// Copyright 2025 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.
/* eslint-disable rulesdir/no-lit-render-outside-of-view */

import '../../ui/legacy/legacy.js';
import '../../ui/components/markdown_view/markdown_view.js';
import '../../ui/components/spinners/spinners.js';

import * as Common from '../../core/common/common.js';
import * as Host from '../../core/host/host.js';
import * as i18n from '../../core/i18n/i18n.js';
import * as Platform from '../../core/platform/platform.js';
import * as Root from '../../core/root/root.js';
import * as AiAssistanceModel from '../../models/ai_assistance/ai_assistance.js';
import * as Persistence from '../../models/persistence/persistence.js';
import * as Workspace from '../../models/workspace/workspace.js';
import * as WorkspaceDiff from '../../models/workspace_diff/workspace_diff.js';
import * as Buttons from '../../ui/components/buttons/buttons.js';
import * as UI from '../../ui/legacy/legacy.js';
import {Directives, html, type LitTemplate, nothing, render} from '../../ui/lit/lit.js';
import * as VisualLogging from '../../ui/visual_logging/visual_logging.js';
import * as ChangesPanel from '../changes/changes.js';
import * as PanelCommon from '../common/common.js';

import {SelectWorkspaceDialog} from './SelectWorkspaceDialog.js';

/*
* Strings that don't need to be translated at this time.
*/
const UIStringsNotTranslate = {
  /**
   *@description Text displayed for showing patch widget view.
   */
  unsavedChanges: 'Unsaved changes',
  /**
   *@description Loading text displayed as a summary title when the patch suggestion is getting loaded
   */
  applyingToWorkspace: 'Applying to workspace…',
  /**
   *@description Button text for staging changes to workspace.
   */
  applyToWorkspace: 'Apply to workspace',
  /**
   *@description Button text to change the selected workspace
   */
  change: 'Change',
  /**
   * @description Accessible title of the Change button to indicate that
   * the button can be used to change the root folder.
   */
  changeRootFolder: 'Change project root folder',
  /**
   *@description Button text to cancel applying to workspace
   */
  cancel: 'Cancel',
  /**
   *@description Button text to discard the suggested changes and not save them to file system
   */
  discard: 'Discard',
  /**
   *@description Button text to save all the suggested changes to file system
   */
  saveAll: 'Save all',
  /**
   *@description Header text after the user saved the changes to the disk.
   */
  savedToDisk: 'Saved to disk',
  /**
   *@description Disclaimer text shown for using code snippets with caution
   */
  codeDisclaimer: 'Use code snippets with caution',
  /**
   *@description Tooltip text for the info icon beside the "Apply to workspace" button
   */
  applyToWorkspaceTooltip: 'Source code from the selected folder is sent to Google to generate code suggestions.',
  /**
   *@description Tooltip text for the info icon beside the "Apply to workspace" button when enterprise logging is off
   */
  applyToWorkspaceTooltipNoLogging:
      'Source code from the selected folder is sent to Google to generate code suggestions. This data will not be used to improve Google’s AI models.',
  /**
   *@description The footer disclaimer that links to more information
   * about the AI feature. Same text as in ChatView.
   */
  learnMore: 'Learn about AI in DevTools',
  /**
   *@description Header text for the AI-powered code suggestions disclaimer dialog.
   */
  freDisclaimerHeader: 'Get AI-powered code suggestions for your workspace',
  /**
   *@description First disclaimer item text for the fre dialog.
   */
  freDisclaimerTextAiWontAlwaysGetItRight: 'This feature uses AI and won’t always get it right',
  /**
   *@description Second disclaimer item text for the fre dialog.
   */
  freDisclaimerTextPrivacy: 'Source code from the selected folder is sent to Google to generate code suggestions',
  /**
   *@description Second disclaimer item text for the fre dialog when enterprise logging is off.
   */
  freDisclaimerTextPrivacyNoLogging:
      'Source code from the selected folder is sent to Google to generate code suggestions. This data will not be used to improve Google’s AI models.',
  /**
   *@description Third disclaimer item text for the fre dialog.
   */
  freDisclaimerTextUseWithCaution: 'Use generated code snippets with caution',
  /**
   * @description Title of the link opening data that was used to
   * produce a code suggestion.
   */
  viewUploadedFiles: 'View data sent to Google',
  /**
   * @description Text indicating that a link opens in a new tab (for a11y).
   */
  opensInNewTab: '(opens in a new tab)',
  /**
   * @description Generic error text for the case the changes were not applied to the workspace.
   */
  genericErrorMessage: 'Changes couldn’t be applied to your workspace.',
} as const;

