solana-json 0.1.2

use borsh::BorshDeserialize;
use mpl_utils::{assert_derivation, assert_signer, resize_or_reallocate_account_raw};
use solana_program::{
    account_info::{next_account_info, AccountInfo},
    entrypoint::ProgramResult,
    program_memory::sol_memcpy,
    system_program,
};

use crate::{
    error::OnchainMetadataError, instruction::AppendValueArgs, pda::PREFIX, state::JsonMetadata,
};

pub(crate) fn process_append_value(
    accounts: &[AccountInfo],
    args: AppendValueArgs,
) -> ProgramResult {
    let account_info_iter = &mut accounts.iter();
    let json_account = next_account_info(account_info_iter)?;
    // Check that the account isn't already initialized.
    if (json_account.owner != &crate::ID) || json_account.data_is_empty() {
        return Err(OnchainMetadataError::NotInitialized.into());
    }

    let json_metadata_account = next_account_info(account_info_iter)?;
    // Check that the account isn't already initialized.
    if (json_metadata_account.owner != &crate::ID) || json_metadata_account.data_is_empty() {
        return Err(OnchainMetadataError::NotInitialized.into());
    }
    let json_metadata = JsonMetadata::try_from_slice(&json_metadata_account.data.borrow())?;

    // Verify that the derived address is correct for the JSON metadata account.
    let bump = assert_derivation(
        &crate::ID,
        json_metadata_account,
        &[
            PREFIX.as_bytes(),
            crate::ID.as_ref(),
            json_account.key.as_ref(),
        ],
        OnchainMetadataError::MetadataDerivedKeyInvalid,
    )?;
    if bump != json_metadata.bump {
        return Err(OnchainMetadataError::MetadataDerivedKeyInvalid.into());
    }

    let payer = next_account_info(account_info_iter)?;
    // The payer and authority must sign.
    assert_signer(payer)?;
    if !json_metadata.authorities.contains(payer.key) {
        return Err(OnchainMetadataError::InvalidAuthority.into());
    }

    let system_program = next_account_info(account_info_iter)?;
    if system_program.key != &system_program::ID {
        return Err(OnchainMetadataError::InvalidSystemProgram.into());
    }

    let mut json_data: serde_json::Value = serde_json::from_slice(&json_account.data.borrow())
        .map_err(|_| OnchainMetadataError::InvalidJson)?;

    let new_data: serde_json::Value =
        serde_json::from_str(&args.value).map_err(|_| OnchainMetadataError::InvalidJson)?;

    merge_append(&mut json_data, new_data)?;

    // Write the updated JSON metadata account back to the account.
    let serialized_data =
        serde_json::to_vec(&json_data).map_err(|_| OnchainMetadataError::InvalidJson)?;

    // Resize the account to fit the new authority.
    resize_or_reallocate_account_raw(json_account, payer, system_program, serialized_data.len())?;

    // Write the JSON metadata to the JSON metadata account.
    sol_memcpy(
        &mut json_account.try_borrow_mut_data()?,
        &serialized_data,
        serialized_data.len(),
    );

    let json_data: serde_json::Value = serde_json::from_slice(&json_account.data.borrow())
        .map_err(|_| OnchainMetadataError::InvalidJson)?;
    solana_program::msg!("JSON account data: {:?}", json_data);

    Ok(())
}

fn merge_append(a: &mut serde_json::Value, b: serde_json::Value) -> ProgramResult {
    if let serde_json::Value::Object(a) = a {
        if let serde_json::Value::Object(b) = b {
            for (k, v) in b {
                merge_append(a.entry(k).or_insert(serde_json::Value::Null), v)?;
            }

            return Ok(());
        }
    }

    match a {
        serde_json::Value::String(a) => {
            if let serde_json::Value::String(b) = b {
                a.push_str(&b);
                Ok(())
            } else {
                Err(OnchainMetadataError::InvalidJson.into())
            }
        }
        serde_json::Value::Array(a) => {
            if let serde_json::Value::Array(b) = b {
                a.extend(b);
                Ok(())
            } else {
                Err(OnchainMetadataError::InvalidJson.into())
            }
        }
        _ => Err(OnchainMetadataError::InvalidJson.into()),
    }
}