use {
    crate::stake::{
        config,
        program::id,
        state::{Authorized, Lockup, StakeAuthorize, StakeState},
    },
    crate::{
        clock::{Epoch, UnixTimestamp},
        decode_error::DecodeError,
        instruction::{AccountMeta, Instruction},
        pubkey::Pubkey,
        system_instruction, sysvar,
    },
    log::*,
    num_derive::{FromPrimitive, ToPrimitive},
    serde_derive::{Deserialize, Serialize},
    thiserror::Error,
};

/// Reasons the stake might have had an error
#[derive(Error, Debug, Clone, PartialEq, FromPrimitive, ToPrimitive)]
pub enum StakeError {
    #[error("not enough credits to redeem")]
    NoCreditsToRedeem,

    #[error("lockup has not yet expired")]
    LockupInForce,

    #[error("stake already deactivated")]
    AlreadyDeactivated,

    #[error("one re-delegation permitted per epoch")]
    TooSoonToRedelegate,

    #[error("split amount is more than is staked")]
    InsufficientStake,

    #[error("stake account with transient stake cannot be merged")]
    MergeTransientStake,

    #[error("stake account merge failed due to different authority, lockups or state")]
    MergeMismatch,

    #[error("custodian address not present")]
    CustodianMissing,

    #[error("custodian signature not present")]
    CustodianSignatureMissing,
}

impl<E> DecodeError<E> for StakeError {
    fn type_of() -> &'static str {
        "StakeError"
    }
}

#[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
pub enum StakeInstruction {
    /// Initialize a stake with lockup and authorization information
    ///
    /// # Account references
    ///   0. [WRITE] Uninitialized stake account
    ///   1. [] Rent sysvar
    ///
    /// Authorized carries pubkeys that must sign staker transactions
    ///   and withdrawer transactions.
    /// Lockup carries information about withdrawal restrictions
    Initialize(Authorized, Lockup),

    /// Authorize a key to manage stake or withdrawal
    ///
    /// # Account references
    ///   0. [WRITE] Stake account to be updated
    ///   1. [] Clock sysvar
    ///   2. [SIGNER] The stake or withdraw authority
    ///   3. Optional: [SIGNER] Lockup authority, if updating StakeAuthorize::Withdrawer before
    ///      lockup expiration
    Authorize(Pubkey, StakeAuthorize),

    /// Delegate a stake to a particular vote account
    ///
    /// # Account references
    ///   0. [WRITE] Initialized stake account to be delegated
    ///   1. [] Vote account to which this stake will be delegated
    ///   2. [] Clock sysvar
    ///   3. [] Stake history sysvar that carries stake warmup/cooldown history
    ///   4. [] Address of config account that carries stake config
    ///   5. [SIGNER] Stake authority
    ///
    /// The entire balance of the staking account is staked.  DelegateStake
    ///   can be called multiple times, but re-delegation is delayed
    ///   by one epoch
    DelegateStake,

    /// Split u64 tokens and stake off a stake account into another stake account.
    ///
    /// # Account references
    ///   0. [WRITE] Stake account to be split; must be in the Initialized or Stake state
    ///   1. [WRITE] Uninitialized stake account that will take the split-off amount
    ///   2. [SIGNER] Stake authority
    Split(u64),

    /// Withdraw unstaked lamports from the stake account
    ///
    /// # Account references
    ///   0. [WRITE] Stake account from which to withdraw
    ///   1. [WRITE] Recipient account
    ///   2. [] Clock sysvar
    ///   3. [] Stake history sysvar that carries stake warmup/cooldown history
    ///   4. [SIGNER] Withdraw authority
    ///   5. Optional: [SIGNER] Lockup authority, if before lockup expiration
    ///
    /// The u64 is the portion of the stake account balance to be withdrawn,
    ///    must be `<= StakeAccount.lamports - staked_lamports`.
    Withdraw(u64),