const lockedString = i18n.i18n.lockedString;

const CODE_SNIPPET_WARNING_URL = 'https://support.google.com/legal/answer/13505487';

export enum PatchSuggestionState {
  /**
   * The user did not attempt patching yet
   */
  INITIAL = 'initial',
  /**
   * Applying to page tree is in progress
   */
  LOADING = 'loading',
  /**
   * Applying to page tree succeeded
   */
  SUCCESS = 'success',
  /**
   * Applying to page tree failed
   */
  ERROR = 'error',
}

enum SelectedProjectType {
  /**
   * No project selected
   */
  NONE = 'none',
  /**
   * The selected project is not an automatic workspace project
   */
  REGULAR = 'regular',
  /**
   * The selected project is a disconnected automatic workspace project
   */
  AUTOMATIC_DISCONNECTED = 'automaticDisconncted',
  /**
   * The selected project is a connected automatic workspace project
   */
  AUTOMATIC_CONNECTED = 'automaticConnected',
}

export interface ViewInput {
  workspaceDiff: WorkspaceDiff.WorkspaceDiff.WorkspaceDiffImpl;
  patchSuggestionState: PatchSuggestionState;
  changeSummary?: string;
  sources?: string;
  projectName: string;
  projectPath: Platform.DevToolsPath.RawPathString;
  projectType: SelectedProjectType;
  savedToDisk?: boolean;
  applyToWorkspaceTooltipText: Platform.UIString.LocalizedString;
  onLearnMoreTooltipClick: () => void;
  onApplyToWorkspace: () => void;
  onCancel: () => void;
  onDiscard: () => void;
  onSaveAll: () => void;
  onChangeWorkspaceClick?: () => void;
}

export interface ViewOutput {
  tooltipRef?: Directives.Ref<HTMLElement>;
  changeRef?: Directives.Ref<HTMLElement>;
  summaryRef?: Directives.Ref<HTMLElement>;
}

type View = (input: ViewInput, output: ViewOutput, target: HTMLElement) => void;

export class PatchWidget extends UI.Widget.Widget {
  changeSummary = '';
  changeManager: AiAssistanceModel.ChangeManager|undefined;
  // Whether the user completed first run experience dialog or not.
  #aiPatchingFreCompletedSetting =
      Common.Settings.Settings.instance().createSetting('ai-assistance-patching-fre-completed', false);
  #projectIdSetting =
      Common.Settings.Settings.instance().createSetting('ai-assistance-patching-selected-project-id', '');
  #view: View;
  #viewOutput: ViewOutput = {};
  #aidaClient: Host.AidaClient.AidaClient;
  #applyPatchAbortController?: AbortController;
  #project?: Workspace.Workspace.Project;
  #patchSources?: string;
  #savedToDisk?: boolean;
  #noLogging: boolean;  // Whether the enterprise setting is `ALLOW_WITHOUT_LOGGING` or not.
  #patchSuggestionState = PatchSuggestionState.INITIAL;
  #workspaceDiff = WorkspaceDiff.WorkspaceDiff.workspaceDiff();
  #workspace = Workspace.Workspace.WorkspaceImpl.instance();
  #automaticFileSystem =
      Persistence.AutomaticFileSystemManager.AutomaticFileSystemManager.instance().automaticFileSystem;
  #applyToDisconnectedAutomaticWorkspace = false;
  #popoverHelper: UI.PopoverHelper.PopoverHelper|null = null;
  // `rpcId` from the `applyPatch` request
  #rpcId: Host.AidaClient.RpcGlobalId|null = null;

  constructor(element?: HTMLElement, view?: View, opts?: {
    aidaClient: Host.AidaClient.AidaClient,
  }) {
    super(false, false, element);
    this.#aidaClient = opts?.aidaClient ?? new Host.AidaClient.AidaClient();
    this.#noLogging = Root.Runtime.hostConfig.aidaAvailability?.enterprisePolicyValue ===
        Root.Runtime.GenAiEnterprisePolicyValue.ALLOW_WITHOUT_LOGGING;

