sdk_client/src/api.rs

use std::any::Any;
use std::borrow::Borrow;
use std::collections::{HashMap, HashSet};
use std::io::Write;
use std::ops::Index;
use std::str::FromStr;
use std::string::FromUtf8Error;
use std::sync::{Mutex, MutexGuard, OnceLock, PoisonError};
use std::time::{Duration, Instant};
use std::u32;

use rand::{thread_rng, Fill, Rng, RngCore};
use sdk_common::aes_gcm::aead::generic_array::GenericArray;
use sdk_common::aes_gcm::aes::cipher::ArrayLength;
use sdk_common::aes_gcm::Nonce;
use sdk_common::log::{debug, warn, info};

use anyhow::Context;
use anyhow::Error as AnyhowError;
use anyhow::Result as AnyhowResult;
use sdk_common::aes_gcm::aead::{Aead, Payload};
use sdk_common::crypto::{
    encrypt_with_key, AeadCore, Aes256Gcm, AnkSharedSecretHash, KeyInit, AAD,
};
use sdk_common::process::{lock_processes, Process, ProcessState};
use sdk_common::signature::{AnkHash, AnkValidationNoHash, AnkValidationYesHash, Proof};
use sdk_common::sp_client::bitcoin::blockdata::fee_rate;
use sdk_common::sp_client::bitcoin::consensus::{deserialize, serialize};
use sdk_common::sp_client::bitcoin::hashes::{sha256, sha256t, Hash};
use sdk_common::sp_client::bitcoin::hashes::{FromSliceError, HashEngine};
use sdk_common::sp_client::bitcoin::hex::{
    self, parse, DisplayHex, FromHex, HexToArrayError, HexToBytesError,
};
use sdk_common::sp_client::bitcoin::key::{Parity, Secp256k1};
use sdk_common::sp_client::bitcoin::network::ParseNetworkError;
use sdk_common::sp_client::bitcoin::p2p::message::NetworkMessage;
use sdk_common::sp_client::bitcoin::psbt::raw;
use sdk_common::sp_client::bitcoin::secp256k1::ecdh::shared_secret_point;
use sdk_common::sp_client::bitcoin::secp256k1::{PublicKey, Scalar, SecretKey};
use sdk_common::sp_client::bitcoin::transaction::ParseOutPointError;
use sdk_common::sp_client::bitcoin::{
    Amount, Network, OutPoint, Psbt, Transaction, Txid, XOnlyPublicKey,
};
use sdk_common::sp_client::constants::{
    DUST_THRESHOLD, PSBT_SP_ADDRESS_KEY, PSBT_SP_PREFIX, PSBT_SP_SUBTYPE,
};
use sdk_common::sp_client::silentpayments::utils as sp_utils;
use sdk_common::sp_client::silentpayments::{
    utils::{Network as SpNetwork, SilentPaymentAddress},
    Error as SpError,
};
use sdk_common::{signature, MAX_PRD_PAYLOAD_SIZE};
use serde_json::{Error as SerdeJsonError, Map, Value};

use serde::{Deserialize, Serialize};
use tsify::{JsValueSerdeExt, Tsify};
use wasm_bindgen::convert::{FromWasmAbi, VectorFromWasmAbi};
use wasm_bindgen::prelude::*;

use sdk_common::device::Device;
use sdk_common::network::{
    self, AnkFlag, CachedMessage, CachedMessageStatus, CommitMessage, Envelope, FaucetMessage,
    NewTxMessage,
};
use sdk_common::pcd::{
    compare_maps, AnkPcdHash, AnkPcdTag, Member, Pcd, RoleDefinition, ValidationRule,
};
use sdk_common::prd::{AnkPrdHash, Prd, PrdType};
use sdk_common::silentpayments::{create_transaction, map_outputs_to_sp_address};
use sdk_common::sp_client::spclient::{
    derive_keys_from_seed, OutputList, OutputSpendStatus, OwnedOutput, Recipient, SpClient,
};
use sdk_common::sp_client::spclient::{SpWallet, SpendKey};

use crate::user::{lock_local_device, set_new_device, LOCAL_DEVICE};
use crate::wallet::{generate_sp_wallet, lock_freezed_utxos};
use crate::{lock_messages, CACHEDMESSAGES};

#[derive(Debug, PartialEq, Tsify, Serialize, Deserialize, Default)]
#[tsify(into_wasm_abi, from_wasm_abi)]
#[allow(non_camel_case_types)]
pub struct ApiReturn {
    pub updated_cached_msg: Vec<CachedMessage>,
    pub updated_process: Option<(String, Process)>,
    pub new_tx_to_send: Option<NewTxMessage>,
    pub ciphers_to_send: Vec<String>,
    pub commit_to_send: Option<CommitMessage>,
}

pub type ApiResult<T: FromWasmAbi> = Result<T, ApiError>;

const IS_TESTNET: bool = true;
const DEFAULT_AMOUNT: Amount = Amount::from_sat(1000);

#[derive(Debug, PartialEq, Eq)]
pub struct ApiError {
    pub message: String,
}

impl ApiError {
    pub fn new(message: String) -> Self {
        ApiError { message }
    }
}

impl From<AnyhowError> for ApiError {
    fn from(value: AnyhowError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<SpError> for ApiError {
    fn from(value: SpError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<FromSliceError> for ApiError {
    fn from(value: FromSliceError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<SerdeJsonError> for ApiError {
    fn from(value: SerdeJsonError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<HexToBytesError> for ApiError {
    fn from(value: HexToBytesError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<HexToArrayError> for ApiError {
    fn from(value: HexToArrayError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<sdk_common::sp_client::bitcoin::psbt::PsbtParseError> for ApiError {
    fn from(value: sdk_common::sp_client::bitcoin::psbt::PsbtParseError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<sdk_common::sp_client::bitcoin::psbt::ExtractTxError> for ApiError {
    fn from(value: sdk_common::sp_client::bitcoin::psbt::ExtractTxError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<sdk_common::sp_client::bitcoin::secp256k1::Error> for ApiError {
    fn from(value: sdk_common::sp_client::bitcoin::secp256k1::Error) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<sdk_common::sp_client::bitcoin::consensus::encode::Error> for ApiError {
    fn from(value: sdk_common::sp_client::bitcoin::consensus::encode::Error) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<FromUtf8Error> for ApiError {
    fn from(value: FromUtf8Error) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<ParseNetworkError> for ApiError {
    fn from(value: ParseNetworkError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl From<ParseOutPointError> for ApiError {
    fn from(value: ParseOutPointError) -> Self {
        ApiError::new(value.to_string())
    }
}

impl Into<JsValue> for ApiError {
    fn into(self) -> JsValue {
        JsValue::from_str(&self.message)
    }
}

