// Copyright (c) 2012 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 GOOGLE_APIS_DRIVE_DRIVE_API_REQUESTS_H_
#define GOOGLE_APIS_DRIVE_DRIVE_API_REQUESTS_H_

#include <string>
#include <vector>

#include "base/callback_forward.h"
#include "base/location.h"
#include "base/memory/scoped_ptr.h"
#include "base/sequenced_task_runner.h"
#include "base/task_runner_util.h"
#include "base/time/time.h"
#include "base/values.h"
#include "google_apis/drive/base_requests.h"
#include "google_apis/drive/drive_api_parser.h"
#include "google_apis/drive/drive_api_url_generator.h"
#include "google_apis/drive/drive_common_callbacks.h"

namespace google_apis {

// Callback used for requests that the server returns FileList data
// formatted into JSON value.
typedef base::Callback<void(DriveApiErrorCode error,
                            scoped_ptr<FileList> entry)> FileListCallback;

// Callback used for requests that the server returns ChangeList data
// formatted into JSON value.
typedef base::Callback<void(DriveApiErrorCode error,
                            scoped_ptr<ChangeList> entry)> ChangeListCallback;

namespace drive {

// Represents a property for a file or a directory.
// https://developers.google.com/drive/v2/reference/properties
class Property {
 public:
  Property();
  ~Property();

  // Visibility of the property. Either limited to the same client, or to any.
  enum Visibility { VISIBILITY_PRIVATE, VISIBILITY_PUBLIC };

  // Whether the property is public or private.
  Visibility visibility() const { return visibility_; }

  // Name of the property.
  const std::string& key() const { return key_; }

  // Value of the property.
  const std::string& value() const { return value_; }

  void set_visibility(Visibility visibility) { visibility_ = visibility; }
  void set_key(const std::string& key) { key_ = key; }
  void set_value(const std::string& value) { value_ = value; }

 private:
  Visibility visibility_;
  std::string key_;
  std::string value_;
};

// List of properties for a single file or a directory.
typedef std::vector<Property> Properties;

//============================ DriveApiPartialFieldRequest ====================

// This is base class of the Drive API related requests. All Drive API requests
// support partial request (to improve the performance). The function can be
// shared among the Drive API requests.
// See also https://developers.google.com/drive/performance
class DriveApiPartialFieldRequest : public UrlFetchRequestBase {
 public:
  explicit DriveApiPartialFieldRequest(RequestSender* sender);
  ~DriveApiPartialFieldRequest() override;

  // Optional parameter.
  const std::string& fields() const { return fields_; }
  void set_fields(const std::string& fields) { fields_ = fields; }

 protected:
  // UrlFetchRequestBase overrides.
  GURL GetURL() const override;

  // Derived classes should override GetURLInternal instead of GetURL()
  // directly.
  virtual GURL GetURLInternal() const = 0;

 private:
  std::string fields_;

  DISALLOW_COPY_AND_ASSIGN(DriveApiPartialFieldRequest);
};

//============================ DriveApiDataRequest ===========================

// The base class of Drive API related requests that receive a JSON response
// representing |DataType|.
template<class DataType>
class DriveApiDataRequest : public DriveApiPartialFieldRequest {
 public:
  typedef base::Callback<void(DriveApiErrorCode error,
                              scoped_ptr<DataType> data)> Callback;

  // |callback| is called when the request finishes either by success or by
  // failure. On success, a JSON Value object is passed. It must not be null.
  DriveApiDataRequest(RequestSender* sender, const Callback& callback)
      : DriveApiPartialFieldRequest(sender),
        callback_(callback),
        weak_ptr_factory_(this) {
    DCHECK(!callback_.is_null());
  }
  virtual ~DriveApiDataRequest() {}

 protected:
  // UrlFetchRequestBase overrides.
  virtual void ProcessURLFetchResults(const net::URLFetcher* source) override {
    DriveApiErrorCode error = GetErrorCode();
    switch (error) {
      case HTTP_SUCCESS:
      case HTTP_CREATED:
        base::PostTaskAndReplyWithResult(
            blocking_task_runner(),
            FROM_HERE,
            base::Bind(&DriveApiDataRequest::Parse, response_writer()->data()),
            base::Bind(&DriveApiDataRequest::OnDataParsed,
                       weak_ptr_factory_.GetWeakPtr(), error));
        break;
      default:
        RunCallbackOnPrematureFailure(error);
        OnProcessURLFetchResultsComplete();
        break;
    }
  }

  virtual void RunCallbackOnPrematureFailure(DriveApiErrorCode error) override {
    callback_.Run(error, scoped_ptr<DataType>());
  }

 private:
  // Parses the |json| string by using DataType::CreateFrom.
  static scoped_ptr<DataType> Parse(const std::string& json) {
    scoped_ptr<base::Value> value = ParseJson(json);
    return value ? DataType::CreateFrom(*value) : scoped_ptr<DataType>();
  }