    // clang-format off
    this.#view = view ?? ((input, output, target) => {
      if (!input.changeSummary && input.patchSuggestionState === PatchSuggestionState.INITIAL) {
        return;
      }
      output.tooltipRef = output.tooltipRef ?? Directives.createRef<HTMLElement>();
      output.changeRef = output.changeRef ?? Directives.createRef<HTMLElement>();
      output.summaryRef = output.summaryRef ?? Directives.createRef<HTMLElement>();

      function renderSourcesLink(): LitTemplate {
        if (!input.sources) {
          return nothing;
        }

        return html`<x-link
          class="link"
          title="${UIStringsNotTranslate.viewUploadedFiles} ${UIStringsNotTranslate.opensInNewTab}"
          href="data:text/plain;charset=utf-8,${encodeURIComponent(input.sources)}"
          jslog=${VisualLogging.link('files-used-in-patching').track({click: true})}>
          ${UIStringsNotTranslate.viewUploadedFiles}
        </x-link>`;
      }

      function renderHeader(): LitTemplate {
        if (input.savedToDisk) {
          return html`
            <devtools-icon class="green-bright-icon summary-badge" .name=${'check-circle'}></devtools-icon>
            <span class="header-text">
              ${lockedString(UIStringsNotTranslate.savedToDisk)}
            </span>
          `;
        }

        if (input.patchSuggestionState === PatchSuggestionState.SUCCESS) {
          return html`
            <devtools-icon class="on-tonal-icon summary-badge" .name=${'difference'}></devtools-icon>
            <span class="header-text">
              ${lockedString(`File changes in ${input.projectName}`)}
            </span>
            <devtools-icon
              class="arrow"
              .name=${'chevron-down'}
            ></devtools-icon>
          `;
        }

        return html`
          <devtools-icon class="on-tonal-icon summary-badge" .name=${'pen-spark'}></devtools-icon>
          <span class="header-text">
            ${lockedString(UIStringsNotTranslate.unsavedChanges)}
          </span>
          <devtools-icon
            class="arrow"
            .name=${'chevron-down'}
          ></devtools-icon>
        `;
      }

      function renderContent(): LitTemplate {
        if ((!input.changeSummary && input.patchSuggestionState === PatchSuggestionState.INITIAL) || input.savedToDisk) {
          return nothing;
        }

        if (input.patchSuggestionState === PatchSuggestionState.SUCCESS) {
          return html`<devtools-widget .widgetConfig=${UI.Widget.widgetConfig(ChangesPanel.CombinedDiffView.CombinedDiffView, {
            workspaceDiff: input.workspaceDiff,
            // Ignore user creates inspector-stylesheets
            ignoredUrls: ['inspector://']
          })}></devtools-widget>`;
        }

        return html`<devtools-code-block
          .code=${input.changeSummary ?? ''}
          .codeLang=${'css'}
          .displayNotice=${true}
        ></devtools-code-block>
        ${input.patchSuggestionState === PatchSuggestionState.ERROR
          ? html`<div class="error-container">
              <devtools-icon .name=${'cross-circle-filled'}></devtools-icon>${
              lockedString(UIStringsNotTranslate.genericErrorMessage)
              } ${renderSourcesLink()}
            </div>`
          : nothing
        }`;
      }

      function renderFooter(): LitTemplate {
        if (input.savedToDisk) {
          return nothing;
        }

        if (input.patchSuggestionState === PatchSuggestionState.SUCCESS) {
          return html`
          <div class="footer">
            <div class="left-side">
              <x-link class="link disclaimer-link" href="https://support.google.com/legal/answer/13505487" jslog=${
                VisualLogging.link('code-disclaimer').track({
                  click: true,
                })}>
                ${lockedString(UIStringsNotTranslate.codeDisclaimer)}
              </x-link>
              ${renderSourcesLink()}
            </div>
            <div class="save-or-discard-buttons">
              <devtools-button
                @click=${input.onDiscard}
                .jslogContext=${'patch-widget.discard'}
                .variant=${Buttons.Button.Variant.OUTLINED}>
                  ${lockedString(UIStringsNotTranslate.discard)}
              </devtools-button>
              <devtools-button
                @click=${input.onSaveAll}
                .jslogContext=${'patch-widget.save-all'}
                .variant=${Buttons.Button.Variant.PRIMARY}>
                  ${lockedString(UIStringsNotTranslate.saveAll)}
              </devtools-button>
            </div>
          </div>
          `;
        }

