/* Copyright 2017 - 2026 R. Thomas
 * Copyright 2017 - 2026 Quarkslab
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <sstream>
#include <spdlog/fmt/fmt.h>
#include "LIEF/PE/debug/FPO.hpp"
#include "LIEF/BinaryStream/SpanStream.hpp"

#include "PE/Structures.hpp"

namespace LIEF::PE {

namespace details {
// From um/winnt.h -- typedef struct _FPO_DATA { ... } FPO_DATA, *PFPO_DATA
struct FPO_DATA {
  uint32_t ulOffStart;   // offset 1st byte of function code
  uint32_t cbProcSize;   // # bytes in function
  uint32_t cdwLocals;    // # bytes in locals/4
  uint16_t cdwParams;    // # bytes in params/4
  uint16_t cbProlog : 8; // # bytes in prolog
  uint16_t cbRegs : 3;   // # regs saved
  uint16_t fHasSEH : 1;  // TRUE if SEH in func
  uint16_t fUseBP : 1;   // TRUE if EBP has been allocated
  uint16_t reserved : 1; // reserved for future use
  uint16_t cbFrame : 2;  // frame type
};

static_assert(sizeof(FPO_DATA) == 16, "Wrong size");
}

std::unique_ptr<FPO> FPO::parse(const details::pe_debug& hdr, Section* section,
                                span<uint8_t> payload) {
  SpanStream stream(payload);

  auto fpo = std::make_unique<FPO>(hdr, section);

  while (stream) {
    auto entry = stream.read<details::FPO_DATA>();
    if (!entry) {
      break;
    }
    fpo->entries_.push_back({
        /*rva=*/entry->ulOffStart,
        /*proc_size=*/entry->cbProcSize,
        /*nb_locals=*/entry->cdwLocals * 4,
        /*parameters_size=*/(uint32_t)entry->cdwParams * 4,
        /*prolog_size=*/(uint16_t)entry->cbProcSize,
        /*nb_saved_regs=*/(uint16_t)entry->cbRegs,
        /*use_seh=*/(bool)entry->fHasSEH,
        /*use_bp=*/(bool)entry->fUseBP,
        /*reserved=*/(uint16_t)entry->reserved,
        /*type=*/(FRAME_TYPE)entry->cbFrame,
    });
  }
  return fpo;
}

std::string FPO::entry_t::to_string() const {
  std::ostringstream os;
  os << fmt::format("{:10} {:<13} {:<9} {:<8} {:<9} {:<5} {:<6} {:<8} {}",
                    fmt::format("{:#010x}", rva), proc_size, nb_locals,
                    nb_saved_regs, prolog_size, use_bp ? 'Y' : 'N',
                    use_seh ? 'Y' : 'N', PE::to_string(type), parameters_size);
  return os.str();
}

std::string FPO::to_string() const {
  std::ostringstream os;
  os << fmt::format("{:10} {:13} {:9} {:8} {:9} {:5} {:6} {:8} {}\n", "RVA",
                    "Proc Size", "Locals", "Regs", "Prolog", "BP", "SEH", "Type",
                    "Params");
  for (const entry_t& entry : entries()) {
    os << entry.to_string() << '\n';
  }
  return os.str();
}

const char* to_string(FPO::FRAME_TYPE e) {
  switch (e) {
    default: return "UNKNOWN";
    case FPO::FRAME_TYPE::FPO: return "FPO";
    case FPO::FRAME_TYPE::TRAP: return "TRAP";
    case FPO::FRAME_TYPE::TSS: return "TSS";
    case FPO::FRAME_TYPE::NON_FPO: return "NON_FPO";
  }

  return "UNKNOWN";
}

}