// 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.
//
// This file provides utility functions for "file tasks".
//
// WHAT ARE FILE TASKS?
//
// File tasks are representation of actions that can be performed over the
// currently selected files from the Files app. A task can be either of:
//
// 1) Chrome extension or app, registered via "file_handlers" or
// "file_browser_handlers" in manifest.json (ex. Text.app). This information
// comes from FileBrowserHandler::GetHandlers()
//
// See also:
// https://developer.chrome.com/extensions/manifest.html#file_handlers
// https://developer.chrome.com/extensions/fileBrowserHandler.html
//
// 2) Built-in handlers provided from the Files app. The Files app provides
// lots of file_browser_handlers, such as "play", "mount-archive".  These
// built-in handlers are often handled in special manners inside the Files
// app. This information also comes from FileBrowserHandler::GetHandlers().
//
// See also:
// ui/file_manager/file_manager/manifest.json
//
// For example, if the user is now selecting a JPEG file, the Files app will
// receive file tasks represented as a JSON object via
// chrome.fileManagerPrivate.getFileTasks() API, which look like:
//
// [
//   {
//     "iconUrl":
//       "chrome://extension-icon/hhaomjibdihmijegdhdafkllkbggdgoj/16/1",
//     "isDefault": true,
//     "descriptor": {
//       appId: "hhaomjibdihmijegdhdafkllkbggdgoj",
//       taskType: "file",
//       actionId: "gallery"
//     }
//     "title": "__MSG_OPEN_ACTION__"
//   }
// ]
//
// The file task is a built-in handler from the Files app.
//
// WHAT ARE TASK IDS?
//
// "TaskId" is a string of the format "appId|taskType|actionId". We used to
// store these three fields together in a string so we could easily store this
// data in user preferences. We are removing taskId wherever possible in favour
// of the TaskDescriptor struct, which contains the same information but in a
// more typical struct format. TaskId will remain in some parts of the code
// where we need to serialize TaskDescriptors, like for UMA.
//
// What are the three types of information encoded here?
//
// The "TaskId" format encoding is as follows:
//
//     <app-id>|<task-type>|<task-action-id>
//
// <app-id> is a Chrome Extension/App ID.
//
// <task-type> is either of
// - "file" - File browser handler - app/extension declaring
//            "file_browser_handlers" in manifest.
// - "app" - File handler - app declaring "file_handlers" in manifest.json.
// - "arc" - ARC App
// - "crostini" - Crostini App
//
// <task-action-id> is an ID string used for identifying actions provided
// from a single Chrome Extension/App. In other words, a single
// Chrome/Extension can provide multiple file handlers hence each of them
// needs to have a unique action ID. For Crostini apps, <task-action-id> is
// always "open-with".
//
// HOW TASKS ARE EXECUTED?
//
// chrome.fileManagerPrivate.executeTask() is used to open a file with a
// handler (Chrome Extension/App), and to open files directly in the browser
// without any handler, e.g. PDF.
//
// Some built-in handlers such as "play" are handled internally in the Files
// app. "mount-archive" is handled very differently.
//
// See also:
// ui/file_manager/file_manager/foreground/js/file_tasks.js
//

#ifndef CHROME_BROWSER_ASH_FILE_MANAGER_FILE_TASKS_H_
#define CHROME_BROWSER_ASH_FILE_MANAGER_FILE_TASKS_H_

#include <memory>
#include <set>
#include <string>
#include <vector>

#include "base/callback_forward.h"
#include "chrome/common/extensions/api/file_manager_private.h"
#include "extensions/browser/api/file_handlers/app_file_handler_util.h"
#include "url/gurl.h"

class PrefService;
class Profile;

namespace apps {
struct FileHandler;
struct FileHandlerInfo;
}

namespace extensions {
struct EntryInfo;
}

namespace storage {
class FileSystemURL;
}

namespace file_manager {
namespace file_tasks {

extern const char kActionIdView[];
extern const char kActionIdSend[];
extern const char kActionIdSendMultiple[];

// Task types as explained in the comment above. Search for <task-type>.
enum TaskType {
  TASK_TYPE_UNKNOWN = 0,  // Used only for handling errors.
  TASK_TYPE_FILE_BROWSER_HANDLER,
  TASK_TYPE_FILE_HANDLER,
  DEPRECATED_TASK_TYPE_DRIVE_APP,
  TASK_TYPE_ARC_APP,
  TASK_TYPE_CROSTINI_APP,
  TASK_TYPE_WEB_APP,
  TASK_TYPE_PLUGIN_VM_APP,
  // The enum values must be kept in sync with FileManagerTaskType in
  // tools/metrics/histograms/enums.xml. Since enums for histograms are
  // append-only (for keeping the number consistent across versions), new values
  // for this enum also has to be always appended at the end (i.e., here).
  NUM_TASK_TYPE,
};

TaskType StringToTaskType(const std::string& str);
std::string TaskTypeToString(TaskType task_type);

// Describes a task.
// See the comment above for <app-id>, <task-type>, and <action-id>.
struct TaskDescriptor {
  TaskDescriptor(const std::string& in_app_id,
                 TaskType in_task_type,
                 const std::string& in_action_id)
      : app_id(in_app_id),
        task_type(in_task_type),
        action_id(in_action_id) {
  }
  TaskDescriptor() = default;

  bool operator<(const TaskDescriptor& other) const {
    return app_id < other.app_id || task_type < other.task_type ||
           action_id < other.action_id;
  }

  std::string app_id;
  TaskType task_type;
  std::string action_id;
};

// Describes a task with extra information such as icon URL.
struct FullTaskDescriptor {
  FullTaskDescriptor(
      const TaskDescriptor& task_descriptor,
      const std::string& task_title,
      const extensions::api::file_manager_private::Verb task_verb,
      const GURL& icon_url,
      bool is_default,
      bool is_generic_file_handler,
      bool is_file_extension_match);

