// 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.

import * as Common from '../../core/common/common.js';
import * as Host from '../../core/host/host.js';

export interface EditorAnchorSignature {
  /** 1-based line number for CodeMirror text editor anchors */
  lineNumber: number;
  /** File path associated with the editor */
  filePath?: string;
}

export interface DOMNodeAnchorSignature {
  /** Backend NodeId for DOM nodes (`data-backend-node-id`) */
  backendNodeId: number;
  /** Target ID associated with the DOM node (`data-target-id`) */
  targetId: string;
}

export interface TimelineAnchorSignature {
  /** Identifier of the trace to scope comments to a specific recording */
  traceId: string;
  /**
   * Serializable key from Trace.EventsSerializer (e.g. 'r-123', 'p-1-2-3-4', 's-5'), or
   * 'fc-<chartLocation>-<entryIndex>' for flame chart entries that EventsSerializer cannot key.
   */
  traceEventKey: string;
  /** Primary event title or category name */
  entryName: string;
  /** Event start timestamp in microseconds */
  startTimeMicro: number;
  /** Chart location */
  chartLocation: 'main'|'network';
  /** Event duration in microseconds (omitted for instant markers) */
  durationMicro?: number;
}

export interface CommentAnchorSignature {
  /** Visual logging tree path, e.g. "Panel: elements > Pane: styles > TreeOutline > TreeItem: color" */
  vePath: string;
  /** Normalized text content of the target node */
  textSignature?: string;
  /** Text content of the parent container VE node for sibling disambiguation */
  parentTextSignature?: string;
  /** 0-indexed position among siblings sharing the same visual logging path */
  siblingIndex?: number;
  /** Optional backend RequestId for Network panel elements (`data-network-request-id`) */
  networkRequestId?: string;
  /** Optional DOM node identifiers (`data-backend-node-id`, `data-target-id`) */
  node?: DOMNodeAnchorSignature;
  /** Optional editor anchor coordinates for CodeMirror text editors */
  editor?: EditorAnchorSignature;
  /** Optional timeline flamechart anchor coordinates for Performance panel trace entries */
  timeline?: TimelineAnchorSignature;
  /**
   * Optional formatted lines that give the AI agent context about the
   * anchored target beyond the VE path and text signature, for example the
   * timing and warnings of a Performance panel trace entry. CD4ABridge
   * appends each line to the comment text that it sends to the agent.
   *
   * These lines are only context for the agent. They are not used to
   * re-match the anchor to its target; the other fields of this signature
   * do that.
   *
   * Currently only the Performance panel sets this field. Before adding
   * context here, consider whether it belongs in a new field on this
   * signature instead. This field is only for text that is already
   * formatted for the agent, not for data that other code needs to read.
   */
  agentContext?: string[];
}

export interface Comment {
  author: 'DEVELOPER'|'AGENT';
  text: string;
  timestamp: number;
}

export type CommentThreadStatus = 'DRAFT'|'ACTIVE'|'SENT_TO_AGENT'|'RESOLVED';

export const enum Events {
  CHANGED = 'Changed',
}

export interface EventTypes {
  [Events.CHANGED]: void;
}

export interface CommentThreadOptions {
  anchor: CommentAnchorSignature;
  comments?: Comment[];
  /** True for comments generated from the change tracker. */
  isGeneratedComment?: boolean;
}

export class CommentThread extends Common.ObjectWrapper.ObjectWrapper<EventTypes> {
  readonly id: string = crypto.randomUUID();
  readonly anchor: CommentAnchorSignature;
  /** True for comments generated from the change tracker. */
  readonly isGeneratedComment: boolean;
  #isOrphaned = false;
  comments: Comment[];
  status: CommentThreadStatus = 'DRAFT';
  #transmitted = false;
  /**
   * False until the developer has opened the thread since the agent last
   * responded. Only meaningful for RESOLVED threads.
   */
  responseSeen: boolean = false;

  constructor(options: CommentThreadOptions) {
    super();
    this.anchor = options.anchor;
    this.comments = options.comments ?? [];
    this.isGeneratedComment = Boolean(options.isGeneratedComment);
  }

  get isOrphaned(): boolean {
    return this.#isOrphaned;
  }

  setOrphaned(isOrphaned: boolean): void {
    if (this.#isOrphaned === isOrphaned) {
      return;
    }
    this.#isOrphaned = isOrphaned;
    this.dispatchEventToListeners(Events.CHANGED);
  }

