/*
 * Copyright 2016 WebAssembly Community Group participants
 *
 * 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 <cstdio>
#include <cstdlib>
#include <cstring>

#include "common.h"
#include "option-parser.h"
#include "stream.h"
#include "writer.h"
#include "binary-reader.h"
#include "binary-reader-objdump.h"

#define PROGRAM_NAME "wasm-objdump"

#define NOPE HasArgument::No
#define YEP HasArgument::Yes

using namespace wabt;

enum {
  FLAG_HEADERS,
  FLAG_SECTION,
  FLAG_RAW,
  FLAG_DISASSEMBLE,
  FLAG_DEBUG,
  FLAG_DETAILS,
  FLAG_RELOCS,
  FLAG_HELP,
  NUM_FLAGS
};

static const char s_description[] =
    "  Print information about the contents of wasm binaries.\n"
    "\n"
    "examples:\n"
    "  $ wasm-objdump test.wasm\n";

static Option s_options[] = {
    {FLAG_HEADERS, 'h', "headers", nullptr, NOPE, "print headers"},
    {FLAG_SECTION, 'j', "section", nullptr, YEP, "select just one section"},
    {FLAG_RAW, 's', "full-contents", nullptr, NOPE,
     "print raw section contents"},
    {FLAG_DISASSEMBLE, 'd', "disassemble", nullptr, NOPE,
     "disassemble function bodies"},
    {FLAG_DEBUG, '\0', "debug", nullptr, NOPE, "print extra debug information"},
    {FLAG_DETAILS, 'x', "details", nullptr, NOPE, "Show section details"},
    {FLAG_RELOCS, 'r', "reloc", nullptr, NOPE,
     "show relocations inline with disassembly"},
    {FLAG_HELP, 'h', "help", nullptr, NOPE, "print this help message"},
};

WABT_STATIC_ASSERT(NUM_FLAGS == WABT_ARRAY_SIZE(s_options));

static ObjdumpOptions s_objdump_options;

static std::vector<const char*> s_infiles;

static std::unique_ptr<FileStream> s_log_stream;

static void on_argument(struct OptionParser* parser, const char* argument) {
  s_infiles.push_back(argument);
}

static void on_option(struct OptionParser* parser,
                      struct Option* option,
                      const char* argument) {
  switch (option->id) {
    case FLAG_HEADERS:
      s_objdump_options.headers = true;
      break;

    case FLAG_RAW:
      s_objdump_options.raw = true;
      break;

    case FLAG_DEBUG:
      s_objdump_options.debug = true;
      s_log_stream = FileStream::CreateStdout();
      s_objdump_options.log_stream = s_log_stream.get();
      break;

    case FLAG_DISASSEMBLE:
      s_objdump_options.disassemble = true;
      break;

    case FLAG_DETAILS:
      s_objdump_options.details = true;
      break;

    case FLAG_RELOCS:
      s_objdump_options.relocs = true;
      break;

    case FLAG_SECTION:
      s_objdump_options.section_name = argument;
      break;

    case FLAG_HELP:
      print_help(parser, PROGRAM_NAME);
      exit(0);
      break;
  }
}

static void on_option_error(struct OptionParser* parser, const char* message) {
  WABT_FATAL("%s\n", message);
}

static void parse_options(int argc, char** argv) {
  OptionParser parser;
  WABT_ZERO_MEMORY(parser);
  parser.description = s_description;
  parser.options = s_options;
  parser.num_options = WABT_ARRAY_SIZE(s_options);
  parser.on_option = on_option;
  parser.on_argument = on_argument;
  parser.on_error = on_option_error;
  parse_options(&parser, argc, argv);

  if (s_infiles.size() == 0) {
    print_help(&parser, PROGRAM_NAME);
    WABT_FATAL("No filename given.\n");
  }
}

Result dump_file(const char* filename) {
  char* char_data;
  size_t size;
  Result result = read_file(filename, &char_data, &size);
  if (WABT_FAILED(result))
    return result;

  uint8_t* data = reinterpret_cast<uint8_t*>(char_data);

  // Perform serveral passed over the binary in order to print out different
  // types of information.
  s_objdump_options.filename = filename;
  printf("\n");

  ObjdumpState state;

  // Pass 0: Prepass
  s_objdump_options.mode = ObjdumpMode::Prepass;
  result = read_binary_objdump(data, size, &s_objdump_options, &state);
  if (WABT_FAILED(result))
    goto done;
  s_objdump_options.log_stream = nullptr;

  // Pass 1: Print the section headers
  if (s_objdump_options.headers) {
    s_objdump_options.mode = ObjdumpMode::Headers;
    result = read_binary_objdump(data, size, &s_objdump_options, &state);
    if (WABT_FAILED(result))
      goto done;
  }

  // Pass 2: Print extra information based on section type
  if (s_objdump_options.details) {
    s_objdump_options.mode = ObjdumpMode::Details;
    result = read_binary_objdump(data, size, &s_objdump_options, &state);
    if (WABT_FAILED(result))
      goto done;
  }

  // Pass 3: Disassemble code section
  if (s_objdump_options.disassemble) {
    s_objdump_options.mode = ObjdumpMode::Disassemble;
    result = read_binary_objdump(data, size, &s_objdump_options, &state);
    if (WABT_FAILED(result))
      goto done;
  }

  // Pass 4: Dump to raw contents of the sections
  if (s_objdump_options.raw) {
    s_objdump_options.mode = ObjdumpMode::RawData;
    result = read_binary_objdump(data, size, &s_objdump_options, &state);
  }

done:
  delete[] data;
  return result;
}

int ProgramMain(int argc, char** argv) {
  init_stdio();

  parse_options(argc, argv);
  if (!s_objdump_options.headers && !s_objdump_options.details &&
      !s_objdump_options.disassemble && !s_objdump_options.raw) {
    fprintf(stderr, "At least one of the following switches must be given:\n");
    fprintf(stderr, " -d/--disassemble\n");
    fprintf(stderr, " -h/--headers\n");
    fprintf(stderr, " -x/--details\n");
    fprintf(stderr, " -s/--full-contents\n");
    return 1;
  }

  for (const char* filename: s_infiles) {
    if (WABT_FAILED(dump_file(filename))) {
      return 1;
    }
  }

  return 0;
}

int main(int argc, char** argv) {
  WABT_TRY
  return ProgramMain(argc, argv);
  WABT_CATCH_BAD_ALLOC_AND_EXIT
}