lightcone 0.5.1

//! Order types, serialization, hashing, and signing.
//!
//! This module provides the signed and compact order structures with
//! Keccak256 hashing and Ed25519 signing functionality.

use sha3::{Digest, Keccak256};
use solana_pubkey::Pubkey;
use solana_signature::Signature;

#[cfg(feature = "native-auth")]
use solana_keypair::Keypair;
#[cfg(feature = "native-auth")]
use solana_signer::Signer;

use crate::program::constants::{ORDER_SIZE, SIGNED_ORDER_SIZE};
use crate::program::error::{SdkError, SdkResult};
use crate::program::types::{AskOrderParams, BidOrderParams, OrderSide};
use crate::shared::SubmitOrderRequest;

// ============================================================================
// Signed Order (225 bytes)
// ============================================================================

/// Signed order structure with full context and signature.
///
/// Layout (233 bytes):
/// - [0..8]     nonce (8 bytes, u64)
/// - [8..16]    salt (8 bytes, u64)
/// - [16..48]   maker (32 bytes)
/// - [48..80]   market (32 bytes)
/// - [80..112]  base_mint (32 bytes)
/// - [112..144] quote_mint (32 bytes)
/// - [144]      side (1 byte)
/// - [145..153] amount_in (8 bytes)
/// - [153..161] amount_out (8 bytes)
/// - [161..169] expiration (8 bytes)
/// - [169..233] signature (64 bytes)
#[derive(Debug, Clone)]
pub struct OrderPayload {
    /// Unique order ID and replay protection
    pub nonce: u64,
    /// Random salt for order uniqueness
    pub salt: u64,
    /// Order maker's pubkey
    pub maker: Pubkey,
    /// Market pubkey
    pub market: Pubkey,
    /// Base mint (token being bought/sold)
    pub base_mint: Pubkey,
    /// Quote mint (token used for payment)
    pub quote_mint: Pubkey,
    /// Order side (0 = Bid, 1 = Ask)
    pub side: OrderSide,
    /// Amount maker gives
    pub amount_in: u64,
    /// Amount maker receives
    pub amount_out: u64,
    /// Expiration timestamp (0 = no expiration)
    pub expiration: i64,
    /// Ed25519 signature
    pub signature: [u8; 64],
}

impl OrderPayload {
    /// Order size in bytes
    pub const LEN: usize = SIGNED_ORDER_SIZE;

    /// Size of the signed portion of the order (for hashing)
    pub const HASH_SIZE: usize = 169;

    /// Create a new bid order (maker buys base, gives quote)
    pub fn new_bid(params: BidOrderParams) -> Self {
        Self {
            nonce: params.nonce,
            salt: params.salt,
            maker: params.maker,
            market: params.market,
            base_mint: params.base_mint,
            quote_mint: params.quote_mint,
            side: OrderSide::Bid,
            amount_in: params.amount_in,
            amount_out: params.amount_out,
            expiration: params.expiration,
            signature: [0u8; 64],
        }
    }

    /// Create a new ask order (maker sells base, receives quote)
    pub fn new_ask(params: AskOrderParams) -> Self {
        Self {
            nonce: params.nonce,
            salt: params.salt,
            maker: params.maker,
            market: params.market,
            base_mint: params.base_mint,
            quote_mint: params.quote_mint,
            side: OrderSide::Ask,
            amount_in: params.amount_in,
            amount_out: params.amount_out,
            expiration: params.expiration,
            signature: [0u8; 64],
        }
    }

