use {
    serde::{Deserialize, Serialize},
    safecoin_measure::measure::Measure,
    safecoin_program_runtime::{
        compute_budget::ComputeBudget,
        invoke_context::{BuiltinProgram, Executors, InvokeContext},
        log_collector::LogCollector,
        sysvar_cache::SysvarCache,
        timings::{ExecuteDetailsTimings, ExecuteTimings},
    },
    safecoin_sdk::{
        account::WritableAccount,
        feature_set::{
            prevent_calling_precompiles_as_programs,
            record_instruction_in_transaction_context_push, FeatureSet,
        },
        hash::Hash,
        message::SanitizedMessage,
        precompiles::is_precompile,
        rent::Rent,
        saturating_add_assign,
        sysvar::instructions,
        transaction::TransactionError,
        transaction_context::{InstructionAccount, TransactionContext},
    },
    std::{borrow::Cow, cell::RefCell, rc::Rc, sync::Arc},
};

#[derive(Debug, Default, Clone, Deserialize, Serialize)]
pub struct MessageProcessor {}

#[cfg(RUSTC_WITH_SPECIALIZATION)]
impl ::safecoin_frozen_abi::abi_example::AbiExample for MessageProcessor {
    fn example() -> Self {
        // MessageProcessor's fields are #[serde(skip)]-ed and not Serialize
        // so, just rely on Default anyway.
        MessageProcessor::default()
    }
}

/// Resultant information gathered from calling process_message()
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
pub struct ProcessedMessageInfo {
    /// The change in accounts data len
    pub accounts_data_len_delta: i64,
}

impl MessageProcessor {
    /// Process a message.
    /// This method calls each instruction in the message over the set of loaded accounts.
    /// For each instruction it calls the program entrypoint method and verifies that the result of
    /// the call does not violate the bank's accounting rules.
    /// The accounts are committed back to the bank only if every instruction succeeds.
    #[allow(clippy::too_many_arguments)]
    pub fn process_message(
        builtin_programs: &[BuiltinProgram],
        message: &SanitizedMessage,
        program_indices: &[Vec<usize>],
        transaction_context: &mut TransactionContext,
        rent: Rent,
        log_collector: Option<Rc<RefCell<LogCollector>>>,
        executors: Rc<RefCell<Executors>>,
        feature_set: Arc<FeatureSet>,
        compute_budget: ComputeBudget,
        timings: &mut ExecuteTimings,
        sysvar_cache: &SysvarCache,
        blockhash: Hash,
        lamports_per_signature: u64,
        current_accounts_data_len: u64,
        accumulated_consumed_units: &mut u64,
    ) -> Result<ProcessedMessageInfo, TransactionError> {
        let mut invoke_context = InvokeContext::new(
            transaction_context,
            rent,
            builtin_programs,
            Cow::Borrowed(sysvar_cache),
            log_collector,
            compute_budget,
            executors,
            feature_set,
            blockhash,
            lamports_per_signature,
            current_accounts_data_len,
        );

        debug_assert_eq!(program_indices.len(), message.instructions().len());
        for (instruction_index, ((program_id, instruction), program_indices)) in message
            .program_instructions_iter()
            .zip(program_indices.iter())
            .enumerate()
        {
            let is_precompile = invoke_context
                .feature_set
                .is_active(&prevent_calling_precompiles_as_programs::id())
                && is_precompile(program_id, |id| invoke_context.feature_set.is_active(id));
            if is_precompile
                && !invoke_context
                    .feature_set
                    .is_active(&record_instruction_in_transaction_context_push::id())
            {
                // Precompiled programs don't have an instruction processor
                continue;
            }

            // Fixup the special instructions key if present
            // before the account pre-values are taken care of
            if let Some(account_index) = invoke_context
                .transaction_context
                .find_index_of_account(&instructions::id())
            {
                let mut mut_account_ref = invoke_context
                    .transaction_context
                    .get_account_at_index(account_index)
                    .map_err(|_| TransactionError::InvalidAccountIndex)?
                    .borrow_mut();
                instructions::store_current_index(
                    mut_account_ref.data_as_mut_slice(),
                    instruction_index as u16,
                );
            }

            let instruction_accounts = instruction
                .accounts
                .iter()
                .map(|index_in_transaction| {
                    let index_in_transaction = *index_in_transaction as usize;
                    InstructionAccount {
                        index_in_transaction,
                        index_in_caller: program_indices.len().saturating_add(index_in_transaction),
                        is_signer: message.is_signer(index_in_transaction),
                        is_writable: message.is_writable(index_in_transaction),
                    }
                })
                .collect::<Vec<_>>();

