import cloud from '@lafjs/cloud'
import { createHash } from 'crypto';

const db = cloud.database();
const CONFIG_COLLECTION = "sign_in_activity_config";
const CLAIM_COLLECTION = "sign_in_activity_claims";
const USERS_COLLECTION = "users";
const DAY_MS = 24 * 60 * 60 * 1000;
const UTC_8_OFFSET_MS = 8 * 60 * 60 * 1000;
const REWARD_DAYS = 7;

export type SignInRewardItem = {
  type: "coin" | "freeze" | "hammer" | "magic_wand" | "infinite_health" | "cat_skin";
  count: number;
  itemId?: number;
};

export type SignInActivityConfig = {
  activityId: string;
  enabled: boolean;
  triggerLevel: number;
  durationDays: number;
  timezone?: string;
  rewards: Array<{
    day: number;
    items: SignInRewardItem[];
  }>;
  updatedAt?: number;
  createdAt?: number;
};

export type SignInActivityState = {
  activityId: string;
  startAt: number;
  endAt: number;
  activatedAt: number;
  completedAt?: number | null;
};

export function getChinaDayStart(now = Date.now()) {
  return Math.floor((now + UTC_8_OFFSET_MS) / DAY_MS) * DAY_MS - UTC_8_OFFSET_MS;
}

export function getChinaDateKey(now = Date.now()) {
  return String(Math.floor((now + UTC_8_OFFSET_MS) / DAY_MS));
}

export function getUserSignInLevel(user: any) {
  const level = Number(user?.endLevelNum);
  return Number.isFinite(level) && level > 0 ? level : 0;
}

export function normalizeSignInState(value: any): SignInActivityState | null {
  if (!value) {
    return null;
  }
  if (typeof value === "string") {
    try {
      value = JSON.parse(value);
    } catch {
      return null;
    }
  }
  if (!value.activityId || !Number.isFinite(Number(value.startAt)) || !Number.isFinite(Number(value.endAt))) {
    return null;
  }
  return {
    activityId: String(value.activityId),
    startAt: Number(value.startAt),
    endAt: Number(value.endAt),
    activatedAt: Number(value.activatedAt) || Number(value.startAt),
    completedAt: Number(value.completedAt) || null,
  };
}

export function isValidSignInConfig(config: any): config is SignInActivityConfig {
  if (!config?.activityId) {
    return false;
  }
  if (!Number.isFinite(Number(config.triggerLevel)) || Number(config.triggerLevel) < 0) {
    return false;
  }
  if (!Number.isInteger(Number(config.durationDays)) || Number(config.durationDays) <= 0) {
    return false;
  }
  if (!Array.isArray(config.rewards) || config.rewards.length !== REWARD_DAYS) {
    return false;
  }
  return config.rewards.every((reward, index) =>
    Number(reward?.day) === index + 1
    && Array.isArray(reward.items)
    && reward.items.length > 0
    && reward.items.every(isValidRewardItem)
  );
}

function isValidRewardItem(item: any) {
  const validTypes = ["coin", "freeze", "hammer", "magic_wand", "infinite_health", "cat_skin"];
  const validCatId = item?.type !== "cat_skin"
    || (Number.isInteger(Number(item.itemId)) && Number(item.itemId) > 0);
  return validTypes.includes(item?.type)
    && Number.isFinite(Number(item.count))
    && Number(item.count) > 0
    && validCatId
    && (item.itemId === undefined || Number.isFinite(Number(item.itemId)));
}

export async function getActiveSignInConfig(): Promise<SignInActivityConfig | null> {
  try {
    const result = await db.collection(CONFIG_COLLECTION).where({ enabled: true }).get();
    const configs = Array.isArray(result.data) ? result.data.filter(isValidSignInConfig) : [];
    if (configs.length !== 1) {
      return null;
    }
    configs.sort((left, right) => Number(right.updatedAt || right.createdAt || 0) - Number(left.updatedAt || left.createdAt || 0));
    return configs[0];
  } catch {
    return null;
  }
}

export async function getSignInConfig(activityId: string): Promise<SignInActivityConfig | null> {
  try {
    const result = await db.collection(CONFIG_COLLECTION).where({ activityId }).getOne();
    return isValidSignInConfig(result.data) ? result.data : null;
  } catch {
    return null;
  }
}

export async function activateSignInActivity(user: any, now = Date.now()) {
  if (!user?._id || normalizeSignInState(user.signInActivity)) {
    return { activated: false, state: normalizeSignInState(user?.signInActivity), config: null };
  }
  const config = await getActiveSignInConfig();
  if (!config || getUserSignInLevel(user) < Number(config.triggerLevel)) {
    return { activated: false, state: null, config };
  }
  const startAt = getChinaDayStart(now);
  const state: SignInActivityState = {
    activityId: config.activityId,
    startAt,
    endAt: startAt + Number(config.durationDays) * DAY_MS,
    activatedAt: now,
    completedAt: null,
  };
  const result = await db.collection(USERS_COLLECTION)
    .where({ _id: user._id })
    .update({ signInActivity: state });
  const activated = getUpdatedCount(result) > 0;
  if (activated) {
    user.signInActivity = state;
  }
  return { activated, state: activated ? state : normalizeSignInState(user.signInActivity), config };
}

function getUpdatedCount(result: any) {
  const count = Number(result?.updated ?? result?.matched ?? result?.data?.updated);
  return Number.isFinite(count) ? count : 1;
}

export async function getSignInClaims(uid: string, activityId: string) {
  const result = await db.collection(CLAIM_COLLECTION).where({ uid, activityId }).get();
  const claims = Array.isArray(result.data) ? result.data.slice() : [];
  claims.sort((left, right) => Number(left.rewardDay) - Number(right.rewardDay));
  return claims;
}

export function buildClaimId(uid: string, activityId: string, dateKey: string) {
  return createHash("sha256").update(`${uid}:${activityId}:${dateKey}`).digest("hex");
}

export async function addSignInClaim(payload: any) {
  return db.collection(CLAIM_COLLECTION).add(payload);
}

export async function markSignInCompleted(uid: string, state: SignInActivityState, completedAt: number) {
  const nextState = { ...state, completedAt };
  await db.collection(USERS_COLLECTION).where({ _id: uid }).update({ signInActivity: nextState });
  return nextState;
}

export function getSignInActivityStatus(state: SignInActivityState | null, claimedCount: number, now = Date.now()) {
  if (!state) {
    return "locked" as const;
  }
  if (claimedCount >= REWARD_DAYS || state.completedAt) {
    return "completed" as const;
  }
  if (now >= state.endAt) {
    return "expired" as const;
  }
  return "active" as const;
}

export const SIGN_IN_REWARD_DAYS = REWARD_DAYS;