#!/usr/bin/env python3
############################################################################
# apps/tools/mkwamrglue.py
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.  The
# ASF licenses this file to you 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.
#
############################################################################

import argparse
import os
import sys

NAME_INDEX = 0
HEADER_INDEX = 1
COND_INDEX = 2
RETTYPE_INDEX = 3
PARM1_INDEX = 4

POINTER_SIGNATURE = ['...', '*', '_sa_handler_t', ',mbstate_t']

BLACK_LIST = ['sigqueue', 'pthread_create', 'pthread_detach',
              'pthread_cancel', 'pthread_key_create', 'pthread_key_delete',
              'pthread_getspecific', 'pthread_setspecific', 'mallinfo',
              'crypt', 'crypt_r']

VA_ADDITIONAL_FUNCS = [
    'asprintf', 'fprintf', 'fscanf', 'printf', 'snprintf', 'sprintf',
    'sprintf', 'sscanf', 'sscanf', 'swprintf', 'syslog',
]

VA_LIST_FUNCS = [
    'vasprintf', 'vfprintf', 'vprintf', 'vscanf', 'vsnprintf', 'vsprintf',
    'vsscanf', 'vsyslog',
]


def is_strip_function(name):
  for black in BLACK_LIST:
    if black == name:
      return True

  return False


def is_va_additional_function(name):
  for va in VA_ADDITIONAL_FUNCS:
    if va == name:
      return True

  return False


def is_va_list_function(name):
  for va in VA_LIST_FUNCS:
    if va == name:
      return True

  return False


def generate_include(csv, out):
  headers = []
  for line in csv.readlines():
    sline = line.strip()
    if sline == '':
      break
    args = []
    for arg in sline.split(","):
      args.append(arg.strip().strip('\"'))

    if is_strip_function(args[NAME_INDEX]):
      continue

    if len(args[HEADER_INDEX]) != 0 and args[HEADER_INDEX] not in headers:
      headers.append(args[HEADER_INDEX])

  headers.sort()

  for header in headers:
    out.write(f"#include <{header}>\n")

  out.write("\n")
  out.write("#include <wasm_export.h>\n")
  out.write("\n")
  csv.seek(0)


def generate_functions(csv, out, lib):
  for line in csv.readlines():
    sline = line.strip()
    if sline == '':
      break
    args = []
    # Source data: "qsort","stdlib.h","","void","FAR void *","size_t","size_t","int(*)(FAR const void *,FAR const void *)"
    # After split：
    # 1."qsort  2."stdlib.h 3." 4."void 5."FAR void *
    # 6."size_t 7."size_t 8."int(*)(FAR const void *,FAR const void *)
    for arg in sline.split("\","):
      args.append(arg.strip().strip('\"'))

    if is_strip_function(args[NAME_INDEX]):
      continue

    nodef = (len(args[COND_INDEX]) != 0)
    if nodef:
      out.write("#if " + args[COND_INDEX] + "\n\n")

    out.write(f"#ifndef GLUE_FUNCTION_{args[NAME_INDEX]}\n")
    out.write(f"#define GLUE_FUNCTION_{args[NAME_INDEX]}\n")

    noreturn = args[RETTYPE_INDEX] == 'void' or \
        args[RETTYPE_INDEX] == 'noreturn'

    if noreturn:
      out.write(f"void glue_{args[NAME_INDEX]}(wasm_exec_env_t env")
    else:
      out.write(f"uintptr_t glue_{args[NAME_INDEX]}(wasm_exec_env_t env")

    if is_va_additional_function(args[NAME_INDEX]):
      findex = len(args) - 2
      vprefix = 'v'
    elif is_va_list_function(args[NAME_INDEX]):
      findex = len(args) - 2
    else:
      findex = 0
      vprefix = ''

    for index in range(PARM1_INDEX, len(args)):
      if findex == index:
        out.write(", uintptr_t format")
      elif args[index] == '...':
        out.write(", va_list ap")
        break
      elif args[index] == 'va_list' and findex != 0:
        out.write(", va_list ap")
        break
      elif args[index] == 'void':
        continue
      else:
        out.write(f", uintptr_t parm{index - PARM1_INDEX + 1}")

    out.write(")\n{\n")

    out.write("  wasm_module_inst_t module_inst = get_module_inst(env);\n")
    out.write("  uintptr_t ret;\n")