        const iconName = input.projectType === SelectedProjectType.AUTOMATIC_DISCONNECTED ? 'folder-off' : input.projectType === SelectedProjectType.AUTOMATIC_CONNECTED ? 'folder-asterisk' : 'folder';
        return html`
        <div class="footer">
          ${input.projectName ? html`
            <div class="change-workspace" jslog=${VisualLogging.section('patch-widget.workspace')}>
                <devtools-icon .name=${iconName}></devtools-icon>
                <span class="folder-name" title=${input.projectPath}>${input.projectName}</span>
              ${input.onChangeWorkspaceClick ? html`
                <devtools-button
                  @click=${input.onChangeWorkspaceClick}
                  .jslogContext=${'change-workspace'}
                  .variant=${Buttons.Button.Variant.TEXT}
                  .title=${lockedString(UIStringsNotTranslate.changeRootFolder)}
                  .disabled=${input.patchSuggestionState === PatchSuggestionState.LOADING}
                  ${Directives.ref(output.changeRef)}
                >${lockedString(UIStringsNotTranslate.change)}</devtools-button>
              ` : nothing}
            </div>
          ` : nothing}
          <div class="apply-to-workspace-container" aria-live="polite">
            ${input.patchSuggestionState === PatchSuggestionState.LOADING ? html`
              <div class="loading-text-container" jslog=${VisualLogging.section('patch-widget.apply-to-workspace-loading')}>
                <devtools-spinner></devtools-spinner>
                <span>
                  ${lockedString(UIStringsNotTranslate.applyingToWorkspace)}
                </span>
              </div>
            ` : html`
                <devtools-button
                @click=${input.onApplyToWorkspace}
                .jslogContext=${'patch-widget.apply-to-workspace'}
                .variant=${Buttons.Button.Variant.OUTLINED}>
                ${lockedString(UIStringsNotTranslate.applyToWorkspace)}
              </devtools-button>
            `}
            ${input.patchSuggestionState === PatchSuggestionState.LOADING ? html`<devtools-button
              @click=${input.onCancel}
              .jslogContext=${'cancel'}
              .variant=${Buttons.Button.Variant.OUTLINED}>
              ${lockedString(UIStringsNotTranslate.cancel)}
            </devtools-button>` : nothing}
            <devtools-button
              aria-details="info-tooltip"
              .jslogContext=${'patch-widget.info-tooltip-trigger'}
              .iconName=${'info'}
              .variant=${Buttons.Button.Variant.ICON}
              .title=${input.applyToWorkspaceTooltipText}
            ></devtools-button>
          </div>
        </div>`;
      }

      // Use a simple div for the "Saved to disk" state as it's not expandable,
      // otherwise use the interactive <details> element.
      const template = input.savedToDisk
        ? html`
          <div class="change-summary saved-to-disk" role="status" aria-live="polite">
            <div class="header-container">
             ${renderHeader()}
             </div>
          </div>`
        : html`
          <details class="change-summary" jslog=${VisualLogging.section('patch-widget')}>
            <summary class="header-container" ${Directives.ref(output.summaryRef)}>
              ${renderHeader()}
            </summary>
            ${renderContent()}
            ${renderFooter()}
          </details>
        `;

      render(template, target, {host: target});
    });
    // We're using PopoverHelper as a workaround instead of using <devtools-tooltip>. See the bug for more details.
    // TODO: Update here when b/409965560 is fixed.
    this.#popoverHelper = new UI.PopoverHelper.PopoverHelper(this.contentElement, event => {
      // There are two ways this event is received for showing a popover case:
      // * The latest element on the composed path is `<devtools-button>`
      // * The 2nd element on the composed path is `<devtools-button>` (the last element is the `<button>` inside it.)
      const hoveredNode = event.composedPath()[0];
      const maybeDevToolsButton = event.composedPath()[2];

      const popoverShownNode = hoveredNode instanceof HTMLElement && hoveredNode.getAttribute('aria-details') === 'info-tooltip' ? hoveredNode
        : maybeDevToolsButton instanceof HTMLElement && maybeDevToolsButton.getAttribute('aria-details') === 'info-tooltip' ? maybeDevToolsButton
        : null;
      if (!popoverShownNode) {
        return null;
      }
      return {
        box: popoverShownNode.boxInWindow(),
        show: async (popover: UI.GlassPane.GlassPane) => {
          // clang-format off
          render(html`
            <style>
              .info-tooltip-container {
                max-width: var(--sys-size-28);
                padding: var(--sys-size-4) var(--sys-size-5);

