/*
 * Copyright (c) 2009-2021, Google LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Google LLC nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "upb/util/def_to_proto.h"

#include <inttypes.h>
#include <setjmp.h>
#include <stdio.h>

#include "upb/reflection.h"

/* Must be last. */
#include "upb/port_def.inc"

typedef struct {
  upb_Arena* arena;
  jmp_buf err;
} upb_ToProto_Context;

#define CHK_OOM(val) \
  if (!(val)) UPB_LONGJMP(ctx->err, 1);

// We want to copy the options verbatim into the destination options proto.
// We use serialize+parse as our deep copy.
#define SET_OPTIONS(proto, desc_type, options_type, src)                    \
  {                                                                         \
    size_t size;                                                            \
    /* MEM: could use a temporary arena here instead. */                    \
    char* pb =                                                              \
        google_protobuf_##options_type##_serialize(src, ctx->arena, &size); \
    CHK_OOM(pb);                                                            \
    google_protobuf_##options_type* dst =                                   \
        google_protobuf_##options_type##_parse(pb, size, ctx->arena);       \
    CHK_OOM(dst);                                                           \
    google_protobuf_##desc_type##_set_options(proto, dst);                  \
  }

static upb_StringView strviewdup2(upb_ToProto_Context* ctx,
                                  upb_StringView str) {
  char* p = upb_Arena_Malloc(ctx->arena, str.size);
  CHK_OOM(p);
  memcpy(p, str.data, str.size);
  return (upb_StringView){.data = p, .size = str.size};
}

static upb_StringView strviewdup(upb_ToProto_Context* ctx, const char* s) {
  return strviewdup2(ctx, (upb_StringView){.data = s, .size = strlen(s)});
}

static upb_StringView qual_dup(upb_ToProto_Context* ctx, const char* s) {
  size_t n = strlen(s);
  char* p = upb_Arena_Malloc(ctx->arena, n + 1);
  CHK_OOM(p);
  p[0] = '.';
  memcpy(p + 1, s, n);
  return (upb_StringView){.data = p, .size = n + 1};
}

UPB_PRINTF(2, 3)
static upb_StringView printf_dup(upb_ToProto_Context* ctx, const char* fmt,
                                 ...) {
  const size_t max = 32;
  char* p = upb_Arena_Malloc(ctx->arena, max);
  CHK_OOM(p);
  va_list args;
  va_start(args, fmt);
  size_t n = vsnprintf(p, max, fmt, args);
  va_end(args);
  UPB_ASSERT(n < max);
  return (upb_StringView){.data = p, .size = n};
}

static bool upb_isprint(char ch) { return ch >= 0x20 && ch <= 0x7f; }

static upb_StringView default_bytes(upb_ToProto_Context* ctx,
                                    upb_StringView val) {
  size_t n = 0;
  for (size_t i = 0; i < val.size; i++) {
    n += upb_isprint(val.data[i]) ? 1 : 4;  // '\123'
  }
  char* p = upb_Arena_Malloc(ctx->arena, n);
  CHK_OOM(p);
  char* dst = p;
  const char* src = val.data;
  const char* end = src + val.size;
  while (src < end) {
    unsigned char ch = *src++;
    if (upb_isprint(ch)) {
      *dst++ = ch;
    } else {
      *dst++ = '\\';
      *dst++ = '0' + (ch >> 6);
      *dst++ = '0' + ((ch >> 3) & 0x7);
      *dst++ = '0' + (ch & 0x7);
    }
  }
  return (upb_StringView){.data = p, .size = n};
}