            let result = if is_precompile
                && invoke_context
                    .feature_set
                    .is_active(&record_instruction_in_transaction_context_push::id())
            {
                invoke_context
                    .transaction_context
                    .push(
                        program_indices,
                        &instruction_accounts,
                        &instruction.data,
                        true,
                    )
                    .and_then(|_| invoke_context.transaction_context.pop())
            } else {
                let mut time = Measure::start("execute_instruction");
                let mut compute_units_consumed = 0;
                let result = invoke_context.process_instruction(
                    &instruction.data,
                    &instruction_accounts,
                    program_indices,
                    &mut compute_units_consumed,
                    timings,
                );
                time.stop();
                *accumulated_consumed_units =
                    accumulated_consumed_units.saturating_add(compute_units_consumed);
                timings.details.accumulate_program(
                    program_id,
                    time.as_us(),
                    compute_units_consumed,
                    result.is_err(),
                );
                invoke_context.timings = {
                    timings.details.accumulate(&invoke_context.timings);
                    ExecuteDetailsTimings::default()
                };
                saturating_add_assign!(
                    timings.execute_accessories.process_instructions.total_us,
                    time.as_us()
                );
                result
            };

            result
                .map_err(|err| TransactionError::InstructionError(instruction_index as u8, err))?;
        }
        Ok(ProcessedMessageInfo {
            accounts_data_len_delta: invoke_context.get_accounts_data_meter().delta(),
        })
    }
}

#[cfg(test)]
mod tests {
    use {
        super::*,
        crate::rent_collector::RentCollector,
        safecoin_sdk::{
            account::{AccountSharedData, ReadableAccount},
            instruction::{AccountMeta, Instruction, InstructionError},
            message::{AccountKeys, Message},
            native_loader::{self, create_loadable_account_for_test},
            pubkey::Pubkey,
            secp256k1_instruction::new_secp256k1_instruction,
            secp256k1_program,
        },
    };

    #[derive(Debug, Serialize, Deserialize)]
    enum MockInstruction {
        NoopSuccess,
        NoopFail,
        ModifyOwned,
        ModifyNotOwned,
        ModifyReadonly,
    }

    #[test]
    fn test_process_message_readonly_handling() {
        #[derive(Serialize, Deserialize)]
        enum MockSystemInstruction {
            Correct,
            TransferLamports { lamports: u64 },
            ChangeData { data: u8 },
        }

        fn mock_system_process_instruction(
            _first_instruction_account: usize,
            data: &[u8],
            invoke_context: &mut InvokeContext,
        ) -> Result<(), InstructionError> {
            let transaction_context = &invoke_context.transaction_context;
            let instruction_context = transaction_context.get_current_instruction_context()?;
            if let Ok(instruction) = bincode::deserialize(data) {
                match instruction {
                    MockSystemInstruction::Correct => Ok(()),
                    MockSystemInstruction::TransferLamports { lamports } => {
                        instruction_context
                            .try_borrow_instruction_account(transaction_context, 0)?
                            .checked_sub_lamports(lamports)?;
                        instruction_context
                            .try_borrow_instruction_account(transaction_context, 1)?
                            .checked_add_lamports(lamports)?;
                        Ok(())
                    }
                    MockSystemInstruction::ChangeData { data } => {
                        instruction_context
                            .try_borrow_instruction_account(transaction_context, 1)?
                            .set_data(&[data]);
                        Ok(())
                    }
                }
            } else {
                Err(InstructionError::InvalidInstructionData)
            }
        }

        let writable_pubkey = Pubkey::new_unique();
        let readonly_pubkey = Pubkey::new_unique();
        let mock_system_program_id = Pubkey::new_unique();

        let rent_collector = RentCollector::default();
        let builtin_programs = &[BuiltinProgram {
            program_id: mock_system_program_id,
            process_instruction: mock_system_process_instruction,
        }];

        let accounts = vec![
            (
                writable_pubkey,
                AccountSharedData::new(100, 1, &mock_system_program_id),
            ),
            (
                readonly_pubkey,
                AccountSharedData::new(0, 1, &mock_system_program_id),
            ),
            (
                mock_system_program_id,
                create_loadable_account_for_test("mock_system_program"),
            ),
        ];
        let mut transaction_context = TransactionContext::new(accounts, 1, 3);
        let program_indices = vec![vec![2]];
        let executors = Rc::new(RefCell::new(Executors::default()));
        let account_keys = transaction_context.get_keys_of_accounts().to_vec();
        let account_metas = vec![
            AccountMeta::new(writable_pubkey, true),
            AccountMeta::new_readonly(readonly_pubkey, false),
        ];

