// Copyright 2026 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/* eslint-disable @devtools/no-imperative-dom-api */

import '../../core/sdk/sdk-meta.js';
import '../../models/workspace/workspace-meta.js';
import '../../panels/sensors/sensors-meta.js';
import '../../entrypoints/inspector_main/inspector_main-meta.js';
import '../../entrypoints/main/main-meta.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 type * as Platform from '../../core/platform/platform.js';
import type * as ExperimentNames from '../../core/root/ExperimentNames.js';
import * as Root from '../../core/root/root.js';
import * as SDK from '../../core/sdk/sdk.js';
import * as Foundation from '../../foundation/foundation.js';
import type * as Protocol from '../../generated/protocol.js';
import * as AiAssistance from '../../models/ai_assistance/ai_assistance.js';
import type {SyncMessage} from '../../panels/greendev/GreenDevShared.js';
import * as UI from '../../ui/legacy/legacy.js';
import * as ThemeSupport from '../../ui/legacy/theme_support/theme_support.js';

const {AidaClient} = Host.AidaClient;
const {ResponseType} = AiAssistance.AiAgent;

let pendingActivationSessionId: number|null = null;

class GreenDevFloaty {
  #chatContainer!: HTMLDivElement;
  #textField!: HTMLInputElement;
  #playButton!: HTMLButtonElement;
  #node?: SDK.DOMModel.DOMNode;
  #agent?: AiAssistance.StylingAgent.StylingAgent;
  #nodeContext?: AiAssistance.StylingAgent.NodeContext;
  #backendNodeId?: Protocol.DOM.BackendNodeId;
  #syncChannel: BroadcastChannel;
  #isFloatyWindow: boolean;

  constructor(document: Document) {
    const params = new URLSearchParams(window.location.hash.substring(1));
    this.#backendNodeId = parseInt(params.get('backendNodeId') || '0', 10) as Protocol.DOM.BackendNodeId;
    this.#isFloatyWindow = !!this.#backendNodeId;

    this.#syncChannel = new BroadcastChannel('green-dev-sync');
    this.#syncChannel.onmessage = event => {
      this.#onSyncMessage(event.data);
    };

    this.#initFloatyMode(document);
  }

  #initFloatyMode(doc: Document): void {
    this.#chatContainer = doc.getElementById('chat-container') as HTMLDivElement;
    this.#textField = doc.querySelector('.green-dev-floaty-dialog-text-field') as HTMLInputElement;
    this.#playButton = doc.querySelector('.green-dev-floaty-dialog-play-button') as HTMLButtonElement;

    this.#playButton?.addEventListener('click', () => {
      if (this.#node) {
        void this.runConversation();
      }
    });

    const contextText = doc.querySelector('.green-dev-floaty-dialog-context-text') as HTMLSpanElement;
    if (contextText) {
      contextText.style.cursor = 'pointer';
      contextText.title = 'Click to show in DevTools Panel';
      contextText.addEventListener('click', () => {
        this.#broadcastFullState();
      });
    }

    const learnMoreLink = doc.querySelector('.learn-more-link');
    if (learnMoreLink) {
      learnMoreLink.addEventListener('click', event => {
        event.preventDefault();
        Host.InspectorFrontendHost.InspectorFrontendHostInstance.openInNewTab(
            'https://developer.chrome.com/docs/devtools/ai-assistance' as Platform.DevToolsPath.UrlString);
      });
    }

    const nodeDescriptionElement = doc.querySelector('.green-dev-floaty-dialog-node-description') as HTMLDivElement;
    nodeDescriptionElement?.addEventListener('mousemove', () => {
      if (this.#node) {
        this.#node.highlight();
      }
    });
    nodeDescriptionElement?.addEventListener('mouseleave', () => {
      if (this.#node && this.#backendNodeId) {
        const msg = JSON.stringify({
          id: 9999,
          method: 'Overlay.setShowInspectedElementAnchor',
          params: {inspectedElementAnchorConfig: {backendNodeId: this.#backendNodeId}}
        });
        Host.InspectorFrontendHost.InspectorFrontendHostInstance.sendMessageToBackend(msg);
      }
    });

    this.#textField?.addEventListener('keydown', event => {
      if (event.key === 'Enter' && this.#node) {
        void this.runConversation();
      }
    });

    this.#textField?.focus();
  }

  #broadcastFullState(): void {
    const state = {
      type: 'full-state',
      messages: this.#getMessages(),
      sessionId: this.#backendNodeId,
      nodeDescription: document.querySelector('.green-dev-floaty-dialog-node-description')?.textContent
    };
    this.#syncChannel.postMessage(state);
  }

