// Copyright (c) 2016 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#include "atom/browser/api/atom_api_url_request.h"
#include <string>
#include "atom/browser/api/atom_api_session.h"
#include "atom/browser/net/atom_url_request.h"
#include "atom/common/api/event_emitter_caller.h"
#include "atom/common/native_mate_converters/callback.h"
#include "atom/common/native_mate_converters/gurl_converter.h"
#include "atom/common/native_mate_converters/net_converter.h"
#include "atom/common/native_mate_converters/string16_converter.h"
#include "atom/common/node_includes.h"
#include "native_mate/dictionary.h"

namespace mate {

template <>
struct Converter<scoped_refptr<const net::IOBufferWithSize>> {
  static v8::Local<v8::Value> ToV8(
      v8::Isolate* isolate,
      scoped_refptr<const net::IOBufferWithSize> buffer) {
    return node::Buffer::Copy(isolate, buffer->data(), buffer->size())
        .ToLocalChecked();
  }

  static bool FromV8(v8::Isolate* isolate,
                     v8::Local<v8::Value> val,
                     scoped_refptr<const net::IOBufferWithSize>* out) {
    auto size = node::Buffer::Length(val);

    if (size == 0) {
      // Support conversion from empty buffer. A use case is
      // a GET request without body.
      // Since zero-sized IOBuffer(s) are not supported, we set the
      // out pointer to null.
      *out = nullptr;
      return true;
    }
    auto data = node::Buffer::Data(val);
    if (!data) {
      // This is an error as size is positive but data is null.
      return false;
    }

    *out = new net::IOBufferWithSize(size);
    // We do a deep copy. We could have used Buffer's internal memory
    // but that is much more complicated to be properly handled.
    memcpy((*out)->data(), data, size);
    return true;
  }
};

}  // namespace mate

namespace atom {
namespace api {

template <typename Flags>
URLRequest::StateBase<Flags>::StateBase(Flags initialState)
    : state_(initialState) {}

template <typename Flags>
void URLRequest::StateBase<Flags>::SetFlag(Flags flag) {
  state_ =
      static_cast<Flags>(static_cast<int>(state_) | static_cast<int>(flag));
}

template <typename Flags>
bool URLRequest::StateBase<Flags>::operator==(Flags flag) const {
  return state_ == flag;
}

template <typename Flags>
bool URLRequest::StateBase<Flags>::IsFlagSet(Flags flag) const {
  return static_cast<int>(state_) & static_cast<int>(flag);
}

URLRequest::RequestState::RequestState()
    : StateBase(RequestStateFlags::kNotStarted) {}

bool URLRequest::RequestState::NotStarted() const {
  return *this == RequestStateFlags::kNotStarted;
}

bool URLRequest::RequestState::Started() const {
  return IsFlagSet(RequestStateFlags::kStarted);
}

bool URLRequest::RequestState::Finished() const {
  return IsFlagSet(RequestStateFlags::kFinished);
}

bool URLRequest::RequestState::Canceled() const {
  return IsFlagSet(RequestStateFlags::kCanceled);
}

bool URLRequest::RequestState::Failed() const {
  return IsFlagSet(RequestStateFlags::kFailed);
}

bool URLRequest::RequestState::Closed() const {
  return IsFlagSet(RequestStateFlags::kClosed);
}

URLRequest::ResponseState::ResponseState()
    : StateBase(ResponseStateFlags::kNotStarted) {}

bool URLRequest::ResponseState::NotStarted() const {
  return *this == ResponseStateFlags::kNotStarted;
}

bool URLRequest::ResponseState::Started() const {
  return IsFlagSet(ResponseStateFlags::kStarted);
}

bool URLRequest::ResponseState::Ended() const {
  return IsFlagSet(ResponseStateFlags::kEnded);
}

bool URLRequest::ResponseState::Failed() const {
  return IsFlagSet(ResponseStateFlags::kFailed);
}

URLRequest::URLRequest(v8::Isolate* isolate, v8::Local<v8::Object> wrapper) {
  InitWith(isolate, wrapper);
}

URLRequest::~URLRequest() {
  // A request has been created in JS, it was not used and then
  // it got collected, no close event to cleanup, only destructor
  // is called.
  if (atom_request_) {
    atom_request_->Terminate();
  }
}

