// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: Copyright The WasmEdge Authors

//===-- wasmedge/ast/component/canonical.h - Canon class definitions ------===//

//

// Part of the WasmEdge Project.

//

//===----------------------------------------------------------------------===//

///

/// \file

/// This file contains the declaration of the Canon node related classes.

///

//===----------------------------------------------------------------------===//

#pragma once

#include "ast/component/valtype.h"

#include "common/enum_ast.hpp"

#include "common/span.h"

#include <cstdint>

#include <utility>

#include <vector>

namespace WasmEdge {

namespace AST {

namespace Component {

// canonopt ::= 0x00                  => string-encoding=utf8

//            | 0x01                  => string-encoding=utf16

//            | 0x02                  => string-encoding=latin1+utf16

//            | 0x03 m:<core:memidx>  => (memory m)

//            | 0x04 f:<core:funcidx> => (realloc f)

//            | 0x05 f:<core:funcidx> => (post-return f)

//            | 0x06                  => async 🔀

//            | 0x07 f:<core:funcidx> => (callback f) 🔀

/// AST Component::CanonOpt definition.

class CanonOpt {

public:

  CanonOpt() noexcept : Code(ComponentCanonOptCode::Encode_UTF8), Idx(0) {}

  ComponentCanonOptCode getCode() const noexcept { return Code; }

  void setCode(const ComponentCanonOptCode C) noexcept { Code = C; }

  uint32_t getIndex() const noexcept { return Idx; }

  void setIndex(const uint32_t I) noexcept { Idx = I; }

private:

  ComponentCanonOptCode Code;

  uint32_t Idx;

};

// canon ::= 0x00 0x00 f:<core:funcidx> opts:<opts> ft:<typeidx>

//           => (canon lift f opts type-index-space[ft])

//         | 0x01 0x00 f:<funcidx> opts:<opts>

//           => (canon lower f opts (core func))

//         | 0x02 rt:<typeidx>    => (canon resource.new rt (core func))

//         | 0x03 rt:<typeidx>    => (canon resource.drop rt (core func))

//         | 0x04 rt:<typeidx>    => (canon resource.rep rt (core func))

