import cloud from "@lafjs/cloud";
import Utils from "@/Utils";
import {
  WUCAI_TYPE_AUTO_MIGRATED,
  WUCAI_TYPE_CHOSE_CURRENT,
  WUCAI_TYPE_CHOSE_WUCAI,
  WUCAI_TYPE_PENDING_CHOICE,
  addWucaiReward,
  fetchWucaiUser,
  isValidWucaiType,
  normalizeWucaiUser,
} from "./wucaiMigration";

const db = cloud.database();

export default async function wucaiTransfer(ctx: FunctionContext) {
  const body = ctx.body || {};
  const uid = body.uid;
  const action = String(body.action || "");

  if (body.gameName === "iaa") {
    return fail("WUCAI_UNSUPPORTED_GAME", "五彩账号迁移仅支持主用户库");
  }
  if (!uid) {
    return fail("WUCAI_UID_REQUIRED", "未获取到uid");
  }
  if (!isSupportedAction(action)) {
    return fail("WUCAI_INVALID_ACTION", "无效的五彩迁移动作");
  }

  const userResult = await db.collection("users").where({ _id: uid }).getOne();
  const user = userResult.data;
  if (!user) {
    return fail("WUCAI_USER_NOT_FOUND", "未获取到玩家信息");
  }
  if (!user.token || !body.token || !Utils.checkToken(body.token, user.token)) {
    return fail("TOKEN_INVALID", "token校验失败");
  }
  if (!isValidWucaiType(user.wucai_type)) {
    return fail("WUCAI_INVALID_STATE", "五彩迁移状态异常");
  }

  const expectedType = action === "claim_reward"
    ? WUCAI_TYPE_AUTO_MIGRATED
    : WUCAI_TYPE_PENDING_CHOICE;
  const nextType = action === "choose_current"
    ? WUCAI_TYPE_CHOSE_CURRENT
    : WUCAI_TYPE_CHOSE_WUCAI;
  const currentType = Number(user.wucai_type);

  if (currentType === nextType) {
    return success(nextType);
  }
  if (currentType !== expectedType) {
    return fail("WUCAI_INVALID_STATE", "当前状态不能执行该迁移动作", { wucai_type: currentType });
  }

  let update: any;
  if (action === "choose_wucai") {
    const source = await fetchWucaiUser(user.unionid);
    if (!source) {
      return fail("WUCAI_SOURCE_UNAVAILABLE", "五彩数据获取失败，请重新进入游戏后重试");
    }
    const migratedUser = normalizeWucaiUser(source);
    update = {
      ...migratedUser,
      ...addWucaiReward(migratedUser),
      wucai_type: nextType,
      forcedUpdate: true,
    };
  } else {
    update = {
      ...addWucaiReward(user),
      wucai_type: nextType,
      forcedUpdate: true,
    };
  }

  const updateResult = await db.collection("users").where({
    _id: uid,
    wucai_type: expectedType,
  }).update(update);
  if (isUpdateFailed(updateResult)) {
    const latestResult = await db.collection("users").where({ _id: uid }).getOne();
    const latestType = Number(latestResult.data?.wucai_type);
    if (latestType === nextType) {
      return success(nextType);
    }
    return fail("WUCAI_STATE_CHANGED", "迁移状态已经变化，请重新登录", { wucai_type: latestType });
  }

  return success(nextType);
}

function isSupportedAction(action: string): boolean {
  return action === "claim_reward" || action === "choose_wucai" || action === "choose_current";
}

function isUpdateFailed(result: any): boolean {
  return Boolean(result && (result.ok === false || result.updated === 0));
}

function success(wucaiType: number) {
  return {
    code: 1,
    data: {
      wucai_type: wucaiType,
      forcedUpdate: true,
    },
    msg: "五彩账号迁移处理成功",
  };
}

function fail(errorCode: string, msg: string, data: any = null) {
  return { code: 0, errorCode, data, msg };
}