#[wasm_bindgen]
pub fn setup() {
    wasm_logger::init(wasm_logger::Config::default());
}

#[wasm_bindgen]
pub fn get_address() -> ApiResult<String> {
    let local_device = lock_local_device()?;

    Ok(local_device
        .get_wallet()
        .get_client()
        .get_receiving_address())
}

#[wasm_bindgen]
pub fn restore_device(device_str: String) -> ApiResult<()> {
    let device: Device = serde_json::from_str(&device_str)?;

    let mut local_device = lock_local_device()?;

    *local_device = device;

    Ok(())
}

#[wasm_bindgen]
pub fn create_device_from_sp_wallet(sp_wallet: String) -> ApiResult<String> {
    let sp_wallet: SpWallet = serde_json::from_str(&sp_wallet)?;

    let our_address = set_new_device(sp_wallet)?;

    Ok(our_address)
}

#[wasm_bindgen]
pub fn create_new_device(birthday: u32, network_str: String) -> ApiResult<String> {
    let sp_wallet = generate_sp_wallet(None, Network::from_core_arg(&network_str)?)?;

    let our_address = set_new_device(sp_wallet)?;

    Ok(our_address)
}

#[wasm_bindgen]
pub fn pair_device(commitment_tx: String, mut sp_addresses: Vec<String>) -> ApiResult<()> {
    let mut local_device = lock_local_device()?;

    if local_device.is_linked() {
        return Err(ApiError::new("Already paired".to_owned()));
    }

    sp_addresses.push(
        local_device
            .get_wallet()
            .get_client()
            .get_receiving_address(),
    );

    local_device.pair(
        OutPoint::from_str(&commitment_tx)?.txid,
        Member::new(
            sp_addresses
                .into_iter()
                .map(|a| TryInto::<SilentPaymentAddress>::try_into(a).unwrap())
                .collect(),
        )?,
    );

    Ok(())
}

#[wasm_bindgen]
pub fn unpair_device() -> ApiResult<()> {
    let mut local_device = lock_local_device()?;

    local_device.unpair();

    Ok(())
}

#[derive(Debug, Tsify, Serialize, Deserialize)]
#[tsify(from_wasm_abi, into_wasm_abi)]
#[allow(non_camel_case_types)]
pub struct outputs_list(OutputList);

impl outputs_list {
    fn as_inner(&self) -> &OutputList {
        &self.0
    }
}

#[wasm_bindgen]
pub fn login(previous_login_tx: String, fee_rate: u32) -> ApiResult<ApiReturn> {
    // We first create a transaction that spends both pairing tx outputs
    let previous_tx: Txid = deserialize(&Vec::from_hex(&previous_login_tx)?)?;

    let device = lock_local_device()?;
    if !device.is_linked() {
        return Err(ApiError::new("Device is not linked".to_owned()));
    }

    let member = device.to_member().unwrap();
    let nb_outputs = member.get_addresses().len();

    let other_addresses = device.get_other_addresses();

    // We get the pairing process out of cache
    let commitment_txid = device.get_process_commitment().unwrap();
    let commitment_outpoint = OutPoint::new(commitment_txid, 0);

    let process = lock_processes()?.get(&commitment_outpoint).unwrap().clone();
    let state = process.get_latest_state().unwrap().clone();

    let mut shared_secrets = Vec::new();
    for address in other_addresses {
        let shared_secret =
            process.get_shared_secret_for_address(&SilentPaymentAddress::try_from(address)?);
        if let Some(shared_secret) = shared_secret {
            shared_secrets.push(shared_secret);
        }
    }

    let mut decrypted_pcd = Map::new();
    state
        .encrypted_pcd
        .decrypt_fields(&state.keys, &mut decrypted_pcd)?;

    let pairing_tx = decrypted_pcd.get("pairing_tx").unwrap().as_str().unwrap();

    let wallet = device.get_wallet();

    let freezed_utxos = lock_freezed_utxos()?;

    let recipients: Vec<Recipient> = device
        .to_member()
        .unwrap()
        .get_addresses()
        .iter()
        .map(|a| Recipient {
            address: a.clone(),
            amount: DEFAULT_AMOUNT,
            nb_outputs: 1,
        })
        .collect();

    let mut mandatory_inputs = Vec::new();
    for i in 0u32..nb_outputs.try_into().unwrap() {
        mandatory_inputs.push(OutPoint::new(previous_tx, i));
    }

    let signed_psbt = create_transaction(
        mandatory_inputs,
        &freezed_utxos,
        wallet,
        recipients,
        None,
        Amount::from_sat(fee_rate.into()),
        None,
    )?;

    // We send it in a TxProposal prd
    let tx_proposal = Prd::new_tx_proposal(commitment_outpoint, member, signed_psbt);

    debug!("tx_proposal: {:?}", tx_proposal);
    // We encrypt the prd with the shared_secret for pairing process
    let prd_msg = tx_proposal.to_network_msg(wallet)?;
    debug!("prd_msg: {:?}", prd_msg);
    let mut ciphers = Vec::new();
    for shared_secret in shared_secrets {
        let cipher = encrypt_with_key(shared_secret.as_byte_array(), prd_msg.as_bytes())?;
        ciphers.push(cipher.to_lower_hex_string());
    }
    // We return the cipher
    Ok(ApiReturn {
        ciphers_to_send: ciphers,
        ..Default::default()
    })
}