    is_addr = False
    for index in range(PARM1_INDEX, len(args)):
      if '*' in args[index]:
        is_addr = True
        continue
      if 'va_list' in args[index] or '...' in args[index]:
        is_addr = False
        break

    if is_addr:
      out.write("  void *addr_app = addr_app_to_native((uintptr_t)NULL);\n")
      for index in range(PARM1_INDEX, len(args)):
        if '*' in args[index]:
          out.write(f"  if ((void *)parm{index - PARM1_INDEX + 1} == addr_app)\n")
          out.write(f"    parm{index - PARM1_INDEX + 1} = (uintptr_t)NULL;\n")
          out.write("\n")

    if findex != 0:
      if 'scanf' in args[NAME_INDEX]:
        out.write("  scanf_begin(module_inst, ap);\n")
      else:
        out.write("  va_list_string2native(env, format, ap);\n")

    if noreturn:
      noret = ''
    else:
      noret = 'return'

    addrcov = ''
    if '*' in args[RETTYPE_INDEX]:
      addrcov = 'addr_native_to_app((uintptr_t)'

    if noreturn:
      out.write(f"  {addrcov}{vprefix}{args[NAME_INDEX]}(")
    else:
      out.write(f"  ret = {addrcov}{vprefix}{args[NAME_INDEX]}(")

    for index in range(PARM1_INDEX, len(args)):
      if index > PARM1_INDEX:
        out.write(", ")
      if args[index] == '...':
        if index < len(args) - 1 and args[NAME_INDEX] == 'ioctl':
          out.write(
              f"(*(uintptr_t **)&ap != NULL && **(uintptr_t **)&ap != (uintptr_t)NULL) ? (uintptr_t)addr_app_to_native((uintptr_t)va_arg(ap, {args[index + 1]})) : (uintptr_t)NULL")
        elif index < len(args) - 1:
          out.write(
              f"(*(uintptr_t **)&ap != NULL && **(uintptr_t **)&ap != (uintptr_t)NULL) ? (uintptr_t)va_arg(ap, {args[index + 1]}) : (uintptr_t)NULL")
        else:
          out.write("ap")
        break
      if args[index] == 'va_list' and findex != 0:
        out.write("ap")
        break
      if args[index] == 'void':
        continue
      if '|' in args[index]:
        args[index] = args[index].split("|")[1]
      if findex == index:
        out.write(f"({args[index]})format")
      else:
        out.write(f"({args[index]})parm{index - PARM1_INDEX + 1}")

    if addrcov != '':
      out.write(")")

    out.write(");\n")

    if findex != 0:
      if 'scanf' in args[NAME_INDEX]:
        out.write("  scanf_end(module_inst, ap);\n")
      else:
        out.write("  va_list_string2app(env, format, ap);\n")

    if noreturn:
      pass
    else:
      out.write("  return ret;\n")

    out.write("}\n\n")

    out.write(f"#endif /* GLUE_FUNCTION_{args[NAME_INDEX]} */\n")

    if nodef:
      out.write(f"#endif /* {args[COND_INDEX]} */\n\n")
  csv.seek(0)


def generate_table(csv, out, lib):
  out.write("#ifndef native_function\n")
  out.write("#define native_function(func_name, signature) \\\n")
  out.write("  { #func_name, glue_##func_name, signature, NULL }\n\n")
  out.write("#endif\n")

  lib.write("static void empty_stub(void) {}\n\n")
  lib.write("#ifndef native_function\n")
  lib.write("#define native_function(func_name, signature) \\\n")
  lib.write("  { #func_name, empty_stub, signature, NULL }\n\n")
  lib.write("#endif\n")

  out.write(f"static NativeSymbol g_{os.path.splitext(os.path.basename(csv.name))[0]}_native_symbols[] =\n")
  lib.write(f"static NativeSymbol g_{os.path.splitext(os.path.basename(csv.name))[0]}_native_symbols[] =\n")
  out.write("{\n")
  lib.write("{\n")

  for line in csv.readlines():
    sline = line.strip()
    if sline == '':
      break
    args = []
    for arg in sline.split("\","):
      args.append(arg.strip().strip('\"'))

    if is_strip_function(args[NAME_INDEX]):
      continue

    nodef = (len(args[COND_INDEX]) != 0)
    if nodef:
      out.write("#if " + args[COND_INDEX] + "\n")