static upb_StringView default_string(upb_ToProto_Context* ctx,
                                     const upb_FieldDef* f) {
  upb_MessageValue d = upb_FieldDef_Default(f);
  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      return strviewdup(ctx, d.bool_val ? "true" : "false");
    case kUpb_CType_Enum: {
      const upb_EnumDef* e = upb_FieldDef_EnumSubDef(f);
      const upb_EnumValueDef* ev =
          upb_EnumDef_FindValueByNumber(e, d.int32_val);
      return strviewdup(ctx, upb_EnumValueDef_Name(ev));
    }
    case kUpb_CType_Int64:
      return printf_dup(ctx, "%" PRId64, d.int64_val);
    case kUpb_CType_UInt64:
      return printf_dup(ctx, "%" PRIu64, d.uint64_val);
    case kUpb_CType_Int32:
      return printf_dup(ctx, "%" PRId32, d.int32_val);
    case kUpb_CType_UInt32:
      return printf_dup(ctx, "%" PRIu32, d.uint32_val);
    case kUpb_CType_Float:
      return printf_dup(ctx, "%.9g", d.float_val);
    case kUpb_CType_Double:
      return printf_dup(ctx, "%.17g", d.double_val);
    case kUpb_CType_String:
      return strviewdup2(ctx, d.str_val);
    case kUpb_CType_Bytes:
      return default_bytes(ctx, d.str_val);
    default:
      UPB_UNREACHABLE();
  }
}

static google_protobuf_FieldDescriptorProto* fielddef_toproto(
    upb_ToProto_Context* ctx, const upb_FieldDef* f) {
  google_protobuf_FieldDescriptorProto* proto =
      google_protobuf_FieldDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_FieldDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_FieldDef_Name(f)));
  google_protobuf_FieldDescriptorProto_set_number(proto,
                                                  upb_FieldDef_Number(f));
  google_protobuf_FieldDescriptorProto_set_label(proto, upb_FieldDef_Label(f));
  google_protobuf_FieldDescriptorProto_set_type(proto, upb_FieldDef_Type(f));

  if (upb_FieldDef_HasJsonName(f)) {
    google_protobuf_FieldDescriptorProto_set_json_name(
        proto, strviewdup(ctx, upb_FieldDef_JsonName(f)));
  }

  if (upb_FieldDef_IsSubMessage(f)) {
    google_protobuf_FieldDescriptorProto_set_type_name(
        proto,
        qual_dup(ctx, upb_MessageDef_FullName(upb_FieldDef_MessageSubDef(f))));
  } else if (upb_FieldDef_CType(f) == kUpb_CType_Enum) {
    google_protobuf_FieldDescriptorProto_set_type_name(
        proto, qual_dup(ctx, upb_EnumDef_FullName(upb_FieldDef_EnumSubDef(f))));
  }

  if (upb_FieldDef_IsExtension(f)) {
    google_protobuf_FieldDescriptorProto_set_extendee(
        proto,
        qual_dup(ctx, upb_MessageDef_FullName(upb_FieldDef_ContainingType(f))));
  }

  if (upb_FieldDef_HasDefault(f)) {
    google_protobuf_FieldDescriptorProto_set_default_value(
        proto, default_string(ctx, f));
  }

  const upb_OneofDef* o = upb_FieldDef_ContainingOneof(f);
  if (o) {
    google_protobuf_FieldDescriptorProto_set_oneof_index(proto,
                                                         upb_OneofDef_Index(o));
  }

  if (_upb_FieldDef_IsProto3Optional(f)) {
    google_protobuf_FieldDescriptorProto_set_proto3_optional(proto, true);
  }

  if (upb_FieldDef_HasOptions(f)) {
    SET_OPTIONS(proto, FieldDescriptorProto, FieldOptions,
                upb_FieldDef_Options(f));
  }

  return proto;
}

static google_protobuf_OneofDescriptorProto* oneofdef_toproto(
    upb_ToProto_Context* ctx, const upb_OneofDef* o) {
  google_protobuf_OneofDescriptorProto* proto =
      google_protobuf_OneofDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_OneofDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_OneofDef_Name(o)));

  if (upb_OneofDef_HasOptions(o)) {
    SET_OPTIONS(proto, OneofDescriptorProto, OneofOptions,
                upb_OneofDef_Options(o));
  }

