tenzro-types 0.1.0

//! Core primitive types for Tenzro Network
//!
//! This module defines the fundamental building blocks used throughout
//! the Tenzro Network blockchain.

use serde::{Deserialize, Serialize};
use std::fmt;

/// A 32-byte hash value used throughout Tenzro Network
///
/// Hashes are used for block hashes, transaction hashes, Merkle roots,
/// and other cryptographic commitments.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub struct Hash(pub [u8; 32]);

impl Hash {
    /// Creates a new Hash from a 32-byte array
    pub fn new(bytes: [u8; 32]) -> Self {
        Self(bytes)
    }

    /// Returns the hash as a byte slice
    pub fn as_bytes(&self) -> &[u8] {
        &self.0
    }

    /// Creates a Hash from a byte slice
    ///
    /// Returns None if the slice is not exactly 32 bytes
    pub fn from_bytes(bytes: &[u8]) -> Option<Self> {
        if bytes.len() == 32 {
            let mut arr = [0u8; 32];
            arr.copy_from_slice(bytes);
            Some(Self(arr))
        } else {
            None
        }
    }

    /// Returns a zero hash (all zeros)
    pub fn zero() -> Self {
        Self([0u8; 32])
    }

    /// Combines two hashes using SHA-256
    ///
    /// This method is collision-resistant, unlike XOR-based combination.
    /// It concatenates the two hashes and returns the SHA-256 hash of the result.
    pub fn combine(&self, other: &Hash) -> Self {
        use sha2::{Digest, Sha256};
        let mut hasher = Sha256::new();
        hasher.update(self.0);
        hasher.update(other.0);
        let result = hasher.finalize();
        Self(result.into())
    }
}

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

impl From<[u8; 32]> for Hash {
    fn from(bytes: [u8; 32]) -> Self {
        Self(bytes)
    }
}

impl Default for Hash {
    fn default() -> Self {
        Self::zero()
    }
}

/// An address on Tenzro Network
///
/// Addresses are derived from public keys and identify accounts,
/// smart contracts, and other entities on the network.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub struct Address(pub [u8; 32]);

impl Address {
    /// Creates a new Address from a 32-byte array
    pub fn new(bytes: [u8; 32]) -> Self {
        Self(bytes)
    }

    /// Returns the address as a byte slice
    pub fn as_bytes(&self) -> &[u8] {
        &self.0
    }

    /// Creates an Address from a byte slice
    ///
    /// Returns None if the slice is not exactly 32 bytes
    pub fn from_bytes(bytes: &[u8]) -> Option<Self> {
        if bytes.len() == 32 {
            let mut arr = [0u8; 32];
            arr.copy_from_slice(bytes);
            Some(Self(arr))
        } else {
            None
        }
    }

    /// Returns a zero address (all zeros)
    pub fn zero() -> Self {
        Self([0u8; 32])
    }

    /// Encodes the address as a base58 string
    pub fn to_base58(&self) -> String {
        bs58::encode(&self.0).into_string()
    }

    /// Decodes an address from a base58 string
    pub fn from_base58(s: &str) -> Result<Self, bs58::decode::Error> {
        let bytes = bs58::decode(s).into_vec()?;
        Self::from_bytes(&bytes).ok_or(bs58::decode::Error::BufferTooSmall)
    }

    /// Validates that a hex string is properly formatted
    ///
    /// Returns true if the string is valid hexadecimal (with or without 0x prefix)
    pub fn is_valid_hex(s: &str) -> bool {
        let s = s.strip_prefix("0x").unwrap_or(s);
        s.len() == 64 && s.chars().all(|c| c.is_ascii_hexdigit())
    }

    /// Creates an address from a hex string.
    ///
    /// For 20-byte Ethereum addresses (40 hex chars), validates EIP-55 checksum.
    /// For 32-byte Tenzro addresses (64 hex chars), validates hex format.
    /// Use this as the default entry point for hex address parsing.
    pub fn from_hex(s: &str) -> Result<Self, crate::error::TenzroError> {
        Self::from_hex_checksummed(s)
    }

