# Nimbus
# Copyright (c) 2018-2024 Status Research & Development GmbH
# Licensed under either of
#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
#    http://www.apache.org/licenses/LICENSE-2.0)
#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
#    http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.

## EVM Opcode Handlers: Push Operations
## ====================================
##

{.push raises: [].}

import
  std/[sequtils],
  ../../code_stream,
  ../../stack,
  ../../evm_errors,
  ../op_codes,
  ./oph_defs,
  ./oph_gen_handlers

# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------

proc fnName(n: int): string {.compileTime.} =
  "push" & $n & "Op"

proc opName(n: int): string {.compileTime.} =
  "Push" & $n

proc fnInfo(n: int): string {.compileTime.} =
  var blurb = case n
              of 1: "byte"
              else: $n & " bytes"
  "Push " & blurb & " on the stack"


template pushImpl(cpt: VmCpt; n: static int): EvmResultVoid =
  cpt.stack.push cpt.code.readVmWord(n)

const
  inxRange = toSeq(1 .. 32)

# ------------------------------------------------------------------------------
# Private, op handlers implementation
# ------------------------------------------------------------------------------

genOphHandlers fnName, fnInfo, inxRange, pushImpl

# ------------------------------------------------------------------------------
# Public, op exec table entries
# ------------------------------------------------------------------------------

genOphList fnName, fnInfo, inxRange, "VmOpExecPush", opName


# Push0 needs to be slightly different because it's only available after
# Shanghai (EIP-3855). But it still seems like it belongs in this file.
# (Alternatively, we could make genOphList accept some more information
# about which opcodes are for which forks, but that seems uglier than
# just adding Push0 here as a special case.)

proc push0Op(cpt: VmCpt): EvmResultVoid =
  ## 0x5f, push 0 onto the stack
  cpt.stack.push(0)

const
  VmOpExecPushZero*: seq[VmOpExec] = @[

    (opCode: Push0,       ## 0x5f, push 0 onto the stack
     forks: VmOpShanghaiAndLater,
     name: "Push0",
     info: "Push 0 on the stack",
     exec: push0Op)]

# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------