    /// Deactivates the stake in the account
    ///
    /// # Account references
    ///   0. [WRITE] Delegated stake account
    ///   1. [] Clock sysvar
    ///   2. [SIGNER] Stake authority
    Deactivate,

    /// Set stake lockup
    ///
    /// If a lockup is not active, the withdraw authority may set a new lockup
    /// If a lockup is active, the lockup custodian may update the lockup parameters
    ///
    /// # Account references
    ///   0. [WRITE] Initialized stake account
    ///   1. [SIGNER] Lockup authority or withdraw authority
    SetLockup(LockupArgs),

    /// Merge two stake accounts.
    ///
    /// Both accounts must have identical lockup and authority keys. A merge
    /// is possible between two stakes in the following states with no additional
    /// conditions:
    ///
    /// * two deactivated stakes
    /// * an inactive stake into an activating stake during its activation epoch
    ///
    /// For the following cases, the voter pubkey and vote credits observed must match:
    ///
    /// * two activated stakes
    /// * two activating accounts that share an activation epoch, during the activation epoch
    ///
    /// All other combinations of stake states will fail to merge, including all
    /// "transient" states, where a stake is activating or deactivating with a
    /// non-zero effective stake.
    ///
    /// # Account references
    ///   0. [WRITE] Destination stake account for the merge
    ///   1. [WRITE] Source stake account for to merge.  This account will be drained
    ///   2. [] Clock sysvar
    ///   3. [] Stake history sysvar that carries stake warmup/cooldown history
    ///   4. [SIGNER] Stake authority
    Merge,

    /// Authorize a key to manage stake or withdrawal with a derived key
    ///
    /// # Account references
    ///   0. [WRITE] Stake account to be updated
    ///   1. [SIGNER] Base key of stake or withdraw authority
    ///   2. [] Clock sysvar
    ///   3. Optional: [SIGNER] Lockup authority, if updating StakeAuthorize::Withdrawer before
    ///      lockup expiration
    AuthorizeWithSeed(AuthorizeWithSeedArgs),
}

#[derive(Default, Debug, Serialize, Deserialize, PartialEq, Clone, Copy)]
pub struct LockupArgs {
    pub unix_timestamp: Option<UnixTimestamp>,
    pub epoch: Option<Epoch>,
    pub custodian: Option<Pubkey>,
}

#[derive(Debug, Serialize, Deserialize, PartialEq, Clone)]
pub struct AuthorizeWithSeedArgs {
    pub new_authorized_pubkey: Pubkey,
    pub stake_authorize: StakeAuthorize,
    pub authority_seed: String,
    pub authority_owner: Pubkey,
}

pub fn initialize(stake_pubkey: &Pubkey, authorized: &Authorized, lockup: &Lockup) -> Instruction {
    Instruction::new_with_bincode(
        id(),
        &StakeInstruction::Initialize(*authorized, *lockup),
        vec![
            AccountMeta::new(*stake_pubkey, false),
            AccountMeta::new_readonly(sysvar::rent::id(), false),
        ],
    )
}

pub fn create_account_with_seed(
    from_pubkey: &Pubkey,
    stake_pubkey: &Pubkey,
    base: &Pubkey,
    seed: &str,
    authorized: &Authorized,
    lockup: &Lockup,
    lamports: u64,
) -> Vec<Instruction> {
    vec![
        system_instruction::create_account_with_seed(
            from_pubkey,
            stake_pubkey,
            base,
            seed,
            lamports,
            std::mem::size_of::<StakeState>() as u64,
            &id(),
        ),
        initialize(stake_pubkey, authorized, lockup),
    ]
}

pub fn create_account(
    from_pubkey: &Pubkey,
    stake_pubkey: &Pubkey,
    authorized: &Authorized,
    lockup: &Lockup,
    lamports: u64,
) -> Vec<Instruction> {
    vec![
        system_instruction::create_account(
            from_pubkey,
            stake_pubkey,
            lamports,
            std::mem::size_of::<StakeState>() as u64,
            &id(),
        ),
        initialize(stake_pubkey, authorized, lockup),
    ]
}

fn _split(
    stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
    lamports: u64,
    split_stake_pubkey: &Pubkey,
) -> Instruction {
    let account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new(*split_stake_pubkey, false),
        AccountMeta::new_readonly(*authorized_pubkey, true),
    ];