    /// Build the raw 161-byte order message from the signed fields.
    /// This is hashed (keccak256) and hex-encoded to produce the bytes that users sign.
    fn signing_message(&self) -> [u8; Self::HASH_SIZE] {
        let mut data = [0u8; Self::HASH_SIZE];

        data[0..8].copy_from_slice(&self.nonce.to_le_bytes());
        data[8..16].copy_from_slice(&self.salt.to_le_bytes());
        data[16..48].copy_from_slice(self.maker.as_ref());
        data[48..80].copy_from_slice(self.market.as_ref());
        data[80..112].copy_from_slice(self.base_mint.as_ref());
        data[112..144].copy_from_slice(self.quote_mint.as_ref());
        data[144] = self.side as u8;
        data[145..153].copy_from_slice(&self.amount_in.to_le_bytes());
        data[153..161].copy_from_slice(&self.amount_out.to_le_bytes());
        data[161..169].copy_from_slice(&self.expiration.to_le_bytes());

        data
    }

    /// Compute the 32-byte Keccak256 hash of the signed fields.
    pub fn hash(&self) -> [u8; 32] {
        Keccak256::digest(self.signing_message()).into()
    }

    /// Compute the order hash as a hex string.
    pub fn hash_hex(&self) -> String {
        hex::encode(self.hash())
    }

    /// Sign the order with the given keypair.
    #[cfg(feature = "native-auth")]
    pub fn sign(&mut self, keypair: &Keypair) {
        let hash = self.hash_hex();
        let sig = keypair.sign_message(hash.as_bytes());

        self.signature.copy_from_slice(sig.as_ref());
    }

    /// Create and sign an order in one step.
    #[cfg(feature = "native-auth")]
    pub fn new_bid_signed(params: BidOrderParams, keypair: &Keypair) -> Self {
        let mut order = Self::new_bid(params);
        order.sign(keypair);
        order
    }

    /// Create and sign an ask order in one step.
    #[cfg(feature = "native-auth")]
    pub fn new_ask_signed(params: AskOrderParams, keypair: &Keypair) -> Self {
        let mut order = Self::new_ask(params);
        order.sign(keypair);
        order
    }

    /// Verify the Ed25519 signature over hex(keccak256(order_message)).
    /// The signed payload is a 64-char ASCII hex string (UTF-8 safe for wallet compatibility).
    pub fn verify_signature(&self) -> SdkResult<()> {
        let hash_hex = self.hash_hex();
        let sig = Signature::try_from(self.signature.as_slice())
            .map_err(|_| SdkError::InvalidSignature)?;

        if !sig.verify(self.maker.as_ref(), hash_hex.as_bytes()) {
            return Err(SdkError::SignatureVerificationFailed);
        }
        Ok(())
    }

    /// Apply a signature to the order.
    pub fn apply_signature(&mut self, sig_bs58: String) -> SdkResult<()> {
        let signature = sig_bs58
            .parse::<Signature>()
            .map_err(|_| SdkError::InvalidSignature)?;

        self.signature = signature.into();
        Ok(())
    }

    /// Serialize to bytes (233 bytes).
    pub fn serialize(&self) -> [u8; SIGNED_ORDER_SIZE] {
        let mut data = [0u8; SIGNED_ORDER_SIZE];

        data[0..8].copy_from_slice(&self.nonce.to_le_bytes());
        data[8..16].copy_from_slice(&self.salt.to_le_bytes());
        data[16..48].copy_from_slice(self.maker.as_ref());
        data[48..80].copy_from_slice(self.market.as_ref());
        data[80..112].copy_from_slice(self.base_mint.as_ref());
        data[112..144].copy_from_slice(self.quote_mint.as_ref());
        data[144] = self.side as u8;
        data[145..153].copy_from_slice(&self.amount_in.to_le_bytes());
        data[153..161].copy_from_slice(&self.amount_out.to_le_bytes());
        data[161..169].copy_from_slice(&self.expiration.to_le_bytes());
        data[169..233].copy_from_slice(&self.signature);

        data
    }

    /// Deserialize from bytes.
    pub fn deserialize(data: &[u8]) -> SdkResult<Self> {
        if data.len() < SIGNED_ORDER_SIZE {
            return Err(SdkError::InvalidDataLength {
                expected: SIGNED_ORDER_SIZE,
                actual: data.len(),
            });
        }

        let mut nonce_bytes = [0u8; 8];
        nonce_bytes.copy_from_slice(&data[0..8]);

        let mut salt_bytes = [0u8; 8];
        salt_bytes.copy_from_slice(&data[8..16]);

