/**
 * ProjectionClient - Local TUI-side projection consumer.
 * TUI keeps a contracts-only copy of the ProjectionClient surface so it never imports runtime.
 *
 * @module packages/tui/src/ProjectionClient
 */

import type { ProjectionSubscriber, SessionProjection } from './types.js'

export type {
  SessionProjection,
  TaskProjection,
  AgentProjection,
  ToolRunProjection,
  CommandRunProjection,
  ArtifactProjection,
  PermissionPromptProjection,
  BlockerProjection,
  ProjectionSubscriber,
} from './types.js'

export class ProjectionClient {
  private snapshot: SessionProjection | null = null
  private subscribers: Set<ProjectionSubscriber> = new Set()

  receive_snapshot(projection: SessionProjection): void {
    this.snapshot = projection
    for (const sub of this.subscribers) {
      sub(projection)
    }
  }

  subscribe(subscriber: ProjectionSubscriber): () => void {
    this.subscribers.add(subscriber)
    return () => this.subscribers.delete(subscriber)
  }

  get_snapshot(): SessionProjection | null {
    return this.snapshot
  }
}