use {
    borsh::{ 
        BorshSerialize, 
        BorshDeserialize 
    },
    solana_program::{
        account_info::{next_account_info, AccountInfo}, 
        entrypoint,
        entrypoint::ProgramResult, 
        msg, 
        program::invoke,
        program_pack::Pack,
        pubkey::Pubkey,
        rent::Rent,
        system_instruction,
        sysvar::Sysvar,
    },
    spl_token::{
        instruction as token_instruction,
        state::Mint,
    },
    mpl_token_metadata::{
        instruction as mpl_instruction,
    },
};


#[derive(BorshSerialize, BorshDeserialize, Debug)]
pub struct CreateTokenArgs {
    pub token_title: String,
    pub token_symbol: String,
    pub token_uri: String,
}


entrypoint!(process_instruction);


fn process_instruction(
    _program_id: &Pubkey,
    accounts: &[AccountInfo],
    instruction_data: &[u8],
) -> ProgramResult {

    let args = CreateTokenArgs::try_from_slice(instruction_data)?;

    let accounts_iter = &mut accounts.iter();

    let mint_account = next_account_info(accounts_iter)?;
    let mint_authority = next_account_info(accounts_iter)?;
    let metadata_account = next_account_info(accounts_iter)?;
    let payer = next_account_info(accounts_iter)?;
    let rent = next_account_info(accounts_iter)?;
    let system_program = next_account_info(accounts_iter)?;
    let token_program = next_account_info(accounts_iter)?;
    let token_metadata_program = next_account_info(accounts_iter)?;

    // First create the account for the Mint
    //
    msg!("Creating mint account...");
    msg!("Mint: {}", mint_account.key);
    invoke(
        &system_instruction::create_account(
            &payer.key,
            &mint_account.key,
            (Rent::get()?).minimum_balance(Mint::LEN),
            Mint::LEN as u64,
            &token_program.key,
        ),
        &[
            mint_account.clone(),
            payer.clone(),
            system_program.clone(),
            token_program.clone(),
        ]
    )?;

    // Now initialize that account as a Mint (standard Mint)
    //
    msg!("Initializing mint account...");
    msg!("Mint: {}", mint_account.key);
    invoke(
        &token_instruction::initialize_mint(
            &token_program.key,
            &mint_account.key,
            &mint_authority.key,
            Some(&mint_authority.key),
            9,                          // 9 Decimals for the default SPL Token standard
        )?,
        &[
            mint_account.clone(),
            mint_authority.clone(),
            token_program.clone(),
            rent.clone(),
        ]
    )?;

    // Now create the account for that Mint's metadata
    //
    msg!("Creating metadata account...");
    msg!("Metadata account address: {}", metadata_account.key);
    invoke(
        &mpl_instruction::create_metadata_accounts_v2(
            *token_metadata_program.key,
            *metadata_account.key,
            *mint_account.key,
            *mint_authority.key,
            *payer.key,
            *mint_authority.key,
            args.token_title,
            args.token_symbol,
            args.token_uri,
            None,
            0,
            true,
            false,
            None,
            None,
        ),
        &[
            metadata_account.clone(),
            mint_account.clone(),
            mint_authority.clone(),
            payer.clone(),
            token_metadata_program.clone(),
            rent.clone(),
        ]
    )?;

    msg!("Token mint created successfully.");

    Ok(())
}