#[wasm_bindgen]
pub fn logout() -> ApiResult<()> {
    unimplemented!();
}

#[wasm_bindgen]
pub fn dump_wallet() -> ApiResult<String> {
    let device = lock_local_device()?;

    Ok(serde_json::to_string(device.get_wallet()).unwrap())
}

#[wasm_bindgen]
pub fn reset_process_cache() -> ApiResult<()> {
    let mut cached_processes = lock_processes()?;

    *cached_processes = HashMap::new();

    debug_assert!(cached_processes.is_empty());

    Ok(())
}

#[wasm_bindgen]
pub fn dump_process_cache() -> ApiResult<String> {
    let cached_processes = lock_processes()?;

    let serializable_cache = cached_processes
        .iter()
        .map(|(outpoint, process)| {
            (
                outpoint.to_string(),
                serde_json::to_value(&process).unwrap(),
            )
        })
        .collect::<serde_json::Map<String, Value>>();

    let json_string = serde_json::to_string(&serializable_cache)
        .map_err(|e| ApiError::new(format!("Failed to serialize process cache: {}", e)))?;

    Ok(json_string)
}

#[wasm_bindgen]
pub fn set_process_cache(processes: String) -> ApiResult<()> {
    let processes: Map<String, Value> = serde_json::from_str(&processes)?;

    let parsed_processes: anyhow::Result<HashMap<OutPoint, Process>> = processes.into_iter()
        .map(|(key, value)| {
            Ok((OutPoint::from_str(&key)?, serde_json::from_value(value)?))
        })
        .collect();

    let mut cached_processes = lock_processes()?;

    *cached_processes = parsed_processes?;

    Ok(())
}

#[wasm_bindgen]
pub fn reset_message_cache() -> ApiResult<()> {
    let mut cached_msg = lock_messages()?;

    *cached_msg = vec![];

    debug_assert!(cached_msg.is_empty());

    Ok(())
}

#[wasm_bindgen]
pub fn set_message_cache(msg_cache: Vec<String>) -> ApiResult<()> {
    let mut cached_msg = lock_messages()?;

    if !cached_msg.is_empty() {
        return Err(ApiError::new("Message cache not empty".to_owned()));
    }

    let new_cache: Result<Vec<CachedMessage>, serde_json::Error> =
        msg_cache.iter().map(|m| serde_json::from_str(m)).collect();

    *cached_msg = new_cache?;

    Ok(())
}

#[wasm_bindgen]
pub fn dump_message_cache() -> ApiResult<Vec<String>> {
    let cached_msg = lock_messages()?;

    let res: Vec<String> = cached_msg
        .iter()
        .map(|m| serde_json::to_string(m).unwrap())
        .collect();

    Ok(res)
}

#[wasm_bindgen]
pub fn dump_device() -> ApiResult<String> {
    let local_device = lock_local_device()?;

    Ok(serde_json::to_string(&local_device.clone())?)
}

#[wasm_bindgen]
pub fn reset_device() -> ApiResult<()> {
    let mut device = lock_local_device()?;

    *device = Device::default();

    reset_message_cache()?;
    reset_process_cache()?;

    Ok(())
}

#[wasm_bindgen]
pub fn get_txid(transaction: String) -> ApiResult<String> {
    let tx: Transaction = deserialize(&Vec::from_hex(&transaction)?)?;

    Ok(tx.txid().to_string())
}

fn handle_transaction(
    updated: HashMap<OutPoint, OwnedOutput>,
    tx: &Transaction,
    tweak_data: PublicKey,
) -> AnyhowResult<ApiReturn> {
    let b_scan = lock_local_device()?.get_wallet().get_client().get_scan_key();

    let op_return: Vec<&sdk_common::sp_client::bitcoin::TxOut> = tx
        .output
        .iter()
        .filter(|o| o.script_pubkey.is_op_return())
        .collect();
    if op_return.len() != 1 {
        return Err(AnyhowError::msg(
            "Transaction must have exactly one op_return output",
        ));
    }
    let commitment =
        AnkPrdHash::from_slice(&op_return.first().unwrap().script_pubkey.as_bytes()[2..])?;

    // Basically a transaction that destroyed utxo is a transaction we sent.
    let utxo_destroyed: HashMap<&OutPoint, &OwnedOutput> = updated
        .iter()
        .filter(|(outpoint, output)| output.spend_status != OutputSpendStatus::Unspent)
        .collect();

    let mut messages = lock_messages()?;

    // empty utxo_destroyed means we received this transaction
    if utxo_destroyed.is_empty() {
        let shared_point = sp_utils::receiving::calculate_ecdh_shared_secret(
            &tweak_data,
            &b_scan,
        );
        let shared_secret = AnkSharedSecretHash::from_shared_point(shared_point);

        let mut plaintext: Vec<u8> = vec![];
        if let Some(message) = messages.iter_mut().find(|m| {
            if m.status != CachedMessageStatus::CipherWaitingTx {
                return false;
            }
            let res = m.try_decrypt_with_shared_secret(shared_secret.to_byte_array());
            if res.is_ok() {
                plaintext = res.unwrap();
                return true;
            } else {
                return false;
            }
        }) {
            // Calling this check that the prd we found check with the hashed commitment in transaction
            // We also check the signed proof that is included in the prd
            let prd = Prd::extract_from_message_with_commitment(&plaintext, &commitment)?;

            // for now the previous method doesn't error if proof is missing, 
            // We must define if there are cases where a valid prd doesn't have proof

            let outpoint = OutPoint::from_str(&prd.root_commitment)?;

            handle_decrypted_message(plaintext, Some(shared_secret), Some(outpoint))
        } else {
            // store it and wait for the message
            let mut new_msg = CachedMessage::new();
            new_msg.commitment = Some(commitment.as_byte_array().to_lower_hex_string());
            new_msg
                .shared_secrets
                .push(shared_secret.to_byte_array().to_lower_hex_string());
            new_msg.status = CachedMessageStatus::TxWaitingPrd;

            messages.push(new_msg.clone());

            return Ok(ApiReturn {
                updated_cached_msg: vec![new_msg.clone()],
                ..Default::default()
            });
        }
    } else {
        // We're sender of the transaction, do nothing
        return Ok(ApiReturn {
            ..Default::default()
        });
    }
}