  /**
   * True once the thread has been taken by the agent (e.g. via CD4ABridge).
   */
  get transmitted(): boolean {
    return this.#transmitted;
  }

  /**
   * Marks the thread as taken by the agent.
   */
  markTransmitted(): void {
    if (this.#transmitted) {
      return;
    }
    this.#transmitted = true;
    this.dispatchEventToListeners(Events.CHANGED);
  }

  /**
   * Returns whether it was changed.
   */
  #saveText(text?: string, author: 'DEVELOPER'|'AGENT' = 'DEVELOPER'): boolean {
    if (text && text.trim().length > 0) {
      this.comments.push({
        author,
        text: text.trim(),
        timestamp: Date.now(),
      });
      return true;
    }
    return false;
  }

  /**
   * Records UMA for a developer-authored comment when it leaves the DRAFT state.
   * Returns true if this is the first user comment. Returns false otherwise.
   */
  #recordCommentCreated(queued: boolean = false): void {
    if (this.isGeneratedComment) {
      return;
    }
    const text = this.comments.find(c => c.author === 'DEVELOPER')?.text.trim();
    if (!text) {
      return;
    }
    Host.userMetrics.commentCreated(1);
    Host.userMetrics.commentSize(text.length);
    if (queued) {
      Host.userMetrics.commentQueued(1);
    }

    return;
  }

  save(text?: string, author: 'DEVELOPER'|'AGENT' = 'DEVELOPER'): void {
    let changed = this.#saveText(text, author);
    if (this.status === 'DRAFT') {
      this.#recordCommentCreated(true);
      this.status = 'ACTIVE';
      changed = true;
    }
    if (changed) {
      this.dispatchEventToListeners(Events.CHANGED);
    }
  }

  editComment(text: string): void {
    const trimmed = text.trim();
    if (this.status !== 'ACTIVE' || !trimmed) {
      return;
    }
    const comment = this.comments.find(c => c.author === 'DEVELOPER');
    if (!comment || comment.text === trimmed) {
      return;
    }
    comment.text = trimmed;
    this.dispatchEventToListeners(Events.CHANGED);
  }

  sendToAgent(text?: string, author: 'DEVELOPER'|'AGENT' = 'DEVELOPER'): void {
    let changed = this.#saveText(text, author);
    if (this.status === 'DRAFT') {
      this.#recordCommentCreated();
    }
    if (this.status === 'DRAFT' || this.status === 'ACTIVE') {
      this.status = 'SENT_TO_AGENT';
      changed = true;
    }
    if (changed) {
      this.dispatchEventToListeners(Events.CHANGED);
    }
  }

  resolve(replyText?: string): void {
    const reply = replyText?.trim();
    if (reply) {
      this.comments.push({
        author: 'AGENT',
        text: reply,
        timestamp: Date.now(),
      });
    }
    // A new response, or a thread that is newly resolved, has not been seen yet.
    if (this.status !== 'RESOLVED' || reply) {
      this.responseSeen = false;
    }
    this.status = 'RESOLVED';
    this.dispatchEventToListeners(Events.CHANGED);
  }

  /**
   * Marks the agent response of a RESOLVED thread as seen by the developer.
   */
  markResponseSeen(): void {
    if (this.status !== 'RESOLVED' || this.responseSeen) {
      return;
    }
    this.responseSeen = true;
    this.dispatchEventToListeners(Events.CHANGED);
  }
}

export class RevealableThread {
  constructor(
      readonly thread: CommentThread,
      readonly position?: {left: number, top: number},
  ) {
  }
}