    Instruction::new_with_bincode(id(), &StakeInstruction::Split(lamports), account_metas)
}

pub fn split(
    stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
    lamports: u64,
    split_stake_pubkey: &Pubkey,
) -> Vec<Instruction> {
    vec![
        system_instruction::allocate(split_stake_pubkey, std::mem::size_of::<StakeState>() as u64),
        system_instruction::assign(split_stake_pubkey, &id()),
        _split(
            stake_pubkey,
            authorized_pubkey,
            lamports,
            split_stake_pubkey,
        ),
    ]
}

pub fn split_with_seed(
    stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
    lamports: u64,
    split_stake_pubkey: &Pubkey, // derived using create_with_seed()
    base: &Pubkey,               // base
    seed: &str,                  // seed
) -> Vec<Instruction> {
    vec![
        system_instruction::allocate_with_seed(
            split_stake_pubkey,
            base,
            seed,
            std::mem::size_of::<StakeState>() as u64,
            &id(),
        ),
        _split(
            stake_pubkey,
            authorized_pubkey,
            lamports,
            split_stake_pubkey,
        ),
    ]
}

pub fn merge(
    destination_stake_pubkey: &Pubkey,
    source_stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
) -> Vec<Instruction> {
    let account_metas = vec![
        AccountMeta::new(*destination_stake_pubkey, false),
        AccountMeta::new(*source_stake_pubkey, false),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
        AccountMeta::new_readonly(sysvar::stake_history::id(), false),
        AccountMeta::new_readonly(*authorized_pubkey, true),
    ];

    vec![Instruction::new_with_bincode(
        id(),
        &StakeInstruction::Merge,
        account_metas,
    )]
}

pub fn create_account_and_delegate_stake(
    from_pubkey: &Pubkey,
    stake_pubkey: &Pubkey,
    vote_pubkey: &Pubkey,
    authorized: &Authorized,
    lockup: &Lockup,
    lamports: u64,
) -> Vec<Instruction> {
    let mut instructions = create_account(from_pubkey, stake_pubkey, authorized, lockup, lamports);
    instructions.push(delegate_stake(
        stake_pubkey,
        &authorized.staker,
        vote_pubkey,
    ));
    instructions
}

pub fn create_account_with_seed_and_delegate_stake(
    from_pubkey: &Pubkey,
    stake_pubkey: &Pubkey,
    base: &Pubkey,
    seed: &str,
    vote_pubkey: &Pubkey,
    authorized: &Authorized,
    lockup: &Lockup,
    lamports: u64,
) -> Vec<Instruction> {
    let mut instructions = create_account_with_seed(
        from_pubkey,
        stake_pubkey,
        base,
        seed,
        authorized,
        lockup,
        lamports,
    );
    instructions.push(delegate_stake(
        stake_pubkey,
        &authorized.staker,
        vote_pubkey,
    ));
    instructions
}

pub fn authorize(
    stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
    new_authorized_pubkey: &Pubkey,
    stake_authorize: StakeAuthorize,
    custodian_pubkey: Option<&Pubkey>,
) -> Instruction {
    let mut account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
        AccountMeta::new_readonly(*authorized_pubkey, true),
    ];

    if let Some(custodian_pubkey) = custodian_pubkey {
        account_metas.push(AccountMeta::new_readonly(*custodian_pubkey, true));
    }

