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open Protocol

type context = Alpha_context.context * Script_interpreter.step_constants

let initial_balance = 4_000_000_000_000L

let context_init_memory ~rng_state =
  Context.init_n
    ~rng_state
    ~bootstrap_balances:
      [
        initial_balance;
        initial_balance;
        initial_balance;
        initial_balance;
        initial_balance;
      ]
    5
    ()
  >>=? fun (block, accounts) ->
  match accounts with
  | [bs1; bs2; bs3; bs4; bs5] ->
      return (`Mem_block (block, (bs1, bs2, bs3, bs4, bs5)))
  | _ -> assert false

let context_init ~rng_state = context_init_memory ~rng_state

let make ~rng_state =
  context_init_memory ~rng_state >>=? fun context ->
  let amount = Alpha_context.Tez.one in
  let chain_id = Tezos_crypto.Hashed.Chain_id.zero in
  let now = Script_timestamp.of_zint Z.zero in
  let level = Script_int.zero_n in
  let open Script_interpreter in
  (match context with
  | `Mem_block (block, (bs1, _, _, _, _)) ->
      let sender = Alpha_context.Destination.Contract bs1 in
      let payer = Contract_helpers.default_payer in
      let self = Contract_helpers.default_self in
      let step_constants =
        {
          sender;
          payer;
          self;
          amount;
          balance = Alpha_context.Tez.of_mutez_exn initial_balance;
          chain_id;
          now;
          level;
        }
      in
      return (block, step_constants))
  >>=? fun (block, step_constants) ->
  Context.get_constants (B block) >>=? fun csts ->
  let minimal_block_delay =
    Protocol.Alpha_context.Period.to_seconds csts.parametric.minimal_block_delay
  in
  Incremental.begin_construction
    ~timestamp:
      (Time.Protocol.add block.header.shell.timestamp minimal_block_delay)
    block
  >>=? fun vs ->
  let ctxt = Incremental.alpha_ctxt vs in
  let ctxt =
    (* Required for eg Create_contract *)
    Protocol.Alpha_context.Origination_nonce.init
      ctxt
      Tezos_crypto.Hashed.Operation_hash.zero
  in
  return (ctxt, step_constants)