use std::{fs::File, io::Write, path::PathBuf, str::FromStr, sync::Arc};

use base64::Engine;
use common::{
    ExecutionFailureKind,
    sequencer_client::{SequencerClient, json::SendTxResponse},
    transaction::{EncodedTransaction, NSSATransaction},
};

use anyhow::Result;
use chain_storage::WalletChainStore;
use config::WalletConfig;
use k256::elliptic_curve::group::GroupEncoding;
use k256::elliptic_curve::sec1::ToEncodedPoint;
use key_protocol::key_management::ephemeral_key_holder::EphemeralKeyHolder;
use log::info;
use nssa::Address;

use clap::{Parser, Subcommand};

use crate::{
    helperfunctions::{
        fetch_config, fetch_persistent_accounts, get_home, produce_account_addr_from_hex,
        produce_data_for_storage,
    },
    poller::TxPoller,
};

pub const HOME_DIR_ENV_VAR: &str = "NSSA_WALLET_HOME_DIR";

pub mod chain_storage;
pub mod config;
pub mod helperfunctions;
pub mod poller;

pub struct WalletCore {
    pub storage: WalletChainStore,
    pub poller: TxPoller,
    pub sequencer_client: Arc<SequencerClient>,
}

impl WalletCore {
    pub fn start_from_config_update_chain(config: WalletConfig) -> Result<Self> {
        let client = Arc::new(SequencerClient::new(config.sequencer_addr.clone())?);
        let tx_poller = TxPoller::new(config.clone(), client.clone());

        let mut storage = WalletChainStore::new(config)?;

        let persistent_accounts = fetch_persistent_accounts()?;
        for pers_acc_data in persistent_accounts {
            storage.insert_account_data(pers_acc_data);
        }

        Ok(Self {
            storage,
            poller: tx_poller,
            sequencer_client: client.clone(),
        })
    }

    ///Store persistent accounts at home
    pub fn store_persistent_accounts(&self) -> Result<PathBuf> {
        let home = get_home()?;
        let accs_path = home.join("curr_accounts.json");

        let data = produce_data_for_storage(&self.storage.user_data);
        let accs = serde_json::to_vec_pretty(&data)?;

        let mut accs_file = File::create(accs_path.as_path())?;
        accs_file.write_all(&accs)?;

        info!("Stored accounts data at {accs_path:#?}");

        Ok(accs_path)
    }

    pub fn create_new_account_public(&mut self) -> Address {
        self.storage
            .user_data
            .generate_new_public_transaction_private_key()
    }

    pub fn create_new_account_private(&mut self) -> Address {
        self.storage
            .user_data
            .generate_new_privacy_preserving_transaction_key_chain()
    }

    pub async fn send_public_native_token_transfer(
        &self,
        from: Address,
        to: Address,
        balance_to_move: u128,
    ) -> Result<SendTxResponse, ExecutionFailureKind> {
        let Ok(balance) = self.get_account_balance(from).await else {
            return Err(ExecutionFailureKind::SequencerError);
        };

        if balance >= balance_to_move {
            let Ok(nonces) = self.get_accounts_nonces(vec![from]).await else {
                return Err(ExecutionFailureKind::SequencerError);
            };

            let addresses = vec![from, to];
            let program_id = nssa::program::Program::authenticated_transfer_program().id();
            let message = nssa::public_transaction::Message::try_new(
                program_id,
                addresses,
                nonces,
                balance_to_move,
            )
            .unwrap();

            let signing_key = self.storage.user_data.get_pub_account_signing_key(&from);

            let Some(signing_key) = signing_key else {
                return Err(ExecutionFailureKind::KeyNotFoundError);
            };

            let witness_set =
                nssa::public_transaction::WitnessSet::for_message(&message, &[signing_key]);

            let tx = nssa::PublicTransaction::new(message, witness_set);

            Ok(self.sequencer_client.send_tx_public(tx).await?)
        } else {
            Err(ExecutionFailureKind::InsufficientFundsError)
        }
    }

    pub async fn send_private_native_token_transfer(
        &self,
        from: Address,
        to: Address,
        balance_to_move: u128,
    ) -> Result<SendTxResponse, ExecutionFailureKind> {
        let from_data = self.storage.user_data.get_private_account(&from);
        let to_data = self.storage.user_data.get_private_account(&to);

        let Some((from_keys, from_acc)) = from_data else {
            return Err(ExecutionFailureKind::KeyNotFoundError);
        };

        let Some((to_keys, to_acc)) = to_data else {
            return Err(ExecutionFailureKind::KeyNotFoundError);
        };