        let mut maker_bytes = [0u8; 32];
        maker_bytes.copy_from_slice(&data[16..48]);

        let mut market_bytes = [0u8; 32];
        market_bytes.copy_from_slice(&data[48..80]);

        let mut base_mint_bytes = [0u8; 32];
        base_mint_bytes.copy_from_slice(&data[80..112]);

        let mut quote_mint_bytes = [0u8; 32];
        quote_mint_bytes.copy_from_slice(&data[112..144]);

        let mut amount_in_bytes = [0u8; 8];
        amount_in_bytes.copy_from_slice(&data[145..153]);

        let mut amount_out_bytes = [0u8; 8];
        amount_out_bytes.copy_from_slice(&data[153..161]);

        let mut expiration_bytes = [0u8; 8];
        expiration_bytes.copy_from_slice(&data[161..169]);

        let mut signature = [0u8; 64];
        signature.copy_from_slice(&data[169..233]);

        Ok(Self {
            nonce: u64::from_le_bytes(nonce_bytes),
            salt: u64::from_le_bytes(salt_bytes),
            maker: Pubkey::new_from_array(maker_bytes),
            market: Pubkey::new_from_array(market_bytes),
            base_mint: Pubkey::new_from_array(base_mint_bytes),
            quote_mint: Pubkey::new_from_array(quote_mint_bytes),
            side: OrderSide::try_from(data[144])?,
            amount_in: u64::from_le_bytes(amount_in_bytes),
            amount_out: u64::from_le_bytes(amount_out_bytes),
            expiration: i64::from_le_bytes(expiration_bytes),
            signature,
        })
    }

    /// Convert to compact order format (37 bytes, no maker field).
    pub fn to_order(&self) -> Order {
        Order {
            nonce: self.nonce as u32,
            salt: self.salt,
            side: self.side,
            amount_in: self.amount_in,
            amount_out: self.amount_out,
            expiration: self.expiration,
        }
    }

    /// Get the signature as a hex string (128 chars).
    pub fn signature_hex(&self) -> String {
        hex::encode(self.signature)
    }

    /// Check if the order has been signed.
    pub fn is_signed(&self) -> bool {
        self.signature != [0u8; 64]
    }

    /// Convert a signed payload to a `SubmitOrderRequest` (limit order, no trigger fields).
    ///
    /// Intended for internal use by envelope types. Prefer using
    /// `LimitOrderEnvelope::sign()` or `TriggerOrderEnvelope::sign()`.
    pub(crate) fn to_submit_request(
        &self,
        orderbook_id: impl Into<String>,
        time_in_force: Option<crate::shared::TimeInForce>,
        trigger_price: Option<f64>,
        trigger_type: Option<crate::shared::TriggerType>,
        deposit_source: Option<crate::shared::DepositSource>,
    ) -> Result<SubmitOrderRequest, SdkError> {
        if self.signature == [0u8; 64] {
            return Err(SdkError::UnsignedOrder);
        }

        Ok(SubmitOrderRequest {
            maker: self.maker.to_string(),
            nonce: self.nonce,
            salt: self.salt,
            market_pubkey: self.market.to_string(),
            base_token: self.base_mint.to_string(),
            quote_token: self.quote_mint.to_string(),
            side: self.side as u32,
            amount_in: self.amount_in,
            amount_out: self.amount_out,
            expiration: self.expiration,
            signature: hex::encode(self.signature),
            orderbook_id: orderbook_id.into(),
            time_in_force,
            trigger_price,
            trigger_type,
            deposit_source,
        })
    }

    /// Derive the orderbook ID for this order.
    ///
    /// Format: `{base_token[0:8]}_{quote_token[0:8]}`
    pub fn derive_orderbook_id(&self) -> String {
        crate::shared::derive_orderbook_id(
            &self.base_mint.to_string(),
            &self.quote_mint.to_string(),
        )
        .to_string()
    }
}

// ============================================================================
// Order (29 bytes)
// ============================================================================