  // Receives the parsed result and invokes the callback.
  void OnDataParsed(DriveApiErrorCode error, scoped_ptr<DataType> value) {
    if (!value)
      error = DRIVE_PARSE_ERROR;
    callback_.Run(error, value.Pass());
    OnProcessURLFetchResultsComplete();
  }

  const Callback callback_;

  // Note: This should remain the last member so it'll be destroyed and
  // invalidate its weak pointers before any other members are destroyed.
  base::WeakPtrFactory<DriveApiDataRequest> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(DriveApiDataRequest);
};

//=============================== FilesGetRequest =============================

// This class performs the request for fetching a file.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/get
class FilesGetRequest : public DriveApiDataRequest<FileResource> {
 public:
  FilesGetRequest(RequestSender* sender,
                  const DriveApiUrlGenerator& url_generator,
                  bool use_internal_endpoint,
                  const FileResourceCallback& callback);
  ~FilesGetRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }

  // Optional parameter.
  const GURL& embed_origin() const { return embed_origin_; }
  void set_embed_origin(const GURL& embed_origin) {
    embed_origin_ = embed_origin;
  }

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  const bool use_internal_endpoint_;
  std::string file_id_;
  GURL embed_origin_;

  DISALLOW_COPY_AND_ASSIGN(FilesGetRequest);
};

//============================ FilesAuthorizeRequest ===========================

// This class performs request for authorizing an app to access a file.
// This request is mapped to /drive/v2internal/file/authorize internal endpoint.
class FilesAuthorizeRequest : public DriveApiDataRequest<FileResource> {
 public:
  FilesAuthorizeRequest(RequestSender* sender,
                        const DriveApiUrlGenerator& url_generator,
                        const FileResourceCallback& callback);
  ~FilesAuthorizeRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }
  const std::string& app_id() const { return app_id_; }
  void set_app_id(const std::string& app_id) { app_id_ = app_id; }

 protected:
  // Overridden from GetDataRequest.
  net::URLFetcher::RequestType GetRequestType() const override;

  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string file_id_;
  std::string app_id_;

  DISALLOW_COPY_AND_ASSIGN(FilesAuthorizeRequest);
};

//============================ FilesInsertRequest =============================

// This class performs the request for creating a resource.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/insert
// See also https://developers.google.com/drive/manage-uploads and
// https://developers.google.com/drive/folder
class FilesInsertRequest : public DriveApiDataRequest<FileResource> {
 public:
  FilesInsertRequest(RequestSender* sender,
                     const DriveApiUrlGenerator& url_generator,
                     const FileResourceCallback& callback);
  ~FilesInsertRequest() override;

  // Optional request body.
  const base::Time& last_viewed_by_me_date() const {
    return last_viewed_by_me_date_;
  }
  void set_last_viewed_by_me_date(const base::Time& last_viewed_by_me_date) {
    last_viewed_by_me_date_ = last_viewed_by_me_date;
  }

  const std::string& mime_type() const { return mime_type_; }
  void set_mime_type(const std::string& mime_type) {
    mime_type_ = mime_type;
  }

  const base::Time& modified_date() const { return modified_date_; }
  void set_modified_date(const base::Time& modified_date) {
    modified_date_ = modified_date;
  }

  const std::vector<std::string>& parents() const { return parents_; }
  void add_parent(const std::string& parent) { parents_.push_back(parent); }

  const std::string& title() const { return title_; }
  void set_title(const std::string& title) { title_ = title; }

  const Properties& properties() const { return properties_; }
  void set_properties(const Properties& properties) {
    properties_ = properties;
  }

 protected:
  // Overridden from GetDataRequest.
  net::URLFetcher::RequestType GetRequestType() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;

  base::Time last_viewed_by_me_date_;
  std::string mime_type_;
  base::Time modified_date_;
  std::vector<std::string> parents_;
  std::string title_;
  Properties properties_;