    /// Creates an address from a hex string with EIP-55 checksum validation
    ///
    /// For Ethereum-style addresses (20 bytes), this validates the EIP-55 mixed-case
    /// checksum. The hex string should be 40 characters (or 42 with 0x prefix).
    pub fn from_hex_checksummed(s: &str) -> Result<Self, crate::error::TenzroError> {
        let s = s.strip_prefix("0x").unwrap_or(s);

        // For 20-byte Ethereum addresses, validate EIP-55 checksum
        if s.len() == 40 {
            // Decode the hex
            let bytes = hex::decode(s).map_err(|e| crate::error::TenzroError::InvalidAddress(format!("Invalid hex: {}", e)))?;

            // Compute Keccak-256 hash of the lowercase address
            use sha3::{Digest, Keccak256};
            let mut hasher = Keccak256::new();
            hasher.update(s.to_lowercase().as_bytes());
            let hash = hasher.finalize();

            // Verify checksum (mixed case encoding)
            for (i, c) in s.chars().enumerate() {
                if c.is_alphabetic() {
                    let hash_byte = hash[i / 2];
                    let hash_nibble = if i % 2 == 0 {
                        hash_byte >> 4
                    } else {
                        hash_byte & 0x0f
                    };

                    let should_be_uppercase = hash_nibble >= 8;
                    if c.is_uppercase() != should_be_uppercase {
                        return Err(crate::error::TenzroError::InvalidAddress("Invalid EIP-55 checksum".to_string()));
                    }
                }
            }

            // Pad to 32 bytes for our Address type
            let mut addr = [0u8; 32];
            addr[12..].copy_from_slice(&bytes);
            Ok(Self(addr))
        } else if s.len() == 64 {
            // 32-byte address (full Tenzro address)
            let bytes = hex::decode(s).map_err(|e| crate::error::TenzroError::InvalidAddress(format!("Invalid hex: {}", e)))?;
            let mut addr = [0u8; 32];
            addr.copy_from_slice(&bytes);
            Ok(Self(addr))
        } else {
            Err(crate::error::TenzroError::InvalidAddress(format!("Invalid address length: expected 40 or 64 hex chars, got {}", s.len())))
        }
    }
}

impl fmt::Display for Address {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.to_base58())
    }
}

impl From<[u8; 32]> for Address {
    fn from(bytes: [u8; 32]) -> Self {
        Self(bytes)
    }
}

impl Default for Address {
    fn default() -> Self {
        Self::zero()
    }
}

/// A cryptographic signature on Tenzro Network
///
/// Signatures are used to prove ownership and authorize transactions.
///
/// Both `bytes` and `public_key` are bounded at deserialization time to
/// `MAX_SIGNATURE_BYTES` and `MAX_PUBLIC_KEY_BYTES` respectively, to protect
/// against OOM via untrusted payloads (HIGH #69 in the production audit).
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[derive(Default)]
pub struct Signature {
    /// The signature bytes
    #[serde(deserialize_with = "crate::validation::bounded_signature_bytes")]
    pub bytes: Vec<u8>,
    /// The public key used to verify the signature
    #[serde(deserialize_with = "crate::validation::bounded_public_key_bytes")]
    pub public_key: Vec<u8>,
}

impl Signature {
    /// Creates a new Signature
    pub fn new(bytes: Vec<u8>, public_key: Vec<u8>) -> Self {
        Self { bytes, public_key }
    }
}


/// The height of a block in the Tenzro Network blockchain
///
/// Block height starts at 0 for the genesis block and increments by 1 for each block.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
pub struct BlockHeight(pub u64);

impl BlockHeight {
    /// Creates a new BlockHeight
    pub fn new(height: u64) -> Self {
        Self(height)
    }

    /// Returns the genesis block height (0)
    pub fn genesis() -> Self {
        Self(0)
    }

    /// Returns the next block height
    pub fn next(self) -> Self {
        Self(self.0 + 1)
    }

    /// Returns the previous block height, or None if this is the genesis block
    pub fn prev(self) -> Option<Self> {
        if self.0 > 0 {
            Some(Self(self.0 - 1))
        } else {
            None
        }
    }
}

