exchain-blockchain-validate-chain-function-01.ex

defmodule ExChain.Blockchain do
  @moduledoc """
  This module contains the blockchain related functions
  """
  alias __MODULE__
  alias ExChain.Blockchain.Block
  
  ...
  
  @spec valid_chain?(Blockchain.t()) :: boolean()
  def valid_chain?(%__MODULE__{chain: chain}) do
    chain
    |> Enum.chunk_every(2, 1, :discard)
    |> Enum.all?(fn [prev_block, block] ->
      valid_last_hash?(prev_block, block) && valid_block_hash?(prev_block)
    end)
  end

  # Private functions

  defp valid_last_hash?(
         %Block{hash: hash} = _last_block,
         %Block{last_hash: last_hash} = _current_block
       ) do
    hash == last_hash
  end

  defp valid_block_hash?(current_block) do
    current_block.hash == Block.block_hash(current_block)
  end
  
  ...
  
  end