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use crate::program::error::assert_with_msg;
use solana_program::{
    account_info::AccountInfo, program_error::ProgramError, program_pack::Pack, pubkey::Pubkey,
};
use spl_token::state::{Account, Mint};
use std::ops::Deref;

#[derive(Clone)]
pub struct MintAccountInfo<'a, 'info> {
    pub mint: Mint,
    pub info: &'a AccountInfo<'info>,
}

impl<'a, 'info> MintAccountInfo<'a, 'info> {
    pub fn new(info: &'a AccountInfo<'info>) -> Result<MintAccountInfo<'a, 'info>, ProgramError> {
        assert_with_msg(
            info.owner == &spl_token::id(),
            ProgramError::IllegalOwner,
            "Mint account must be owned by the Token Program",
        )?;
        let mint = Mint::unpack(&info.try_borrow_data()?)?;

        Ok(Self { mint, info })
    }
}

impl<'a, 'info> AsRef<AccountInfo<'info>> for MintAccountInfo<'a, 'info> {
    fn as_ref(&self) -> &AccountInfo<'info> {
        self.info
    }
}

impl<'a, 'info> Deref for MintAccountInfo<'a, 'info> {
    type Target = Mint;

    fn deref(&self) -> &Self::Target {
        &self.mint
    }
}

#[derive(Clone)]
pub struct TokenAccountInfo<'a, 'info> {
    pub info: &'a AccountInfo<'info>,
}

impl<'a, 'info> TokenAccountInfo<'a, 'info> {
    pub fn new(
        info: &'a AccountInfo<'info>,
        mint: &Pubkey,
    ) -> Result<TokenAccountInfo<'a, 'info>, ProgramError> {
        assert_with_msg(
            info.owner == &spl_token::id(),
            ProgramError::IllegalOwner,
            "Token account must be owned by the Token Program",
        )?;
        assert_with_msg(
            info.data_len() == Account::LEN,
            ProgramError::InvalidAccountData,
            "Token account data length must be 165 bytes",
        )?;
        // The mint key is found at offset 0 of the token account
        assert_with_msg(
            &info.try_borrow_data()?[0..32] == mint.as_ref(),
            ProgramError::InvalidAccountData,
            "Token account mint mismatch",
        )?;
        Ok(Self { info })
    }

    pub fn new_with_owner(
        info: &'a AccountInfo<'info>,
        mint: &Pubkey,
        owner: &Pubkey,
    ) -> Result<TokenAccountInfo<'a, 'info>, ProgramError> {
        let token_account_info = Self::new(info, mint)?;
        // The owner key is found at offset 32 of the token account
        assert_with_msg(
            &info.try_borrow_data()?[32..64] == owner.as_ref(),
            ProgramError::IllegalOwner,
            "Token account owner mismatch",
        )?;
        Ok(token_account_info)
    }

    pub fn new_with_owner_and_key(
        info: &'a AccountInfo<'info>,
        mint: &Pubkey,
        owner: &Pubkey,
        key: &Pubkey,
    ) -> Result<TokenAccountInfo<'a, 'info>, ProgramError> {
        assert_with_msg(
            info.key == key,
            ProgramError::InvalidInstructionData,
            "Invalid pubkey for Token Account",
        )?;
        Self::new_with_owner(info, mint, owner)
    }
}

impl<'a, 'info> TokenAccountInfo<'a, 'info> {
    /// Function copied from https://github.com/coral-xyz/anchor/blob/master/spl/src/token.rs#L534
    pub fn amount(&self) -> Result<u64, ProgramError> {
        let bytes = self.info.try_borrow_data()?;
        let mut amount_bytes = [0u8; 8];
        amount_bytes.copy_from_slice(&bytes[64..72]);
        Ok(u64::from_le_bytes(amount_bytes))
    }
}

impl<'a, 'info> AsRef<AccountInfo<'info>> for TokenAccountInfo<'a, 'info> {
    fn as_ref(&self) -> &AccountInfo<'info> {
        self.info
    }
}

impl<'a, 'info> Deref for TokenAccountInfo<'a, 'info> {
    type Target = AccountInfo<'info>;

    fn deref(&self) -> &Self::Target {
        self.info
    }
}