/// Compact order format for on-chain transaction data.
///
/// No `maker` field (derived from Position PDA on-chain).
///
/// Layout (37 bytes):
/// - [0..4]   nonce (4 bytes, u32)
/// - [4..12]  salt (8 bytes, u64)
/// - [12]     side (1 byte)
/// - [13..21] amount_in (8 bytes)
/// - [21..29] amount_out (8 bytes)
/// - [29..37] expiration (8 bytes)
#[derive(Debug, Clone)]
pub struct Order {
    /// Unique order ID and replay protection
    pub nonce: u32,
    /// Random salt for order uniqueness
    pub salt: u64,
    /// Order side (0 = Bid, 1 = Ask)
    pub side: OrderSide,
    /// Amount maker gives
    pub amount_in: u64,
    /// Amount maker receives
    pub amount_out: u64,
    /// Expiration timestamp (0 = no expiration)
    pub expiration: i64,
}

impl Order {
    /// Order size in bytes
    pub const LEN: usize = ORDER_SIZE;

    /// Serialize to bytes (37 bytes).
    pub fn serialize(&self) -> [u8; ORDER_SIZE] {
        let mut data = [0u8; ORDER_SIZE];

        data[0..4].copy_from_slice(&self.nonce.to_le_bytes());
        data[4..12].copy_from_slice(&self.salt.to_le_bytes());
        data[12] = self.side as u8;
        data[13..21].copy_from_slice(&self.amount_in.to_le_bytes());
        data[21..29].copy_from_slice(&self.amount_out.to_le_bytes());
        data[29..37].copy_from_slice(&self.expiration.to_le_bytes());

        data
    }

    /// Deserialize from bytes.
    pub fn deserialize(data: &[u8]) -> SdkResult<Self> {
        if data.len() < ORDER_SIZE {
            return Err(SdkError::InvalidDataLength {
                expected: ORDER_SIZE,
                actual: data.len(),
            });
        }

        let mut nonce_bytes = [0u8; 4];
        nonce_bytes.copy_from_slice(&data[0..4]);

        let mut salt_bytes = [0u8; 8];
        salt_bytes.copy_from_slice(&data[4..12]);

        let mut amount_in_bytes = [0u8; 8];
        amount_in_bytes.copy_from_slice(&data[13..21]);

        let mut amount_out_bytes = [0u8; 8];
        amount_out_bytes.copy_from_slice(&data[21..29]);

        let mut expiration_bytes = [0u8; 8];
        expiration_bytes.copy_from_slice(&data[29..37]);

        Ok(Self {
            nonce: u32::from_le_bytes(nonce_bytes),
            salt: u64::from_le_bytes(salt_bytes),
            side: OrderSide::try_from(data[12])?,
            amount_in: u64::from_le_bytes(amount_in_bytes),
            amount_out: u64::from_le_bytes(amount_out_bytes),
            expiration: i64::from_le_bytes(expiration_bytes),
        })
    }

    /// Expand to signed order using pubkeys from accounts.
    pub fn to_signed(
        &self,
        maker: Pubkey,
        market: Pubkey,
        base_mint: Pubkey,
        quote_mint: Pubkey,
        signature: [u8; 64],
    ) -> OrderPayload {
        OrderPayload {
            nonce: self.nonce as u64,
            salt: self.salt,
            maker,
            market,
            base_mint,
            quote_mint,
            side: self.side,
            amount_in: self.amount_in,
            amount_out: self.amount_out,
            expiration: self.expiration,
            signature,
        }
    }
}

// ============================================================================
// Order Validation Helpers
// ============================================================================

/// Check if an order is expired.
pub fn is_order_expired(order: &OrderPayload, current_time: i64) -> bool {
    order.expiration != 0 && current_time >= order.expiration
}

/// Check if two orders can cross (prices are compatible).
///
/// Returns true if the buyer's price >= seller's price.
pub fn orders_can_cross(buy_order: &OrderPayload, sell_order: &OrderPayload) -> bool {
    if buy_order.side != OrderSide::Bid || sell_order.side != OrderSide::Ask {
        return false;
    }

    if buy_order.amount_in == 0
        || buy_order.amount_out == 0
        || sell_order.amount_in == 0
        || sell_order.amount_out == 0
    {
        return false;
    }