  #onSyncMessage(data: SyncMessage): void {
    if (data.type === 'main-window-alive') {
      if (pendingActivationSessionId) {
        const syncChannel = new BroadcastChannel('green-dev-sync');
        syncChannel.postMessage({type: 'activate-panel', sessionId: pendingActivationSessionId});
        syncChannel.close();
      }
    } else if (data.type === 'request-session-state') {
      this.#broadcastFullState();

      if (pendingActivationSessionId) {
        this.#syncChannel.postMessage({type: 'select-tab', sessionId: pendingActivationSessionId});
        pendingActivationSessionId = null;
      }
    } else if (data.type === 'user-input' && data.sessionId === this.#backendNodeId) {
      if (this.#textField) {
        this.#textField.value = data.text ?? '';
        void this.runConversation();
      }
    } else if (data.type === 'restore-floaty' && data.sessionId === this.#backendNodeId) {
      // The main DevTools window will bring the floaty to the front,
      // so the floaty window itself doesn't need to do it.
      Host.InspectorFrontendHost.InspectorFrontendHostInstance.bringToFront();
    }
  }

  static instance(opts: {
    forceNew: boolean|null,
    document: Document,
  } = {forceNew: null, document}): GreenDevFloaty {
    const {forceNew, document} = opts;
    if (!greenDevFloatyInstance || forceNew) {
      greenDevFloatyInstance = new GreenDevFloaty(document);
    }
    return greenDevFloatyInstance;
  }

  handlePanelRequest = (event: Common.EventTarget.EventTargetEvent<number>): void => {
    pendingActivationSessionId = event.data;
    this.#sendActivatePanelMessage(pendingActivationSessionId, 0);
    Host.InspectorFrontendHost.InspectorFrontendHostInstance.openInNewTab(
        'magic:open-devtools' as Platform.DevToolsPath.UrlString);
  };

  readonly #maxActivationRetries = 10;
  readonly #activationRetryDelayMs = 200;

  #sendActivatePanelMessage(sessionId: number, retryCount: number): void {
    if (retryCount >= this.#maxActivationRetries) {
      return;
    }

    const syncChannel = new BroadcastChannel('green-dev-sync');
    syncChannel.postMessage({type: 'activate-panel', sessionId});
    syncChannel.close();

    // To ensure the activate-panel is always received, let's add a small delay and retry.
    // This is a pragmatic fix for the prototype given the existing async message flow.
    setTimeout(() => {
      // Check if pendingActivationSessionId is still set. If it is, it means
      // the panel hasn't been activated yet (or the confirmation message
      // hasn't arrived), so we retry.
      if (pendingActivationSessionId === sessionId) {
        this.#sendActivatePanelMessage(sessionId, retryCount + 1);
      }
    }, this.#activationRetryDelayMs);
  }

  handleRestoreEvent(event: Common.EventTarget.EventTargetEvent<number>): void {
    const sessionId = event.data;
    // Only the main DevTools window (which is NOT a floaty window) should broadcast the restore request.
    if (!this.#isFloatyWindow) {
      this.#syncChannel.postMessage({type: 'restore-floaty', sessionId});
    } else if (this.#backendNodeId === sessionId) {
      // If a floaty window receives a restore request for its own session,
      // it should bring itself to the front.
      console.error('[GreenDev] Calling bringToFront for session ' + sessionId);
      Host.InspectorFrontendHost.InspectorFrontendHostInstance.bringToFront();
    }
  }

  setNode(node: SDK.DOMModel.DOMNode): void {
    if (this.#node) {
      this.#node.domModel().overlayModel().removeEventListener(
          SDK.OverlayModel.Events.INSPECT_PANEL_SHOW_REQUESTED, this.handlePanelRequest);
    }
    if (this.#node === node) {
      return;
    }
    this.#node = node;
    this.#node.domModel().overlayModel().addEventListener(
        SDK.OverlayModel.Events.INSPECT_PANEL_SHOW_REQUESTED, this.handlePanelRequest);
    this.#backendNodeId = node.backendNodeId();