                .tooltip-link {
                  display: block;
                  margin-top: var(--sys-size-4);
                  color: var(--sys-color-primary);
                  padding-left: 0;
                }
              }
            </style>
            <div class="info-tooltip-container">
              ${UIStringsNotTranslate.applyToWorkspaceTooltip}
              <button
                class="link tooltip-link"
                role="link"
                jslog=${VisualLogging.link('open-ai-settings').track({
                  click: true,
                })}
                @click=${this.#onLearnMoreTooltipClick}
              >${lockedString(UIStringsNotTranslate.learnMore)}</button>
            </div>`, popover.contentElement, {host: this});
          // clang-forat on
          return true;
        },
      };
    }, 'patch-widget.info-tooltip');
    this.#popoverHelper.setTimeout(0);
    // clang-format on
    this.requestUpdate();
  }

  #onLearnMoreTooltipClick(): void {
    this.#viewOutput.tooltipRef?.value?.hidePopover();
    void UI.ViewManager.ViewManager.instance().showView('chrome-ai');
  }

  #getDisplayedProject(): {projectName: string, projectPath: Platform.DevToolsPath.RawPathString} {
    if (this.#project) {
      return {
        projectName: Common.ParsedURL.ParsedURL.encodedPathToRawPathString(
            this.#project.displayName() as Platform.DevToolsPath.EncodedPathString),
        projectPath: Common.ParsedURL.ParsedURL.urlToRawPathString(
            this.#project.id() as Platform.DevToolsPath.UrlString, Host.Platform.isWin()),
      };
    }
    if (this.#automaticFileSystem) {
      return {
        projectName: Common.ParsedURL.ParsedURL.extractName(this.#automaticFileSystem.root),
        projectPath: this.#automaticFileSystem.root,
      };
    }
    return {
      projectName: '',
      projectPath: Platform.DevToolsPath.EmptyRawPathString,
    };
  }

  #shouldShowChangeButton(): boolean {
    const automaticFileSystemProject =
        this.#automaticFileSystem ? this.#workspace.projectForFileSystemRoot(this.#automaticFileSystem.root) : null;
    const regularProjects = this.#workspace.projectsForType(Workspace.Workspace.projectTypes.FileSystem)
                                .filter(
                                    project => project instanceof Persistence.FileSystemWorkspaceBinding.FileSystem &&
                                        project.fileSystem().type() ===
                                            Persistence.PlatformFileSystem.PlatformFileSystemType.WORKSPACE_PROJECT)
                                .filter(project => project !== automaticFileSystemProject);
    return regularProjects.length > 0;
  }

  #getSelectedProjectType(projectPath: Platform.DevToolsPath.RawPathString): SelectedProjectType {
    if (this.#automaticFileSystem && this.#automaticFileSystem.root === projectPath) {
      return this.#project ? SelectedProjectType.AUTOMATIC_CONNECTED : SelectedProjectType.AUTOMATIC_DISCONNECTED;
    }
    return this.#project ? SelectedProjectType.NONE : SelectedProjectType.REGULAR;
  }

  override performUpdate(): void {
    const {projectName, projectPath} = this.#getDisplayedProject();

    this.#view(
        {
          workspaceDiff: this.#workspaceDiff,
          changeSummary: this.changeSummary,
          patchSuggestionState: this.#patchSuggestionState,
          sources: this.#patchSources,
          projectName,
          projectPath,
          projectType: this.#getSelectedProjectType(projectPath),
          savedToDisk: this.#savedToDisk,
          applyToWorkspaceTooltipText: this.#noLogging ?
              lockedString(UIStringsNotTranslate.applyToWorkspaceTooltipNoLogging) :
              lockedString(UIStringsNotTranslate.applyToWorkspaceTooltip),
          onLearnMoreTooltipClick: this.#onLearnMoreTooltipClick.bind(this),
          onApplyToWorkspace: this.#onApplyToWorkspace.bind(this),
          onCancel: () => {
            this.#applyPatchAbortController?.abort();
          },
          onDiscard: this.#onDiscard.bind(this),
          onSaveAll: this.#onSaveAll.bind(this),
          onChangeWorkspaceClick: this.#shouldShowChangeButton() ?
              this.#showSelectWorkspaceDialog.bind(this, {applyPatch: false}) :
              undefined,
        },
        this.#viewOutput, this.contentElement);
  }