//         | 0x09 rs:<resultlist> opts:<opts>

//           => (canon task.return rs opts (core func)) 🔀

//         | 0x05                 => (canon task.cancel (core func)) 🔀

//         | 0x0a t:<core:valtype> i:<u32>

//           => (canon context.get t i (core func)) 🔀

//         | 0x0b t:<core:valtype> i:<u32>

//           => (canon context.set t i (core func)) 🔀

//         | 0x0c cancel?:<cancel?>

//           => (canon thread.yield cancel? (core func)) 🔀

//         | 0x06 async?:<async?>

//           => (canon subtask.cancel async? (core func)) 🔀

//         | 0x0d                 => (canon subtask.drop (core func)) 🔀

//         | 0x0e t:<typeidx>     => (canon stream.new t (core func)) 🔀

//         | 0x0f t:<typeidx> opts:<opts>

//           => (canon stream.read t opts (core func)) 🔀

//         | 0x10 t:<typeidx> opts:<opts>

//           => (canon stream.write t opts (core func)) 🔀

//         | 0x11 t:<typeidx> async?:<async?>

//           => (canon stream.cancel-read t async? (core func)) 🔀

//         | 0x12 t:<typeidx> async?:<async?>

//           => (canon stream.cancel-write t async? (core func)) 🔀

//         | 0x13 t:<typeidx> => (canon stream.drop-readable t (core func)) 🔀

//         | 0x14 t:<typeidx> => (canon stream.drop-writable t (core func)) 🔀

//         | 0x15 t:<typeidx> => (canon future.new t (core func)) 🔀

//         | 0x16 t:<typeidx> opts:<opts>

//           => (canon future.read t opts (core func)) 🔀

//         | 0x17 t:<typeidx> opts:<opts>

//           => (canon future.write t opts (core func)) 🔀

//         | 0x18 t:<typeidx> async?:<async?>

//           => (canon future.cancel-read t async? (core func)) 🔀

//         | 0x19 t:<typeidx> async?:<async?>

//           => (canon future.cancel-write t async? (core func)) 🔀

//         | 0x1a t:<typeidx> => (canon future.drop-readable t (core func)) 🔀

//         | 0x1b t:<typeidx> => (canon future.drop-writable t (core func)) 🔀

//         | 0x1c opts:<opts> => (canon error-context.new opts (core func)) 📝

//         | 0x1d opts:<opts>

//           => (canon error-context.debug-message opts (core func)) 📝

//         | 0x1e                 => (canon error-context.drop (core func)) 📝

//         | 0x1f                 => (canon waitable-set.new (core func)) 🔀

//         | 0x20 cancel?:<cancel?> m:<core:memoryidx>

//           => (canon waitable-set.wait cancel? (memory m) (core func)) 🔀

//         | 0x21 cancel?:<cancel?> m:<core:memoryidx>

//           => (canon waitable-set.poll cancel? (memory m) (core func)) 🔀

//         | 0x22                 => (canon waitable-set.drop (core func)) 🔀

//         | 0x23                 => (canon waitable.join (core func)) 🔀

//         | 0x24                 => (canon backpressure.inc (core func)) 🔀

//         | 0x25                 => (canon backpressure.dec (core func)) 🔀

//         | 0x26                 => (canon thread.index (core func)) 🧵

//         | 0x27 ft:<core:typeidx> tbl:<core:tableidx>

//           => (canon thread.new-indirect ft tbl (core func)) 🧵

//         | 0x28                 => (canon thread.resume-later (core func)) 🧵

//         | 0x29 cancel?:<cancel?>

//           => (canon thread.suspend cancel? (core func)) 🧵

//         | 0x2a cancel?:<cancel?>

//           => (canon thread.suspend-then-resume cancel? (core func)) 🧵

//         | 0x2b cancel?:<cancel?>

//           => (canon thread.yield-then-resume cancel? (core func)) 🧵

//         | 0x2c cancel?:<cancel?>

//           => (canon thread.suspend-then-promote cancel? (core func)) 🧵

//         | 0x2d cancel?:<cancel?>

//           => (canon thread.yield-then-promote cancel? (core func)) 🧵

//         | 0x40 shared?:<sh?> ft:<core:typeidx>

//           => (canon thread.spawn-ref shared? ft (core func)) 🧵②

//         | 0x41 shared?:<sh?> ft:<core:typeidx> tbl:<core:tableidx>

//           => (canon thread.spawn-indirect shared? ft tbl (core func)) 🧵②

//         | 0x42 shared?:<sh?>

//           => (canon thread.available-parallelism shared? (core func)) 🧵②

// opts    ::= opt*:vec(<canonopt>) => opt*

// async?  ::= 0x00 => ϵ

//           | 0x01 => async

// cancel? ::= 0x00 => ϵ

//           | 0x01 => cancellable

// sh?     ::= 0x00 => ϵ

//           | 0x01 => shared 🧵②

// Currently implementing:

//   0x00 0x00 (canon lift f opts type-index-space[ft])

//   0x01 0x00 (canon lower f opts (core func))

//   0x02      (canon resource.new rt (core func))

//   0x03      (canon resource.drop rt (core func))

//   0x04      (canon resource.rep rt (core func))

class Canonical {

public:

  Canonical() noexcept = default;

  ComponentCanonOpCode getOpCode() const noexcept { return Code; }

  void setOpCode(const ComponentCanonOpCode C) noexcept { Code = C; }

  // The one-byte flag immediate. It reads as `async?` on subtask.cancel and

  // the stream and future cancel forms, and as `cancel?` on thread.yield,

  // waitable-set.wait and poll, and the thread.suspend forms.

  bool getFlagImmediate() const noexcept { return FlagImm; }

  void setFlagImmediate(const bool V) noexcept { FlagImm = V; }

  uint32_t getIndex() const noexcept { return Idx; }

  void setIndex(const uint32_t I) noexcept { Idx = I; }

  uint32_t getTargetIndex() const noexcept { return TargetIdx; }

  void setTargetIndex(const uint32_t I) noexcept { TargetIdx = I; }

  uint32_t getConstVal() const noexcept { return I32; }

  void setConstVal(const uint32_t V) noexcept { I32 = V; }

  ValType getContextType() const noexcept { return CtxType; }

  void setContextType(const ValType T) noexcept { CtxType = T; }

  Span<const CanonOpt> getOptions() const noexcept { return Opts; }

  /// True when the definition carries the option OptCode.

