use crate::error::{ProxyError, Result};
use serde::Serialize;
use serde_json::{Map, Value};
use sha2::{Digest, Sha256};
pub fn canonical_bytes<T: Serialize>(value: &T) -> Result<Vec<u8>> {
let json_value = serde_json::to_value(value)
.map_err(|error| ProxyError::Serialization(error.to_string()))?;
let mut output = Vec::new();
write_canonical_value(&json_value, &mut output)?;
Ok(output)
}
pub fn blake3_hash<T: Serialize>(value: &T) -> Result<String> {
let bytes = canonical_bytes(value)?;
Ok(format!("blake3:{}", blake3::hash(&bytes).to_hex()))
}
pub fn sha256_hex_of_canonical<T: Serialize>(value: &T) -> Result<String> {
let bytes = canonical_bytes(value)?;
let digest = Sha256::digest(&bytes);
Ok(hex::encode(digest))
}
fn write_canonical_value(value: &Value, output: &mut Vec<u8>) -> Result<()> {
match value {
Value::Null => output.extend_from_slice(b"null"),
Value::Bool(true) => output.extend_from_slice(b"true"),
Value::Bool(false) => output.extend_from_slice(b"false"),
Value::Number(number) => output.extend_from_slice(number.to_string().as_bytes()),
Value::String(text) => {
let encoded = serde_json::to_string(text)
.map_err(|error| ProxyError::Serialization(error.to_string()))?;
output.extend_from_slice(encoded.as_bytes());
}
Value::Array(items) => {
output.push(b'[');
for (index, item) in items.iter().enumerate() {
if index > 0 {
output.push(b',');
}
write_canonical_value(item, output)?;
}
output.push(b']');
}
Value::Object(object) => write_canonical_object(object, output)?,
}
Ok(())
}
fn write_canonical_object(object: &Map<String, Value>, output: &mut Vec<u8>) -> Result<()> {
output.push(b'{');
let mut entries: Vec<_> = object.iter().collect();
entries.sort_by(|left, right| left.0.cmp(right.0));
for (index, (key, value)) in entries.into_iter().enumerate() {
if index > 0 {
output.push(b',');
}
let encoded_key = serde_json::to_string(key)
.map_err(|error| ProxyError::Serialization(error.to_string()))?;
output.extend_from_slice(encoded_key.as_bytes());
output.push(b':');
write_canonical_value(value, output)?;
}
output.push(b'}');
Ok(())
}