import { Injectable, NotFoundException } from '@nestjs/common';
import { Prisma } from '@prisma/client';
import { PrismaService } from '../../common/prisma/prisma.module';
import { serializeBigInt } from '../../common/decorators/current-user.decorator';
import type { AdminWechatBindingsQueryDto } from './dto/admin-query.dto';

type ActorType = 'USER' | 'STORE' | 'PARTNER' | 'HQ';

type BindingRow = {
  actorType: ActorType;
  actorId: bigint;
  phone: string | null;
  name: string | null;
  wxOpenId: string;
  wxUnionId: string | null;
  phoneVerified?: boolean;
  refLabel?: string | null;
  refId?: bigint | null;
  lastLoginAt: Date | null;
  status: string | number;
};

function buildGroupKey(row: BindingRow): string {
  if (row.wxUnionId) return `union:${row.wxUnionId}`;
  return `solo:${row.actorType}:${row.actorId.toString()}`;
}

function mapBindingRow(row: BindingRow) {
  return {
    actorType: row.actorType,
    actorId: row.actorId.toString(),
    phone: row.phone,
    name: row.name,
    wxOpenId: row.wxOpenId,
    wxUnionId: row.wxUnionId,
    phoneVerified: row.phoneVerified,
    refLabel: row.refLabel ?? null,
    refId: row.refId?.toString() ?? null,
    lastLoginAt: row.lastLoginAt,
    status: row.status,
  };
}

function summarizeGroup(groupKey: string, rows: BindingRow[]) {
  const unionId = groupKey.startsWith('union:') ? groupKey.slice('union:'.length) : null;
  const actorTypes = [...new Set(rows.map((r) => r.actorType))];
  const phones = rows.map((r) => r.phone).filter((p): p is string => !!p);
  const latestLoginAt = rows.reduce<Date | null>((max, r) => {
    if (!r.lastLoginAt) return max;
    if (!max || r.lastLoginAt > max) return r.lastLoginAt;
    return max;
  }, null);

  return {
    groupKey,
    unionId,
    identityCount: rows.length,
    actorTypes,
    multiRole: rows.length > 1,
    primaryPhone: phones[0] ?? null,
    latestLoginAt,
    identities: rows.map(mapBindingRow),
  };
}

@Injectable()
export class AdminWechatBindingsService {
  constructor(private readonly prisma: PrismaService) {}

  async list(query: AdminWechatBindingsQueryDto) {
    const page = query.page ?? 1;
    const pageSize = query.pageSize ?? 20;
    let rows = await this.fetchBindings(query);
    const shouldExpandUnion = !!(query.phone || query.openId || query.actorType);
    if (shouldExpandUnion) {
      const unionIds = [
        ...new Set(rows.map((r) => r.wxUnionId).filter((id): id is string => !!id)),
      ];
      if (unionIds.length > 0) {
        const expanded = (
          await Promise.all(unionIds.map((unionId) => this.fetchBindings({ unionId })))
        ).flat();
        const soloRows = rows.filter((r) => !r.wxUnionId);
        rows = this.dedupeBindings([...expanded, ...soloRows]);
      }
    }
    const groups = this.groupBindings(rows);
    const summaries = [...groups.entries()]
      .map(([groupKey, groupRows]) => summarizeGroup(groupKey, groupRows))
      .sort((a, b) => {
        if (a.multiRole !== b.multiRole) return a.multiRole ? -1 : 1;
        const ta = a.latestLoginAt ? new Date(a.latestLoginAt).getTime() : 0;
        const tb = b.latestLoginAt ? new Date(b.latestLoginAt).getTime() : 0;
        return tb - ta;
      });

    const total = summaries.length;
    const items = summaries.slice((page - 1) * pageSize, page * pageSize);

    return serializeBigInt({ items, total, page, pageSize });
  }

  async detail(groupKey: string) {
    const rows = await this.fetchBindings({});
    const groups = this.groupBindings(rows);
    const groupRows = groups.get(groupKey);
    if (!groupRows?.length) {
      throw new NotFoundException('微信绑定分组不存在');
    }
    return serializeBigInt(summarizeGroup(groupKey, groupRows));
  }

  private groupBindings(rows: BindingRow[]): Map<string, BindingRow[]> {
    const groups = new Map<string, BindingRow[]>();
    for (const row of rows) {
      const key = buildGroupKey(row);
      const list = groups.get(key) ?? [];
      list.push(row);
      groups.set(key, list);
    }
    for (const [key, list] of groups) {
      list.sort((a, b) => {
        const ta = a.lastLoginAt?.getTime() ?? 0;
        const tb = b.lastLoginAt?.getTime() ?? 0;
        return tb - ta;
      });
      groups.set(key, list);
    }
    return groups;
  }