  bool hasOption(ComponentCanonOptCode OptCode) const noexcept {

    for (const auto &Opt : Opts) {

      if (Opt.getCode() == OptCode) {

        return true;

      }

    }

    return false;

  }

  void setOptions(std::vector<CanonOpt> &&List) noexcept {

    Opts = std::move(List);

  }

  Span<const LabelValType> getResultList() const noexcept { return ResultList; }

  void setResultList(std::vector<LabelValType> &&R) noexcept {

    ResultList = std::move(R);

  }

  void setResultList(const ComponentValType &VT) noexcept {

    ResultList.clear();

    ResultList.emplace_back(VT);

  }

  /// The core function type of the canonical built-in Code, as the Explainer's

  /// synopsis tables give it, with AddrType for the address type of the memory

  /// the definition names, or of the table for thread.new-indirect.

  /// context.get and context.set take the context slot type, and task.return

  /// the lowered results, so their callers form those types themselves.

  static std::pair<std::vector<ValType>, std::vector<ValType>>

  getBuiltinCoreFuncType(ComponentCanonOpCode Code,

                         const ValType &AddrType) noexcept {

    const ValType I32(TypeCode::I32);

    const ValType I64(TypeCode::I64);

    switch (Code) {

    case ComponentCanonOpCode::Backpressure__inc:

    case ComponentCanonOpCode::Backpressure__dec:

    case ComponentCanonOpCode::Task__cancel:

      return {{}, {}};

    case ComponentCanonOpCode::Yield:

    case ComponentCanonOpCode::Waitable_set__new:

    case ComponentCanonOpCode::Thread__index:

    case ComponentCanonOpCode::Thread__suspend:

      return {{}, {I32}};

    case ComponentCanonOpCode::Waitable_set__wait:

    case ComponentCanonOpCode::Waitable_set__poll:

      return {{I32, AddrType}, {I32}};

    case ComponentCanonOpCode::Waitable_set__drop:

    case ComponentCanonOpCode::Subtask__drop:

    case ComponentCanonOpCode::Stream__drop_readable:

    case ComponentCanonOpCode::Stream__drop_writable:

    case ComponentCanonOpCode::Future__drop_readable:

    case ComponentCanonOpCode::Future__drop_writable:

    case ComponentCanonOpCode::Error_context__drop:

    case ComponentCanonOpCode::Thread__resume_later:

      return {{I32}, {}};

    case ComponentCanonOpCode::Waitable__join:

      return {{I32, I32}, {}};

    case ComponentCanonOpCode::Subtask__cancel:

    case ComponentCanonOpCode::Stream__cancel_read:

    case ComponentCanonOpCode::Stream__cancel_write:

    case ComponentCanonOpCode::Future__cancel_read:

    case ComponentCanonOpCode::Future__cancel_write:

    case ComponentCanonOpCode::Thread__yield_then_resume:

    case ComponentCanonOpCode::Thread__suspend_then_resume:

    case ComponentCanonOpCode::Thread__yield_then_promote:

    case ComponentCanonOpCode::Thread__suspend_then_promote:

      return {{I32}, {I32}};

    case ComponentCanonOpCode::Stream__new:

    case ComponentCanonOpCode::Future__new:

      return {{}, {I64}};

    case ComponentCanonOpCode::Stream__read:

    case ComponentCanonOpCode::Stream__write:

      return {{I32, AddrType, AddrType}, {AddrType}};

    case ComponentCanonOpCode::Future__read:

    case ComponentCanonOpCode::Future__write:

      return {{I32, AddrType}, {I32}};

    case ComponentCanonOpCode::Error_context__new:

      return {{AddrType, AddrType}, {I32}};

    case ComponentCanonOpCode::Error_context__debug_message:

      return {{I32, AddrType}, {}};

    case ComponentCanonOpCode::Thread__new_indirect:

      return {{AddrType, I32}, {I32}};

    default:

      assumingUnreachable();

    }

  }

private:

  ComponentCanonOpCode Code = ComponentCanonOpCode::Lift;

  bool FlagImm = false;

  uint32_t Idx = 0, TargetIdx = 0;

  uint32_t I32 = 0;

  ValType CtxType = TypeCode::I32;

  std::vector<CanonOpt> Opts;

  std::vector<LabelValType> ResultList;

};

} // namespace Component

} // namespace AST

} // namespace WasmEdge