    Instruction::new_with_bincode(
        id(),
        &StakeInstruction::Authorize(*new_authorized_pubkey, stake_authorize),
        account_metas,
    )
}

pub fn authorize_with_seed(
    stake_pubkey: &Pubkey,
    authority_base: &Pubkey,
    authority_seed: String,
    authority_owner: &Pubkey,
    new_authorized_pubkey: &Pubkey,
    stake_authorize: StakeAuthorize,
    custodian_pubkey: Option<&Pubkey>,
) -> Instruction {
    let mut account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new_readonly(*authority_base, true),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
    ];

    if let Some(custodian_pubkey) = custodian_pubkey {
        account_metas.push(AccountMeta::new_readonly(*custodian_pubkey, true));
    }

    let args = AuthorizeWithSeedArgs {
        new_authorized_pubkey: *new_authorized_pubkey,
        stake_authorize,
        authority_seed,
        authority_owner: *authority_owner,
    };

    Instruction::new_with_bincode(
        id(),
        &StakeInstruction::AuthorizeWithSeed(args),
        account_metas,
    )
}

pub fn delegate_stake(
    stake_pubkey: &Pubkey,
    authorized_pubkey: &Pubkey,
    vote_pubkey: &Pubkey,
) -> Instruction {
    let account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new_readonly(*vote_pubkey, false),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
        AccountMeta::new_readonly(sysvar::stake_history::id(), false),
        AccountMeta::new_readonly(config::id(), false),
        AccountMeta::new_readonly(*authorized_pubkey, true),
    ];
    Instruction::new_with_bincode(id(), &StakeInstruction::DelegateStake, account_metas)
}

pub fn withdraw(
    stake_pubkey: &Pubkey,
    withdrawer_pubkey: &Pubkey,
    to_pubkey: &Pubkey,
    lamports: u64,
    custodian_pubkey: Option<&Pubkey>,
) -> Instruction {
    let mut account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new(*to_pubkey, false),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
        AccountMeta::new_readonly(sysvar::stake_history::id(), false),
        AccountMeta::new_readonly(*withdrawer_pubkey, true),
    ];

    if let Some(custodian_pubkey) = custodian_pubkey {
        account_metas.push(AccountMeta::new_readonly(*custodian_pubkey, true));
    }

    Instruction::new_with_bincode(id(), &StakeInstruction::Withdraw(lamports), account_metas)
}

pub fn deactivate_stake(stake_pubkey: &Pubkey, authorized_pubkey: &Pubkey) -> Instruction {
    let account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new_readonly(sysvar::clock::id(), false),
        AccountMeta::new_readonly(*authorized_pubkey, true),
    ];
    Instruction::new_with_bincode(id(), &StakeInstruction::Deactivate, account_metas)
}

pub fn set_lockup(
    stake_pubkey: &Pubkey,
    lockup: &LockupArgs,
    custodian_pubkey: &Pubkey,
) -> Instruction {
    let account_metas = vec![
        AccountMeta::new(*stake_pubkey, false),
        AccountMeta::new_readonly(*custodian_pubkey, true),
    ];
    Instruction::new_with_bincode(id(), &StakeInstruction::SetLockup(*lockup), account_metas)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::instruction::InstructionError;

    #[test]
    fn test_custom_error_decode() {
        use num_traits::FromPrimitive;
        fn pretty_err<T>(err: InstructionError) -> String
        where
            T: 'static + std::error::Error + DecodeError<T> + FromPrimitive,
        {
            if let InstructionError::Custom(code) = err {
                let specific_error: T = T::decode_custom_error_to_enum(code).unwrap();
                format!(
                    "{:?}: {}::{:?} - {}",
                    err,
                    T::type_of(),
                    specific_error,
                    specific_error,
                )
            } else {
                "".to_string()
            }
        }
        assert_eq!(
            "Custom(0): StakeError::NoCreditsToRedeem - not enough credits to redeem",
            pretty_err::<StakeError>(StakeError::NoCreditsToRedeem.into())
        )
    }
}