text: /*
  Copyright 2018 Ryan Dahl <ry@tinyclouds.org>. All rights reserved.
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to
  deal in the Software without restriction, including without limitation the
  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  sell copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  IN THE SOFTWARE.
  */
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <string>
  
  #include "v8/include/libplatform/libplatform.h"
  #include "v8/include/v8.h"
  #include "v8/src/base/logging.h"
  
  #include "./deno_internal.h"
  #include "include/deno.h"
  
  namespace deno {
  
  // Extracts a C string from a v8::V8 Utf8Value.
  const char* ToCString(const v8::String::Utf8Value& value) {
    return *value ? *value : "<string conversion failed>";
  }
  
  static inline v8::Local<v8::String> v8_str(const char* x) {
    return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x,
                                   v8::NewStringType::kNormal)
        .ToLocalChecked();
  }
  
  void HandleException(v8::Local<v8::Context> context,
                       v8::Local<v8::Value> exception) {
    auto* isolate = context->GetIsolate();
    v8::HandleScope handle_scope(isolate);
    v8::Context::Scope context_scope(context);
  
    auto message = v8::Exception::CreateMessage(isolate, exception);
    auto onerrorStr = v8::String::NewFromUtf8(isolate, "onerror");
    auto onerror = context->Global()->Get(onerrorStr);
  
    if (onerror->IsFunction()) {
      auto func = v8::Local<v8::Function>::Cast(onerror);
      v8::Local<v8::Value> args[5];
      auto origin = message->GetScriptOrigin();
      args[0] = exception->ToString();
      args[1] = message->GetScriptResourceName();
      args[2] = origin.ResourceLineOffset();
      args[3] = origin.ResourceColumnOffset();
      args[4] = exception;
      func->Call(context->Global(), 5, args);
      /* message, source, lineno, colno, error */
    } else {
      v8::String::Utf8Value exceptionStr(isolate, exception);
      printf("Unhandled Exception %s\n", ToCString(exceptionStr));
      message->PrintCurrentStackTrace(isolate, stdout);
    }
  }
  
  /*
  bool AbortOnUncaughtExceptionCallback(v8::Isolate* isolate) {
    return true;
  }
  
  void MessageCallback2(Local<Message> message, v8::Local<v8::Value> data) {
    printf("MessageCallback2\n\n");
  }
  
  void FatalErrorCallback2(const char* location, const char* message) {
    printf("FatalErrorCallback2\n");
  }
  */
  
  void ExitOnPromiseRejectCallback(
      v8::PromiseRejectMessage promise_reject_message) {
    auto* isolate = v8::Isolate::GetCurrent();
    Deno* d = static_cast<Deno*>(isolate->GetData(0));
    DCHECK_EQ(d->isolate, isolate);
    v8::HandleScope handle_scope(d->isolate);
    auto exception = promise_reject_message.GetValue();
    auto context = d->context.Get(d->isolate);
    HandleException(context, exception);
  }
  
  void Print(const v8::FunctionCallbackInfo<v8::Value>& args) {
    CHECK_EQ(args.Length(), 1);
    auto* isolate = args.GetIsolate();
    v8::HandleScope handle_scope(isolate);
    v8::String::Utf8Value str(isolate, args[0]);
    const char* cstr = ToCString(str);
    printf("%s\n", cstr);
    fflush(stdout);
  }
  
  // Sets the sub callback.
  void Sub(const v8::FunctionCallbackInfo<v8::Value>& args) {
    v8::Isolate* isolate = args.GetIsolate();
    Deno* d = reinterpret_cast<Deno*>(isolate->GetData(0));
    DCHECK_EQ(d->isolate, isolate);
  
    v8::HandleScope handle_scope(isolate);
  
    if (!d->sub.IsEmpty()) {
      isolate->ThrowException(v8_str("denoSub already called."));
      return;
    }
  
    v8::Local<v8::Value> v = args[0];
    CHECK(v->IsFunction());
    v8::Local<v8::Function> func = v8::Local<v8::Function>::Cast(v);
  
    d->sub.Reset(isolate, func);
  }
  
  void Pub(const v8::FunctionCallbackInfo<v8::Value>& args) {
    v8::Isolate* isolate = args.GetIsolate();
    Deno* d = static_cast<Deno*>(isolate->GetData(0));
    DCHECK_EQ(d->isolate, isolate);
  
    v8::Locker locker(d->isolate);
    v8::EscapableHandleScope handle_scope(isolate);
  
