Files
page-agent/src/utils/bus.ts
2025-09-29 16:33:15 +08:00

129 lines
3.6 KiB
TypeScript

/**
* Type-safe event bus for decoupling PageAgent and Panel
*/
import type { Step } from '@/ui/UIState'
/**
* Event mapping definitions
* @note Event bus callbacks must be repeatable without errors
*/
export interface PageAgentEventMap {
// Panel control events
// call panel.show()
'panel:show': { params: undefined }
// call panel.hide()
'panel:hide': { params: undefined }
// call panel.reset()
'panel:reset': { params: undefined }
// call panel.update()
'panel:update': { params: Omit<Step, 'id' | 'stepNumber' | 'timestamp'> }
// call panel.expand()
'panel:expand': { params: undefined }
// call panel.collapse()
'panel:collapse': { params: undefined }
// PageAgent status events
// 'agent:beforeUpdate': { params: undefined }
// 'agent:afterUpdate': { params: undefined }
// 'agent:execute': { params: { task: string } }
// 'agent:done': { params: { text: string; success: boolean } }
// 'agent:paused': { params: undefined }
// 'agent:resumed': { params: undefined }
// 'agent:disposed': { params: undefined }
// 'agent:error': { params: { error: string | Error } }
// Task status change events
// 'task:start': { params: { task: string } }
// 'task:step': { params: Omit<AgentStep, 'id' | 'stepNumber' | 'timestamp'> }
// 'task:complete': { params: { text: string; success: boolean } }
// 'task:error': { params: { error: string | Error } }
// Index signature for dynamic event names
// [key: string]: { params: any }
}
/**
* Event handler type definitions
*/
export type EventHandler<T extends keyof PageAgentEventMap> =
PageAgentEventMap[T]['params'] extends undefined
? () => void
: (params: PageAgentEventMap[T]['params']) => void
/**
* Async event handler type definitions
*/
export type AsyncEventHandler<T extends keyof PageAgentEventMap> =
PageAgentEventMap[T]['params'] extends undefined
? () => Promise<void>
: (params: PageAgentEventMap[T]['params']) => Promise<void>
/**
* Type-safe event bus
* @note Mainly used to decouple logic and UI
* @note All modules of a PageAgent instance share the same EventBus instance for communication
* @note Use with caution if delivery guarantee is needed for logic communication
* @note `on` `once` `emit` methods handle built-in events with type protection, use `addEventListener` for other events
*/
class EventBus extends EventTarget {
/**
* Listen to built-in events
*/
on<T extends keyof PageAgentEventMap>(
event: T,
handler: EventHandler<T & keyof PageAgentEventMap>
): void {
const wrappedHandler = (e: Event) => {
const customEvent = e as CustomEvent
const params = customEvent.detail?.[0]
return handler(params)
}
this.addEventListener(event, wrappedHandler)
}
/**
* Listen to built-in events (one-time)
*/
once<T extends keyof PageAgentEventMap>(
event: T,
handler: EventHandler<T & keyof PageAgentEventMap>
): void {
const wrappedHandler = (e: Event) => {
const customEvent = e as CustomEvent
const params = customEvent.detail?.[0]
return handler(params)
}
this.addEventListener(event, wrappedHandler, { once: true })
}
/**
* Emit built-in events
*/
emit<T extends keyof PageAgentEventMap>(
event: T,
...args: PageAgentEventMap[T]['params'] extends undefined
? []
: [PageAgentEventMap[T]['params']]
): void {
const customEvent = new CustomEvent(event, { detail: args })
this.dispatchEvent(customEvent)
return
}
}
const buses = new Map<string, EventBus>()
/**
* Get the event bus for a given channel
*/
export function getEventBus(channel: string) {
if (buses.has(channel)) {
return buses.get(channel)!
}
const bus = new EventBus()
buses.set(channel, bus)
return bus
}
export type { EventBus }