  override wasShown(): void {
    super.wasShown();
    this.#selectDefaultProject();

    if (isAiAssistancePatchingEnabled()) {
      this.#workspace.addEventListener(Workspace.Workspace.Events.ProjectAdded, this.#onProjectAdded, this);
      this.#workspace.addEventListener(Workspace.Workspace.Events.ProjectRemoved, this.#onProjectRemoved, this);
    }
  }

  override willHide(): void {
    this.#applyToDisconnectedAutomaticWorkspace = false;
    if (isAiAssistancePatchingEnabled()) {
      this.#workspace.removeEventListener(Workspace.Workspace.Events.ProjectAdded, this.#onProjectAdded, this);
      this.#workspace.removeEventListener(Workspace.Workspace.Events.ProjectRemoved, this.#onProjectRemoved, this);
    }
  }

  async #showFreDisclaimerIfNeeded(): Promise<boolean> {
    const isAiPatchingFreCompleted = this.#aiPatchingFreCompletedSetting.get();
    if (isAiPatchingFreCompleted) {
      return true;
    }

    const result = await PanelCommon.FreDialog.show({
      header: {iconName: 'smart-assistant', text: lockedString(UIStringsNotTranslate.freDisclaimerHeader)},
      reminderItems: [
        {
          iconName: 'psychiatry',
          content: lockedString(UIStringsNotTranslate.freDisclaimerTextAiWontAlwaysGetItRight),
        },
        {
          iconName: 'google',
          content: this.#noLogging ? lockedString(UIStringsNotTranslate.freDisclaimerTextPrivacyNoLogging) :
                                     lockedString(UIStringsNotTranslate.freDisclaimerTextPrivacy),
        },
        {
          iconName: 'warning',
          // clang-format off
          content: html`<x-link
            href=${CODE_SNIPPET_WARNING_URL}
            class="link devtools-link"
            jslog=${VisualLogging.link('code-snippets-explainer.patch-widget').track({
              click: true
            })}
          >${lockedString(UIStringsNotTranslate.freDisclaimerTextUseWithCaution)}</x-link>`,
          // clang-format on
        }
      ],
      onLearnMoreClick: () => {
        void UI.ViewManager.ViewManager.instance().showView('chrome-ai');
      },
      ariaLabel: lockedString(UIStringsNotTranslate.freDisclaimerHeader),
      learnMoreButtonTitle: lockedString(UIStringsNotTranslate.learnMore),
    });

    if (result) {
      this.#aiPatchingFreCompletedSetting.set(true);
    }
    return result;
  }

  #selectDefaultProject(): void {
    const project = this.#automaticFileSystem ?
        this.#workspace.projectForFileSystemRoot(this.#automaticFileSystem.root) :
        this.#workspace.project(this.#projectIdSetting.get());
    if (project) {
      this.#project = project;
    } else {
      this.#project = undefined;
      this.#projectIdSetting.set('');
    }
    this.requestUpdate();
  }

  #onProjectAdded(event: Common.EventTarget.EventTargetEvent<Workspace.Workspace.Project>): void {
    const addedProject = event.data;
    if (this.#applyToDisconnectedAutomaticWorkspace && this.#automaticFileSystem &&
        addedProject === this.#workspace.projectForFileSystemRoot(this.#automaticFileSystem.root)) {
      this.#applyToDisconnectedAutomaticWorkspace = false;
      this.#project = addedProject;
      void this.#applyPatchAndUpdateUI();
    } else if (this.#project === undefined) {
      this.#selectDefaultProject();
    }
  }

  #onProjectRemoved(): void {
    if (this.#project && !this.#workspace.project(this.#project.id())) {
      this.#projectIdSetting.set('');
      this.#project = undefined;
      this.requestUpdate();
    }
  }