    void node.domModel().overlayModel().clearHighlight();
    this.#textField?.focus();
    this.#agent = undefined;
    this.#nodeContext = undefined;

    const nodeDescriptionElement = document.querySelector('.green-dev-floaty-dialog-node-description');
    let description = '';
    if (nodeDescriptionElement) {
      const id = node.getAttribute('id');
      if (id) {
        description = `#${id}`;
      } else {
        const classes = node.classNames().join('.');
        description = node.nodeName().toLowerCase() + (classes ? `.${classes}` : '');
      }
      nodeDescriptionElement.textContent = description;
    }

    this.#syncChannel.postMessage({type: 'node-changed', sessionId: this.#backendNodeId, nodeDescription: description});

    if (this.#backendNodeId) {
      const msg = JSON.stringify({
        id: 9999,
        method: 'Overlay.setShowInspectedElementAnchor',
        params: {inspectedElementAnchorConfig: {backendNodeId: this.#backendNodeId}}
      });
      Host.InspectorFrontendHost.InspectorFrontendHostInstance.sendMessageToBackend(msg);
    }
  }

  #getMessages(): Array<{text: string, isUser: boolean}> {
    const messages = [];
    if (this.#chatContainer) {
      const messageElements = this.#chatContainer.querySelectorAll('.message');
      for (const el of messageElements) {
        const isUser = el.classList.contains('user-message');
        const content = el.querySelector('.message-content')?.textContent || '';
        messages.push({text: content, isUser});
      }
    }
    return messages;
  }

  #formatError(errorMessage: string): string {
    return `Error: '${errorMessage}' - Protip: to use AI features you need to be signed in.`;
  }

  runConversation = async(): Promise<void> => {
    if (!this.#textField || !this.#node) {
      return;
    }
    const query = this.#textField.value || this.#textField.placeholder;
    this.#textField.value = '';

    if (!this.#agent) {
      const aidaClient = new AidaClient();
      this.#agent = new AiAssistance.StylingAgent.StylingAgent({aidaClient});
      this.#nodeContext = new AiAssistance.StylingAgent.NodeContext(this.#node);
    }

    this.#addMessageInternal(query, true);
    this.#syncChannel.postMessage({
      type: 'new-message',
      text: query,
      isUser: true,
      sessionId: this.#backendNodeId,
      nodeDescription: document.querySelector('.green-dev-floaty-dialog-node-description')?.textContent,
    });

    const aiContent = this.#addMessageInternal('Thinking...', false);
    this.#syncChannel.postMessage({
      type: 'new-message',
      text: 'Thinking...',
      isUser: false,
      sessionId: this.#backendNodeId,
      nodeDescription: document.querySelector('.green-dev-floaty-dialog-node-description')?.textContent,
    });

    try {
      if (!this.#nodeContext) {
        throw new Error('Node context not found.');
      }
      for await (const result of this.#agent.run(query, {selected: this.#nodeContext})) {
        switch (result.type) {
          case ResponseType.ANSWER:
            aiContent.textContent = result.text;
            this.#syncChannel.postMessage(
                {type: 'update-last-message', text: result.text, sessionId: this.#backendNodeId});
            break;
          case ResponseType.ERROR:
            aiContent.textContent = this.#formatError(result.error);
            this.#syncChannel.postMessage(
                {type: 'update-last-message', text: this.#formatError(result.error), sessionId: this.#backendNodeId});
            break;
          case ResponseType.SIDE_EFFECT:
            result.confirm(true);
            break;
          default:
            break;
        }
        if (this.#chatContainer) {
          this.#chatContainer.scrollTop = this.#chatContainer.scrollHeight;
        }
      }
    } catch (e) {
      aiContent.textContent = `Exception: ${e instanceof Error ? e.message : String(e)}`;
    }
  };