/// If the transaction has anything to do with us, we create/update the relevant process
/// and return it to caller for persistent storage
fn process_transaction(
    tx_hex: String,
    blockheight: u32,
    tweak_data_hex: String,
) -> anyhow::Result<ApiReturn> {
    let tx = deserialize::<Transaction>(&Vec::from_hex(&tx_hex)?)?;

    let tweak_data = PublicKey::from_str(&tweak_data_hex)?;

    let updated: HashMap<OutPoint, OwnedOutput>;
    {
        let mut device = lock_local_device()?;
        let wallet = device.get_mut_wallet();
        updated = wallet.update_wallet_with_transaction(&tx, blockheight, tweak_data)?;
    }

    if updated.len() > 0 {
        return handle_transaction(updated, &tx, tweak_data);
    }

    Err(anyhow::Error::msg("Transaction is not our"))
}

#[wasm_bindgen]
pub fn parse_new_tx(new_tx_msg: String, block_height: u32, fee_rate: u32) -> ApiResult<ApiReturn> {
    let new_tx: NewTxMessage = serde_json::from_str(&new_tx_msg)?;

    if let Some(error) = new_tx.error {
        return Err(ApiError::new(format!(
            "NewTx returned with an error: {}",
            error
        )));
    }

    if new_tx.tweak_data.is_none() {
        return Err(ApiError::new("Missing tweak_data".to_owned()));
    }

    Ok(process_transaction(
        new_tx.transaction,
        block_height,
        new_tx.tweak_data.unwrap(),
    )?)
}

fn try_decrypt_with_processes(
    cipher: &[u8],
    processes: MutexGuard<HashMap<OutPoint, Process>>,
) -> Option<(Vec<u8>, SilentPaymentAddress, OutPoint)> {
    let nonce = Nonce::from_slice(&cipher[..12]);

    for (outpoint, process) in processes.iter() {
        for (address, secret) in process.get_all_secrets() {
            let engine = Aes256Gcm::new(&secret.to_byte_array().into());
            if let Ok(plain) = engine.decrypt(
                &nonce,
                Payload {
                    msg: &cipher[12..],
                    aad: AAD,
                },
            ) {
                return Some((plain, address, *outpoint));
            }
        }
    }
    None
}

#[wasm_bindgen]
/// Produce a proof and append it to a prd
pub fn add_validation_token_to_prd(
    root_commitment: String,
    prd_commitment: String,
    approval: bool,
) -> ApiResult<ApiReturn> {
    let prd_hash = AnkPrdHash::from_str(&prd_commitment)?;
    let outpoint = OutPoint::from_str(&root_commitment)?;

    // find the prd in the registered process
    let mut processes = lock_processes()?;
    let process = processes
        .get_mut(&outpoint)
        .ok_or(ApiError::new("Unknown process".to_owned()))?;

    let prd_ref = process
        .get_impending_requests_mut()
        .into_iter()
        .find(|r| r.create_commitment() == prd_hash)
        .ok_or(ApiError::new(
            "Failed to find the prd in registered processes".to_owned(),
        ))?;

    let local_device = lock_local_device()?;

    let wallet = local_device.get_wallet();

    let spend_key: SecretKey = wallet.get_client().get_spend_key().try_into()?;

    match prd_ref.prd_type {
        PrdType::Update => {
            let new_state = Value::from_str(&prd_ref.payload)?;

            let new_state_commitment = new_state.tagged_hash();

            let message_hash = if approval {
                AnkHash::ValidationYes(AnkValidationYesHash::from_commitment(new_state_commitment))
            } else {
                AnkHash::ValidationNo(AnkValidationNoHash::from_commitment(new_state_commitment))
            };

            let proof = Proof::new(message_hash, spend_key);

            prd_ref.validation_tokens.push(proof);

            Ok(ApiReturn {
                updated_process: Some((root_commitment, process.clone())),
                ..Default::default()
            })
        }
        _ => return Err(ApiError::new("Can't validate that prd".to_owned())),
    }
}

#[wasm_bindgen]
pub fn response_prd(
    root_commitment: String,
    prd_commitment: String, // The commitment to the Prd we respond to
    approval: bool,
) -> ApiResult<ApiReturn> {
    let prd_hash = AnkPrdHash::from_str(&prd_commitment)?;
    let outpoint = OutPoint::from_str(&root_commitment)?;
    let local_device = lock_local_device()?;
    let member = local_device
        .to_member()
        .ok_or(ApiError::new("Unpaired device".to_owned()))?;

    // find the prd in the registered process
    let mut processes = lock_processes()?;
    let process = processes
        .get_mut(&outpoint)
        .ok_or(ApiError::new("Unknown process".to_owned()))?;

    let prd_ref = process
        .get_impending_requests_mut()
        .into_iter()
        .find(|r| r.create_commitment() == prd_hash)
        .ok_or(ApiError::new(
            "Failed to find the prd in registered processes".to_owned(),
        ))?;

    match prd_ref.prd_type {
        PrdType::Update => {
            let pcd_hash: AnkPcdHash = AnkPcdHash::from_value(&Value::from_str(&prd_ref.payload)?);

            let prd_response = Prd::new_response(
                OutPoint::from_str(&root_commitment)?,
                serde_json::to_string(&member)?,
                prd_ref.validation_tokens.clone(),
                pcd_hash,
            );

            let prd_msg = prd_response.to_network_msg(local_device.get_wallet())?;

            let mut ciphers = vec![];
            for (sp_address, shared_secret) in process.get_all_secrets() {
                if sp_address.to_string()
                    == local_device
                        .get_wallet()
                        .get_client()
                        .get_receiving_address()
                {
                    continue;
                }
                let cipher = encrypt_with_key(shared_secret.as_byte_array(), prd_msg.as_bytes())?;
                ciphers.push(cipher.to_lower_hex_string());
            }

            return Ok(ApiReturn {
                ciphers_to_send: ciphers,
                ..Default::default()
            });
        }
        _ => unimplemented!(),
    };
}