    // Buyer gives quote, receives base
    // Seller gives base, receives quote
    // Cross condition: buyer's price >= seller's price
    // buyer_price = buyer.amount_in / buyer.amount_out (quote per base)
    // seller_price = seller.amount_out / seller.amount_in (quote per base)
    // Cross: buyer.amount_in / buyer.amount_out >= seller.amount_out / seller.amount_in
    // Rearrange: buyer.amount_in * seller.amount_in >= buyer.amount_out * seller.amount_out

    let buyer_cross = (buy_order.amount_in as u128) * (sell_order.amount_in as u128);
    let seller_cross = (buy_order.amount_out as u128) * (sell_order.amount_out as u128);

    buyer_cross >= seller_cross
}

/// Calculate the taker fill amount given a maker fill amount.
pub fn calculate_taker_fill(maker_order: &OrderPayload, maker_fill_amount: u64) -> SdkResult<u64> {
    if maker_order.amount_in == 0 {
        return Err(SdkError::Overflow);
    }

    let result = (maker_fill_amount as u128)
        .checked_mul(maker_order.amount_out as u128)
        .ok_or(SdkError::Overflow)?
        .checked_div(maker_order.amount_in as u128)
        .ok_or(SdkError::Overflow)?;

    if result > u64::MAX as u128 {
        return Err(SdkError::Overflow);
    }

    Ok(result as u64)
}

/// Derive condition ID from oracle, question_id, and num_outcomes.
pub fn derive_condition_id(oracle: &Pubkey, question_id: &[u8; 32], num_outcomes: u8) -> [u8; 32] {
    let mut hasher = Keccak256::new();
    hasher.update(oracle.as_ref());
    hasher.update(question_id);
    hasher.update([num_outcomes]);
    hasher.finalize().into()
}

// ============================================================================
// Cancel Order Signing Helpers
// ============================================================================

/// Build the message bytes for cancelling an order.
///
/// The message is the order hash hex string as UTF-8 bytes (same protocol as order signing).
pub fn cancel_order_message(order_hash: &str) -> Vec<u8> {
    order_hash.as_bytes().to_vec()
}

/// Build the message bytes for cancelling a trigger order.
///
/// The message is the trigger_order_id as UTF-8 bytes.
pub fn cancel_trigger_order_message(trigger_order_id: &str) -> Vec<u8> {
    trigger_order_id.as_bytes().to_vec()
}

/// Build the message string for cancelling all orders.
///
/// Format: `"cancel_all:{pubkey}:{orderbook_id}:{timestamp}:{salt}"`
pub fn cancel_all_message(
    user_pubkey: &str,
    orderbook_id: &str,
    timestamp: i64,
    salt: &str,
) -> String {
    format!(
        "cancel_all:{}:{}:{}:{}",
        user_pubkey, orderbook_id, timestamp, salt
    )
}

/// Generate a random salt for order uniqueness.
pub fn generate_salt() -> u64 {
    rand::random::<u64>()
}

/// Generate a random UUID v4 salt for cancel-all replay protection.
pub fn generate_cancel_all_salt() -> String {
    let mut bytes = rand::random::<[u8; 16]>();
    bytes[6] = (bytes[6] & 0x0f) | 0x40;
    bytes[8] = (bytes[8] & 0x3f) | 0x80;

    format!(
        "{}-{}-{}-{}-{}",
        hex::encode(&bytes[0..4]),
        hex::encode(&bytes[4..6]),
        hex::encode(&bytes[6..8]),
        hex::encode(&bytes[8..10]),
        hex::encode(&bytes[10..16]),
    )
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_order_payload_serialization_roundtrip() {
        let order = OrderPayload {
            nonce: 12345,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 1000000,
            amount_out: 500000,
            expiration: 1234567890,
            signature: [0u8; 64],
        };