  DISALLOW_COPY_AND_ASSIGN(FilesInsertRequest);
};

//============================== FilesPatchRequest ============================

// This class performs the request for patching file metadata.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/patch
class FilesPatchRequest : public DriveApiDataRequest<FileResource> {
 public:
  FilesPatchRequest(RequestSender* sender,
                    const DriveApiUrlGenerator& url_generator,
                    const FileResourceCallback& callback);
  ~FilesPatchRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }

  // Optional parameter.
  bool set_modified_date() const { return set_modified_date_; }
  void set_set_modified_date(bool set_modified_date) {
    set_modified_date_ = set_modified_date;
  }

  bool update_viewed_date() const { return update_viewed_date_; }
  void set_update_viewed_date(bool update_viewed_date) {
    update_viewed_date_ = update_viewed_date;
  }

  // Optional request body.
  // Note: "Files: patch" accepts any "Files resource" data, but this class
  // only supports limited members of it for now. We can extend it upon
  // requirments.
  const std::string& title() const { return title_; }
  void set_title(const std::string& title) { title_ = title; }

  const base::Time& modified_date() const { return modified_date_; }
  void set_modified_date(const base::Time& modified_date) {
    modified_date_ = modified_date;
  }

  const base::Time& last_viewed_by_me_date() const {
    return last_viewed_by_me_date_;
  }
  void set_last_viewed_by_me_date(const base::Time& last_viewed_by_me_date) {
    last_viewed_by_me_date_ = last_viewed_by_me_date;
  }

  const std::vector<std::string>& parents() const { return parents_; }
  void add_parent(const std::string& parent) { parents_.push_back(parent); }

  const Properties& properties() const { return properties_; }
  void set_properties(const Properties& properties) {
    properties_ = properties;
  }

 protected:
  // Overridden from URLFetchRequestBase.
  net::URLFetcher::RequestType GetRequestType() const override;
  std::vector<std::string> GetExtraRequestHeaders() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;

  std::string file_id_;
  bool set_modified_date_;
  bool update_viewed_date_;

  std::string title_;
  base::Time modified_date_;
  base::Time last_viewed_by_me_date_;
  std::vector<std::string> parents_;
  Properties properties_;

  DISALLOW_COPY_AND_ASSIGN(FilesPatchRequest);
};

//============================= FilesCopyRequest ==============================

// This class performs the request for copying a resource.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/copy
class FilesCopyRequest : public DriveApiDataRequest<FileResource> {
 public:
  // Upon completion, |callback| will be called. |callback| must not be null.
  FilesCopyRequest(RequestSender* sender,
                   const DriveApiUrlGenerator& url_generator,
                   const FileResourceCallback& callback);
  ~FilesCopyRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }

  // Optional request body.
  const std::vector<std::string>& parents() const { return parents_; }
  void add_parent(const std::string& parent) { parents_.push_back(parent); }

  const base::Time& modified_date() const { return modified_date_; }
  void set_modified_date(const base::Time& modified_date) {
    modified_date_ = modified_date;
  }

  const std::string& title() const { return title_; }
  void set_title(const std::string& title) { title_ = title; }

 protected:
  // Overridden from URLFetchRequestBase.
  net::URLFetcher::RequestType GetRequestType() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;

  std::string file_id_;
  base::Time modified_date_;
  std::vector<std::string> parents_;
  std::string title_;

  DISALLOW_COPY_AND_ASSIGN(FilesCopyRequest);
};

//============================= FilesListRequest =============================

// This class performs the request for fetching FileList.
// The result may contain only first part of the result. The remaining result
// should be able to be fetched by ContinueGetFileListRequest defined below,
// or by FilesListRequest with setting page token.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/list
class FilesListRequest : public DriveApiDataRequest<FileList> {
 public:
  FilesListRequest(RequestSender* sender,
                   const DriveApiUrlGenerator& url_generator,
                   const FileListCallback& callback);
  ~FilesListRequest() override;

  // Optional parameter
  int max_results() const { return max_results_; }
  void set_max_results(int max_results) { max_results_ = max_results; }

  const std::string& page_token() const { return page_token_; }
  void set_page_token(const std::string& page_token) {
    page_token_ = page_token;
  }

  const std::string& q() const { return q_; }
  void set_q(const std::string& q) { q_ = q; }

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  int max_results_;
  std::string page_token_;
  std::string q_;

  DISALLOW_COPY_AND_ASSIGN(FilesListRequest);
};