    CHECK_EQ(args.Length(), 2);
    v8::Local<v8::Value> channel_v = args[0];
    CHECK(channel_v->IsString());
    v8::String::Utf8Value channel_vstr(isolate, channel_v);
    const char* channel = *channel_vstr;
  
    v8::Local<v8::Value> ab_v = args[1];
    CHECK(ab_v->IsArrayBuffer());
  
    auto ab = v8::Local<v8::ArrayBuffer>::Cast(ab_v);
    auto contents = ab->GetContents();
  
    // data is only a valid pointer until the end of this call.
    const char* data =
        const_cast<const char*>(reinterpret_cast<char*>(contents.Data()));
    deno_buf buf{data, contents.ByteLength()};
  
    DCHECK_EQ(d->currentArgs, nullptr);
    d->currentArgs = &args;
  
    d->cb(d, channel, buf);
  
    d->currentArgs = nullptr;
  }
  
  bool Execute(v8::Local<v8::Context> context, const char* js_filename,
               const char* js_source) {
    auto* isolate = context->GetIsolate();
    v8::Isolate::Scope isolate_scope(isolate);
    v8::HandleScope handle_scope(isolate);
  
    v8::Context::Scope context_scope(context);
  
    v8::TryCatch try_catch(isolate);
  
    auto name = v8_str(js_filename);
    auto source = v8_str(js_source);
  
    v8::ScriptOrigin origin(name);
  
    auto script = v8::Script::Compile(context, source, &origin);
  
    if (script.IsEmpty()) {
      DCHECK(try_catch.HasCaught());
      HandleException(context, try_catch.Exception());
      return false;
    }
  
    auto result = script.ToLocalChecked()->Run(context);
  
    if (result.IsEmpty()) {
      DCHECK(try_catch.HasCaught());
      HandleException(context, try_catch.Exception());
      return false;
    }
  
    return true;
  }
  
  v8::StartupData SerializeInternalFields(v8::Local<v8::Object> holder, int index,
                                          void* data) {
    DCHECK_EQ(data, nullptr);  // TODO(ry) pass Deno* object here.
    InternalFieldData* embedder_field = static_cast<InternalFieldData*>(
        holder->GetAlignedPointerFromInternalField(index));
    if (embedder_field == nullptr) return {nullptr, 0};
    int size = sizeof(*embedder_field);
    char* payload = new char[size];
    // We simply use memcpy to serialize the content.
    memcpy(payload, embedder_field, size);
    return {payload, size};
  }
  
  void InitializeContext(v8::Isolate* isolate, v8::Local<v8::Context> context,
                         const char* js_filename, const char* js_source) {
    v8::HandleScope handle_scope(isolate);
    v8::Context::Scope context_scope(context);
  
    auto global = context->Global();
  
    auto deno_val = v8::Object::New(isolate);
    CHECK(global->Set(context, deno::v8_str("deno"), deno_val).FromJust());
  
    auto print_tmpl = v8::FunctionTemplate::New(isolate, Print);
    auto print_val = print_tmpl->GetFunction(context).ToLocalChecked();
    CHECK(deno_val->Set(context, deno::v8_str("print"), print_val).FromJust());
  
    auto sub_tmpl = v8::FunctionTemplate::New(isolate, Sub);
    auto sub_val = sub_tmpl->GetFunction(context).ToLocalChecked();
    CHECK(deno_val->Set(context, deno::v8_str("sub"), sub_val).FromJust());
  
    auto pub_tmpl = v8::FunctionTemplate::New(isolate, Pub);
    auto pub_val = pub_tmpl->GetFunction(context).ToLocalChecked();
    CHECK(deno_val->Set(context, deno::v8_str("pub"), pub_val).FromJust());
  
    bool r = Execute(context, js_filename, js_source);
    CHECK(r);
  }
  
  v8::StartupData MakeSnapshot(v8::StartupData* prev_natives_blob,
                               v8::StartupData* prev_snapshot_blob,
                               const char* js_filename, const char* js_source) {
    v8::V8::SetNativesDataBlob(prev_natives_blob);
    v8::V8::SetSnapshotDataBlob(prev_snapshot_blob);
  
