import { updateSessionStore } from "../../config/sessions/store.js";
import { mergeSessionEntry, type SessionEntry } from "../../config/sessions/types.js";
import {
  formatAgentInternalEventsForPlainPrompt,
  formatAgentInternalEventsForPrompt,
} from "../internal-events.js";
import {
  hasInternalRuntimeContext,
  stripInternalRuntimeContext,
} from "../internal-runtime-context.js";
import type { AgentCommandOpts } from "./types.js";

export type PersistSessionEntryParams = {
  sessionStore: Record<string, SessionEntry>;
  sessionKey: string;
  storePath: string;
  entry: SessionEntry;
  clearedFields?: string[];
};

export async function persistSessionEntry(params: PersistSessionEntryParams): Promise<void> {
  const persisted = await updateSessionStore(params.storePath, (store) => {
    const merged = mergeSessionEntry(store[params.sessionKey], params.entry);
    for (const field of params.clearedFields ?? []) {
      if (!Object.hasOwn(params.entry, field)) {
        Reflect.deleteProperty(merged, field);
      }
    }
    store[params.sessionKey] = merged;
    return merged;
  });
  params.sessionStore[params.sessionKey] = persisted;
}

export function prependInternalEventContext(
  body: string,
  events: AgentCommandOpts["internalEvents"],
): string {
  if (hasInternalRuntimeContext(body)) {
    return body;
  }
  const renderedEvents = formatAgentInternalEventsForPrompt(events);
  if (!renderedEvents) {
    return body;
  }
  return [renderedEvents, body].filter(Boolean).join("\n\n");
}

function resolvePlainInternalEventBody(
  body: string,
  events: AgentCommandOpts["internalEvents"],
): string {
  const renderedEvents = formatAgentInternalEventsForPlainPrompt(events);
  if (!renderedEvents) {
    return body;
  }
  const visibleBody = stripInternalRuntimeContext(body).trim();
  return [renderedEvents, visibleBody].filter(Boolean).join("\n\n") || body;
}

export function resolveAcpPromptBody(
  body: string,
  events: AgentCommandOpts["internalEvents"],
): string {
  return events?.length ? resolvePlainInternalEventBody(body, events) : body;
}

export function resolveInternalEventTranscriptBody(
  body: string,
  events: AgentCommandOpts["internalEvents"],
): string {
  if (!hasInternalRuntimeContext(body)) {
    return body;
  }
  return resolvePlainInternalEventBody(body, events);
}