  private async fetchBindings(query: AdminWechatBindingsQueryDto): Promise<BindingRow[]> {
    const actorType = query.actorType as ActorType | undefined;
    const phoneFilter = query.phone?.trim();
    const unionIdFilter = query.unionId?.trim();
    const openIdFilter = query.openId?.trim();

    const rows: BindingRow[] = [];

    if (!actorType || actorType === 'USER') {
      const where: Prisma.UserWhereInput = {
        wxOpenId: { not: null },
        status: 1,
        mergedIntoUserId: null,
      };
      if (phoneFilter) where.phone = { contains: phoneFilter };
      if (unionIdFilter) where.wxUnionId = unionIdFilter;
      if (openIdFilter) where.wxOpenId = openIdFilter;

      const users = await this.prisma.user.findMany({
        where,
        select: {
          id: true,
          phone: true,
          nickname: true,
          phoneVerifiedAt: true,
          wxOpenId: true,
          wxUnionId: true,
          status: true,
          updatedAt: true,
        },
      });

      for (const u of users) {
        if (!u.wxOpenId) continue;
        rows.push({
          actorType: 'USER',
          actorId: u.id,
          phone: u.phone,
          name: u.nickname,
          wxOpenId: u.wxOpenId,
          wxUnionId: u.wxUnionId,
          phoneVerified: !!u.phoneVerifiedAt,
          lastLoginAt: u.updatedAt,
          status: u.status,
        });
      }
    }

    if (!actorType || actorType === 'STORE') {
      const where: Prisma.StoreAccountWhereInput = { wxOpenId: { not: null } };
      if (phoneFilter) where.phone = { contains: phoneFilter };
      if (unionIdFilter) where.wxUnionId = unionIdFilter;
      if (openIdFilter) where.wxOpenId = openIdFilter;

      const accounts = await this.prisma.storeAccount.findMany({
        where,
        include: { store: { select: { id: true, name: true } } },
      });

      for (const a of accounts) {
        if (!a.wxOpenId) continue;
        rows.push({
          actorType: 'STORE',
          actorId: a.id,
          phone: a.phone,
          name: a.name,
          wxOpenId: a.wxOpenId,
          wxUnionId: a.wxUnionId,
          refId: a.storeId,
          refLabel: a.store.name,
          lastLoginAt: a.lastLoginAt,
          status: a.status,
        });
      }
    }

    if (!actorType || actorType === 'PARTNER') {
      const where: Prisma.PartnerAccountWhereInput = { wxOpenId: { not: null } };
      if (phoneFilter) where.phone = { contains: phoneFilter };
      if (unionIdFilter) where.wxUnionId = unionIdFilter;
      if (openIdFilter) where.wxOpenId = openIdFilter;

      const accounts = await this.prisma.partnerAccount.findMany({
        where,
        include: { partner: { select: { id: true, companyName: true } } },
      });

      for (const a of accounts) {
        if (!a.wxOpenId) continue;
        rows.push({
          actorType: 'PARTNER',
          actorId: a.id,
          phone: a.phone,
          name: a.name,
          wxOpenId: a.wxOpenId,
          wxUnionId: a.wxUnionId,
          refId: a.partnerId,
          refLabel: a.partner.companyName,
          lastLoginAt: a.lastLoginAt,
          status: a.status,
        });
      }
    }

    if (!actorType || actorType === 'HQ') {
      const where: Prisma.HqAccountWhereInput = { wxOpenId: { not: null } };
      if (phoneFilter) where.phone = { contains: phoneFilter };
      if (unionIdFilter) where.wxUnionId = unionIdFilter;
      if (openIdFilter) where.wxOpenId = openIdFilter;

      const accounts = await this.prisma.hqAccount.findMany({
        where,
        select: {
          id: true,
          phone: true,
          name: true,
          adminRole: true,
          wxOpenId: true,
          wxUnionId: true,
          lastLoginAt: true,
          status: true,
        },
      });

      for (const a of accounts) {
        if (!a.wxOpenId) continue;
        rows.push({
          actorType: 'HQ',
          actorId: a.id,
          phone: a.phone,
          name: a.name,
          wxOpenId: a.wxOpenId,
          wxUnionId: a.wxUnionId,
          refLabel: a.adminRole,
          lastLoginAt: a.lastLoginAt,
          status: a.status,
        });
      }
    }

    return rows;
  }

  private dedupeBindings(rows: BindingRow[]): BindingRow[] {
    const map = new Map<string, BindingRow>();
    for (const row of rows) {
      map.set(`${row.actorType}:${row.actorId.toString()}`, row);
    }
    return [...map.values()];
  }
}