        let message = SanitizedMessage::Legacy(Message::new_with_compiled_instructions(
            1,
            0,
            2,
            account_keys.clone(),
            Hash::default(),
            AccountKeys::new(&account_keys, None).compile_instructions(&[
                Instruction::new_with_bincode(
                    mock_system_program_id,
                    &MockSystemInstruction::Correct,
                    account_metas.clone(),
                ),
            ]),
        ));
        let sysvar_cache = SysvarCache::default();
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors.clone(),
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert!(result.is_ok());
        assert_eq!(
            transaction_context
                .get_account_at_index(0)
                .unwrap()
                .borrow()
                .lamports(),
            100
        );
        assert_eq!(
            transaction_context
                .get_account_at_index(1)
                .unwrap()
                .borrow()
                .lamports(),
            0
        );

        let message = SanitizedMessage::Legacy(Message::new_with_compiled_instructions(
            1,
            0,
            2,
            account_keys.clone(),
            Hash::default(),
            AccountKeys::new(&account_keys, None).compile_instructions(&[
                Instruction::new_with_bincode(
                    mock_system_program_id,
                    &MockSystemInstruction::TransferLamports { lamports: 50 },
                    account_metas.clone(),
                ),
            ]),
        ));
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors.clone(),
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert_eq!(
            result,
            Err(TransactionError::InstructionError(
                0,
                InstructionError::ReadonlyLamportChange
            ))
        );

        let message = SanitizedMessage::Legacy(Message::new_with_compiled_instructions(
            1,
            0,
            2,
            account_keys.clone(),
            Hash::default(),
            AccountKeys::new(&account_keys, None).compile_instructions(&[
                Instruction::new_with_bincode(
                    mock_system_program_id,
                    &MockSystemInstruction::ChangeData { data: 50 },
                    account_metas,
                ),
            ]),
        ));
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors,
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert_eq!(
            result,
            Err(TransactionError::InstructionError(
                0,
                InstructionError::ReadonlyDataModified
            ))
        );
    }

    #[test]
    fn test_process_message_duplicate_accounts() {
        #[derive(Serialize, Deserialize)]
        enum MockSystemInstruction {
            BorrowFail,
            MultiBorrowMut,
            DoWork { lamports: u64, data: u8 },
        }

        fn mock_system_process_instruction(
            _first_instruction_account: usize,
            data: &[u8],
            invoke_context: &mut InvokeContext,
        ) -> Result<(), InstructionError> {
            let transaction_context = &invoke_context.transaction_context;
            let instruction_context = transaction_context.get_current_instruction_context()?;
            let mut to_account =
                instruction_context.try_borrow_instruction_account(transaction_context, 1)?;
            if let Ok(instruction) = bincode::deserialize(data) {
                match instruction {
                    MockSystemInstruction::BorrowFail => {
                        let from_account = instruction_context
                            .try_borrow_instruction_account(transaction_context, 0)?;
                        let dup_account = instruction_context
                            .try_borrow_instruction_account(transaction_context, 2)?;
                        if from_account.get_lamports() != dup_account.get_lamports() {
                            return Err(InstructionError::InvalidArgument);
                        }
                        Ok(())
                    }
                    MockSystemInstruction::MultiBorrowMut => {
                        let lamports_a = instruction_context
                            .try_borrow_instruction_account(transaction_context, 0)?
                            .get_lamports();
                        let lamports_b = instruction_context
                            .try_borrow_instruction_account(transaction_context, 2)?
                            .get_lamports();
                        if lamports_a != lamports_b {
                            return Err(InstructionError::InvalidArgument);
                        }
                        Ok(())
                    }
                    MockSystemInstruction::DoWork { lamports, data } => {
                        let mut dup_account = instruction_context
                            .try_borrow_instruction_account(transaction_context, 2)?;
                        dup_account.checked_sub_lamports(lamports)?;
                        to_account.checked_add_lamports(lamports)?;
                        dup_account.set_data(&[data]);
                        drop(dup_account);
                        let mut from_account = instruction_context
                            .try_borrow_instruction_account(transaction_context, 0)?;
                        from_account.checked_sub_lamports(lamports)?;
                        to_account.checked_add_lamports(lamports)?;
                        Ok(())
                    }
                }
            } else {
                Err(InstructionError::InvalidInstructionData)
            }
        }

        let mock_program_id = Pubkey::new(&[2u8; 32]);
        let rent_collector = RentCollector::default();
        let builtin_programs = &[BuiltinProgram {
            program_id: mock_program_id,
            process_instruction: mock_system_process_instruction,
        }];

