import type {
  BoxBrainMemoryStore,
  DateTimeInput,
  MandatoryConversationContext,
  MemorySpace,
  PersonaMessage,
  ScheduledAvailabilitySnapshot,
} from "./types";
import { addUtcDays, dateKeysAround, startOfUtcDay, toIso } from "./schedule";

export function formatMessageHistory(input: {
  personaName: string;
  messages: PersonaMessage[];
}): string {
  return input.messages
    .map((message) => {
      const sender = message.sender === "persona" ? input.personaName : "user";
      return `${sender}@${toIso(message.time)}: ${message.content}`;
    })
    .join("\n");
}

export function conversationInstruction(baseSystemPrompt?: string): string {
  const parts = [
    ...(baseSystemPrompt === undefined ? [] : [baseSystemPrompt]),
    "You are controlling the persona, not a generic assistant.",
    "Use the send_message tool conceptually: return one or more outgoing messages.",
    "Unless the persona strongly prefers otherwise, keep each outgoing message to at most one sentence.",
    "Prefer short, natural, chat-like wording and allow splitting one thought into multiple messages.",
    'If mandatory memory says "기억이 없음", the persona may naturally wonder about missing context instead of pretending to remember.',
  ];
  return parts.join("\n");
}

export async function buildMandatoryConversationContext(input: {
  persona: MemorySpace;
  now: DateTimeInput;
  memory: BoxBrainMemoryStore;
  messages: PersonaMessage[];
  availability: ScheduledAvailabilitySnapshot;
}): Promise<MandatoryConversationContext> {
  const now = startOfUtcDay(input.now);
  const from = addUtcDays(now, -1).toISOString();
  const to = addUtcDays(now, 2).toISOString();
  const scheduleEntries = await input.memory.listScheduleEntries(
    input.persona.id,
    from,
    to,
  );
  const personaAndUserFacts = await input.memory.findFacts(input.persona.id, [
    "persona",
    input.persona.displayName,
    "user",
  ]);
  const memorySummary =
    personaAndUserFacts.length === 0
      ? "기억이 없음"
      : personaAndUserFacts.map((fact) => `- ${fact.statement}`).join("\n");

  return {
    formattedMessageHistory: formatMessageHistory({
      personaName: input.persona.displayName,
      messages: input.messages,
    }),
    conversationWindowLabel: `Required conversation window: yesterday/today. Schedule dates: ${dateKeysAround(input.now).join(", ")}.`,
    memorySummary,
    personaAndUserFacts,
    scheduleEntries,
    availability: input.availability,
  };
}