fn confirm_prd(prd: Prd, shared_secret: &AnkSharedSecretHash) -> AnyhowResult<String> {
    match prd.prd_type {
        PrdType::Confirm | PrdType::Response | PrdType::List => {
            return Err(AnyhowError::msg("Invalid prd type"));
        }
        _ => (),
    }

    let outpoint = OutPoint::from_str(&prd.root_commitment)?;

    let local_device = lock_local_device()?;
    let member = match local_device.to_member() {
        Some(member) => member,
        None => {
            // This might be because we're pairing, let's see if our address is part of sender of the initial prd
            let remote_member: Member = serde_json::from_str(&prd.sender)?;
            let addresses = remote_member.get_addresses();
            let this_device_address = local_device
                .get_wallet()
                .get_client()
                .get_receiving_address();
            if let Some(_) = addresses.into_iter().find(|a| *a == this_device_address) {
                remote_member
            } else {
                return Err(AnyhowError::msg("Must pair device first"));
            }
        }
    };

    let pcd_commitment = AnkPcdHash::from_str(&prd.payload)?;

    let prd_confirm = Prd::new_confirm(outpoint, member, pcd_commitment);

    let prd_msg = prd_confirm.to_network_msg(local_device.get_wallet())?;

    Ok(encrypt_with_key(shared_secret.as_byte_array(), prd_msg.as_bytes())?.to_lower_hex_string())
}

fn send_data(prd: &Prd, shared_secret: &AnkSharedSecretHash) -> AnyhowResult<ApiReturn> {
    let pcd = &prd.payload;

    let cipher = encrypt_with_key(shared_secret.as_byte_array(), pcd.as_bytes())?;

    Ok(ApiReturn {
        ciphers_to_send: vec![cipher.to_lower_hex_string()],
        ..Default::default()
    })
}

fn decrypt_with_cached_messages(
    cipher: &[u8],
    messages: &mut MutexGuard<Vec<CachedMessage>>
) -> anyhow::Result<Option<(Vec<u8>, AnkSharedSecretHash)>> {
    let nonce = Nonce::from_slice(&cipher[..12]);

    for message in messages.iter_mut() {
        for shared_secret in message.shared_secrets.iter() {
            let aes_key = match AnkSharedSecretHash::from_str(shared_secret) {
                Ok(key) => key,
                Err(_) => {
                    debug!(
                        "Invalid shared secret for message{}: {}",
                        message.id, shared_secret
                    );
                    continue;
                }
            };

            let engine = Aes256Gcm::new(aes_key.as_byte_array().into());

            let plain = match engine.decrypt(
                &nonce,
                Payload {
                    msg: &cipher[12..],
                    aad: AAD,
                },
            ) {
                Ok(plain) => plain,
                Err(_) => continue,
            };

            let commitment = AnkPrdHash::from_str(
                message
                    .commitment
                    .as_ref()
                    .ok_or(anyhow::Error::msg("Missing commitment".to_owned()))?,
            )?;
            // A message matched against a new transaction must be a prd
            // We just check the commitment while we're at it
            let _ = Prd::extract_from_message_with_commitment(&plain, &commitment)?;
            // Update the message status
            message.status = CachedMessageStatus::NoStatus;
            message.shared_secrets = vec![]; // this way we won't check it again

            return Ok(Some((
                plain,
                aes_key,
            )));
        }
    }

    Ok(None)
}

fn decrypt_with_known_processes(cipher: &[u8], processes: MutexGuard<HashMap<OutPoint, Process>>) -> anyhow::Result<Option<(Vec<u8>, OutPoint)>> {
    let nonce = Nonce::from_slice(&cipher[..12]);

    for (outpoint, process) in processes.iter() {
        for (address, secret) in process.get_all_secrets() {
            debug!("Attempting decryption with key {} for {}", secret, address);
            let engine = Aes256Gcm::new(secret.as_byte_array().into());

            if let Ok(plain) = engine.decrypt(
                &nonce,
                Payload {
                    msg: &cipher[12..],
                    aad: AAD,
                },
            ) {
                return Ok(Some((plain, *outpoint)));
            }
        }
    }
    Ok(None)
}

/// Prd can come with an attached transaction or without
/// It's useful to commit it in a transaction in the case there are multiple recipients (guarantee that everyone gets the same payload)
/// Or if for some reasons we don't want to use the same shared secret again
fn handle_prd(
    plain: &[u8],
    new_shared_secret: Option<AnkSharedSecretHash>,
) -> AnyhowResult<ApiReturn> {
    // We already checked the commitment if any
    let prd = Prd::extract_from_message(plain)?;

    debug!("found prd: {:#?}", prd);

    let proof_key = prd.proof.unwrap().get_key();

    let sp_address = serde_json::from_str::<Member>(&prd.sender)?
        .get_addresses()
        .into_iter()
        .find_map(|address| {
            let parsed_address = SilentPaymentAddress::try_from(address.as_str()).ok()?;
            let spend_key = parsed_address.get_spend_key().x_only_public_key().0;
            if spend_key == proof_key {
                Some(parsed_address)
            } else {
                None
            }
        })
        .ok_or_else(|| anyhow::Error::msg("No matching address found for the proof key"))?;

    let outpoint = OutPoint::from_str(&prd.root_commitment)?;

    let mut processes = lock_processes()?;
    let relevant_process = match processes.entry(outpoint) {
        std::collections::hash_map::Entry::Occupied(entry) => entry.into_mut(),
        std::collections::hash_map::Entry::Vacant(entry) => {
            debug!("Creating new process for outpoint: {}", outpoint);
            let shared_secret = new_shared_secret
                .ok_or_else(|| anyhow::Error::msg("Missing shared secret for new process"))?;
            let mut shared_secrets = HashMap::new();
            shared_secrets.insert(sp_address, shared_secret);
            entry.insert(Process::new(vec![], shared_secrets, vec![]))
        }
    };

