// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef HEADLESS_PUBLIC_HEADLESS_BROWSER_CONTEXT_H_
#define HEADLESS_PUBLIC_HEADLESS_BROWSER_CONTEXT_H_

#include <list>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>

#include "base/callback.h"
#include "base/optional.h"
#include "content/public/common/web_preferences.h"
#include "headless/public/headless_export.h"
#include "headless/public/headless_web_contents.h"
#include "net/base/host_port_pair.h"
#include "net/url_request/url_request_job_factory.h"

namespace base {
class FilePath;
}

namespace headless {
class HeadlessBrowserImpl;
class HeadlessBrowserContextOptions;

// Imported into headless namespace for
// Builder::SetOverrideWebPreferencesCallback().
using content::WebPreferences;

using ProtocolHandlerMap = std::unordered_map<
    std::string,
    std::unique_ptr<net::URLRequestJobFactory::ProtocolHandler>>;

// Represents an isolated session with a unique cache, cookies, and other
// profile/session related data.
// When browser context is deleted, all associated web contents are closed.
class HEADLESS_EXPORT HeadlessBrowserContext {
 public:
  class Builder;

  virtual ~HeadlessBrowserContext() {}

  // Open a new tab. Returns a builder object which can be used to set
  // properties for the new tab.
  // Pointer to HeadlessWebContents becomes invalid after:
  // a) Calling HeadlessWebContents::Close, or
  // b) Calling HeadlessBrowserContext::Close on associated browser context, or
  // c) Calling HeadlessBrowser::Shutdown.
  virtual HeadlessWebContents::Builder CreateWebContentsBuilder() = 0;

  // Returns all web contents owned by this browser context.
  virtual std::vector<HeadlessWebContents*> GetAllWebContents() = 0;

  // See HeadlessBrowser::GetWebContentsForDevToolsAgentHostId.
  virtual HeadlessWebContents* GetWebContentsForDevToolsAgentHostId(
      const std::string& devtools_agent_host_id) = 0;

  // Destroy this BrowserContext and all WebContents associated with it.
  virtual void Close() = 0;

  // GUID for this browser context.
  virtual const std::string& Id() const = 0;

  // TODO(skyostil): Allow saving and restoring contexts (crbug.com/617931).

 protected:
  HeadlessBrowserContext() {}

 private:
  DISALLOW_COPY_AND_ASSIGN(HeadlessBrowserContext);
};

class HEADLESS_EXPORT HeadlessBrowserContext::Builder {
 public:
  Builder(Builder&&);
  ~Builder();

  // Set custom network protocol handlers. These can be used to override URL
  // fetching for different network schemes.
  Builder& SetProtocolHandlers(ProtocolHandlerMap protocol_handlers);

  // Specify JS mojo module bindings to be installed, one per mojom file.
  // Note a single mojom file could potentially define many interfaces.
  // |mojom_name| the name including path of the .mojom file.
  // |js_bindings| compiletime generated javascript bindings. Typically loaded
  // from gen/path/name.mojom.js.
  Builder& AddJsMojoBindings(const std::string& mojom_name,
                             const std::string& js_bindings);

  // By default if you add mojo bindings, http and https are disabled because
  // its almost certinly unsafe for arbitary sites on the internet to have
  // access to these bindings.  If you know what you're doing it may be OK to
  // turn them back on. E.g. if headless_lib is being used in a testing
  // framework which serves the web content from disk that's likely ok.
  //
  // That said, best pratice is to add a ProtocolHandler to serve the
  // webcontent over a custom protocol. That way you can be sure that only the
  // things you intend have access to mojo.
  Builder& EnableUnsafeNetworkAccessWithMojoBindings(
      bool enable_http_and_https_if_mojo_used);

  // Set a callback that is invoked to override WebPreferences for RenderViews
  // created within this HeadlessBrowserContext. Called whenever the
  // WebPreferences of a RenderView change. Executed on the browser main thread.
  //
  // WARNING: We cannot provide any guarantees about the stability of the
  // exposed WebPreferences API, so use with care.
  Builder& SetOverrideWebPreferencesCallback(
      base::Callback<void(WebPreferences*)> callback);

  // By default |HeadlessBrowserContext| inherits the following options from
  // the browser instance. The methods below can be used to override these
  // settings. See HeadlessBrowser::Options for their meaning.
  Builder& SetUserAgent(const std::string& user_agent);
  Builder& SetProxyServer(const net::HostPortPair& proxy_server);
  Builder& SetHostResolverRules(const std::string& host_resolver_rules);
  Builder& SetWindowSize(const gfx::Size& window_size);
  Builder& SetUserDataDir(const base::FilePath& user_data_dir);
  Builder& SetIncognitoMode(bool incognito_mode);

  HeadlessBrowserContext* Build();

 private:
  friend class HeadlessBrowserImpl;
  friend class HeadlessBrowserContextImpl;

  explicit Builder(HeadlessBrowserImpl* browser);

  struct MojoBindings {
    MojoBindings();
    MojoBindings(const std::string& mojom_name, const std::string& js_bindings);
    ~MojoBindings();

    std::string mojom_name;
    std::string js_bindings;

   private:
    DISALLOW_COPY_AND_ASSIGN(MojoBindings);
  };

  HeadlessBrowserImpl* browser_;
  std::unique_ptr<HeadlessBrowserContextOptions> options_;

  std::list<MojoBindings> mojo_bindings_;
  bool enable_http_and_https_if_mojo_used_;

  DISALLOW_COPY_AND_ASSIGN(Builder);
};

}  // namespace headless

#endif  // HEADLESS_PUBLIC_HEADLESS_BROWSER_CONTEXT_H_