  #addMessageInternal(text: string, isUser: boolean): HTMLDivElement {
    const messageElement = document.createElement('div');
    messageElement.className = `message ${isUser ? 'user-message' : 'ai-message'}`;

    const content = document.createElement('div');
    content.className = 'message-content';
    content.textContent = text;
    messageElement.appendChild(content);

    if (this.#chatContainer) {
      this.#chatContainer.appendChild(messageElement);
      this.#chatContainer.scrollTop = this.#chatContainer.scrollHeight;
    }
    return content;
  }
}

let greenDevFloatyInstance: GreenDevFloaty;

function safeRegisterExperiment(name: string, title: string): void {
  try {
    Root.Runtime.experiments.register(name as ExperimentNames.ExperimentName, title);
  } catch (e) {
    console.error('Unable to register experiment ', name, title, e);
  }
}

async function init(): Promise<void> {
  try {
    Root.Runtime.Runtime.setPlatform(Host.Platform.platform());
    const [config, prefs] = await Promise.all([
      new Promise<Root.Runtime.HostConfig>(
          resolve => Host.InspectorFrontendHost.InspectorFrontendHostInstance.getHostConfig(resolve)),
      new Promise<Record<string, string>>(
          resolve => Host.InspectorFrontendHost.InspectorFrontendHostInstance.getPreferences(resolve)),
    ]);
    Object.assign(Root.Runtime.hostConfig, config);

    safeRegisterExperiment(
        Root.ExperimentNames.ExperimentName.CAPTURE_NODE_CREATION_STACKS, 'Capture node creation stacks');
    safeRegisterExperiment(
        Root.ExperimentNames.ExperimentName.INSTRUMENTATION_BREAKPOINTS, 'Enable instrumentation breakpoints');
    safeRegisterExperiment(
        Root.ExperimentNames.ExperimentName.USE_SOURCE_MAP_SCOPES, 'Use scope information from source maps');
    safeRegisterExperiment(Root.ExperimentNames.ExperimentName.LIVE_HEAP_PROFILE, 'Live heap profile');
    safeRegisterExperiment(Root.ExperimentNames.ExperimentName.PROTOCOL_MONITOR, 'Protocol Monitor');
    safeRegisterExperiment(
        Root.ExperimentNames.ExperimentName.SAMPLING_HEAP_PROFILER_TIMELINE, 'Sampling heap profiler timeline');

    const hostUnsyncedStorage: Common.Settings.SettingsBackingStore = {
      register: (name: string) =>
          Host.InspectorFrontendHost.InspectorFrontendHostInstance.registerPreference(name, {synced: false}),
      set: Host.InspectorFrontendHost.InspectorFrontendHostInstance.setPreference,
      get: (name: string) =>
          new Promise(resolve => Host.InspectorFrontendHost.InspectorFrontendHostInstance.getPreference(name, resolve)),
      remove: Host.InspectorFrontendHost.InspectorFrontendHostInstance.removePreference,
      clear: Host.InspectorFrontendHost.InspectorFrontendHostInstance.clearPreferences,
    };
    const syncedStorage = new Common.Settings.SettingsStorage(prefs, hostUnsyncedStorage, '');
    const globalStorage = new Common.Settings.SettingsStorage(prefs, hostUnsyncedStorage, '');
    const localStorage = new Common.Settings.SettingsStorage(
        window.localStorage, {
          register(_setting: string): void{},
          async get(setting: string): Promise<string> {
            return window.localStorage.getItem(setting) as unknown as string;
          },
          set(setting: string, value: string): void {
            window.localStorage.setItem(setting, value);
          },
          remove(setting: string): void {
            window.localStorage.removeItem(setting);
          },
          clear: () => window.localStorage.clear(),
        },
        '');

    Common.Settings.Settings.instance({
      forceNew: true,
      syncedStorage,
      globalStorage,
      localStorage,
      settingRegistrations: Common.SettingRegistration.getRegisteredSettings(),
    });

