import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import { AccountingEntityType, AccountingOutboxStatus, Prisma } from '@prisma/client';
import { PrismaService } from '../../prisma/prisma.service';
import { cleanUrl } from './accounting-config';
import { AccountingConfigService, JobName } from './accounting-config.service';
import { fetchServerCertificate } from './accounting-http';
import { AccountingSyncService } from './accounting-sync.service';
import { AccountingWorkerService, PULL_FEATURE } from './accounting-worker.service';
import { parseJalali, toJalali } from './jalali';
import { ACCOUNTING_PROVIDERS, ProviderName, isProviderName } from './providers';

const JOBS: JobName[] = ['customers', 'balances', 'products', 'outbox'];
const STATUSES: AccountingOutboxStatus[] = ['PENDING', 'SENDING', 'SENT', 'FAILED', 'NEEDS_REVIEW', 'RESOLVED'];

function page(v: unknown) {
  const n = Number(v);
  return Number.isInteger(n) && n > 0 ? n : 1;
}

function limit(v: unknown, max = 100) {
  const n = Number(v);
  return Number.isInteger(n) && n > 0 ? Math.min(n, max) : 25;
}

/** Backs the «اتصال حسابداری» admin screen (plan §5). */
@Injectable()
export class AccountingAdminService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly config: AccountingConfigService,
    private readonly sync: AccountingSyncService,
    private readonly worker: AccountingWorkerService,
  ) {}

  async overview() {
    const [config, state, counts, openIssues, raw] = await Promise.all([
      this.config.getPublic(),
      this.config.getState(),
      this.prisma.accountingOutbox.groupBy({ by: ['status'], _count: { _all: true } }),
      this.prisma.accountingIssue.count({ where: { resolvedAt: null } }),
      this.config.get(),
    ]);
    return {
      config,
      inactiveReason: this.config.inactiveReason(raw),
      state,
      busy: this.worker.busy,
      realtime: this.worker.realtime,
      outbox: Object.fromEntries(counts.map((c) => [c.status, c._count._all])),
      openIssues,
    };
  }

  async save(body: Record<string, unknown>) {
    const { providerChanged } = await this.config.save(body);
    return { ...(await this.overview()), providerChanged };
  }

  private async settingsOf(name: unknown) {
    const config = await this.config.get();
    const provider = isProviderName(name) ? name : config.provider;
    if (provider === 'none') throw new BadRequestException('نرم‌افزار حسابداری انتخاب نشده است');
    const settings = this.config.settingsFor(config, provider);
    if (!settings) throw new BadRequestException('آدرس یا توکن این نرم‌افزار تنظیم نشده (یا توکن قابل‌خواندن نیست)');
    return { provider: ACCOUNTING_PROVIDERS[provider], settings, config };
  }

  /** For the sync buttons on the lists: connected or not, nothing more. */
  async connectionStatus() {
    const config = await this.config.get();
    const reason = this.config.inactiveReason(config);
    return {
      connected: !reason,
      provider: reason || config.provider === 'none' ? null : ACCOUNTING_PROVIDERS[config.provider].label,
    };
  }

  /** The list-page sync buttons (plan §12): run now, wait, report. */
  async syncNow(jobs: ('customers' | 'balances' | 'products')[]) {
    const reason = this.config.inactiveReason(await this.config.get());
    if (reason) throw new BadRequestException(`سینک با حسابداری انجام نمی‌شود: ${reason}`);
    const results = await this.worker.runPullsNow(jobs);
    if (!results) throw new BadRequestException('یک همگام‌سازی دیگر در حال اجراست؛ کمی بعد دوباره امتحان کنید');
    return { ok: Object.values(results).every((r) => r.ok), results };
  }

  /** Tests the connection as typed in the form (`connection`), falling back to what is saved. */
  async test(name: unknown, connection?: Record<string, unknown>) {
    if (!isProviderName(name)) throw new BadRequestException('نرم‌افزار حسابداری نامعتبر است');
    const provider = ACCOUNTING_PROVIDERS[name];
    const settings = this.config.draftSettings(await this.config.get(), name, connection);
    if (!settings) throw new BadRequestException('آدرس و توکن را وارد کنید');
    const started = Date.now();
    try {
      const info = await provider.health(settings);
      return { ok: true, provider: provider.label, ms: Date.now() - started, info };
    } catch (err) {
      return { ok: false, provider: provider.label, ms: Date.now() - started, error: this.sync.describeError(err) };
    }
  }

