import type { EmotionTag, RelationshipStage } from "@kokorone/shared";

const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL ?? "http://localhost:3001";

export interface ChatResponseStyle {
  tone: string;
  sentenceLength: "short" | "medium" | "long";
  initiative: "low" | "medium" | "high";
}

export interface ChatContext {
  emotion: { dominant: EmotionTag; style: ChatResponseStyle };
  relationship: { intimacy: number; trust: number; stage: RelationshipStage };
}

export type ChatAvailability = "NORMAL" | "BRIEF" | "DELAYED" | "NO_REPLY";

export interface ChatResult {
  text: string;
  actions: string[];
  isFastChannel: boolean;
  availability: ChatAvailability;
  exceptionType: string | null;
  // I-2：作息為睡眠且未破例時不會組裝上下文，此時為 null。
  context: ChatContext | null;
}

export async function sendChatMessage(
  characterId: string,
  userId: string,
  sessionId: string,
  text: string,
): Promise<ChatResult> {
  const res = await fetch(`${API_BASE_URL}/chat/${characterId}`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ userId, sessionId, text }),
  });
  if (!res.ok) {
    throw new Error(`對話請求失敗（${res.status}）`);
  }
  return res.json();
}

export async function endChatSession(sessionId: string, characterId: string): Promise<void> {
  await fetch(`${API_BASE_URL}/session/${sessionId}/end`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ characterId }),
  });
}

export interface TachieExpressionResponse {
  emotionTag: EmotionTag;
  rawEmotionTag: EmotionTag;
  eyebrow: string;
  eye: string;
  mouth: string;
  effect: string | null;
  pose: string;
  magnitude: number;
  gaze: "UP" | "AWAY" | "DIRECT" | "NEUTRAL";
  availableCostumes: string[];
  lockedFallbackApplied: boolean;
  usedCryingVariant: boolean;
}

// O-2 表情演出：情緒引擎已經在對話文字生成之前更新完畢，這裡獨立查詢目前的表情狀態，
// 讓前端可以在文字訊息出現前先套用新的表情差分。
export async function fetchExpression(characterId: string, userId: string): Promise<TachieExpressionResponse> {
  const res = await fetch(`${API_BASE_URL}/tachie/${characterId}/${userId}/expression`);
  if (!res.ok) {
    throw new Error(`表情查詢失敗（${res.status}）`);
  }
  return res.json();
}