  FullTaskDescriptor(const FullTaskDescriptor& other);
  FullTaskDescriptor& operator=(const FullTaskDescriptor& other);

  // Unique ID for the task.
  TaskDescriptor task_descriptor;
  // The user-visible title/name of the app/extension/thing to be launched.
  std::string task_title;
  // Describes different ways the same Task might handle file/s, e.g. open with,
  // pack with, share with, etc.
  extensions::api::file_manager_private::Verb task_verb;
  // The icon URL for the task (ex. app icon)
  GURL icon_url;
  // The default task is stored in user preferences and will be used when the
  // user doesn't explicitly pick another e.g. double click.
  bool is_default;
  // True if this task is from generic file handler. Generic file handler is a
  // file handler which handles any type of files (e.g. extensions: ["*"],
  // types: ["*/*"]). Partial wild card (e.g. types: ["image/*"]) is not
  // generic file handler.
  bool is_generic_file_handler;
  // True if this task is from a file extension only. e.g. an extension/app
  // that declares no MIME types in its manifest, but matches with the
  // file_handlers "extensions" instead.
  bool is_file_extension_match;
};

// Update the default file handler for the given sets of suffixes and MIME
// types.
void UpdateDefaultTask(PrefService* pref_service,
                       const TaskDescriptor& task_descriptor,
                       const std::set<std::string>& suffixes,
                       const std::set<std::string>& mime_types);

// Returns the default task for the given |mime_type|/|suffix| combination in
// |task_out|. If it finds a MIME type match, then it prefers that over a suffix
// match. If a default can't be found, then it returns false.
bool GetDefaultTaskFromPrefs(const PrefService& pref_service,
                             const std::string& mime_type,
                             const std::string& suffix,
                             TaskDescriptor* task_out);

// Generates task id for the task specified by |app_id|, |task_type| and
// |action_id|.
//
// |app_id| is the Chrome Extension/App ID.
// |action_id| is a free-form string ID for the action.
std::string MakeTaskID(const std::string& app_id,
                       TaskType task_type,
                       const std::string& action_id);

// Converts |task_descriptor| to a task ID.
std::string TaskDescriptorToId(const TaskDescriptor& task_descriptor);

// Parses the task ID and extracts app ID, task type, and action ID into
// |task|. On failure, returns false, and the contents of |task| are
// undefined.
//
// See also the comment at the beginning of the file for details for how
// "task_id" looks like.
bool ParseTaskID(const std::string& task_id, TaskDescriptor* task);

// The callback is used for ExecuteFileTask().
typedef base::OnceCallback<void(
    extensions::api::file_manager_private::TaskResult result,
    std::string error_message)>
    FileTaskFinishedCallback;

// Executes file handler task for each element of |file_urls|.
// Returns |false| if the execution cannot be initiated. Otherwise returns
// |true| and then eventually calls |done| when all the files have been handled.
// |done| can be a null callback.
//
// Parameters:
// profile    - The profile used for making this function call.
// source_url - The source URL which originates this function call.
// task       - See the comment at TaskDescriptor struct.
// file_urls  - URLs of the target files.
// done       - The callback which will be called on completion.
//              The callback won't be called if the function returns
//              false.
bool ExecuteFileTask(Profile* profile,
                     const GURL& source_url,
                     const TaskDescriptor& task,
                     const std::vector<storage::FileSystemURL>& file_urls,
                     FileTaskFinishedCallback done);

// Returns true if an apps::FileHandler matches with all of |entries|; that is,
// if it doesn't include a blanket wild-card MIME type or file extension, it
// doesn't include text/* and match on an unsupported text MIME type, and if
// |entries| doesn't include directories.
//
// TODO(crbug.com/1060026): For now, this is called only in web_file_tasks,
// where the new apps::FileHandler representation is used. Once this replaces
// apps::FileHandlerInfo, this can be used everywhere.
bool IsGoodMatchAppsFileHandler(
    const apps::FileHandler& file_Handler,
    const std::vector<extensions::EntryInfo>& entries);

// Finds the file browser handler tasks (app/extensions declaring
// "file_browser_handlers" in manifest.json) that can be used with the
// given files, appending them to the |result_list|.
void FindFileBrowserHandlerTasks(
    Profile* profile,
    const std::vector<GURL>& file_urls,
    std::vector<FullTaskDescriptor>* result_list);

// Callback function type for FindAllTypesOfTasks.
typedef base::OnceCallback<void(
    std::unique_ptr<std::vector<FullTaskDescriptor>> result)>
    FindTasksCallback;

// Finds all types (file handlers, file browser handlers) of
// tasks.
//
// If |entries| contains a Google document, only the internal tasks of the
// Files app (i.e., tasks having the app ID of the Files app) are listed.
// This is to avoid listing normal file handler and file browser handler tasks,
// which can handle only normal files.
void FindAllTypesOfTasks(Profile* profile,
                         const std::vector<extensions::EntryInfo>& entries,
                         const std::vector<GURL>& file_urls,
                         FindTasksCallback callback);

// Chooses the default task in |tasks| and sets it as default, if the default
// task is found (i.e. the default task may not exist in |tasks|). No tasks
// should be set as default before calling this function.
void ChooseAndSetDefaultTask(const PrefService& pref_service,
                             const std::vector<extensions::EntryInfo>& entries,
                             std::vector<FullTaskDescriptor>* tasks);

// Returns whether |path| is an HTML file according to its extension.
bool IsHtmlFile(const base::FilePath& path);

}  // namespace file_tasks
}  // namespace file_manager

#endif  // CHROME_BROWSER_ASH_FILE_MANAGER_FILE_TASKS_H_