    match prd.prd_type {
        PrdType::Confirm => {
            // It must match a prd we sent previously
            // We send the whole data in a pcd
            debug!("Received confirm prd {:#?}", prd);
            let original_request = relevant_process
                .get_impending_requests()
                .into_iter()
                .find(|r| {
                    if r.prd_type != PrdType::Update {
                        return false;
                    }
                    let hash = Value::from_str(&r.payload).unwrap().tagged_hash();
                    hash.to_string() == prd.payload
                })
                .ok_or(anyhow::Error::msg("Original request not found"))?;
            let shared_secret = relevant_process
                .get_shared_secret_for_address(&sp_address)
                .ok_or(anyhow::Error::msg(
                    "Missing shared secret for address in original request",
                ))?;

            return send_data(original_request, &shared_secret);
        }
        PrdType::Update | PrdType::TxProposal | PrdType::Message => {
            // Those all have some new data we don't know about yet
            // We send a Confirm to get the pcd
            // Add the prd to our list of actions for this process
            relevant_process.insert_impending_request(prd.clone());
            let shared_secret = relevant_process
                .get_shared_secret_for_address(&sp_address)
                .ok_or(anyhow::Error::msg(
                    "Missing shared secret for address in original request",
                ))?;

            let cipher = confirm_prd(prd, &shared_secret)?;

            return Ok(ApiReturn {
                ciphers_to_send: vec![cipher],
                updated_process: Some((outpoint.to_string(), relevant_process.clone())),
                ..Default::default()
            });
        }
        PrdType::Response => {
            // We must know of a prd update that the response answers to
            let original_request = relevant_process
                .get_impending_requests_mut()
                .into_iter()
                .find(|r| {
                    if r.prd_type != PrdType::Update {
                        return false;
                    }
                    let hash = Value::from_str(&r.payload).unwrap().tagged_hash();
                    hash.to_string() == prd.payload
                })
                .ok_or(anyhow::Error::msg("Original request not found"))?;

            // Once we found the prd update, we can add the received proofs as validation tokens
            original_request
                .validation_tokens
                .extend(prd.validation_tokens);

            // We must return an update of the process
            let updated_process = (prd.root_commitment, relevant_process.clone());

            return Ok(ApiReturn {
                updated_process: Some(updated_process),
                ..Default::default()
            });
        }
        _ => unimplemented!(),
    }
}

fn handle_pcd(plain: Vec<u8>, root_commitment: OutPoint) -> AnyhowResult<ApiReturn> {
    let pcd = Value::from_str(&String::from_utf8(plain)?)?;

    let pcd_commitment = pcd.tagged_hash();

    let mut processes = lock_processes()?;
    let relevant_process = processes.get_mut(&root_commitment).unwrap();

    // We match the pcd with a prd and act accordingly
    let prd = relevant_process
        .get_impending_requests_mut()
        .into_iter()
        .find(|r| *r.payload == pcd_commitment.to_string())
        .ok_or(AnyhowError::msg("Failed to retrieve the matching prd"))?;

    // We update the process and return it
    prd.payload = pcd.to_string();

    return Ok(ApiReturn {
        updated_process: Some((root_commitment.to_string(), relevant_process.clone())),
        ..Default::default()
    });
}

fn handle_decrypted_message(
    plain: Vec<u8>,
    shared_secret: Option<AnkSharedSecretHash>,
    root_commitment: Option<OutPoint>,
) -> anyhow::Result<ApiReturn> {
    // Try to handle as PRD first
    handle_prd(&plain, shared_secret)
        .or_else(|_| {
            // If PRD handling fails, try to handle as PCD
            handle_pcd(
                plain,
                root_commitment.ok_or(anyhow::Error::msg(
                    "root_commitment must be known for a pcd",
                ))?,
            )
        })
        .map_err(|e| anyhow::Error::msg(format!("Failed to handle decrypted message: {}", e)))
}

#[wasm_bindgen]
pub fn parse_cipher(cipher_msg: String) -> ApiResult<ApiReturn> {
    // We lock message cache and processes to prevent race conditions
    let mut messages = lock_messages()?;
    let processes = lock_processes()?;

    // Check that the cipher is not empty or too long
    if cipher_msg.is_empty() || cipher_msg.len() > MAX_PRD_PAYLOAD_SIZE {
        return Err(ApiError::new(
            "Invalid cipher: empty or too long".to_owned(),
        ));
    }

    let cipher = Vec::from_hex(cipher_msg.trim_matches('"'))?;

    // Try decrypting with cached messages first
    if let Ok(Some((plain, shared_secret))) = decrypt_with_cached_messages(&cipher, &mut messages) {
        return handle_decrypted_message(plain, Some(shared_secret), None)
            .map_err(|e| ApiError::new(format!("Failed to handle decrypted message: {}", e)));
    }

    // If that fails, try decrypting with known processes
    if let Ok(Some((plain, root_commitment))) = decrypt_with_known_processes(&cipher, processes) {
        return handle_decrypted_message(plain, None, Some(root_commitment))
            .map_err(|e| ApiError::new(format!("Failed to handle decrypted message: {}", e)));
    }

    // If both decryption attempts fail, we keep it just in case we receive the transaction later 
    let mut return_msg = CachedMessage::new();
    return_msg.cipher = vec![cipher_msg];
    return_msg.status = CachedMessageStatus::CipherWaitingTx;

    messages.push(return_msg.clone());

    Ok(ApiReturn {
        updated_cached_msg: vec![return_msg],
        ..Default::default()
    })
}

#[wasm_bindgen]
pub fn get_outputs() -> ApiResult<JsValue> {
    let device = lock_local_device()?;
    let outputs = device.get_wallet().get_outputs().clone();
    Ok(JsValue::from_serde(&outputs.to_outpoints_list())?)
}

#[wasm_bindgen]
pub fn get_available_amount() -> ApiResult<u64> {
    let device = lock_local_device()?;