  return proto;
}

static google_protobuf_EnumValueDescriptorProto* enumvaldef_toproto(
    upb_ToProto_Context* ctx, const upb_EnumValueDef* e) {
  google_protobuf_EnumValueDescriptorProto* proto =
      google_protobuf_EnumValueDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_EnumValueDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_EnumValueDef_Name(e)));
  google_protobuf_EnumValueDescriptorProto_set_number(
      proto, upb_EnumValueDef_Number(e));

  if (upb_EnumValueDef_HasOptions(e)) {
    SET_OPTIONS(proto, EnumValueDescriptorProto, EnumValueOptions,
                upb_EnumValueDef_Options(e));
  }

  return proto;
}

static google_protobuf_EnumDescriptorProto* enumdef_toproto(
    upb_ToProto_Context* ctx, const upb_EnumDef* e) {
  google_protobuf_EnumDescriptorProto* proto =
      google_protobuf_EnumDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_EnumDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_EnumDef_Name(e)));

  int n;

  n = upb_EnumDef_ValueCount(e);
  google_protobuf_EnumValueDescriptorProto** vals =
      google_protobuf_EnumDescriptorProto_resize_value(proto, n, ctx->arena);
  CHK_OOM(vals);
  for (int i = 0; i < n; i++) {
    vals[i] = enumvaldef_toproto(ctx, upb_EnumDef_Value(e, i));
  }

  // TODO: reserved range, reserved name

  if (upb_EnumDef_HasOptions(e)) {
    SET_OPTIONS(proto, EnumDescriptorProto, EnumOptions,
                upb_EnumDef_Options(e));
  }

  return proto;
}

static google_protobuf_DescriptorProto_ExtensionRange* extrange_toproto(
    upb_ToProto_Context* ctx, const upb_ExtensionRange* e) {
  google_protobuf_DescriptorProto_ExtensionRange* proto =
      google_protobuf_DescriptorProto_ExtensionRange_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_DescriptorProto_ExtensionRange_set_start(
      proto, upb_ExtensionRange_Start(e));
  google_protobuf_DescriptorProto_ExtensionRange_set_end(
      proto, upb_ExtensionRange_End(e));

  if (upb_ExtensionRange_HasOptions(e)) {
    SET_OPTIONS(proto, DescriptorProto_ExtensionRange, ExtensionRangeOptions,
                upb_ExtensionRange_Options(e));
  }

  return proto;
}

static google_protobuf_DescriptorProto* msgdef_toproto(
    upb_ToProto_Context* ctx, const upb_MessageDef* m) {
  google_protobuf_DescriptorProto* proto =
      google_protobuf_DescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_DescriptorProto_set_name(
      proto, strviewdup(ctx, upb_MessageDef_Name(m)));

  int n;

  n = upb_MessageDef_FieldCount(m);
  google_protobuf_FieldDescriptorProto** fields =
      google_protobuf_DescriptorProto_resize_field(proto, n, ctx->arena);
  CHK_OOM(fields);
  for (int i = 0; i < n; i++) {
    fields[i] = fielddef_toproto(ctx, upb_MessageDef_Field(m, i));
  }

  n = upb_MessageDef_OneofCount(m);
  google_protobuf_OneofDescriptorProto** oneofs =
      google_protobuf_DescriptorProto_resize_oneof_decl(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    oneofs[i] = oneofdef_toproto(ctx, upb_MessageDef_Oneof(m, i));
  }

  n = upb_MessageDef_NestedMessageCount(m);
  google_protobuf_DescriptorProto** nested_msgs =
      google_protobuf_DescriptorProto_resize_nested_type(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_msgs[i] = msgdef_toproto(ctx, upb_MessageDef_NestedMessage(m, i));
  }

  n = upb_MessageDef_NestedEnumCount(m);
  google_protobuf_EnumDescriptorProto** nested_enums =
      google_protobuf_DescriptorProto_resize_enum_type(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_enums[i] = enumdef_toproto(ctx, upb_MessageDef_NestedEnum(m, i));
  }

