import { defineEventHandler, getRouterParam, readBody } from "h3";
import { getCurrentUser, getConfigGlobal } from "#server/utils/context";
import { resolveCharacterIdentity } from "#server/service/character/identity";
import { getCharacterSessionByIdAndUser } from "#server/service/character/session";
import { getCharacterCardBySlug } from "#server/service/character/character-card";
import { executeCharacterChat } from "#server/service/character/chat-engine";

export default defineEventHandler(async (event) => {
  const slug = getRouterParam(event, "slug");
  if (!slug) {
    throw createError({ statusCode: 400, statusMessage: "参数无效" });
  }

  const card = await getCharacterCardBySlug(slug);
  if (!card) {
    throw createError({ statusCode: 404, statusMessage: "角色不存在" });
  }

  const identity = await resolveCharacterIdentity(event);
  if (!identity.userId && !identity.tempToken) {
    throw createError({ statusCode: 401, statusMessage: "请先登录或创建会话" });
  }

  const body = await readBody(event);
  const { sessionId, content, modelId } = body as {
    sessionId: string;
    content?: string;
    modelId?: number | null;
  };

  if (!sessionId) {
    throw createError({ statusCode: 400, statusMessage: "参数无效" });
  }
  if (typeof content !== "string" || content.trim().length === 0) {
    throw createError({ statusCode: 400, statusMessage: "内容不能为空" });
  }

  const session = await getCharacterSessionByIdAndUser(sessionId, identity.userId, identity.tempToken);
  if (!session) {
    throw createError({ statusCode: 404, statusMessage: "会话不存在" });
  }
  if (session.cardId !== card.id) {
    throw createError({ statusCode: 400, statusMessage: "会话不属于该角色" });
  }

  const preferredModelId = modelId ?? null;
  const globalDefaultModelId = (await getConfigGlobal("agentDefaultModelId")) ?? null;
  const user = identity.userId ? await getCurrentUser(event) : null;

  const { response } = await executeCharacterChat({
    card,
    session,
    user: user ? { id: user.id } : null,
    content,
    preferredModelId,
    globalDefaultModelId,
    requestId: event.context.requestId,
    onClientClose: (cb) => {
      event.node.req.on("close", cb);
    },
  });

  return response;
});