//========================= FilesListNextPageRequest ==========================

// There are two ways to obtain next pages of "Files: list" result (if paged).
// 1) Set pageToken and all params used for the initial request.
// 2) Use URL in the nextLink field in the previous response.
// This class implements 2)'s request.
class FilesListNextPageRequest : public DriveApiDataRequest<FileList> {
 public:
  FilesListNextPageRequest(RequestSender* sender,
                           const FileListCallback& callback);
  ~FilesListNextPageRequest() override;

  const GURL& next_link() const { return next_link_; }
  void set_next_link(const GURL& next_link) { next_link_ = next_link; }

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  GURL next_link_;

  DISALLOW_COPY_AND_ASSIGN(FilesListNextPageRequest);
};

//============================= FilesDeleteRequest =============================

// This class performs the request for deleting a resource.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/delete
class FilesDeleteRequest : public EntryActionRequest {
 public:
  FilesDeleteRequest(RequestSender* sender,
                     const DriveApiUrlGenerator& url_generator,
                     const EntryActionCallback& callback);
  ~FilesDeleteRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }
  void set_etag(const std::string& etag) { etag_ = etag; }

 protected:
  // Overridden from UrlFetchRequestBase.
  net::URLFetcher::RequestType GetRequestType() const override;
  GURL GetURL() const override;
  std::vector<std::string> GetExtraRequestHeaders() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string file_id_;
  std::string etag_;

  DISALLOW_COPY_AND_ASSIGN(FilesDeleteRequest);
};

//============================= FilesTrashRequest ==============================

// This class performs the request for trashing a resource.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/trash
class FilesTrashRequest : public DriveApiDataRequest<FileResource> {
 public:
  FilesTrashRequest(RequestSender* sender,
                    const DriveApiUrlGenerator& url_generator,
                    const FileResourceCallback& callback);
  ~FilesTrashRequest() override;

  // Required parameter.
  const std::string& file_id() const { return file_id_; }
  void set_file_id(const std::string& file_id) { file_id_ = file_id; }

 protected:
  // Overridden from UrlFetchRequestBase.
  net::URLFetcher::RequestType GetRequestType() const override;

  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string file_id_;

  DISALLOW_COPY_AND_ASSIGN(FilesTrashRequest);
};

//============================== AboutGetRequest =============================

// This class performs the request for fetching About data.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/about/get
class AboutGetRequest : public DriveApiDataRequest<AboutResource> {
 public:
  AboutGetRequest(RequestSender* sender,
                  const DriveApiUrlGenerator& url_generator,
                  const AboutResourceCallback& callback);
  ~AboutGetRequest() override;

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;

  DISALLOW_COPY_AND_ASSIGN(AboutGetRequest);
};

//============================ ChangesListRequest ============================

// This class performs the request for fetching ChangeList.
// The result may contain only first part of the result. The remaining result
// should be able to be fetched by ContinueGetFileListRequest defined below.
// or by ChangesListRequest with setting page token.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/changes/list
class ChangesListRequest : public DriveApiDataRequest<ChangeList> {
 public:
  ChangesListRequest(RequestSender* sender,
                     const DriveApiUrlGenerator& url_generator,
                     const ChangeListCallback& callback);
  ~ChangesListRequest() override;

  // Optional parameter
  bool include_deleted() const { return include_deleted_; }
  void set_include_deleted(bool include_deleted) {
    include_deleted_ = include_deleted;
  }

  int max_results() const { return max_results_; }
  void set_max_results(int max_results) { max_results_ = max_results; }

  const std::string& page_token() const { return page_token_; }
  void set_page_token(const std::string& page_token) {
    page_token_ = page_token;
  }

  int64 start_change_id() const { return start_change_id_; }
  void set_start_change_id(int64 start_change_id) {
    start_change_id_ = start_change_id;
  }

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  bool include_deleted_;
  int max_results_;
  std::string page_token_;
  int64 start_change_id_;

  DISALLOW_COPY_AND_ASSIGN(ChangesListRequest);
};

//======================== ChangesListNextPageRequest =========================

// There are two ways to obtain next pages of "Changes: list" result (if paged).
// 1) Set pageToken and all params used for the initial request.
// 2) Use URL in the nextLink field in the previous response.
// This class implements 2)'s request.
class ChangesListNextPageRequest : public DriveApiDataRequest<ChangeList> {
 public:
  ChangesListNextPageRequest(RequestSender* sender,
                             const ChangeListCallback& callback);
  ~ChangesListNextPageRequest() override;

  const GURL& next_link() const { return next_link_; }
  void set_next_link(const GURL& next_link) { next_link_ = next_link; }

