// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_AUTOFILL_IOS_BROWSER_AUTOFILL_UTIL_H_
#define COMPONENTS_AUTOFILL_IOS_BROWSER_AUTOFILL_UTIL_H_

#import <optional>
#import <set>
#import <variant>

#import "base/strings/string_number_conversions.h"
#import "base/unguessable_token.h"
#import "base/values.h"
#import "components/autofill/core/common/unique_ids.h"
#import "ios/web/public/js_messaging/web_frame.h"

class GURL;

namespace url {
class Origin;
}

namespace web {
class WebFramesManager;
class WebState;
}

namespace autofill {

class FormData;
class FormFieldData;
class FieldDataManager;
struct FrameTokenWithPredecessor;

// Enumeration representing the various reasons why form data extraction might
// fail.
//
// These values are persisted to logs. Entries should not be renumbered and
// numeric values should never be reused.
//
// LINT.IfChange(InvalidSubmittedFormReasonIOS)
enum class ExtractFormDataFailure {
  // The form data is missing the "name" field.
  kMissingName = 0,
  // The form name does not match the expected name when filtering.
  kFilteredNameMismatch = 1,
  // The form data is missing the "origin" field.
  kMissingOrigin = 2,
  // The form origin does not match the expected origin.
  kOriginMismatch = 3,
  // The form data is missing the "host_frame" field.
  kMissingHostFrame = 4,
  // The host frame token is invalid.
  kInvalidHostFrame = 5,
  // The frame ID does not match the host frame parameter.
  kFrameIdMismatch = 6,
  // The form data is missing the "fields" list.
  kMissingFields = 7,
  //  Failed to extract data from one or more form fields.
  kInvalidField = 8,
  kMaxValue = kInvalidField,
};
// LINT.ThenChange(//tools/metrics/histograms/metadata/autofill/enums.xml:InvalidSubmittedFormReasonIOS)

// Checks if current context is secure from an autofill standpoint.
bool IsContextSecureForWebState(web::WebState* web_state);

// Tries to parse a JSON string into base::Value. Returns nullptr if parsing is
// unsuccessful.
std::unique_ptr<base::Value> ParseJson(NSString* json_string);

// Local and remote frame IDs generated in JavaScript are equivalent to
// base::UnguessableToken (128 bits, cryptographically random). Returns a
// base::UnguessableToken equivalent to the given JS-generated ID.
std::optional<base::UnguessableToken> DeserializeJavaScriptFrameId(
    const std::string& frame_id);

// Processes the JSON form data extracted from the page into the format expected
// by BrowserAutofillManager.
// `filtered` and `form_name` limit the field that will be returned.
// `host_frame` is the isolated world frame corresponding to the page content
// world frame where the forms were extracted. For forms extracted in the
// isolated world pass a null `host_frame` as the frame token is derived from
// `frame_id`. Returns an std::optional that contains the extracted vector of
// FormData or nullopt if the data was invalid.
std::optional<std::vector<FormData>> ExtractFormsData(
    NSString* form_json,
    bool filtered,
    const std::u16string& form_name,
    const GURL& main_frame_url,
    const url::Origin& frame_origin,
    const FieldDataManager& field_data_manager,
    const std::string& frame_id,
    LocalFrameToken host_frame = LocalFrameToken());

// Converts |form| into FormData.
// `host_frame` is the isolated world frame corresponding to the page content
// world frame where the forms were extracted. For forms extracted in the
// isolated world pass a null `host_frame` as the frame token is derived from
// `frame_id`. Returns nullopt if a form can not be extracted. Returns nullopt
// if |filtered| == true and |form["name"]| != |formName|. Returns false if
// |form["origin"]| != |form_frame_origin|. Returns an std::optional that
// contains a FormData if the conversion succeeds. Use ExtractFormDataOrFailure
// instead if you need to know the reason for failure.
std::optional<FormData> ExtractFormData(
    const base::Value::Dict& form,
    bool filtered,
    const std::u16string& form_name,
    const GURL& main_frame_url,
    const url::Origin& form_frame_origin,
    const FieldDataManager& field_data_manager,
    const std::string& frame_id,
    LocalFrameToken host_frame = LocalFrameToken());

// Converts |form| into FormData.
// `host_frame` is the isolated world frame corresponding to the page content
// world frame where the forms were extracted. For forms extracted in the
// isolated world pass a null `host_frame` as the frame token is derived from
// `frame_id`. Returns a std::variant containing either a FormData if the
// conversion succeeds, or an ExtractFormDataFailure enum indicating the reason
// for failure.
std::variant<FormData, ExtractFormDataFailure> ExtractFormDataOrFailure(
    const base::Value::Dict& form,
    bool filtered,
    const std::u16string& form_name,
    const GURL& main_frame_url,
    const url::Origin& form_frame_origin,
    const FieldDataManager& field_data_manager,
    const std::string& frame_id,
    LocalFrameToken host_frame = LocalFrameToken());

// Extracts a single form field from the JSON dictionary into a FormFieldData
// object.
// Returns false if the field could not be extracted.
bool ExtractFormFieldData(const base::Value::Dict& field,
                          const FieldDataManager& field_data_manager,
                          FormFieldData* field_data);

// Extracts a single child frame's data from the JSON dictionary into a
// FrameTokenWithPredecessor object. Returns false if the data could not be
// extracted.
bool ExtractRemoteFrameToken(const base::Value::Dict& frame_data,
                             FrameTokenWithPredecessor* token_with_predecessor);

typedef base::OnceCallback<void(const base::Value*)> JavaScriptResultCallback;

// Creates a callback for a string JS function return type.
JavaScriptResultCallback CreateStringCallback(
    void (^completionHandler)(NSString*));
JavaScriptResultCallback CreateStringCallback(
    base::OnceCallback<void(NSString*)> callback);

// Creates a callback for a bool JS function return type.
JavaScriptResultCallback CreateBoolCallback(void (^completionHandler)(BOOL));
JavaScriptResultCallback CreateBoolCallback(base::OnceCallback<void(BOOL)>);

// Executes the JavaScript function with the given name and argument.
// If |callback| is not null, it will be called when the result of the
// command is received, or immediately if the command cannot be executed.
void ExecuteJavaScriptFunction(const std::string& name,
                               const base::Value::List& parameters,
                               web::WebFrame* frame,
                               JavaScriptResultCallback callback);

// Extracts a vector of 32 bits numeric renderer IDs from the JS returned json
// string.
// - IDType: Identifier type must be constructable from uint32_t.
template <typename IDType>
std::optional<std::set<IDType>> ExtractIDs(NSString* json_string) {
  std::unique_ptr<base::Value> ids_value = ParseJson(json_string);

  if (!ids_value || !ids_value->is_list()) {
    return std::nullopt;
  }

  std::set<IDType> ids;

  for (const auto& unique_id : ids_value->GetList()) {
    if (!unique_id.is_string()) {
      return std::nullopt;
    }
    uint32_t id_num = 0;
    if (!base::StringToUint(unique_id.GetString(), &id_num)) {
      return std::nullopt;
    }
    ids.insert(IDType(id_num));
  }

  return ids;
}

// Extracts a map of filled renderer IDs and values from the JS returned json
// string.
bool ExtractFillingResults(NSString* json_string,
                           std::map<uint32_t, std::u16string>* filling_results);

// Returns the WebFramesManager that manages the frame space in which Autofill
// works.
web::WebFramesManager* GetWebFramesManagerForAutofill(web::WebState* web_state);

}  // namespace autofill

#endif  // COMPONENTS_AUTOFILL_IOS_BROWSER_AUTOFILL_UTIL_H_