use zebra_chain::{
    orchard,
    parameters::Network,
    transaction::{
        arbitrary::{fake_v5_transactions_for_network, insert_fake_orchard_shielded_data},
        Transaction,
    },
};

use super::check;

use crate::error::TransactionError;
use color_eyre::eyre::Report;

#[test]
fn v5_fake_transactions() -> Result<(), Report> {
    zebra_test::init();

    let networks = vec![
        (Network::Mainnet, zebra_test::vectors::MAINNET_BLOCKS.iter()),
        (Network::Testnet, zebra_test::vectors::TESTNET_BLOCKS.iter()),
    ];

    for (network, blocks) in networks {
        for transaction in fake_v5_transactions_for_network(network, blocks) {
            match check::has_inputs_and_outputs(&transaction) {
                Ok(()) => (),
                Err(TransactionError::NoInputs) | Err(TransactionError::NoOutputs) => (),
                Err(_) => panic!("error must be NoInputs or NoOutputs"),
            };

            // make sure there are no joinsplits nor spends in coinbase
            check::coinbase_tx_no_prevout_joinsplit_spend(&transaction)?;

            // validate the sapling shielded data
            match transaction {
                Transaction::V5 {
                    sapling_shielded_data,
                    ..
                } => {
                    if let Some(s) = sapling_shielded_data {
                        for spend in s.spends_per_anchor() {
                            check::spend_cv_rk_not_small_order(&spend)?
                        }
                        for output in s.outputs() {
                            check::output_cv_epk_not_small_order(&output)?;
                        }
                    }
                }
                _ => panic!("we should have no tx other than 5"),
            }
        }
    }

    Ok(())
}

#[test]
fn fake_v5_transaction_with_orchard_actions_has_inputs_and_outputs() {
    // Find a transaction with no inputs or outputs to use as base
    let mut transaction = fake_v5_transactions_for_network(
        Network::Mainnet,
        zebra_test::vectors::MAINNET_BLOCKS.iter(),
    )
    .rev()
    .find(|transaction| {
        transaction.inputs().is_empty()
            && transaction.outputs().is_empty()
            && transaction.sapling_spends_per_anchor().next().is_none()
            && transaction.sapling_outputs().next().is_none()
            && transaction.joinsplit_count() == 0
    })
    .expect("At least one fake V5 transaction with no inputs and no outputs");

    // Insert fake Orchard shielded data to the transaction, which has at least one action (this is
    // guaranteed structurally by `orchard::ShieldedData`)
    insert_fake_orchard_shielded_data(&mut transaction);

    // If a transaction has at least one Orchard shielded action, it should be considered to have
    // inputs and/or outputs
    assert!(check::has_inputs_and_outputs(&transaction).is_ok());
}

#[test]
fn v5_transaction_with_no_inputs_fails_validation() {
    let transaction = fake_v5_transactions_for_network(
        Network::Mainnet,
        zebra_test::vectors::MAINNET_BLOCKS.iter(),
    )
    .rev()
    .find(|transaction| {
        transaction.inputs().is_empty()
            && transaction.sapling_spends_per_anchor().next().is_none()
            && transaction.orchard_actions().next().is_none()
            && transaction.joinsplit_count() == 0
            && (!transaction.outputs().is_empty() || transaction.sapling_outputs().next().is_some())
    })
    .expect("At least one fake v5 transaction with no inputs in the test vectors");

    assert_eq!(
        check::has_inputs_and_outputs(&transaction),
        Err(TransactionError::NoInputs)
    );
}

#[test]
fn v5_transaction_with_no_outputs_fails_validation() {
    let transaction = fake_v5_transactions_for_network(
        Network::Mainnet,
        zebra_test::vectors::MAINNET_BLOCKS.iter(),
    )
    .rev()
    .find(|transaction| {
        transaction.outputs().is_empty()
            && transaction.sapling_outputs().next().is_none()
            && transaction.orchard_actions().next().is_none()
            && transaction.joinsplit_count() == 0
            && (!transaction.inputs().is_empty()
                || transaction.sapling_spends_per_anchor().next().is_some())
    })
    .expect("At least one fake v5 transaction with no outputs in the test vectors");

    assert_eq!(
        check::has_inputs_and_outputs(&transaction),
        Err(TransactionError::NoOutputs)
    );
}

#[test]
fn v5_coinbase_transaction_without_enable_spends_flag_passes_validation() {
    let mut transaction = fake_v5_transactions_for_network(
        Network::Mainnet,
        zebra_test::vectors::MAINNET_BLOCKS.iter(),
    )
    .rev()
    .find(|transaction| transaction.is_coinbase())
    .expect("At least one fake V5 coinbase transaction in the test vectors");

    insert_fake_orchard_shielded_data(&mut transaction);

    assert!(check::coinbase_tx_no_prevout_joinsplit_spend(&transaction).is_ok(),);
}

#[test]
fn v5_coinbase_transaction_with_enable_spends_flag_fails_validation() {
    let mut transaction = fake_v5_transactions_for_network(
        Network::Mainnet,
        zebra_test::vectors::MAINNET_BLOCKS.iter(),
    )
    .rev()
    .find(|transaction| transaction.is_coinbase())
    .expect("At least one fake V5 coinbase transaction in the test vectors");

    let shielded_data = insert_fake_orchard_shielded_data(&mut transaction);

    shielded_data.flags = orchard::Flags::ENABLE_SPENDS;

    assert_eq!(
        check::coinbase_tx_no_prevout_joinsplit_spend(&transaction),
        Err(TransactionError::CoinbaseHasEnableSpendsOrchard)
    );
}