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  GURL next_link_;

  DISALLOW_COPY_AND_ASSIGN(ChangesListNextPageRequest);
};

//============================= AppsListRequest ============================

// This class performs the request for fetching AppList.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/apps/list
class AppsListRequest : public DriveApiDataRequest<AppList> {
 public:
  AppsListRequest(RequestSender* sender,
                  const DriveApiUrlGenerator& url_generator,
                  bool use_internal_endpoint,
                  const AppListCallback& callback);
  ~AppsListRequest() override;

 protected:
  // Overridden from DriveApiDataRequest.
  GURL GetURLInternal() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  const bool use_internal_endpoint_;

  DISALLOW_COPY_AND_ASSIGN(AppsListRequest);
};

//============================= AppsDeleteRequest ==============================

// This class performs the request for deleting a Drive app.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/files/trash
class AppsDeleteRequest : public EntryActionRequest {
 public:
  AppsDeleteRequest(RequestSender* sender,
                    const DriveApiUrlGenerator& url_generator,
                    const EntryActionCallback& callback);
  ~AppsDeleteRequest() override;

  // Required parameter.
  const std::string& app_id() const { return app_id_; }
  void set_app_id(const std::string& app_id) { app_id_ = app_id; }

 protected:
  // Overridden from UrlFetchRequestBase.
  net::URLFetcher::RequestType GetRequestType() const override;
  GURL GetURL() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string app_id_;

  DISALLOW_COPY_AND_ASSIGN(AppsDeleteRequest);
};

//========================== ChildrenInsertRequest ============================

// This class performs the request for inserting a resource to a directory.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/children/insert
class ChildrenInsertRequest : public EntryActionRequest {
 public:
  ChildrenInsertRequest(RequestSender* sender,
                        const DriveApiUrlGenerator& url_generator,
                        const EntryActionCallback& callback);
  ~ChildrenInsertRequest() override;

  // Required parameter.
  const std::string& folder_id() const { return folder_id_; }
  void set_folder_id(const std::string& folder_id) {
    folder_id_ = folder_id;
  }

  // Required body.
  const std::string& id() const { return id_; }
  void set_id(const std::string& id) { id_ = id; }

 protected:
  // UrlFetchRequestBase overrides.
  net::URLFetcher::RequestType GetRequestType() const override;
  GURL GetURL() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string folder_id_;
  std::string id_;

  DISALLOW_COPY_AND_ASSIGN(ChildrenInsertRequest);
};

//========================== ChildrenDeleteRequest ============================

// This class performs the request for removing a resource from a directory.
// This request is mapped to
// https://developers.google.com/drive/v2/reference/children/delete
class ChildrenDeleteRequest : public EntryActionRequest {
 public:
  // |callback| must not be null.
  ChildrenDeleteRequest(RequestSender* sender,
                        const DriveApiUrlGenerator& url_generator,
                        const EntryActionCallback& callback);
  ~ChildrenDeleteRequest() override;

  // Required parameter.
  const std::string& child_id() const { return child_id_; }
  void set_child_id(const std::string& child_id) {
    child_id_ = child_id;
  }

  const std::string& folder_id() const { return folder_id_; }
  void set_folder_id(const std::string& folder_id) {
    folder_id_ = folder_id;
  }

 protected:
  // UrlFetchRequestBase overrides.
  net::URLFetcher::RequestType GetRequestType() const override;
  GURL GetURL() const override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string child_id_;
  std::string folder_id_;

  DISALLOW_COPY_AND_ASSIGN(ChildrenDeleteRequest);
};

//======================= InitiateUploadNewFileRequest =======================

// This class performs the request for initiating the upload of a new file.
class InitiateUploadNewFileRequest : public InitiateUploadRequestBase {
 public:
  // |parent_resource_id| should be the resource id of the parent directory.
  // |title| should be set.
  // See also the comments of InitiateUploadRequestBase for more details
  // about the other parameters.
  InitiateUploadNewFileRequest(RequestSender* sender,
                               const DriveApiUrlGenerator& url_generator,
                               const std::string& content_type,
                               int64 content_length,
                               const std::string& parent_resource_id,
                               const std::string& title,
                               const InitiateUploadCallback& callback);
  ~InitiateUploadNewFileRequest() override;