        if from_acc.balance >= balance_to_move {
            let program = nssa::program::Program::authenticated_transfer_program();
            let sender_commitment = nssa_core::Commitment::new(
                &nssa_core::NullifierPublicKey(from_keys.nullifer_public_key),
                from_acc,
            );

            let sender_pre = nssa_core::account::AccountWithMetadata {
                account: from_acc.clone(),
                is_authorized: true,
            };
            let recipient_pre = nssa_core::account::AccountWithMetadata {
                account: to_acc.clone(),
                is_authorized: false,
            };

            let eph_holder = EphemeralKeyHolder::new(
                to_keys.nullifer_public_key,
                from_keys.private_key_holder.outgoing_viewing_secret_key,
                from_acc.nonce.try_into().unwrap(),
            );

            let shared_secret =
                eph_holder.calculate_shared_secret_sender(to_keys.incoming_viewing_public_key);

            let (output, proof) = nssa::privacy_preserving_transaction::circuit::execute_and_prove(
                &[sender_pre, recipient_pre],
                &nssa::program::Program::serialize_instruction(balance_to_move).unwrap(),
                &[1, 2],
                &[from_acc.nonce + 1, to_acc.nonce + 1],
                &[
                    (
                        nssa_core::NullifierPublicKey(from_keys.nullifer_public_key),
                        nssa_core::SharedSecretKey(
                            shared_secret.to_bytes().as_slice().try_into().unwrap(),
                        ),
                    ),
                    (
                        nssa_core::NullifierPublicKey(to_keys.nullifer_public_key),
                        nssa_core::SharedSecretKey(
                            shared_secret.to_bytes().as_slice().try_into().unwrap(),
                        ),
                    ),
                ],
                &[(
                    from_keys.private_key_holder.nullifier_secret_key,
                    self.sequencer_client
                        .get_proof_for_commitment(sender_commitment)
                        .await
                        .unwrap()
                        .unwrap(),
                )],
                &program,
            )
            .unwrap();

            let message =
                nssa::privacy_preserving_transaction::message::Message::try_from_circuit_output(
                    vec![],
                    vec![],
                    vec![
                        (
                            nssa_core::NullifierPublicKey(from_keys.nullifer_public_key),
                            nssa_core::encryption::shared_key_derivation::Secp256k1Point(
                                from_keys
                                    .incoming_viewing_public_key
                                    .to_encoded_point(true)
                                    .as_bytes()
                                    .to_vec(),
                            ),
                            nssa_core::encryption::shared_key_derivation::Secp256k1Point(
                                eph_holder
                                    .generate_ephemeral_public_key()
                                    .to_encoded_point(true)
                                    .as_bytes()
                                    .to_vec(),
                            ),
                        ),
                        (
                            nssa_core::NullifierPublicKey(to_keys.nullifer_public_key),
                            nssa_core::encryption::shared_key_derivation::Secp256k1Point(
                                to_keys
                                    .incoming_viewing_public_key
                                    .to_encoded_point(true)
                                    .as_bytes()
                                    .to_vec(),
                            ),
                            nssa_core::encryption::shared_key_derivation::Secp256k1Point(
                                eph_holder
                                    .generate_ephemeral_public_key()
                                    .to_encoded_point(true)
                                    .as_bytes()
                                    .to_vec(),
                            ),
                        ),
                    ],
                    output,
                )
                .unwrap();

            let witness_set =
                nssa::privacy_preserving_transaction::witness_set::WitnessSet::for_message(
                    &message,
                    proof,
                    &[],
                );

            let tx = nssa::privacy_preserving_transaction::PrivacyPreservingTransaction::new(
                message,
                witness_set,
            );

            Ok(self.sequencer_client.send_tx_private(tx).await?)
        } else {
            Err(ExecutionFailureKind::InsufficientFundsError)
        }
    }

    ///Get account balance
    pub async fn get_account_balance(&self, acc: Address) -> Result<u128> {
        Ok(self
            .sequencer_client
            .get_account_balance(acc.to_string())
            .await?
            .balance)
    }

    ///Get accounts nonces
    pub async fn get_accounts_nonces(&self, accs: Vec<Address>) -> Result<Vec<u128>> {
        Ok(self
            .sequencer_client
            .get_accounts_nonces(accs.into_iter().map(|acc| acc.to_string()).collect())
            .await?
            .nonces)
    }