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

impl From<u64> for BlockHeight {
    fn from(height: u64) -> Self {
        Self(height)
    }
}

impl Default for BlockHeight {
    fn default() -> Self {
        Self::genesis()
    }
}

impl BlockHeight {
    /// Returns the height as a u64
    pub fn as_u64(&self) -> u64 {
        self.0
    }
}

impl std::ops::Add<u64> for BlockHeight {
    type Output = Self;

    fn add(self, rhs: u64) -> Self::Output {
        Self(self.0 + rhs)
    }
}

impl std::ops::Sub<u64> for BlockHeight {
    type Output = Self;

    fn sub(self, rhs: u64) -> Self::Output {
        Self(self.0.saturating_sub(rhs))
    }
}

/// A transaction nonce for replay protection
///
/// The nonce ensures that each transaction from an account is unique
/// and prevents replay attacks.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
pub struct Nonce(pub u64);

impl Nonce {
    /// Creates a new Nonce
    pub fn new(value: u64) -> Self {
        Self(value)
    }

    /// Returns the initial nonce (0)
    pub fn initial() -> Self {
        Self(0)
    }

    /// Returns the next nonce
    pub fn next(self) -> Self {
        Self(self.0 + 1)
    }
}

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

impl From<u64> for Nonce {
    fn from(value: u64) -> Self {
        Self(value)
    }
}

/// A timestamp representing Unix time in milliseconds
///
/// Used for block timestamps and time-based operations.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
#[derive(Default)]
pub struct Timestamp(pub i64);


impl Timestamp {
    /// Creates a new Timestamp
    pub fn new(millis: i64) -> Self {
        Self(millis)
    }

    /// Returns the current timestamp
    pub fn now() -> Self {
        Self(chrono::Utc::now().timestamp_millis())
    }

    /// Returns the timestamp as milliseconds since Unix epoch
    pub fn as_millis(&self) -> i64 {
        self.0
    }

    /// Returns the timestamp as seconds since Unix epoch
    pub fn as_secs(&self) -> i64 {
        self.0 / 1000
    }
}

impl From<Timestamp> for std::time::SystemTime {
    fn from(ts: Timestamp) -> Self {
        std::time::UNIX_EPOCH + std::time::Duration::from_millis(ts.0 as u64)
    }
}

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

impl From<i64> for Timestamp {
    fn from(millis: i64) -> Self {
        Self(millis)
    }
}

/// The chain identifier for Tenzro Network
///
/// Used to prevent cross-chain replay attacks and identify the network.
///
/// Deserialization enforces the EIP-2294 range `[1, (u64::MAX / 2) - 36]`
/// to reject obviously-bad chain ids early (HIGH #70 in the production audit).
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize)]
pub struct ChainId(pub u64);

impl<'de> Deserialize<'de> for ChainId {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let value = u64::deserialize(deserializer)?;
        let chain = ChainId(value);
        crate::validation::validate_chain_id(chain).map_err(serde::de::Error::custom)?;
        Ok(chain)
    }
}

impl ChainId {
    /// Mainnet chain ID
    pub const MAINNET: Self = Self(1);

    /// Testnet chain ID
    pub const TESTNET: Self = Self(1337);

    /// Devnet chain ID
    pub const DEVNET: Self = Self(31337);

    /// Creates a new ChainId without validation.
    ///
    /// Prefer [`ChainId::try_new`] when constructing from untrusted input.
    pub fn new(id: u64) -> Self {
        Self(id)
    }

    /// Creates a new ChainId, returning an error if `id` is outside the
    /// allowed range `[CHAIN_ID_MIN, CHAIN_ID_MAX]`.
    ///
    /// The upper bound (`(u64::MAX / 2) - 36`) follows EIP-2294 to avoid
    /// overflow when combined with EIP-155 transaction signing.
    pub fn try_new(id: u64) -> Result<Self, crate::error::TenzroError> {
        let chain = Self(id);
        crate::validation::validate_chain_id(chain)?;
        Ok(chain)
    }

    /// Returns the mainnet chain ID
    pub fn mainnet() -> Self {
        Self::MAINNET
    }

    /// Returns the testnet chain ID
    pub fn testnet() -> Self {
        Self::TESTNET
    }