  // Optional parameters.
  const base::Time& modified_date() const { return modified_date_; }
  void set_modified_date(const base::Time& modified_date) {
    modified_date_ = modified_date;
  }
  const base::Time& last_viewed_by_me_date() const {
    return last_viewed_by_me_date_;
  }
  void set_last_viewed_by_me_date(const base::Time& last_viewed_by_me_date) {
    last_viewed_by_me_date_ = last_viewed_by_me_date;
  }
  const Properties& properties() const { return properties_; }
  void set_properties(const Properties& properties) {
    properties_ = properties;
  }

 protected:
  // UrlFetchRequestBase overrides.
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

 private:
  const DriveApiUrlGenerator url_generator_;
  const std::string parent_resource_id_;
  const std::string title_;

  base::Time modified_date_;
  base::Time last_viewed_by_me_date_;
  Properties properties_;

  DISALLOW_COPY_AND_ASSIGN(InitiateUploadNewFileRequest);
};

//==================== InitiateUploadExistingFileRequest =====================

// This class performs the request for initiating the upload of an existing
// file.
class InitiateUploadExistingFileRequest : public InitiateUploadRequestBase {
 public:
  // |upload_url| should be the upload_url() of the file
  //    (resumable-create-media URL)
  // |etag| should be set if it is available to detect the upload confliction.
  // See also the comments of InitiateUploadRequestBase for more details
  // about the other parameters.
  InitiateUploadExistingFileRequest(RequestSender* sender,
                                    const DriveApiUrlGenerator& url_generator,
                                    const std::string& content_type,
                                    int64 content_length,
                                    const std::string& resource_id,
                                    const std::string& etag,
                                    const InitiateUploadCallback& callback);
  ~InitiateUploadExistingFileRequest() override;

  // Optional parameters.
  const std::string& parent_resource_id() const { return parent_resource_id_; }
  void set_parent_resource_id(const std::string& parent_resource_id) {
    parent_resource_id_ = parent_resource_id;
  }
  const std::string& title() const { return title_; }
  void set_title(const std::string& title) { title_ = title; }
  const base::Time& modified_date() const { return modified_date_; }
  void set_modified_date(const base::Time& modified_date) {
    modified_date_ = modified_date;
  }
  const base::Time& last_viewed_by_me_date() const {
    return last_viewed_by_me_date_;
  }
  void set_last_viewed_by_me_date(const base::Time& last_viewed_by_me_date) {
    last_viewed_by_me_date_ = last_viewed_by_me_date;
  }
  const Properties& properties() const { return properties_; }
  void set_properties(const Properties& properties) {
    properties_ = properties;
  }

 protected:
  // UrlFetchRequestBase overrides.
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;
  std::vector<std::string> GetExtraRequestHeaders() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

 private:
  const DriveApiUrlGenerator url_generator_;
  const std::string resource_id_;
  const std::string etag_;

  std::string parent_resource_id_;
  std::string title_;
  base::Time modified_date_;
  base::Time last_viewed_by_me_date_;
  Properties properties_;

  DISALLOW_COPY_AND_ASSIGN(InitiateUploadExistingFileRequest);
};

// Callback used for ResumeUpload() and GetUploadStatus().
typedef base::Callback<void(
    const UploadRangeResponse& response,
    scoped_ptr<FileResource> new_resource)> UploadRangeCallback;

//============================ ResumeUploadRequest ===========================

// Performs the request for resuming the upload of a file.
class ResumeUploadRequest : public ResumeUploadRequestBase {
 public:
  // See also ResumeUploadRequestBase's comment for parameters meaning.
  // |callback| must not be null. |progress_callback| may be null.
  ResumeUploadRequest(RequestSender* sender,
                      const GURL& upload_location,
                      int64 start_position,
                      int64 end_position,
                      int64 content_length,
                      const std::string& content_type,
                      const base::FilePath& local_file_path,
                      const UploadRangeCallback& callback,
                      const ProgressCallback& progress_callback);
  ~ResumeUploadRequest() override;

 protected:
  // UploadRangeRequestBase overrides.
  void OnRangeRequestComplete(const UploadRangeResponse& response,
                              scoped_ptr<base::Value> value) override;
  // content::UrlFetcherDelegate overrides.
  void OnURLFetchUploadProgress(const net::URLFetcher* source,
                                int64 current,
                                int64 total) override;

 private:
  const UploadRangeCallback callback_;
  const ProgressCallback progress_callback_;