    Ok(device.get_wallet().get_outputs().get_balance().to_sat())
}

#[wasm_bindgen]
/// This takes a reference to a process and creates a commit msg for the latest state
pub fn create_commit_message(
    init_commitment_outpoint: String,
    relay_address: String,
    fee_rate: u32,
) -> ApiResult<ApiReturn> {
    let outpoint = OutPoint::from_str(&init_commitment_outpoint)?;

    if let Some(process) = lock_processes()?.get(&outpoint) {
        match process.get_number_of_states() {
            0 => Err(ApiError::new("Process has no states".to_owned())),
            1 => {
                // This is a creation
                let state = process.get_latest_state().unwrap();
                if state.commited_in.vout != u32::MAX {
                    return Err(ApiError::new("Latest state is already commited".to_owned()));
                }
                let encrypted_pcd = state.encrypted_pcd.clone();
                let keys = state.keys.clone();

                let freezed_utxos = lock_freezed_utxos()?;

                let local_device = lock_local_device()?;

                let sp_wallet = local_device.get_wallet();

                let signed_psbt = create_transaction(
                    vec![],
                    &freezed_utxos,
                    sp_wallet,
                    vec![Recipient {
                        address: relay_address,
                        amount: Amount::from_sat(1000),
                        nb_outputs: 1,
                    }],
                    None,
                    Amount::from_sat(fee_rate.into()),
                    None,
                )?;

                let tx = signed_psbt.extract_tx()?;

                Ok(ApiReturn {
                    commit_to_send: Some(CommitMessage::new_first_commitment(
                        tx,
                        encrypted_pcd.as_object().unwrap().clone(),
                        keys,
                    )),
                    ..Default::default()
                })
            }
            _ => {
                // We're updating an existing process
                // Check that initial outpoint is not a placeholder and that latest state has a commited_in of null
                if outpoint.vout != u32::MAX {
                    return Err(ApiError::new(
                        "Initial outpoint is a placeholder".to_owned(),
                    ));
                }
                let state = process.get_latest_state().unwrap();
                if state.commited_in != OutPoint::null() {
                    return Err(ApiError::new("Latest state is already commited".to_owned()));
                }
                let encrypted_pcd = state.encrypted_pcd.clone();
                let keys = state.keys.clone();
                // We just send the message with the outpoint
                return Ok(ApiReturn {
                    commit_to_send: Some(CommitMessage::new_update_commitment(
                        outpoint,
                        encrypted_pcd.as_object().unwrap().clone(),
                        keys,
                    )),
                    ..Default::default()
                });
            }
        }
    } else {
        return Err(ApiError::new("Process not found".to_owned()));
    }
}

#[wasm_bindgen]
/// We assume that the provided tx outpoint exist
pub fn create_update_transaction(
    init_commitment: Option<String>,
    new_state: String,
    fee_rate: u32,
) -> ApiResult<ApiReturn> {
    let pcd = Value::from_str(&new_state)?;
    let pcd_map = pcd
        .as_object()
        .ok_or(ApiError::new("new_state must be an object".to_owned()))?;

    let mut processes = lock_processes()?;

    let commitment_outpoint: OutPoint;
    let relevant_process: &mut Process;
    if let Some(s) = init_commitment {
        // We're updating an existing contract
        let outpoint = OutPoint::from_str(&s)?;

        if let Some(p) = processes.get_mut(&outpoint) {
            // compare the provided new_state with the process defined template
            let previous_state = &p.get_state_at(0).unwrap().encrypted_pcd;
            if !compare_maps(previous_state.as_object().unwrap(), pcd_map) {
                return Err(ApiError::new(
                    "Provided updated state is not consistent with the process template".to_owned(),
                ));
            }
            relevant_process = p;
            commitment_outpoint = outpoint;
        } else {
            // This is a process we don't know about, so we insert a new entry
            processes.insert(outpoint, Process::default());
            relevant_process = processes.get_mut(&outpoint).unwrap();
            commitment_outpoint = outpoint;
        }
    } else {
        // This is a creation with an init state, the commitment will come later
        // We need a placeholder to keep track of the process before it's commited on chain
        // We can take the hash of the init_state as a txid, and set the vout to the max as it is very unlikely to ever have a real commitment that will look like this
        let dummy = pcd.tagged_hash();

        let dummy_outpoint = OutPoint::new(Txid::from_slice(dummy.as_byte_array())?, u32::MAX);

        processes.insert(dummy_outpoint, Process::default());

        relevant_process = processes.get_mut(&dummy_outpoint).unwrap();
        commitment_outpoint = dummy_outpoint;
    }

    // We assume that all processes must have a roles key
    let roles = pcd
        .get("roles")
        .ok_or(ApiError::new("No roles in new_state".to_owned()))?;
    let roles_map = roles
        .as_object()
        .ok_or(ApiError::new("roles is not an object".to_owned()))?
        .clone();
    let mut all_members: HashMap<Member, HashSet<String>> = HashMap::new();
    for (name, role_def) in roles_map {
        let role: RoleDefinition = serde_json::from_str(&role_def.to_string())?;
        let fields: Vec<String> = role
            .validation_rules
            .iter()
            .flat_map(|rule| rule.fields.clone())
            .collect();
        for member in role.members {
            if !all_members.contains_key(&member) {
                all_members.insert(member.clone(), HashSet::new());
            }
            all_members.get_mut(&member).unwrap().extend(fields.clone());
        }
    }

    let nb_recipients = all_members.len();
    if nb_recipients == 0 {
        return Err(ApiError::new(
            "Can't create a process with 0 member".to_owned(),
        ));
    }

    let mut recipients: Vec<Recipient> = Vec::with_capacity(nb_recipients * 2); // We suppose that will work most of the time
                                                                                // we actually have multiple "recipients" in a technical sense for each social recipient
                                                                                // that's necessary because we don't want to miss a notification because we don't have a device atm
    for member in all_members.keys() {
        let addresses = member.get_addresses();
        for sp_address in addresses.into_iter() {
            recipients.push(Recipient {
                address: sp_address.into(),
                amount: DEFAULT_AMOUNT,
                nb_outputs: 1,
            });
        }
    }

    let mut fields2keys = Map::new();
    let mut fields2cipher = Map::new();
    let encrypted_pcd = pcd.clone();
    let fields_to_encrypt: Vec<String> = encrypted_pcd
        .as_object()
        .unwrap()
        .keys()
        .map(|k| k.clone())
        .collect();
    encrypted_pcd.encrypt_fields(&fields_to_encrypt, &mut fields2keys, &mut fields2cipher);

    let local_device = lock_local_device()?;

    let sp_wallet = local_device.get_wallet();

    let sender: Member = local_device
        .to_member()
        .ok_or(ApiError::new("unpaired device".to_owned()))?;