        let accounts = vec![
            (
                safecoin_sdk::pubkey::new_rand(),
                AccountSharedData::new(100, 1, &mock_program_id),
            ),
            (
                safecoin_sdk::pubkey::new_rand(),
                AccountSharedData::new(0, 1, &mock_program_id),
            ),
            (
                mock_program_id,
                create_loadable_account_for_test("mock_system_program"),
            ),
        ];
        let mut transaction_context = TransactionContext::new(accounts, 1, 3);
        let program_indices = vec![vec![2]];
        let executors = Rc::new(RefCell::new(Executors::default()));
        let account_metas = vec![
            AccountMeta::new(
                *transaction_context.get_key_of_account_at_index(0).unwrap(),
                true,
            ),
            AccountMeta::new(
                *transaction_context.get_key_of_account_at_index(1).unwrap(),
                false,
            ),
            AccountMeta::new(
                *transaction_context.get_key_of_account_at_index(0).unwrap(),
                false,
            ),
        ];

        // Try to borrow mut the same account
        let message = SanitizedMessage::Legacy(Message::new(
            &[Instruction::new_with_bincode(
                mock_program_id,
                &MockSystemInstruction::BorrowFail,
                account_metas.clone(),
            )],
            Some(transaction_context.get_key_of_account_at_index(0).unwrap()),
        ));
        let sysvar_cache = SysvarCache::default();
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors.clone(),
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert_eq!(
            result,
            Err(TransactionError::InstructionError(
                0,
                InstructionError::AccountBorrowFailed
            ))
        );

        // Try to borrow mut the same account in a safe way
        let message = SanitizedMessage::Legacy(Message::new(
            &[Instruction::new_with_bincode(
                mock_program_id,
                &MockSystemInstruction::MultiBorrowMut,
                account_metas.clone(),
            )],
            Some(transaction_context.get_key_of_account_at_index(0).unwrap()),
        ));
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors.clone(),
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert!(result.is_ok());

        // Do work on the same transaction account but at different instruction accounts
        let message = SanitizedMessage::Legacy(Message::new(
            &[Instruction::new_with_bincode(
                mock_program_id,
                &MockSystemInstruction::DoWork {
                    lamports: 10,
                    data: 42,
                },
                account_metas,
            )],
            Some(transaction_context.get_key_of_account_at_index(0).unwrap()),
        ));
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &program_indices,
            &mut transaction_context,
            rent_collector.rent,
            None,
            executors,
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );
        assert!(result.is_ok());
        assert_eq!(
            transaction_context
                .get_account_at_index(0)
                .unwrap()
                .borrow()
                .lamports(),
            80
        );
        assert_eq!(
            transaction_context
                .get_account_at_index(1)
                .unwrap()
                .borrow()
                .lamports(),
            20
        );
        assert_eq!(
            transaction_context
                .get_account_at_index(0)
                .unwrap()
                .borrow()
                .data(),
            &vec![42]
        );
    }

    #[test]
    fn test_precompile() {
        let mock_program_id = Pubkey::new_unique();
        fn mock_process_instruction(
            _first_instruction_account: usize,
            _data: &[u8],
            _invoke_context: &mut InvokeContext,
        ) -> Result<(), InstructionError> {
            Err(InstructionError::Custom(0xbabb1e))
        }
        let builtin_programs = &[BuiltinProgram {
            program_id: mock_program_id,
            process_instruction: mock_process_instruction,
        }];

        let mut secp256k1_account = AccountSharedData::new(1, 0, &native_loader::id());
        secp256k1_account.set_executable(true);
        let mut mock_program_account = AccountSharedData::new(1, 0, &native_loader::id());
        mock_program_account.set_executable(true);
        let accounts = vec![
            (secp256k1_program::id(), secp256k1_account),
            (mock_program_id, mock_program_account),
        ];
        let mut transaction_context = TransactionContext::new(accounts, 1, 2);

        let message = SanitizedMessage::Legacy(Message::new(
            &[
                new_secp256k1_instruction(
                    &libsecp256k1::SecretKey::random(&mut rand::thread_rng()),
                    b"hello",
                ),
                Instruction::new_with_bytes(mock_program_id, &[], vec![]),
            ],
            None,
        ));
        let sysvar_cache = SysvarCache::default();
        let result = MessageProcessor::process_message(
            builtin_programs,
            &message,
            &[vec![0], vec![1]],
            &mut transaction_context,
            RentCollector::default().rent,
            None,
            Rc::new(RefCell::new(Executors::default())),
            Arc::new(FeatureSet::all_enabled()),
            ComputeBudget::default(),
            &mut ExecuteTimings::default(),
            &sysvar_cache,
            Hash::default(),
            0,
            0,
            &mut 0,
        );

        assert_eq!(
            result,
            Err(TransactionError::InstructionError(
                1,
                InstructionError::Custom(0xbabb1e)
            ))
        );
        assert_eq!(transaction_context.get_instruction_trace().len(), 2);
    }
}