    out.write(f"#ifndef GLUE_ENTRY_{args[NAME_INDEX]}\n")
    out.write(f"#define GLUE_ENTRY_{args[NAME_INDEX]}\n")

    out.write(f"  native_function({args[NAME_INDEX]},\"(")
    lib.write(f"  native_function({args[NAME_INDEX]},\"(")

    noreturn = args[RETTYPE_INDEX] == 'void' or \
        args[RETTYPE_INDEX] == 'noreturn'

    signature = ''

    for index in range(PARM1_INDEX, len(args)):
      if '(*)' in args[index]:
        signature += 'i'
      elif 'float' in args[index]:
        signature += 'f'
      elif 'double' in args[index]:
        signature += 'F'
      elif 'long long' in args[index]:
        signature += 'I'
      elif 'char *' in args[index]:
        signature += '$'
      elif 'off_t' in args[index]:
        signature += 'I'
      elif 'uintptr_t' in args[index]:
        signature += 'i'
      elif 'va_list' in args[index]:
        signature += '*'
      else:
        defval = True
        for sig in POINTER_SIGNATURE:
          if sig in args[index]:
            signature += '*'
            defval = False
            break

        if defval:
          signature += 'i'
        if '...' in args[index]:
          break

    out.write(signature)
    lib.write(signature)

    out.write(")")
    lib.write(")")

    retval = ''

    if not noreturn:
      if '*' in args[RETTYPE_INDEX]:
        retval = 'i'
      elif 'off_t' in args[RETTYPE_INDEX]:
        retval = 'I'
      elif 'time_t' in args[RETTYPE_INDEX]:
        retval = 'I'
      elif 'double' in args[RETTYPE_INDEX]:
        retval = 'F'
      elif 'float' in args[RETTYPE_INDEX]:
        retval = 'f'
      elif 'long long' in args[RETTYPE_INDEX]:
        retval = 'I'
      else:
        retval = 'i'

    out.write(retval)
    lib.write(retval)

    out.write("\"),\n")
    lib.write("\"),\n")

    out.write(f"#endif /* GLUE_ENTRY_{args[NAME_INDEX]} */\n")

    if nodef:
      out.write(f"#endif /* {args[COND_INDEX]} */\n\n")

  out.write("};\n")
  lib.write("};\n")

  lib.write("\n")
  lib.write("uint32_t get_native_lib(char **p_module_name, NativeSymbol **p_base_lib_apis) {\n")
  lib.write(f"  *p_module_name = \"env\";\n")
  lib.write(f"  *p_base_lib_apis = g_{os.path.splitext(os.path.basename(csv.name))[0]}_native_symbols;\n")
  lib.write(f"  return sizeof(g_{os.path.splitext(os.path.basename(csv.name))[0]}_native_symbols) / sizeof(NativeSymbol);\n")
  lib.write("}\n\n")

  csv.seek(0)


def generate_glue(csv, out, lib):
  generate_include(csv, out)
  generate_functions(csv, out, lib)
  generate_table(csv, out, lib)


def parse_args():
  global args
  parser = argparse.ArgumentParser(
      description=__doc__,
      formatter_class=argparse.RawDescriptionHelpFormatter, allow_abbrev=False)
  parser.add_argument("-i", "--input", required=True,
                      help="CSV(Comma-Separated-Value) file")
  parser.add_argument(
      "-o", "--output", help="Output header file", default="glue.c")
  parser.add_argument("-v", "--verbose", action="count", default=0,
                      help="Verbose Output")
  args = parser.parse_args()


def main():
  parse_args()
  if not os.path.isfile(args.input):
    sys.exit(1)

  infile = open(args.input, "r")
  outfile = open(args.output, "w")
  libfile = open(f"signature_{args.output}", "w")

  outfile.write("#include <nuttx/config.h>\n")
  outfile.write("#include <stdint.h>\n")

  libfile.write("#include <stdarg.h>\n")
  libfile.write("#include <stddef.h>\n")
  libfile.write("#include \"wamr/core/iwasm/include/lib_export.h\"\n\n")

  generate_glue(infile, outfile, libfile)

  infile.close()
  outfile.close()
  libfile.close()


if __name__ == "__main__":
  main()