    /// Returns the devnet chain ID
    pub fn devnet() -> Self {
        Self::DEVNET
    }

    /// Returns the inner u64 chain id.
    pub fn as_u64(&self) -> u64 {
        self.0
    }

    /// Validates that the chain ID is within the allowed range.
    ///
    /// Allowed range follows EIP-2294: `[1, (u64::MAX / 2) - 36]`.
    pub fn is_valid(&self) -> bool {
        crate::validation::validate_chain_id(*self).is_ok()
    }
}

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

impl From<u64> for ChainId {
    fn from(id: u64) -> Self {
        Self(id)
    }
}

/// Serde adapter for `u128` fields that may carry values larger than
/// `u64::MAX` (e.g. base-unit token amounts at 10^18 precision).
///
/// `serde_json`'s default number deserializer falls through `u64 → i64 →
/// f64` and refuses values exceeding `u64::MAX` (~1.84×10^19) — which
/// breaks reference templates whose delegation caps are denominated in
/// 10^18-base-unit TNZO (e.g. `5_000_000_000_000_000_000_000`).
///
/// This adapter accepts both:
///   - JSON numbers (any integer up to `u128::MAX` that fits in a
///     `serde_json::Number`)
///   - JSON strings (decimal digits only, no sign, no underscores)
///
/// On serialization it emits a number when the value fits `u64` and a
/// decimal string otherwise, preserving readability for typical small
/// values while remaining lossless for large ones.
///
/// Apply via `#[serde(with = "u128_serde")]` on a `u128` field.
pub mod u128_serde {
    use serde::de::{self, Visitor};
    use serde::{Deserializer, Serializer};
    use std::fmt;

    pub fn serialize<S: Serializer>(value: &u128, serializer: S) -> Result<S::Ok, S::Error> {
        if *value <= u64::MAX as u128 {
            serializer.serialize_u64(*value as u64)
        } else {
            serializer.serialize_str(&value.to_string())
        }
    }

    pub fn deserialize<'de, D: Deserializer<'de>>(deserializer: D) -> Result<u128, D::Error> {
        struct U128Visitor;

        impl<'de> Visitor<'de> for U128Visitor {
            type Value = u128;

            fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
                f.write_str("a non-negative integer or decimal string fitting in u128")
            }

            fn visit_u64<E: de::Error>(self, v: u64) -> Result<u128, E> {
                Ok(v as u128)
            }

            fn visit_u128<E: de::Error>(self, v: u128) -> Result<u128, E> {
                Ok(v)
            }

            fn visit_i64<E: de::Error>(self, v: i64) -> Result<u128, E> {
                if v < 0 {
                    Err(E::custom(format!("negative integer {v} is not a valid u128")))
                } else {
                    Ok(v as u128)
                }
            }

            fn visit_i128<E: de::Error>(self, v: i128) -> Result<u128, E> {
                if v < 0 {
                    Err(E::custom(format!("negative integer {v} is not a valid u128")))
                } else {
                    Ok(v as u128)
                }
            }

            fn visit_str<E: de::Error>(self, s: &str) -> Result<u128, E> {
                s.parse::<u128>()
                    .map_err(|e| E::custom(format!("invalid u128 string {s:?}: {e}")))
            }

            fn visit_string<E: de::Error>(self, s: String) -> Result<u128, E> {
                self.visit_str(&s)
            }
        }

        deserializer.deserialize_any(U128Visitor)
    }
}

/// `Option<u128>` adapter mirroring [`u128_serde`] semantics. Apply via
/// `#[serde(default, with = "u128_serde_opt")]` on an `Option<u128>` field.
///
/// Accepts JSON `null`/missing → `None`, JSON number or decimal string → `Some`.
/// Serializes `None` as `null`, `Some(v)` as a number when it fits `u64`,
/// otherwise as a decimal string.
pub mod u128_serde_opt {
    use serde::de::{self, Visitor};
    use serde::{Deserializer, Serializer};
    use std::fmt;

    pub fn serialize<S: Serializer>(
        value: &Option<u128>,
        serializer: S,
    ) -> Result<S::Ok, S::Error> {
        match value {
            None => serializer.serialize_none(),
            Some(v) if *v <= u64::MAX as u128 => serializer.serialize_u64(*v as u64),
            Some(v) => serializer.serialize_str(&v.to_string()),
        }
    }