  #showSelectWorkspaceDialog(options: {applyPatch: boolean} = {applyPatch: false}): void {
    const onProjectSelected = (project: Workspace.Workspace.Project): void => {
      this.#project = project;
      this.#projectIdSetting.set(project.id());
      if (options.applyPatch) {
        void this.#applyPatchAndUpdateUI();
      } else {
        this.requestUpdate();
        void this.updateComplete.then(() => {
          this.contentElement?.querySelector('.apply-to-workspace-container devtools-button')
              ?.shadowRoot?.querySelector('button')
              ?.focus();
        });
      }
    };

    SelectWorkspaceDialog.show(onProjectSelected, this.#project);
  }

  async #onApplyToWorkspace(): Promise<void> {
    if (!isAiAssistancePatchingEnabled()) {
      return;
    }

    // Show the FRE dialog if needed and only continue when
    // the user accepted the disclaimer.
    const freDisclaimerCompleted = await this.#showFreDisclaimerIfNeeded();
    if (!freDisclaimerCompleted) {
      return;
    }

    if (this.#project) {
      await this.#applyPatchAndUpdateUI();
    } else if (this.#automaticFileSystem) {
      this.#applyToDisconnectedAutomaticWorkspace = true;
      await Persistence.AutomaticFileSystemManager.AutomaticFileSystemManager.instance().connectAutomaticFileSystem(
          /* addIfMissing= */ true);
    } else {
      this.#showSelectWorkspaceDialog({applyPatch: true});
    }
  }

  /**
   * The modified files excluding inspector stylesheets
   */
  get #modifiedFiles(): Workspace.UISourceCode.UISourceCode[] {
    return this.#workspaceDiff.modifiedUISourceCodes().filter(modifiedUISourceCode => {
      return !modifiedUISourceCode.url().startsWith('inspector://');
    });
  }

  async #applyPatchAndUpdateUI(): Promise<void> {
    const changeSummary = this.changeSummary;
    if (!changeSummary) {
      throw new Error('Change summary does not exist');
    }

    this.#patchSuggestionState = PatchSuggestionState.LOADING;
    this.#rpcId = null;
    this.requestUpdate();
    const {response, processedFiles} = await this.#applyPatch(changeSummary);
    if (response && 'rpcId' in response && response.rpcId) {
      this.#rpcId = response.rpcId;
    }

    // Determines if applying the patch resulted in any actual file changes in the workspace.
    // This is crucial because the agent might return an answer (e.g., an explanation)
    // without making any code modifications (i.e., no `writeFile` calls).
    // If no files were modified, we avoid transitioning to a success state,
    // which would otherwise lead to an empty and potentially confusing diff view.
    //
    // Note: The `hasChanges` check below is based on `modifiedUISourceCodes()`, which reflects
    // *all* current modifications in the workspace. It does not differentiate between
    // changes made by this specific AI patch operation versus pre-existing changes
    // made by the user. Consequently, if the AI patch itself makes no changes but the
    // user already had other modified files, the widget will still transition to the
    // success state (displaying all current workspace modifications).
    const hasChanges = this.#modifiedFiles.length > 0;
    if (response?.type === AiAssistanceModel.ResponseType.ANSWER && hasChanges) {
      this.#patchSuggestionState = PatchSuggestionState.SUCCESS;
    } else if (
        response?.type === AiAssistanceModel.ResponseType.ERROR &&
        response.error === AiAssistanceModel.ErrorType.ABORT) {
      // If this is an abort error, we're returning back to the initial state.
      this.#patchSuggestionState = PatchSuggestionState.INITIAL;
    } else {
      this.#patchSuggestionState = PatchSuggestionState.ERROR;
    }
    this.#patchSources = `Filenames in ${this.#project?.displayName()}.
Files:
${processedFiles.map(filename => `* ${filename}`).join('\n')}`;
    this.requestUpdate();

    if (this.#patchSuggestionState === PatchSuggestionState.SUCCESS) {
      void this.updateComplete.then(() => {
        this.#viewOutput.summaryRef?.value?.focus();
      });
    }
  }

  #onDiscard(): void {
    for (const modifiedUISourceCode of this.#modifiedFiles) {
      modifiedUISourceCode.resetWorkingCopy();
    }

    this.#patchSuggestionState = PatchSuggestionState.INITIAL;
    this.#patchSources = undefined;
    void this.changeManager?.popStashedChanges();
    this.#submitRating(Host.AidaClient.Rating.NEGATIVE);
    this.requestUpdate();
    void this.updateComplete.then(() => {
      this.#viewOutput.changeRef?.value?.focus();
    });
  }

