// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "services/proxy_resolver/proxy_resolver_impl.h"

#include <utility>

#include "base/functional/bind.h"
#include "base/memory/raw_ptr.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "net/base/net_errors.h"
#include "net/base/network_anonymization_key.h"
#include "net/base/proxy_string_util.h"
#include "net/proxy_resolution/pac_file_data.h"
#include "net/proxy_resolution/proxy_info.h"
#include "services/proxy_resolver/mojo_proxy_resolver_v8_tracing_bindings.h"
#include "services/proxy_resolver/proxy_resolver_v8_tracing.h"

namespace proxy_resolver {

class ProxyResolverImpl::Job {
 public:
  Job(mojo::PendingRemote<mojom::ProxyResolverRequestClient> client,
      ProxyResolverImpl* resolver,
      const GURL& url);

  Job(const Job&) = delete;
  Job& operator=(const Job&) = delete;

  ~Job();

  void Start(const net::NetworkAnonymizationKey& network_anonymization_key);

 private:
  // Mojo error handler. This is invoked in response to the client
  // disconnecting, indicating cancellation.
  void OnDisconnect();

  void GetProxyDone(int error);

  raw_ptr<ProxyResolverImpl> resolver_;

  mojo::Remote<mojom::ProxyResolverRequestClient> client_;
  net::ProxyInfo result_;
  GURL url_;
  std::unique_ptr<net::ProxyResolver::Request> request_;
  bool done_;
};

ProxyResolverImpl::ProxyResolverImpl(
    std::unique_ptr<ProxyResolverV8Tracing> resolver)
    : resolver_(std::move(resolver)) {}

ProxyResolverImpl::~ProxyResolverImpl() = default;

void ProxyResolverImpl::GetProxyForUrl(
    const GURL& url,
    const net::NetworkAnonymizationKey& network_anonymization_key,
    mojo::PendingRemote<mojom::ProxyResolverRequestClient> client) {
  DVLOG(1) << "GetProxyForUrl(" << url << ")";
  std::unique_ptr<Job> job =
      std::make_unique<Job>(std::move(client), this, url);
  Job* job_ptr = job.get();
  resolve_jobs_[job_ptr] = std::move(job);
  job_ptr->Start(network_anonymization_key);
}

void ProxyResolverImpl::DeleteJob(Job* job) {
  size_t erased_count = resolve_jobs_.erase(job);
  DCHECK_EQ(1U, erased_count);
}

ProxyResolverImpl::Job::Job(
    mojo::PendingRemote<mojom::ProxyResolverRequestClient> client,
    ProxyResolverImpl* resolver,
    const GURL& url)
    : resolver_(resolver),
      client_(std::move(client)),
      url_(url),
      done_(false) {}

ProxyResolverImpl::Job::~Job() = default;

void ProxyResolverImpl::Job::Start(
    const net::NetworkAnonymizationKey& network_anonymization_key) {
  resolver_->resolver_->GetProxyForURL(
      url_, network_anonymization_key, &result_,
      base::BindOnce(&Job::GetProxyDone, base::Unretained(this)), &request_,
      std::make_unique<MojoProxyResolverV8TracingBindings<
          mojom::ProxyResolverRequestClient>>(client_.get()));
  client_.set_disconnect_handler(base::BindOnce(
      &ProxyResolverImpl::Job::OnDisconnect, base::Unretained(this)));
}

void ProxyResolverImpl::Job::GetProxyDone(int error) {
  done_ = true;
  DVLOG(1) << "GetProxyForUrl(" << url_ << ") finished with error " << error
           << ". " << result_.proxy_list().size() << " Proxies returned:";
  for (const auto& proxy_chain : result_.proxy_list().AllChains()) {
    DVLOG(1) << proxy_chain.ToDebugString();
  }
  if (error == net::OK)
    client_->ReportResult(error, result_);
  else
    client_->ReportResult(error, net::ProxyInfo());

  resolver_->DeleteJob(this);
}

void ProxyResolverImpl::Job::OnDisconnect() {
  resolver_->DeleteJob(this);
}

}  // namespace proxy_resolver