  DISALLOW_COPY_AND_ASSIGN(ResumeUploadRequest);
};

//========================== GetUploadStatusRequest ==========================

// Performs the request to fetch the current upload status of a file.
class GetUploadStatusRequest : public GetUploadStatusRequestBase {
 public:
  // See also GetUploadStatusRequestBase's comment for parameters meaning.
  // |callback| must not be null.
  GetUploadStatusRequest(RequestSender* sender,
                         const GURL& upload_url,
                         int64 content_length,
                         const UploadRangeCallback& callback);
  ~GetUploadStatusRequest() override;

 protected:
  // UploadRangeRequestBase overrides.
  void OnRangeRequestComplete(const UploadRangeResponse& response,
                              scoped_ptr<base::Value> value) override;

 private:
  const UploadRangeCallback callback_;

  DISALLOW_COPY_AND_ASSIGN(GetUploadStatusRequest);
};

//======================= MultipartUploadNewFileRequest =======================

// This class performs the request for initiating the upload of a new file.
class MultipartUploadNewFileRequest : public MultipartUploadRequestBase {
 public:
  // |parent_resource_id| should be the resource id of the parent directory.
  // |title| should be set.
  // See also the comments of MultipartUploadRequestBase for more details
  // about the other parameters.
  MultipartUploadNewFileRequest(RequestSender* sender,
                                const std::string& title,
                                const std::string& parent_resource_id,
                                const std::string& content_type,
                                int64 content_length,
                                const base::Time& modified_date,
                                const base::Time& last_viewed_by_me_date,
                                const base::FilePath& local_file_path,
                                const Properties& properties,
                                const DriveApiUrlGenerator& url_generator,
                                const FileResourceCallback& callback,
                                const ProgressCallback& progress_callback);
  ~MultipartUploadNewFileRequest() override;

 protected:
  // UrlFetchRequestBase overrides.
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;

 private:
  const bool has_modified_date_;
  const DriveApiUrlGenerator url_generator_;

  DISALLOW_COPY_AND_ASSIGN(MultipartUploadNewFileRequest);
};

//======================= MultipartUploadExistingFileRequest ===================

// This class performs the request for initiating the upload of a new file.
class MultipartUploadExistingFileRequest : public MultipartUploadRequestBase {
 public:
  // |parent_resource_id| should be the resource id of the parent directory.
  // |title| should be set.
  // See also the comments of MultipartUploadRequestBase for more details
  // about the other parameters.
  MultipartUploadExistingFileRequest(RequestSender* sender,
                                     const std::string& title,
                                     const std::string& resource_id,
                                     const std::string& parent_resource_id,
                                     const std::string& content_type,
                                     int64 content_length,
                                     const base::Time& modified_date,
                                     const base::Time& last_viewed_by_me_date,
                                     const base::FilePath& local_file_path,
                                     const std::string& etag,
                                     const Properties& properties,
                                     const DriveApiUrlGenerator& url_generator,
                                     const FileResourceCallback& callback,
                                     const ProgressCallback& progress_callback);
  ~MultipartUploadExistingFileRequest() override;

 protected:
  // UrlFetchRequestBase overrides.
  std::vector<std::string> GetExtraRequestHeaders() const override;
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;

 private:
  const std::string resource_id_;
  const std::string etag_;
  const bool has_modified_date_;
  const DriveApiUrlGenerator url_generator_;

  DISALLOW_COPY_AND_ASSIGN(MultipartUploadExistingFileRequest);
};

//========================== DownloadFileRequest ==========================

// This class performs the request for downloading of a specified file.
class DownloadFileRequest : public DownloadFileRequestBase {
 public:
  // See also DownloadFileRequestBase's comment for parameters meaning.
  DownloadFileRequest(RequestSender* sender,
                      const DriveApiUrlGenerator& url_generator,
                      const std::string& resource_id,
                      const base::FilePath& output_file_path,
                      const DownloadActionCallback& download_action_callback,
                      const GetContentCallback& get_content_callback,
                      const ProgressCallback& progress_callback);
  ~DownloadFileRequest() override;

  DISALLOW_COPY_AND_ASSIGN(DownloadFileRequest);
};

//========================== PermissionsInsertRequest ==========================

// Enumeration type for specifying type of permissions.
enum PermissionType {
  PERMISSION_TYPE_ANYONE,
  PERMISSION_TYPE_DOMAIN,
  PERMISSION_TYPE_GROUP,
  PERMISSION_TYPE_USER,
};