// static
mate::WrappableBase* URLRequest::New(mate::Arguments* args) {
  auto isolate = args->isolate();
  v8::Local<v8::Object> options;
  args->GetNext(&options);
  mate::Dictionary dict(isolate, options);
  std::string method;
  dict.Get("method", &method);
  std::string url;
  dict.Get("url", &url);
  std::string redirect_policy;
  dict.Get("redirect", &redirect_policy);
  std::string partition;
  mate::Handle<api::Session> session;
  if (dict.Get("session", &session)) {
  } else if (dict.Get("partition", &partition)) {
    session = Session::FromPartition(isolate, partition);
  } else {
    // Use the default session if not specified.
    session = Session::FromPartition(isolate, "");
  }
  auto browser_context = session->browser_context();
  auto api_url_request = new URLRequest(args->isolate(), args->GetThis());
  auto atom_url_request = AtomURLRequest::Create(
      browser_context, method, url, redirect_policy, api_url_request);

  api_url_request->atom_request_ = atom_url_request;

  return api_url_request;
}

// static
void URLRequest::BuildPrototype(v8::Isolate* isolate,
                                v8::Local<v8::FunctionTemplate> prototype) {
  prototype->SetClassName(mate::StringToV8(isolate, "URLRequest"));
  mate::ObjectTemplateBuilder(isolate, prototype->PrototypeTemplate())
      // Request API
      .MakeDestroyable()
      .SetMethod("write", &URLRequest::Write)
      .SetMethod("cancel", &URLRequest::Cancel)
      .SetMethod("setExtraHeader", &URLRequest::SetExtraHeader)
      .SetMethod("removeExtraHeader", &URLRequest::RemoveExtraHeader)
      .SetMethod("setChunkedUpload", &URLRequest::SetChunkedUpload)
      .SetMethod("followRedirect", &URLRequest::FollowRedirect)
      .SetMethod("_setLoadFlags", &URLRequest::SetLoadFlags)
      .SetProperty("notStarted", &URLRequest::NotStarted)
      .SetProperty("finished", &URLRequest::Finished)
      // Response APi
      .SetProperty("statusCode", &URLRequest::StatusCode)
      .SetProperty("statusMessage", &URLRequest::StatusMessage)
      .SetProperty("rawResponseHeaders", &URLRequest::RawResponseHeaders)
      .SetProperty("httpVersionMajor", &URLRequest::ResponseHttpVersionMajor)
      .SetProperty("httpVersionMinor", &URLRequest::ResponseHttpVersionMinor);
}

bool URLRequest::NotStarted() const {
  return request_state_.NotStarted();
}

bool URLRequest::Finished() const {
  return request_state_.Finished();
}

bool URLRequest::Canceled() const {
  return request_state_.Canceled();
}

bool URLRequest::Write(scoped_refptr<const net::IOBufferWithSize> buffer,
                       bool is_last) {
  if (request_state_.Canceled() || request_state_.Failed() ||
      request_state_.Finished() || request_state_.Closed()) {
    return false;
  }

  if (request_state_.NotStarted()) {
    request_state_.SetFlag(RequestStateFlags::kStarted);
    // Pin on first write.
    Pin();
  }

  if (is_last) {
    request_state_.SetFlag(RequestStateFlags::kFinished);
    EmitRequestEvent(true, "finish");
  }

  DCHECK(atom_request_);
  if (atom_request_) {
    return atom_request_->Write(buffer, is_last);
  }
  return false;
}

void URLRequest::Cancel() {
  if (request_state_.Canceled() || request_state_.Closed()) {
    // Cancel only once.
    return;
  }

  // Mark as canceled.
  request_state_.SetFlag(RequestStateFlags::kCanceled);

  DCHECK(atom_request_);
  if (atom_request_ && request_state_.Started()) {
    // Really cancel if it was started.
    atom_request_->Cancel();
  }
  EmitRequestEvent(true, "abort");

  if (response_state_.Started() && !response_state_.Ended()) {
    EmitResponseEvent(true, "aborted");
  }
  Close();
}

void URLRequest::FollowRedirect() {
  if (request_state_.Canceled() || request_state_.Closed()) {
    return;
  }

  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->FollowRedirect();
  }
}

bool URLRequest::SetExtraHeader(const std::string& name,
                                const std::string& value) {
  // Request state must be in the initial non started state.
  if (!request_state_.NotStarted()) {
    // Cannot change headers after send.
    return false;
  }

  if (!net::HttpUtil::IsValidHeaderName(name)) {
    return false;
  }

  if (!net::HttpUtil::IsValidHeaderValue(value)) {
    return false;
  }

  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->SetExtraHeader(name, value);
  }
  return true;
}

void URLRequest::RemoveExtraHeader(const std::string& name) {
  // State must be equal to not started.
  if (!request_state_.NotStarted()) {
    // Cannot change headers after send.
    return;
  }
  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->RemoveExtraHeader(name);
  }
}

void URLRequest::SetChunkedUpload(bool is_chunked_upload) {
  // State must be equal to not started.
  if (!request_state_.NotStarted()) {
    // Cannot change headers after send.
    return;
  }
  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->SetChunkedUpload(is_chunked_upload);
  }
}

void URLRequest::SetLoadFlags(int flags) {
  // State must be equal to not started.
  if (!request_state_.NotStarted()) {
    // Cannot change load flags after start.
    return;
  }
  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->SetLoadFlags(flags);
  }
}

void URLRequest::OnReceivedRedirect(
    int status_code,
    const std::string& method,
    const GURL& url,
    scoped_refptr<net::HttpResponseHeaders> response_headers) {
  if (request_state_.Canceled() || request_state_.Closed()) {
    return;
  }

