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

use base64::{Engine, engine::general_purpose::STANDARD as BASE64};
use common::{
    ExecutionFailureKind,
    sequencer_client::{SequencerClient, json::SendTxResponse},
};

use anyhow::Result;
use chain_storage::WalletChainStore;
use config::WalletConfig;
use log::info;
use nssa::Address;

use clap::{Parser, Subcommand};
use nssa_core::account::Account;

use crate::{
    helperfunctions::{
        HumanReadableAccount, 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(&mut self) -> Address {
        self.storage.user_data.generate_new_account()
    }

    pub fn search_for_initial_account(&self, acc_addr: Address) -> Option<Account> {
        for initial_acc in &self.storage.wallet_config.initial_accounts {
            if initial_acc.address == acc_addr {
                return Some(initial_acc.account.clone());
            }
        }
        None
    }

    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_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(tx).await?)
        } else {
            Err(ExecutionFailureKind::InsufficientFundsError)
        }
    }

    pub async fn send_new_token_definition(
        &self,
        definition_address: Address,
        supply_address: Address,
        name: [u8; 6],
        total_supply: u128,
    ) -> Result<SendTxResponse, ExecutionFailureKind> {
        let addresses = vec![definition_address, supply_address];
        let program_id = nssa::program::Program::token().id();
        // Instruction must be: [0x00 || total_supply (little-endian 16 bytes) || name (6 bytes)]
        let mut instruction = [0; 23];
        instruction[1..17].copy_from_slice(&total_supply.to_le_bytes());
        instruction[17..].copy_from_slice(&name);
        let message =
            nssa::public_transaction::Message::try_new(program_id, addresses, vec![], instruction)
                .unwrap();

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

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

        Ok(self.sequencer_client.send_tx(tx).await?)
    }

    pub async fn send_transfer_token_transaction(
        &self,
        sender_address: Address,
        recipient_address: Address,
        amount: u128,
    ) -> Result<SendTxResponse, ExecutionFailureKind> {
        let addresses = vec![sender_address, recipient_address];
        let program_id = nssa::program::Program::token().id();
        // Instruction must be: [0x01 || amount (little-endian 16 bytes) || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x00].
        let mut instruction = [0; 23];
        instruction[0] = 0x01;
        instruction[1..17].copy_from_slice(&amount.to_le_bytes());
        let Ok(nonces) = self.get_accounts_nonces(vec![sender_address]).await else {
            return Err(ExecutionFailureKind::SequencerError);
        };
        let message =
            nssa::public_transaction::Message::try_new(program_id, addresses, nonces, instruction)
                .unwrap();

        let Some(signing_key) = self
            .storage
            .user_data
            .get_account_signing_key(&sender_address)
        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(tx).await?)
    }
    ///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)
    }

    ///Get account
    pub async fn get_account(&self, addr: Address) -> Result<Account> {
        let response = self.sequencer_client.get_account(addr.to_string()).await?;
        Ok(response.account)
    }

    ///Poll transactions
    pub async fn poll_public_native_token_transfer(
        &self,
        hash: String,
    ) -> Result<nssa::PublicTransaction> {
        let transaction_encoded = self.poller.poll_tx(hash).await?;
        let tx_base64_decode = BASE64.decode(transaction_encoded)?;
        let pub_tx = nssa::PublicTransaction::from_bytes(&tx_base64_decode)?;

        Ok(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`
    SendNativeTokenTransfer {
        ///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 account
    RegisterAccount {},
    ///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,
    },
    ///Get account at address `addr`
    GetAccount {
        #[arg(short, long)]
        addr: String,
    },
    //Create a new token using the token program
    CreateNewToken {
        #[arg(short, long)]
        definition_addr: String,
        #[arg(short, long)]
        supply_addr: String,
        #[arg(short, long)]
        name: String,
        #[arg(short, long)]
        total_supply: u128,
    },
    //Transfer tokens using the token program
    TransferToken {
        #[arg(short, long)]
        sender_addr: String,
        #[arg(short, long)]
        recipient_addr: String,
        #[arg(short, long)]
        balance_to_move: u128,
    },
}

///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::SendNativeTokenTransfer { 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?;

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

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

            println!("Transaction data is {transfer_tx:?}");
        }
        Command::RegisterAccount {} => {
            let addr = wallet_core.create_new_account();
            wallet_core.store_persistent_accounts()?;

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

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

            let balance = wallet_core.get_account_balance(addr).await?;
            println!("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];
            println!("Accounts {addr} nonce is {nonce}");
        }
        Command::GetAccount { addr } => {
            let addr: Address = addr.parse()?;
            let account: HumanReadableAccount = wallet_core.get_account(addr).await?.into();
            println!("{}", serde_json::to_string(&account).unwrap());
        }
        Command::CreateNewToken {
            definition_addr,
            supply_addr,
            name,
            total_supply,
        } => {
            let name = name.as_bytes();
            if name.len() > 6 {
                // TODO: return error
                panic!();
            }
            let mut name_bytes = [0; 6];
            name_bytes[..name.len()].copy_from_slice(name);
            wallet_core
                .send_new_token_definition(
                    definition_addr.parse().unwrap(),
                    supply_addr.parse().unwrap(),
                    name_bytes,
                    total_supply,
                )
                .await?;
        }
        Command::TransferToken {
            sender_addr,
            recipient_addr,
            balance_to_move,
        } => {
            wallet_core
                .send_transfer_token_transaction(
                    sender_addr.parse().unwrap(),
                    recipient_addr.parse().unwrap(),
                    balance_to_move,
                )
                .await?;
        }
    }

    Ok(())
}