        let serialized = order.serialize();
        let deserialized = OrderPayload::deserialize(&serialized).unwrap();

        assert_eq!(order.nonce, deserialized.nonce);
        assert_eq!(order.salt, deserialized.salt);
        assert_eq!(order.maker, deserialized.maker);
        assert_eq!(order.market, deserialized.market);
        assert_eq!(order.base_mint, deserialized.base_mint);
        assert_eq!(order.quote_mint, deserialized.quote_mint);
        assert_eq!(order.side, deserialized.side);
        assert_eq!(order.amount_in, deserialized.amount_in);
        assert_eq!(order.amount_out, deserialized.amount_out);
        assert_eq!(order.expiration, deserialized.expiration);
    }

    #[test]
    fn test_order_serialization_roundtrip() {
        let order = Order {
            nonce: 12345,
            salt: 0,
            side: OrderSide::Ask,
            amount_in: 1000000,
            amount_out: 500000,
            expiration: 1234567890,
        };

        let serialized = order.serialize();
        let deserialized = Order::deserialize(&serialized).unwrap();

        assert_eq!(order.nonce, deserialized.nonce);
        assert_eq!(order.salt, deserialized.salt);
        assert_eq!(order.side, deserialized.side);
        assert_eq!(order.amount_in, deserialized.amount_in);
        assert_eq!(order.amount_out, deserialized.amount_out);
        assert_eq!(order.expiration, deserialized.expiration);
    }

    #[test]
    fn test_order_size() {
        assert_eq!(ORDER_SIZE, 37);
        let order = Order {
            nonce: 1,
            salt: 0,
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
        };
        assert_eq!(order.serialize().len(), 37);
    }

    #[test]
    fn test_order_hash_consistency() {
        let order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_from_array([1u8; 32]),
            market: Pubkey::new_from_array([2u8; 32]),
            base_mint: Pubkey::new_from_array([3u8; 32]),
            quote_mint: Pubkey::new_from_array([4u8; 32]),
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
            signature: [0u8; 64],
        };

        let hash1 = order.hash();
        let hash2 = order.hash();
        assert_eq!(hash1, hash2);
    }

    #[test]
    fn test_signed_order_to_order_roundtrip() {
        let signed = OrderPayload {
            nonce: 42,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 1000,
            amount_out: 500,
            expiration: 12345,
            signature: [7u8; 64],
        };

        let order = signed.to_order();
        assert_eq!(order.nonce, 42);
        assert_eq!(order.side, OrderSide::Bid);
        assert_eq!(order.amount_in, 1000);
        assert_eq!(order.amount_out, 500);
        assert_eq!(order.expiration, 12345);

        let back = order.to_signed(
            signed.maker,
            signed.market,
            signed.base_mint,
            signed.quote_mint,
            signed.signature,
        );
        assert_eq!(back.nonce, 42);
        assert_eq!(back.maker, signed.maker);
        assert_eq!(back.amount_in, 1000);
    }

    #[test]
    fn test_orders_can_cross() {
        let buy_order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 100, // 100 quote
            amount_out: 50, // for 50 base (price = 2 quote/base)
            expiration: 0,
            signature: [0u8; 64],
        };

        let sell_order = OrderPayload {
            nonce: 2,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: buy_order.market,
            base_mint: buy_order.base_mint,
            quote_mint: buy_order.quote_mint,
            side: OrderSide::Ask,
            amount_in: 50,  // 50 base
            amount_out: 90, // for 90 quote (price = 1.8 quote/base)
            expiration: 0,
            signature: [0u8; 64],
        };

        // Buyer pays 2 quote/base, seller wants 1.8 quote/base - should cross
        assert!(orders_can_cross(&buy_order, &sell_order));
    }

    #[test]
    fn test_orders_cannot_cross() {
        let buy_order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 50,  // 50 quote
            amount_out: 50, // for 50 base (price = 1 quote/base)
            expiration: 0,
            signature: [0u8; 64],
        };

        let sell_order = OrderPayload {
            nonce: 2,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: buy_order.market,
            base_mint: buy_order.base_mint,
            quote_mint: buy_order.quote_mint,
            side: OrderSide::Ask,
            amount_in: 50,   // 50 base
            amount_out: 100, // for 100 quote (price = 2 quote/base)
            expiration: 0,
            signature: [0u8; 64],
        };