  n = upb_MessageDef_NestedExtensionCount(m);
  google_protobuf_FieldDescriptorProto** nested_exts =
      google_protobuf_DescriptorProto_resize_extension(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_exts[i] =
        fielddef_toproto(ctx, upb_MessageDef_NestedExtension(m, i));
  }

  n = upb_MessageDef_ExtensionRangeCount(m);
  google_protobuf_DescriptorProto_ExtensionRange** ext_ranges =
      google_protobuf_DescriptorProto_resize_extension_range(proto, n,
                                                             ctx->arena);
  for (int i = 0; i < n; i++) {
    ext_ranges[i] = extrange_toproto(ctx, upb_MessageDef_ExtensionRange(m, i));
  }

  // TODO: reserved ranges and reserved names

  if (upb_MessageDef_HasOptions(m)) {
    SET_OPTIONS(proto, DescriptorProto, MessageOptions,
                upb_MessageDef_Options(m));
  }

  return proto;
}

static google_protobuf_MethodDescriptorProto* methoddef_toproto(
    upb_ToProto_Context* ctx, const upb_MethodDef* m) {
  google_protobuf_MethodDescriptorProto* proto =
      google_protobuf_MethodDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_MethodDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_MethodDef_Name(m)));

  google_protobuf_MethodDescriptorProto_set_input_type(
      proto,
      qual_dup(ctx, upb_MessageDef_FullName(upb_MethodDef_InputType(m))));
  google_protobuf_MethodDescriptorProto_set_output_type(
      proto,
      qual_dup(ctx, upb_MessageDef_FullName(upb_MethodDef_OutputType(m))));

  if (upb_MethodDef_ClientStreaming(m)) {
    google_protobuf_MethodDescriptorProto_set_client_streaming(proto, true);
  }

  if (upb_MethodDef_ServerStreaming(m)) {
    google_protobuf_MethodDescriptorProto_set_server_streaming(proto, true);
  }

  if (upb_MethodDef_HasOptions(m)) {
    SET_OPTIONS(proto, MethodDescriptorProto, MethodOptions,
                upb_MethodDef_Options(m));
  }

  return proto;
}

static google_protobuf_ServiceDescriptorProto* servicedef_toproto(
    upb_ToProto_Context* ctx, const upb_ServiceDef* s) {
  google_protobuf_ServiceDescriptorProto* proto =
      google_protobuf_ServiceDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_ServiceDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_ServiceDef_Name(s)));

  size_t n = upb_ServiceDef_MethodCount(s);
  google_protobuf_MethodDescriptorProto** methods =
      google_protobuf_ServiceDescriptorProto_resize_method(proto, n,
                                                           ctx->arena);
  for (int i = 0; i < n; i++) {
    methods[i] = methoddef_toproto(ctx, upb_ServiceDef_Method(s, i));
  }

  if (upb_ServiceDef_HasOptions(s)) {
    SET_OPTIONS(proto, ServiceDescriptorProto, ServiceOptions,
                upb_ServiceDef_Options(s));
  }

  return proto;
}

static google_protobuf_FileDescriptorProto* filedef_toproto(
    upb_ToProto_Context* ctx, const upb_FileDef* f) {
  google_protobuf_FileDescriptorProto* proto =
      google_protobuf_FileDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_FileDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_FileDef_Name(f)));

  const char* package = upb_FileDef_Package(f);
  if (package) {
    size_t n = strlen(package);
    if (n) {
      google_protobuf_FileDescriptorProto_set_package(
          proto, strviewdup(ctx, upb_FileDef_Package(f)));
    }
  }

  if (upb_FileDef_Syntax(f) == kUpb_Syntax_Proto3) {
    google_protobuf_FileDescriptorProto_set_syntax(proto,
                                                   strviewdup(ctx, "proto3"));
  }

  size_t n;
  n = upb_FileDef_DependencyCount(f);
  upb_StringView* deps = google_protobuf_FileDescriptorProto_resize_dependency(
      proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    deps[i] = strviewdup(ctx, upb_FileDef_Name(upb_FileDef_Dependency(f, i)));
  }