  DCHECK(atom_request_);
  if (!atom_request_) {
    return;
  }

  EmitRequestEvent(false, "redirect", status_code, method, url,
                   response_headers.get());
}

void URLRequest::OnAuthenticationRequired(
    scoped_refptr<const net::AuthChallengeInfo> auth_info) {
  if (request_state_.Canceled() || request_state_.Closed()) {
    return;
  }

  DCHECK(atom_request_);
  if (!atom_request_) {
    return;
  }

  Emit("login", auth_info.get(),
       base::Bind(&AtomURLRequest::PassLoginInformation, atom_request_));
}

void URLRequest::OnResponseStarted(
    scoped_refptr<net::HttpResponseHeaders> response_headers) {
  if (request_state_.Canceled() || request_state_.Failed() ||
      request_state_.Closed()) {
    // Don't emit any event after request cancel.
    return;
  }
  response_headers_ = response_headers;
  response_state_.SetFlag(ResponseStateFlags::kStarted);
  Emit("response");
}

void URLRequest::OnResponseData(
    scoped_refptr<const net::IOBufferWithSize> buffer) {
  if (request_state_.Canceled() || request_state_.Closed() ||
      request_state_.Failed() || response_state_.Failed()) {
    // In case we received an unexpected event from Chromium net,
    // don't emit any data event after request cancel/error/close.
    return;
  }
  if (!buffer || !buffer->data() || !buffer->size()) {
    return;
  }
  Emit("data", buffer);
}

void URLRequest::OnResponseCompleted() {
  if (request_state_.Canceled() || request_state_.Closed() ||
      request_state_.Failed() || response_state_.Failed()) {
    // In case we received an unexpected event from Chromium net,
    // don't emit any data event after request cancel/error/close.
    return;
  }
  response_state_.SetFlag(ResponseStateFlags::kEnded);
  Emit("end");
  Close();
}

void URLRequest::OnError(const std::string& error, bool isRequestError) {
  auto error_object = v8::Exception::Error(mate::StringToV8(isolate(), error));
  if (isRequestError) {
    request_state_.SetFlag(RequestStateFlags::kFailed);
    EmitRequestEvent(false, "error", error_object);
  } else {
    response_state_.SetFlag(ResponseStateFlags::kFailed);
    EmitResponseEvent(false, "error", error_object);
  }
  Close();
}

int URLRequest::StatusCode() const {
  if (response_headers_) {
    return response_headers_->response_code();
  }
  return -1;
}

std::string URLRequest::StatusMessage() const {
  std::string result;
  if (response_headers_) {
    result = response_headers_->GetStatusText();
  }
  return result;
}

net::HttpResponseHeaders* URLRequest::RawResponseHeaders() const {
  return response_headers_.get();
}

uint32_t URLRequest::ResponseHttpVersionMajor() const {
  if (response_headers_) {
    return response_headers_->GetHttpVersion().major_value();
  }
  return 0;
}

uint32_t URLRequest::ResponseHttpVersionMinor() const {
  if (response_headers_) {
    return response_headers_->GetHttpVersion().minor_value();
  }
  return 0;
}

void URLRequest::Close() {
  if (!request_state_.Closed()) {
    request_state_.SetFlag(RequestStateFlags::kClosed);
    if (response_state_.Started()) {
      // Emit a close event if we really have a response object.
      EmitResponseEvent(true, "close");
    }
    EmitRequestEvent(true, "close");
  }
  Unpin();
  if (atom_request_) {
    // A request has been created in JS, used and then it ended.
    // We release unneeded net resources.
    atom_request_->Terminate();
  }
  atom_request_ = nullptr;
}

void URLRequest::Pin() {
  if (wrapper_.IsEmpty()) {
    wrapper_.Reset(isolate(), GetWrapper());
  }
}

void URLRequest::Unpin() {
  wrapper_.Reset();
}

template <typename... Args>
void URLRequest::EmitRequestEvent(Args... args) {
  v8::HandleScope handle_scope(isolate());
  mate::CustomEmit(isolate(), GetWrapper(), "_emitRequestEvent", args...);
}

template <typename... Args>
void URLRequest::EmitResponseEvent(Args... args) {
  v8::HandleScope handle_scope(isolate());
  mate::CustomEmit(isolate(), GetWrapper(), "_emitResponseEvent", args...);
}

}  // namespace api

}  // namespace atom