        // Buyer pays 1 quote/base, seller wants 2 quote/base - should not cross
        assert!(!orders_can_cross(&buy_order, &sell_order));
    }

    #[test]
    fn test_calculate_taker_fill() {
        let maker_order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Ask,
            amount_in: 100,  // gives 100 base
            amount_out: 200, // wants 200 quote
            expiration: 0,
            signature: [0u8; 64],
        };

        // If filling 50 amount_in, taker should get 50 * 200 / 100 = 100
        let taker_fill = calculate_taker_fill(&maker_order, 50).unwrap();
        assert_eq!(taker_fill, 100);
    }

    #[test]
    #[cfg(feature = "native-auth")]
    fn test_to_submit_request() {
        use solana_keypair::Keypair;
        use solana_signer::Signer;

        let keypair = Keypair::new();
        let maker = keypair.pubkey();
        let market = Pubkey::new_unique();
        let base_mint = Pubkey::new_unique();
        let quote_mint = Pubkey::new_unique();

        let mut order = OrderPayload {
            nonce: 42,
            salt: 0,
            maker,
            market,
            base_mint,
            quote_mint,
            side: OrderSide::Bid,
            amount_in: 1_000_000,
            amount_out: 500_000,
            expiration: 1234567890,
            signature: [0u8; 64],
        };

        order.sign(&keypair);

        let request = order
            .to_submit_request("test_orderbook", None, None, None, None)
            .unwrap();

        assert_eq!(request.maker, maker.to_string());
        assert_eq!(request.nonce, 42);
        assert_eq!(request.market_pubkey, market.to_string());
        assert_eq!(request.base_token, base_mint.to_string());
        assert_eq!(request.quote_token, quote_mint.to_string());
        assert_eq!(request.side, 0); // Bid
        assert_eq!(request.amount_in, 1_000_000);
        assert_eq!(request.amount_out, 500_000);
        assert_eq!(request.expiration, 1234567890);
        assert_eq!(request.orderbook_id, "test_orderbook");
        assert_eq!(request.signature.len(), 128); // 64 bytes = 128 hex chars
    }

    #[test]
    fn test_derive_orderbook_id() {
        let order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_from_array([1u8; 32]),
            market: Pubkey::new_from_array([2u8; 32]),
            base_mint: Pubkey::new_from_array([3u8; 32]),
            quote_mint: Pubkey::new_from_array([4u8; 32]),
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
            signature: [0u8; 64],
        };

        let orderbook_id = order.derive_orderbook_id();
        // The orderbook ID should be first 8 chars of each pubkey string
        let base_str = order.base_mint.to_string();
        let quote_str = order.quote_mint.to_string();
        let expected = format!("{}_{}", &base_str[..8], &quote_str[..8]);
        assert_eq!(orderbook_id, expected);
    }

    #[test]
    #[cfg(feature = "native-auth")]
    fn test_is_signed() {
        use solana_keypair::Keypair;
        use solana_signer::Signer;

        let keypair = Keypair::new();
        let mut order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: keypair.pubkey(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
            signature: [0u8; 64],
        };

        assert!(!order.is_signed());

        order.sign(&keypair);

        assert!(order.is_signed());
    }

    #[test]
    #[cfg(feature = "native-auth")]
    fn test_signature_and_hash_hex() {
        use solana_keypair::Keypair;
        use solana_signer::Signer;

        let keypair = Keypair::new();
        let mut order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: keypair.pubkey(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
            signature: [0u8; 64],
        };

        order.sign(&keypair);

        let sig_hex = order.signature_hex();
        let hash_hex = order.hash_hex();

        // Signature should be 128 hex chars (64 bytes)
        assert_eq!(sig_hex.len(), 128);
        // Hash should be 64 hex chars (32 bytes)
        assert_eq!(hash_hex.len(), 64);