  n = upb_FileDef_PublicDependencyCount(f);
  int32_t* public_deps =
      google_protobuf_FileDescriptorProto_resize_public_dependency(proto, n,
                                                                   ctx->arena);
  const int32_t* public_dep_nums = _upb_FileDef_PublicDependencyIndexes(f);
  if (n) memcpy(public_deps, public_dep_nums, n * sizeof(int32_t));

  n = upb_FileDef_WeakDependencyCount(f);
  int32_t* weak_deps =
      google_protobuf_FileDescriptorProto_resize_weak_dependency(proto, n,
                                                                 ctx->arena);
  const int32_t* weak_dep_nums = _upb_FileDef_WeakDependencyIndexes(f);
  if (n) memcpy(weak_deps, weak_dep_nums, n * sizeof(int32_t));

  n = upb_FileDef_TopLevelMessageCount(f);
  google_protobuf_DescriptorProto** msgs =
      google_protobuf_FileDescriptorProto_resize_message_type(proto, n,
                                                              ctx->arena);
  for (int i = 0; i < n; i++) {
    msgs[i] = msgdef_toproto(ctx, upb_FileDef_TopLevelMessage(f, i));
  }

  n = upb_FileDef_TopLevelEnumCount(f);
  google_protobuf_EnumDescriptorProto** enums =
      google_protobuf_FileDescriptorProto_resize_enum_type(proto, n,
                                                           ctx->arena);
  for (int i = 0; i < n; i++) {
    enums[i] = enumdef_toproto(ctx, upb_FileDef_TopLevelEnum(f, i));
  }

  n = upb_FileDef_ServiceCount(f);
  google_protobuf_ServiceDescriptorProto** services =
      google_protobuf_FileDescriptorProto_resize_service(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    services[i] = servicedef_toproto(ctx, upb_FileDef_Service(f, i));
  }

  n = upb_FileDef_TopLevelExtensionCount(f);
  google_protobuf_FieldDescriptorProto** exts =
      google_protobuf_FileDescriptorProto_resize_extension(proto, n,
                                                           ctx->arena);
  for (int i = 0; i < n; i++) {
    exts[i] = fielddef_toproto(ctx, upb_FileDef_TopLevelExtension(f, i));
  }

  if (upb_FileDef_HasOptions(f)) {
    SET_OPTIONS(proto, FileDescriptorProto, FileOptions,
                upb_FileDef_Options(f));
  }

  return proto;
}

google_protobuf_DescriptorProto* upb_MessageDef_ToProto(const upb_MessageDef* m,
                                                        upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return msgdef_toproto(&ctx, m);
}

google_protobuf_EnumDescriptorProto* upb_EnumDef_ToProto(const upb_EnumDef* e,
                                                         upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return enumdef_toproto(&ctx, e);
}

google_protobuf_EnumValueDescriptorProto* upb_EnumValueDef_ToProto(
    const upb_EnumValueDef* e, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return enumvaldef_toproto(&ctx, e);
}

google_protobuf_FieldDescriptorProto* upb_FieldDef_ToProto(
    const upb_FieldDef* f, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return fielddef_toproto(&ctx, f);
}

google_protobuf_OneofDescriptorProto* upb_OneofDef_ToProto(
    const upb_OneofDef* o, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return oneofdef_toproto(&ctx, o);
}

google_protobuf_FileDescriptorProto* upb_FileDef_ToProto(const upb_FileDef* f,
                                                         upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return filedef_toproto(&ctx, f);
}

google_protobuf_MethodDescriptorProto* upb_MethodDef_ToProto(
    const upb_MethodDef* m, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return methoddef_toproto(&ctx, m);
}

google_protobuf_ServiceDescriptorProto* upb_ServiceDef_ToProto(
    const upb_ServiceDef* s, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  if (UPB_SETJMP(ctx.err)) return NULL;
  return servicedef_toproto(&ctx, s);
}