// Enumeration type for specifying the role of permissions.
enum PermissionRole {
  PERMISSION_ROLE_OWNER,
  PERMISSION_ROLE_READER,
  PERMISSION_ROLE_WRITER,
  PERMISSION_ROLE_COMMENTER,
};

// This class performs the request for adding permission on a specified file.
class PermissionsInsertRequest : public EntryActionRequest {
 public:
  // See https://developers.google.com/drive/v2/reference/permissions/insert.
  PermissionsInsertRequest(RequestSender* sender,
                           const DriveApiUrlGenerator& url_generator,
                           const EntryActionCallback& callback);
  ~PermissionsInsertRequest() override;

  void set_id(const std::string& id) { id_ = id; }
  void set_type(PermissionType type) { type_ = type; }
  void set_role(PermissionRole role) { role_ = role; }
  void set_value(const std::string& value) { value_ = value; }

  // UrlFetchRequestBase overrides.
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;
  bool GetContentData(std::string* upload_content_type,
                      std::string* upload_content) override;

 private:
  const DriveApiUrlGenerator url_generator_;
  std::string id_;
  PermissionType type_;
  PermissionRole role_;
  std::string value_;

  DISALLOW_COPY_AND_ASSIGN(PermissionsInsertRequest);
};

//========================== BatchUploadRequest ==========================

struct BatchUploadChildEntry {
  BatchUploadChildEntry() : request(NULL), prepared(false) {}
  explicit BatchUploadChildEntry(BatchableRequestBase* request)
      : request(request), prepared(false) {}
  BatchableRequestBase* request;
  bool prepared;
};

class BatchUploadRequest : public UrlFetchRequestBase {
 public:
  BatchUploadRequest(RequestSender* sender,
                     const DriveApiUrlGenerator& url_generator);
  ~BatchUploadRequest() override;

  // Adds request to the batch request.
  void AddRequest(BatchableRequestBase* request);

  // Completes building batch upload request, and starts to send the request to
  // server. Must add at least one request before calling |Commit|.
  void Commit();

  // Obtains weak pointer of this.
  base::WeakPtr<BatchUploadRequest> GetWeakPtrAsBatchUploadRequest();

  // Set boundary. Only tests can use this method.
  void SetBoundaryForTesting(const std::string& boundary);

  // Obtains reference to RequestSender that owns the request.
  RequestSender* sender() const { return sender_; }

  // Obtains URLGenerator.
  const DriveApiUrlGenerator& url_generator() const { return url_generator_; }

  // UrlFetchRequestBase overrides.
  void Prepare(const PrepareCallback& callback) override;
  void Cancel() override;
  GURL GetURL() const override;
  net::URLFetcher::RequestType GetRequestType() const override;
  std::vector<std::string> GetExtraRequestHeaders() const override;
  bool GetContentData(
      std::string* upload_content_type,
      std::string* upload_content) override;
  void ProcessURLFetchResults(const net::URLFetcher* source) override;
  void RunCallbackOnPrematureFailure(DriveApiErrorCode code) override;

 private:
  typedef void* RequestID;
  // Obtains corresponding child entry of |request_id|. Returns NULL if the
  // entry is not found.
  std::vector<BatchUploadChildEntry>::iterator
  GetChildEntry(RequestID request_id);

  // Called after child requests' |Prepare| method.
  void OnChildRequestPrepared(RequestID request_id, DriveApiErrorCode result);

  // Complete |Prepare| if possible.
  void MayCompletePrepare();

  // Process result for each child.
  void ProcessURLFetchResultsForChild(RequestID id, const std::string& body);

  RequestSender* const sender_;
  const DriveApiUrlGenerator url_generator_;
  std::vector<BatchUploadChildEntry> child_requests_;

  PrepareCallback prepare_callback_;
  bool committed_;

  // Boundary of multipart body.
  std::string boundary_;

  // Multipart of child requests.
  ContentTypeAndData upload_content_;

  // Note: This should remain the last member so it'll be destroyed and
  // invalidate its weak pointers before any other members are destroyed.
  base::WeakPtrFactory<BatchUploadRequest> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(BatchUploadRequest);
};

}  // namespace drive
}  // namespace google_apis

#endif  // GOOGLE_APIS_DRIVE_DRIVE_API_REQUESTS_H_