        // Verify they are valid hex
        assert!(hex::decode(&sig_hex).is_ok());
        assert!(hex::decode(&hash_hex).is_ok());
    }

    #[test]
    fn test_to_submit_request_errors_unsigned() {
        let order = OrderPayload {
            nonce: 1,
            salt: 0,
            maker: Pubkey::new_unique(),
            market: Pubkey::new_unique(),
            base_mint: Pubkey::new_unique(),
            quote_mint: Pubkey::new_unique(),
            side: OrderSide::Bid,
            amount_in: 100,
            amount_out: 50,
            expiration: 0,
            signature: [0u8; 64],
        };

        let result = order.to_submit_request("test_orderbook", None, None, None, None);
        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("must be signed"),);
    }

    #[test]
    fn test_cancel_trigger_order_message() {
        let id = "trigger-order-uuid-123";
        let message = cancel_trigger_order_message(id);
        assert_eq!(message, id.as_bytes());
    }

    #[test]
    fn test_cancel_order_message() {
        let hash = "abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890";
        let message = cancel_order_message(hash);
        assert_eq!(message, hash.as_bytes());
    }

    #[test]
    fn test_cancel_all_message() {
        let pubkey = "SomePubkey123";
        let orderbook_id = "test_orderbook";
        let timestamp = 1700000000i64;
        let salt = "550e8400-e29b-41d4-a716-446655440000";
        let message = cancel_all_message(pubkey, orderbook_id, timestamp, salt);
        assert_eq!(
            message,
            "cancel_all:SomePubkey123:test_orderbook:1700000000:550e8400-e29b-41d4-a716-446655440000"
        );
    }

    #[test]
    fn test_generate_cancel_all_salt() {
        let salt = generate_cancel_all_salt();
        assert_eq!(salt.len(), 36);
        assert_eq!(salt.chars().filter(|c| *c == '-').count(), 4);
        assert_eq!(salt.chars().nth(14), Some('4'));
    }

    #[test]
    #[cfg(feature = "native-auth")]
    fn test_cancel_body_signed() {
        use crate::domain::order::CancelBody;
        use solana_keypair::Keypair;
        use solana_signer::Signer;

        let keypair = Keypair::new();
        let order_hash = "abcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890";
        let maker = crate::shared::PubkeyStr::from_pubkey(keypair.pubkey());

        let body = CancelBody::signed(order_hash.to_string(), maker, &keypair);
        assert_eq!(body.signature.len(), 128);
        assert_eq!(body.order_hash, order_hash);

        let sig_bytes = hex::decode(&body.signature).unwrap();
        let sig = Signature::try_from(sig_bytes.as_slice()).unwrap();
        assert!(sig.verify(keypair.pubkey().as_ref(), order_hash.as_bytes()));
    }

    #[test]
    #[cfg(feature = "native-auth")]
    fn test_cancel_all_body_signed() {
        use crate::domain::order::CancelAllBody;
        use solana_keypair::Keypair;
        use solana_signer::Signer;

        let keypair = Keypair::new();
        let pubkey_str = crate::shared::PubkeyStr::from_pubkey(keypair.pubkey());
        let orderbook_id = crate::shared::OrderBookId::from("");
        let timestamp = 1700000000i64;
        let salt = "550e8400-e29b-41d4-a716-446655440000".to_string();

        let body = CancelAllBody::signed(
            pubkey_str.clone(),
            orderbook_id.clone(),
            timestamp,
            salt.clone(),
            &keypair,
        );
        assert_eq!(body.signature.len(), 128);
        assert_eq!(body.salt, salt);

        let message =
            cancel_all_message(pubkey_str.as_str(), orderbook_id.as_str(), timestamp, &salt);
        let sig_bytes = hex::decode(&body.signature).unwrap();
        let sig = Signature::try_from(sig_bytes.as_slice()).unwrap();
        assert!(sig.verify(keypair.pubkey().as_ref(), message.as_bytes()));
    }
}