    // We first generate the prd with all the keys that we will keep to ourselves
    let full_prd = Prd::new_update(
        commitment_outpoint,
        serde_json::to_string(&sender)?,
        fields2cipher.clone(),
        fields2keys.clone(),
    );

    let prd_commitment = full_prd.create_commitment();

    let freezed_utxos = lock_freezed_utxos()?;

    let signed_psbt = create_transaction(
        vec![],
        &freezed_utxos,
        sp_wallet,
        recipients,
        Some(prd_commitment.as_byte_array().to_vec()),
        Amount::from_sat(fee_rate.into()),
        None,
    )?;

    let sp_address2vouts = map_outputs_to_sp_address(&signed_psbt.to_string())?;

    let partial_secret = sp_wallet
        .get_client()
        .get_partial_secret_from_psbt(&signed_psbt)?;

    let final_tx = signed_psbt.extract_tx()?;

    let mut ciphers = vec![];
    for (member, visible_fields) in all_members {
        let mut prd = full_prd.clone();
        prd.filter_keys(visible_fields);
        // we hash the payload
        prd.payload = Value::from_str(&prd.payload)
            .unwrap()
            .tagged_hash()
            .to_string();
        let prd_msg = prd.to_network_msg(sp_wallet)?;

        let addresses = member.get_addresses();
        for sp_address in addresses.into_iter() {
            let shared_point = sp_utils::sending::calculate_ecdh_shared_secret(
                &<SilentPaymentAddress>::try_from(sp_address.as_str())?.get_scan_key(),
                &partial_secret,
            );

            let shared_secret = AnkSharedSecretHash::from_shared_point(shared_point);

            let cipher = encrypt_with_key(shared_secret.as_byte_array(), prd_msg.as_bytes())?;
            ciphers.push(cipher.to_lower_hex_string());
            relevant_process
                .insert_shared_secret(SilentPaymentAddress::try_from(sp_address)?, shared_secret);
        }
    }
    relevant_process.insert_impending_request(full_prd);
    relevant_process.insert_state(ProcessState {
        commited_in: OutPoint::null(),
        encrypted_pcd: Value::Object(fields2cipher),
        keys: fields2keys,
        validation_tokens: vec![],
    });

    // Create the new_tx message
    let new_tx_msg = NewTxMessage::new(serialize(&final_tx).to_lower_hex_string(), None);

    Ok(ApiReturn {
        new_tx_to_send: Some(new_tx_msg),
        updated_process: Some((commitment_outpoint.to_string(), relevant_process.clone())),
        ciphers_to_send: ciphers,
        ..Default::default()
    })
}

#[derive(Tsify, Serialize, Deserialize)]
#[tsify(into_wasm_abi, from_wasm_abi)]
#[allow(non_camel_case_types)]
pub struct encryptWithNewKeyResult {
    pub cipher: String,
    pub key: String,
}

#[wasm_bindgen]
pub fn create_faucet_msg() -> ApiResult<String> {
    let sp_address = lock_local_device()?
        .get_wallet()
        .get_client()
        .get_receiving_address();

    let faucet_msg = FaucetMessage::new(sp_address.clone());

    Ok(faucet_msg.to_string())
}

/// Get active update proposals for a given process outpoint
/// Returns a vector with the latest commited state first, if any, and all active proposals
#[wasm_bindgen]
pub fn get_update_proposals(process_outpoint: String) -> ApiResult<Vec<String>> {
    let outpoint = OutPoint::from_str(&process_outpoint)?;

    let mut processes = lock_processes()?;

    // TODO: We clone the process to prevent double borrowing issue, this can certainly be improved
    let relevant_process = processes
        .get(&outpoint)
        .ok_or(ApiError::new("process not found".to_owned()))?;

    let mut updated_process = relevant_process.clone();

    let update_proposals: Vec<&Prd> = relevant_process
        .get_impending_requests()
        .into_iter()
        .filter(|r| r.prd_type == PrdType::Update)
        .collect();

    if update_proposals.is_empty() {
        return Err(ApiError::new(format!(
            "No active update proposals for process {}",
            process_outpoint
        )));
    }

    let mut res = vec![];

    // We first push the last commited state, if any
    match relevant_process.get_latest_commited_state() {
        Some(state) => res.push(serde_json::to_string(state)?),
        None => ()
    }

    // Maybe that's the right place for adding a new state with what we've got from the prd update
    // We should probably iterate on every update proposals and see which one don't have a state yet
    let mut update_states = false;
    for proposal in update_proposals {
        // Is there a state that matches this proposal? If not, let's add it
        debug!("Trying proposal {:#?}", proposal);
        let pcd = match Value::from_str(&proposal.payload) {
            Ok(value) => value,
            Err(e) => continue
        };
        debug!("found pcd {:#?}", pcd);
        let pcd_hash = AnkPcdHash::from_value(&pcd);
        // We look for a pending state for the exact same state as the one in the proposal
        if let None = relevant_process.get_latest_concurrent_states()
            .into_iter()
            .find(|state| {
                AnkPcdHash::from_value(&state.encrypted_pcd) == pcd_hash
            })
        {
            // If not, we first add a new state
            updated_process.insert_state(ProcessState { 
                commited_in: OutPoint::new(Txid::from_str(&pcd_hash.to_string())?, u32::MAX), 
                encrypted_pcd: pcd.clone(), 
                keys: proposal.keys.clone(), 
                validation_tokens: proposal.validation_tokens.clone()
            });
            update_states = true;
        }
        // We add the decrypted state to our return variable
        let mut decrypted_pcd = Map::new();
        pcd.decrypt_fields(&proposal.keys, &mut decrypted_pcd)?;
        res.push(serde_json::to_string(&decrypted_pcd)?);
    }

    if update_states {
        // We replace the process
        processes.insert(outpoint, updated_process);
    }
    // else we do nothing

    Ok(res)
}