    ///Poll transactions
    pub async fn poll_native_token_transfer(&self, hash: String) -> Result<NSSATransaction> {
        let transaction_encoded = self.poller.poll_tx(hash).await?;
        let tx_base64_decode =
            base64::engine::general_purpose::STANDARD.decode(transaction_encoded)?;
        let pub_tx = EncodedTransaction::from_bytes(tx_base64_decode);

        Ok(NSSATransaction::try_from(&pub_tx)?)
    }
}

///Represents CLI command for a wallet
#[derive(Subcommand, Debug, Clone)]
#[clap(about)]
pub enum Command {
    ///Send native token transfer from `from` to `to` for `amount`
    ///
    /// Public operation
    SendNativeTokenTransferPublic {
        ///from - valid 32 byte hex string
        #[arg(long)]
        from: String,
        ///to - valid 32 byte hex string
        #[arg(long)]
        to: String,
        ///amount - amount of balance to move
        #[arg(long)]
        amount: u128,
    },
    ///Send native token transfer from `from` to `to` for `amount`
    ///
    /// Private operation
    SendNativeTokenTransferPrivate {
        ///from - valid 32 byte hex string
        #[arg(long)]
        from: String,
        ///to - valid 32 byte hex string
        #[arg(long)]
        to: String,
        ///amount - amount of balance to move
        #[arg(long)]
        amount: u128,
    },
    ///Register new public account
    RegisterAccountPublic {},
    ///Register new private account
    RegisterAccountPrivate {},
    ///Fetch transaction by `hash`
    FetchTx {
        #[arg(short, long)]
        tx_hash: String,
    },
    ///Get account `addr` balance
    GetAccountBalance {
        #[arg(short, long)]
        addr: String,
    },
    ///Get account `addr` nonce
    GetAccountNonce {
        #[arg(short, long)]
        addr: String,
    },
}

///To execute commands, env var NSSA_WALLET_HOME_DIR must be set into directory with config
#[derive(Parser, Debug)]
#[clap(version, about)]
pub struct Args {
    /// Wallet command
    #[command(subcommand)]
    pub command: Command,
}

pub async fn execute_subcommand(command: Command) -> Result<()> {
    let wallet_config = fetch_config()?;
    let mut wallet_core = WalletCore::start_from_config_update_chain(wallet_config)?;

    match command {
        Command::SendNativeTokenTransferPublic { from, to, amount } => {
            let from = produce_account_addr_from_hex(from)?;
            let to = produce_account_addr_from_hex(to)?;

            let res = wallet_core
                .send_public_native_token_transfer(from, to, amount)
                .await?;

            info!("Results of tx send is {res:#?}");

            let transfer_tx = wallet_core.poll_native_token_transfer(res.tx_hash).await?;

            info!("Transaction data is {transfer_tx:?}");
        }
        Command::SendNativeTokenTransferPrivate { from, to, amount } => {
            let from = produce_account_addr_from_hex(from)?;
            let to = produce_account_addr_from_hex(to)?;

            let res = wallet_core
                .send_private_native_token_transfer(from, to, amount)
                .await?;

            info!("Results of tx send is {res:#?}");

            let transfer_tx = wallet_core.poll_native_token_transfer(res.tx_hash).await?;

            info!("Transaction data is {transfer_tx:?}");
        }
        Command::RegisterAccountPublic {} => {
            let addr = wallet_core.create_new_account_public();

            let key = wallet_core
                .storage
                .user_data
                .get_pub_account_signing_key(&addr);

            info!("Generated new account with addr {addr:#?}");
            info!("With key {key:#?}");
        }
        Command::RegisterAccountPrivate {} => {
            let addr = wallet_core.create_new_account_private();

            let (key, account) = wallet_core
                .storage
                .user_data
                .get_private_account(&addr)
                .unwrap();

            info!("Generated new account with addr {addr:#?}");
            info!("With key {key:#?}");
            info!("With account {account:#?}");
        }
        Command::FetchTx { tx_hash } => {
            let tx_obj = wallet_core
                .sequencer_client
                .get_transaction_by_hash(tx_hash)
                .await?;

            info!("Transaction object {tx_obj:#?}");
        }
        Command::GetAccountBalance { addr } => {
            let addr = Address::from_str(&addr)?;

            let balance = wallet_core.get_account_balance(addr).await?;
            info!("Accounts {addr:#?} balance is {balance}");
        }
        Command::GetAccountNonce { addr } => {
            let addr = Address::from_str(&addr)?;

            let nonce = wallet_core.get_accounts_nonces(vec![addr]).await?[0];
            info!("Accounts {addr:#?} nonce is {nonce}");
        }
    }

    wallet_core.store_persistent_accounts()?;

    Ok(())
}