_BITCOIN)]
#[cfg_attr(
    feature = "serde",
    derive(Serialize, Deserialize),
    serde(crate = "serde_crate", rename_all = "camelCase")
)]
pub struct BlockHeader {
    /// Block version, now repurposed for soft fork signalling.
    pub version: i32,
    /// Reference to the previous block in the chain.
    pub prev_block_hash: BlockHash,
    /// The root hash of the merkle tree of transactions in the block.
    pub merkle_root: Bytes32,
    /// The timestamp of the block, as claimed by the miner.
    pub time: u32,
    /// The target value below which the blockhash must lie.
    pub bits: u32,
    /// The nonce, selected to obtain a low enough blockhash.
    pub nonce: u32,
}