    pub fn deserialize<'de, D: Deserializer<'de>>(
        deserializer: D,
    ) -> Result<Option<u128>, D::Error> {
        struct OptU128Visitor;

        impl<'de> Visitor<'de> for OptU128Visitor {
            type Value = Option<u128>;

            fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
                f.write_str("null, a non-negative integer, or a decimal string fitting in u128")
            }

            fn visit_unit<E: de::Error>(self) -> Result<Option<u128>, E> {
                Ok(None)
            }

            fn visit_none<E: de::Error>(self) -> Result<Option<u128>, E> {
                Ok(None)
            }

            fn visit_some<D2: Deserializer<'de>>(
                self,
                deserializer: D2,
            ) -> Result<Option<u128>, D2::Error> {
                super::u128_serde::deserialize(deserializer).map(Some)
            }

            fn visit_u64<E: de::Error>(self, v: u64) -> Result<Option<u128>, E> {
                Ok(Some(v as u128))
            }

            fn visit_u128<E: de::Error>(self, v: u128) -> Result<Option<u128>, E> {
                Ok(Some(v))
            }

            fn visit_i64<E: de::Error>(self, v: i64) -> Result<Option<u128>, E> {
                if v < 0 {
                    Err(E::custom(format!("negative integer {v} is not a valid u128")))
                } else {
                    Ok(Some(v as u128))
                }
            }

            fn visit_i128<E: de::Error>(self, v: i128) -> Result<Option<u128>, E> {
                if v < 0 {
                    Err(E::custom(format!("negative integer {v} is not a valid u128")))
                } else {
                    Ok(Some(v as u128))
                }
            }

            fn visit_str<E: de::Error>(self, s: &str) -> Result<Option<u128>, E> {
                s.parse::<u128>()
                    .map(Some)
                    .map_err(|e| E::custom(format!("invalid u128 string {s:?}: {e}")))
            }

            fn visit_string<E: de::Error>(self, s: String) -> Result<Option<u128>, E> {
                self.visit_str(&s)
            }
        }

        deserializer.deserialize_any(OptU128Visitor)
    }
}

#[cfg(test)]
mod u128_serde_tests {
    use serde::{Deserialize, Serialize};

    #[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
    struct Wrap {
        #[serde(with = "super::u128_serde")]
        v: u128,
    }

    #[test]
    fn round_trips_small_value_as_number() {
        let w = Wrap { v: 42 };
        let json = serde_json::to_string(&w).unwrap();
        assert_eq!(json, r#"{"v":42}"#);
        let back: Wrap = serde_json::from_str(&json).unwrap();
        assert_eq!(back, w);
    }

    #[test]
    fn round_trips_large_value_as_string() {
        let w = Wrap { v: 5_000_000_000_000_000_000_000u128 };
        let json = serde_json::to_string(&w).unwrap();
        assert_eq!(json, r#"{"v":"5000000000000000000000"}"#);
        let back: Wrap = serde_json::from_str(&json).unwrap();
        assert_eq!(back, w);
    }

    #[test]
    fn deserializes_large_raw_number() {
        // The whole point: accept the existing template JSON shape.
        let json = r#"{"v":5000000000000000000000}"#;
        let back: Wrap = serde_json::from_str(json).unwrap();
        assert_eq!(back.v, 5_000_000_000_000_000_000_000u128);
    }

    #[test]
    fn deserializes_string_at_u64_boundary() {
        let json = r#"{"v":"18446744073709551616"}"#; // u64::MAX + 1
        let back: Wrap = serde_json::from_str(json).unwrap();
        assert_eq!(back.v, (u64::MAX as u128) + 1);
    }

    #[test]
    fn rejects_negative_string() {
        let json = r#"{"v":"-1"}"#;
        assert!(serde_json::from_str::<Wrap>(json).is_err());
    }

    #[test]
    fn rejects_negative_number() {
        let json = r#"{"v":-1}"#;
        assert!(serde_json::from_str::<Wrap>(json).is_err());
    }
}