// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ASH_SCANNER_SCANNER_SESSION_H_
#define ASH_SCANNER_SCANNER_SESSION_H_

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

#include "ash/ash_export.h"
#include "ash/scanner/scanner_action_view_model.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/ref_counted_memory.h"
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "base/types/expected.h"
#include "components/manta/manta_status.h"
#include "components/manta/proto/scanner.pb.h"

namespace ash {

class ScannerProfileScopedDelegate;

// A ScannerSession represents a single "use" of the Scanner feature. A session
// will be created when the feature is first triggered, until the feature is
// either dismissed, or commits its final result. The initialization of a
// session will be triggered on the creation of a new SunfishSession, however
// a ScannerSession's lifetime is not strictly bound to the lifetime of a
// SunfishSession.
class ASH_EXPORT ScannerSession {
 public:
  // Contains data about an error that may have occurred while fetching actions
  // during a Scanner session.
  struct FetchError {
    // The error message to show.
    std::u16string error_message;
    // Whether the user can try the same query again after encountering this
    // error.
    bool can_try_again = false;
  };

  using FetchActionsResponse =
      base::expected<std::vector<ScannerActionViewModel>, FetchError>;
  // Callback used to receive the actions returned from a FetchActions call.
  using FetchActionsCallback =
      base::OnceCallback<void(FetchActionsResponse response)>;
  using PopulateActionCallback =
      base::OnceCallback<void(manta::proto::ScannerAction action)>;

  explicit ScannerSession(ScannerProfileScopedDelegate* delegate);
  ScannerSession(const ScannerSession&) = delete;
  ScannerSession& operator=(const ScannerSession&) = delete;
  ~ScannerSession();

  // Fetches Scanner actions that are available based on the contents of
  // `jpeg_bytes`. The actions are returned via `callback`.
  void FetchActionsForImage(scoped_refptr<base::RefCountedMemory> jpeg_bytes,
                            FetchActionsCallback callback);

  // Populates the selected action based on the contents of
  // `downscaled_jpeg_bytes`.
  void PopulateAction(
      scoped_refptr<base::RefCountedMemory> downscaled_jpeg_bytes,
      manta::proto::ScannerAction unpopulated_action,
      PopulateActionCallback callback);

  void SetMockScannerOutput(
      std::unique_ptr<manta::proto::ScannerOutput> mock_output);

 private:
  void OnActionsReturned(
      scoped_refptr<base::RefCountedMemory> downscaled_jpeg_bytes,
      base::TimeTicks request_start_time,
      FetchActionsCallback callback,
      std::unique_ptr<manta::proto::ScannerOutput> output,
      manta::MantaStatus status);

  const raw_ptr<ScannerProfileScopedDelegate> delegate_;
  std::unique_ptr<manta::proto::ScannerOutput> mock_scanner_output_;

  base::WeakPtrFactory<ScannerSession> weak_ptr_factory_{this};
};

}  // namespace ash

#endif  // ASH_SCANNER_SCANNER_SESSION_H_