    auto* creator = new v8::SnapshotCreator(external_references);
    auto* isolate = creator->GetIsolate();
    v8::Isolate::Scope isolate_scope(isolate);
    {
      v8::HandleScope handle_scope(isolate);
      auto context = v8::Context::New(isolate);
      InitializeContext(isolate, context, js_filename, js_source);
      creator->SetDefaultContext(context, v8::SerializeInternalFieldsCallback(
                                              SerializeInternalFields, nullptr));
    }
  
    auto snapshot_blob =
        creator->CreateBlob(v8::SnapshotCreator::FunctionCodeHandling::kKeep);
  
    return snapshot_blob;
  }
  
  void AddIsolate(Deno* d, v8::Isolate* isolate) {
    d->isolate = isolate;
    // Leaving this code here because it will probably be useful later on, but
    // disabling it now as I haven't got tests for the desired behavior.
    // d->isolate->SetCaptureStackTraceForUncaughtExceptions(true);
    // d->isolate->SetAbortOnUncaughtExceptionCallback(AbortOnUncaughtExceptionCallback);
    // d->isolate->AddMessageListener(MessageCallback2);
    // d->isolate->SetFatalErrorHandler(FatalErrorCallback2);
    d->isolate->SetPromiseRejectCallback(deno::ExitOnPromiseRejectCallback);
    d->isolate->SetData(0, d);
  }
  
  }  // namespace deno
  
  extern "C" {
  
  void deno_init() {
    // v8::V8::InitializeICUDefaultLocation(argv[0]);
    // v8::V8::InitializeExternalStartupData(argv[0]);
    auto* p = v8::platform::CreateDefaultPlatform();
    v8::V8::InitializePlatform(p);
    v8::V8::Initialize();
  }
  
  const char* deno_v8_version() { return v8::V8::GetVersion(); }
  
  void deno_set_flags(int* argc, char** argv) {
    v8::V8::SetFlagsFromCommandLine(argc, argv, true);
  }
  
  const char* deno_last_exception(Deno* d) { return d->last_exception.c_str(); }
  
  int deno_execute(Deno* d, const char* js_filename, const char* js_source) {
    auto* isolate = d->isolate;
    v8::Locker locker(isolate);
    v8::Isolate::Scope isolate_scope(isolate);
    v8::HandleScope handle_scope(isolate);
    auto context = d->context.Get(d->isolate);
    return deno::Execute(context, js_filename, js_source) ? 1 : 0;
  }
  
  int deno_pub(Deno* d, const char* channel, deno_buf buf) {
    v8::Locker locker(d->isolate);
    v8::Isolate::Scope isolate_scope(d->isolate);
    v8::HandleScope handle_scope(d->isolate);
  
    auto context = d->context.Get(d->isolate);
    v8::Context::Scope context_scope(context);
  
    v8::TryCatch try_catch(d->isolate);
  
    auto sub = d->sub.Get(d->isolate);
    if (sub.IsEmpty()) {
      d->last_exception = "deno_sub has not been called.";
      return 0;
    }
  
    // TODO(ry) support zero-copy.
    auto ab = v8::ArrayBuffer::New(d->isolate, buf.len);
    memcpy(ab->GetContents().Data(), buf.data, buf.len);
  
    v8::Local<v8::Value> args[2];
    args[0] = deno::v8_str(channel);
    args[1] = ab;
  
    sub->Call(context->Global(), 1, args);
  
    if (try_catch.HasCaught()) {
      deno::HandleException(context, try_catch.Exception());
      return 0;
    }
  
    return 1;
  }
  
  void deno_set_response(Deno* d, deno_buf buf) {
    // TODO(ry) Support zero-copy.
    auto ab = v8::ArrayBuffer::New(d->isolate, buf.len);
    memcpy(ab->GetContents().Data(), buf.data, buf.len);
    d->currentArgs->GetReturnValue().Set(ab);
  }
  
  void deno_delete(Deno* d) {
    d->isolate->Dispose();
    delete d;
  }
  
  void deno_terminate_execution(Deno* d) { d->isolate->TerminateExecution(); }
  
  }  // extern "C"
  