/** Conversation metadata and lifecycle. Summaries remain disabled until the summary port supplies them. */
import { defineExtension, GenerationTask, hook, ROOT_CONVERSATION_ID } from '@earendil-works/pi-durable'
import { ConversationsApi, State, Concluded } from './api.ts'
export default function conversations(host: any) {
  const concludedIn = async (tx: any) => new Set<number>((await tx.doc(Concluded)).ids)
  host.implement(ConversationsApi, {
    concludedIn,
    concluded: async (context: any) => host.harness().commit(concludedIn,context),
    concludeIn: async (tx: any, ids: number[]) => {
      for (const id of ids) {
        const record = await tx.conversation(id)
        if (!record) throw new Error(`Unknown conversation ${id}`)
        if (record.owner) throw new Error(`Conversation ${id} is owned`)
        if (id === ROOT_CONVERSATION_ID || (await tx.doc(State,id)).mainAgent) throw new Error(`Conversation ${id} is fixed`)
      }
      const state = await tx.doc(Concluded)
      state.ids = [...new Set([...state.ids,...ids])]
    },
    setMainAgent: async (tx: any, id: number, mainAgent: boolean) => { (await tx.doc(State,id)).mainAgent = mainAgent },
    setAutomaticSummaries: async (tx: any, id: number, enabled: boolean) => { (await tx.doc(State,id)).automaticSummaries = enabled },
    generatedTitle: async (tx: any, id: number, title: string) => {
      const state = await tx.doc(State,id)
      if (state.generatedTitle === undefined && (await tx.doc(host.metadata,id)).title === title) state.generatedTitle = title
    },
    subject: async (id: number, context: any) => {
      const metadata = await host.harness().snapshot(host.metadata,id,context)
      return metadata?.title ? {title:metadata.title} : {}
    },
    // Later summaries can supply these without changing lifecycle callers.
    summaryModel: async () => undefined,
    requestSummary: async () => {},
  })
  return defineExtension({name:'conversations',hooks:[hook(GenerationTask,{beforeInput:async (_input,{tx,conversationId})=>{
    const ancestors = new Set<number>()
    for (let id = conversationId; id !== undefined && !ancestors.has(id);) {
      ancestors.add(id)
      const record = await tx.conversation(id)
      id = record?.owner?.conversationId ?? record?.parent?.conversationId
    }
    const state = await tx.doc(Concluded)
    state.ids = state.ids.filter(id=>!ancestors.has(id))
  }})]})
}