  #onSaveAll(): void {
    for (const modifiedUISourceCode of this.#modifiedFiles) {
      modifiedUISourceCode.commitWorkingCopy();
    }
    void this.changeManager?.stashChanges().then(() => {
      this.changeManager?.dropStashedChanges();
    });

    this.#savedToDisk = true;
    this.#submitRating(Host.AidaClient.Rating.POSITIVE);
    this.requestUpdate();
  }

  #submitRating(rating: Host.AidaClient.Rating): void {
    if (!this.#rpcId) {
      return;
    }

    void this.#aidaClient.registerClientEvent({
      corresponding_aida_rpc_global_id: this.#rpcId,
      disable_user_content_logging: true,
      do_conversation_client_event: {
        user_feedback: {
          sentiment: rating,
        },
      },
    });
  }

  async #applyPatch(changeSummary: string): Promise<{
    response: AiAssistanceModel.ResponseData | undefined,
    processedFiles: string[],
  }> {
    if (!this.#project) {
      throw new Error('Project does not exist');
    }
    this.#applyPatchAbortController = new AbortController();
    const agent = new AiAssistanceModel.PatchAgent({
      aidaClient: this.#aidaClient,
      serverSideLoggingEnabled: false,
      project: this.#project,
    });
    const {responses, processedFiles} =
        await agent.applyChanges(changeSummary, {signal: this.#applyPatchAbortController.signal});
    return {
      response: responses.at(-1),
      processedFiles,
    };
  }
}

export function isAiAssistancePatchingEnabled(): boolean {
  return Boolean(Root.Runtime.hostConfig.devToolsFreestyler?.patching);
}

interface ExpectedChange {
  path: string;
  matches: string[];
  doesNotMatch?: string[];
}

// @ts-expect-error temporary global function for local testing.
window.aiAssistanceTestPatchPrompt =
    async (projectName: string, changeSummary: string, expectedChanges: ExpectedChange[]) => {
  if (!isAiAssistancePatchingEnabled()) {
    return;
  }
  const workspaceDiff = WorkspaceDiff.WorkspaceDiff.workspaceDiff();
  const workspace = Workspace.Workspace.WorkspaceImpl.instance();
  const project = workspace.projectsForType(Workspace.Workspace.projectTypes.FileSystem)
                      .filter(
                          project => project instanceof Persistence.FileSystemWorkspaceBinding.FileSystem &&
                              project.fileSystem().type() ===
                                  Persistence.PlatformFileSystem.PlatformFileSystemType.WORKSPACE_PROJECT)
                      .find(project => project.displayName() === projectName);

  if (!project) {
    throw new Error('project not found');
  }
  const aidaClient = new Host.AidaClient.AidaClient();
  const agent = new AiAssistanceModel.PatchAgent({
    aidaClient,
    serverSideLoggingEnabled: false,
    project,
  });
  try {
    const assertionFailures = [];
    const {processedFiles, responses} = await agent.applyChanges(changeSummary);
    if (responses.at(-1)?.type === AiAssistanceModel.ResponseType.ERROR) {
      return {
        error: 'failed to patch',
        debugInfo: {
          responses,
          processedFiles,
        },
      };
    }
    for (const file of processedFiles) {
      const change = expectedChanges.find(change => change.path === file);
      if (!change) {
        assertionFailures.push(`Patched ${file} that was not expected`);
        break;
      }
      const agentProject = agent.agentProject;
      const content = await agentProject.readFile(file);
      if (!content) {
        throw new Error(`${file} has no content`);
      }
      for (const m of change.matches) {
        if (!content.match(new RegExp(m, 'gm'))) {
          assertionFailures.push({
            message: `Did not match ${m} in ${file}`,
            file,
            content,
          });
        }
      }
      for (const m of change.doesNotMatch || []) {
        if (content.match(new RegExp(m, 'gm'))) {
          assertionFailures.push({
            message: `Unexpectedly matched ${m} in ${file}`,
            file,
            content,
          });
        }
      }
    }
    return {
      assertionFailures,
      debugInfo: {
        responses,
        processedFiles,
      },
    };
  } finally {
    workspaceDiff.modifiedUISourceCodes().forEach(modifiedUISourceCode => {
      modifiedUISourceCode.resetWorkingCopy();
    });
  }
};