    UI.UIUtils.initializeUIUtils(document);
    ThemeSupport.ThemeSupport.instance({
      forceNew: true,
      setting: Common.Settings.Settings.instance().moduleSetting('ui-theme'),
    });
    UI.ZoomManager.ZoomManager.instance(
        {forceNew: true, win: window, frontendHost: Host.InspectorFrontendHost.InspectorFrontendHostInstance});

    const settingLanguage = Common.Settings.Settings.instance().moduleSetting<string>('language').get();
    i18n.DevToolsLocale.DevToolsLocale.instance({
      create: true,
      data: {
        navigatorLanguage: navigator.language,
        settingLanguage,
        lookupClosestDevToolsLocale: i18n.i18n.lookupClosestSupportedDevToolsLocale,
      },
    });

    const universe = new Foundation.Universe.Universe({
      settingsCreationOptions: {
        syncedStorage,
        globalStorage,
        localStorage,
        settingRegistrations: Common.SettingRegistration.getRegisteredSettings(),
      }
    });
    Root.DevToolsContext.setGlobalInstance(universe.context as Root.DevToolsContext.WritableDevToolsContext);

    await i18n.i18n.fetchAndRegisterLocaleData('en-US');
    Host.InspectorFrontendHost.InspectorFrontendHostInstance.connectionReady();

    const hash = window.location.hash.substring(1);
    const params = new URLSearchParams(hash);
    const backendNodeId = parseInt(params.get('backendNodeId') || '0', 10);

    const floaty = GreenDevFloaty.instance({forceNew: null, document});

    if (backendNodeId) {
      await SDK.Connections.initMainConnection(async () => {
        const targetManager = SDK.TargetManager.TargetManager.instance();
        targetManager.createTarget('main', 'Main', SDK.Target.Type.FRAME, null);
        const mainTarget = await new Promise<SDK.Target.Target|null>(resolve => {
          const t = targetManager.primaryPageTarget();
          if (t) {
            resolve(t);
            return;
          }
          const observer = {
            targetAdded: (target: SDK.Target.Target) => {
              if (target === targetManager.primaryPageTarget()) {
                targetManager.unobserveTargets(observer);
                resolve(target);
              }
            },
            targetRemoved: () => {},
          };
          targetManager.observeTargets(observer);
        });
        if (!mainTarget) {
          return;
        }
        const domModel = mainTarget.model(SDK.DOMModel.DOMModel);
        if (!domModel) {
          return;
        }

        // Add listener for floaty restore events
        const overlayModel = mainTarget.model(SDK.OverlayModel.OverlayModel);
        if (overlayModel) {
          overlayModel.addEventListener(
              SDK.OverlayModel.Events.INSPECTED_ELEMENT_WINDOW_RESTORED, floaty.handleRestoreEvent, floaty);
        }

        const nodesMap =
            await domModel.pushNodesByBackendIdsToFrontend(new Set([backendNodeId as Protocol.DOM.BackendNodeId]));
        const node = nodesMap?.get(backendNodeId as Protocol.DOM.BackendNodeId) || null;
        if (node) {
          floaty.setNode(node);
        }
      }, () => {});
    } else {
      const targetManager = SDK.TargetManager.TargetManager.instance();
      const observer = {
        targetAdded: (target: SDK.Target.Target) => {
          if (target.type() === SDK.Target.Type.FRAME) {
            const overlayModel = target.model(SDK.OverlayModel.OverlayModel);
            if (overlayModel) {
              overlayModel.addEventListener(
                  SDK.OverlayModel.Events.INSPECTED_ELEMENT_WINDOW_RESTORED, floaty.handleRestoreEvent, floaty);
              overlayModel.addEventListener(
                  SDK.OverlayModel.Events.INSPECT_PANEL_SHOW_REQUESTED, floaty.handlePanelRequest);
            }
          }
        },
        targetRemoved: (target: SDK.Target.Target) => {
          if (target.type() === SDK.Target.Type.FRAME) {
            const overlayModel = target.model(SDK.OverlayModel.OverlayModel);
            if (overlayModel) {
              overlayModel.removeEventListener(
                  SDK.OverlayModel.Events.INSPECTED_ELEMENT_WINDOW_RESTORED, floaty.handleRestoreEvent, floaty);
              overlayModel.removeEventListener(
                  SDK.OverlayModel.Events.INSPECT_PANEL_SHOW_REQUESTED, floaty.handlePanelRequest);
            }
          }
        },
      };
      targetManager.observeTargets(observer);
    }
  } catch (err) {
    console.error('[GreenDev] FATAL ERROR during init():', err);
  }
}

void init();