  /**
   * The certificate the server at `baseUrl` presents, for the admin to compare
   * and pin (a self-signed Tahesab install cannot be verified otherwise).
   */
  async certificate(baseUrl: unknown) {
    const url = cleanUrl(baseUrl, 'آدرس');
    if (!url) throw new BadRequestException('آدرس را وارد کنید');
    try {
      return await fetchServerCertificate(url, 10_000);
    } catch (err) {
      throw new BadRequestException(`گواهی دریافت نشد: ${this.sync.describeError(err)}`);
    }
  }

  /** Dropdown options for the mapping tab; each list fails on its own. */
  async options(name: unknown) {
    const { provider, settings } = await this.settingsOf(name);
    const safe = async <T>(fn: () => Promise<T>) => {
      try {
        return { ok: true as const, items: await fn() };
      } catch (err) {
        return { ok: false as const, items: [] as never[], error: this.sync.describeError(err) };
      }
    };
    const [customerGroups, karSakhteGroups, karSakhteTypes] = await Promise.all([
      safe(() => provider.listCustomerGroups(settings)),
      safe(() => provider.listKarSakhteGroups(settings)),
      safe(() => provider.listKarSakhteTypes(settings)),
    ]);
    const categories = await this.prisma.category.findMany({ select: { id: true, title: true }, orderBy: { title: 'asc' } });
    return { provider: provider.name, customerGroups, karSakhteGroups, karSakhteTypes, categories };
  }

  async run(job: string) {
    if (!JOBS.includes(job as JobName)) throw new BadRequestException('کار نامعتبر است');
    const config = await this.config.get();
    const reason = this.config.inactiveReason(config);
    if (reason) throw new BadRequestException(`همگام‌سازی انجام نمی‌شود: ${reason}`);
    if (job !== 'outbox' && !config.features[PULL_FEATURE[job as Exclude<JobName, 'outbox'>]]) {
      throw new BadRequestException('این قابلیت در تب «قابلیت‌ها و زمان‌بندی» خاموش است؛ اول روشن و ذخیره کنید');
    }
    const started = this.worker.runNow(job as JobName);
    return { started, message: started ? 'شروع شد' : 'یک همگام‌سازی دیگر در حال اجراست؛ کمی بعد دوباره امتحان کنید' };
  }

  // ── outbox log ──────────────────────────────────────────────────────

  async outbox(q: Record<string, unknown>) {
    const where: Prisma.AccountingOutboxWhereInput = {};
    if (typeof q.status === 'string' && STATUSES.includes(q.status as AccountingOutboxStatus)) {
      where.status = q.status as AccountingOutboxStatus;
    }
    if (typeof q.kind === 'string' && q.kind) where.kind = q.kind as Prisma.AccountingOutboxWhereInput['kind'];
    if (typeof q.entityId === 'string' && q.entityId) where.entityId = q.entityId;
    const p = page(q.page);
    const l = limit(q.limit);
    const [rows, total] = await Promise.all([
      this.prisma.accountingOutbox.findMany({ where, orderBy: { createdAt: 'desc' }, skip: (p - 1) * l, take: l }),
      this.prisma.accountingOutbox.count({ where }),
    ]);
    const labels = await this.labelsFor(rows.map((r) => ({ kind: r.kind, entityId: r.entityId })));
    return { rows: rows.map((r) => ({ ...r, entityLabel: labels.get(r.entityId) ?? null })), total, page: p, limit: l };
  }

  private async labelsFor(items: { kind: string; entityId: string }[]) {
    const orderIds = items.filter((i) => i.kind.startsWith('ORDER')).map((i) => i.entityId);
    const customerIds = items.filter((i) => i.kind === 'CUSTOMER_PUSH').map((i) => i.entityId);
    const productIds = items.filter((i) => i.kind === 'PRODUCT_PUSH').map((i) => i.entityId);
    const [orders, customers, products] = await Promise.all([
      orderIds.length ? this.prisma.order.findMany({ where: { id: { in: orderIds } }, select: { id: true, orderNumber: true, customer: { select: { fullName: true } } } }) : [],
      customerIds.length ? this.prisma.customer.findMany({ where: { id: { in: customerIds } }, select: { id: true, fullName: true, mobile: true } }) : [],
      productIds.length ? this.prisma.product.findMany({ where: { id: { in: productIds } }, select: { id: true, title: true } }) : [],
    ]);
    const m = new Map<string, string>();
    for (const o of orders) m.set(o.id, `سفارش ${o.orderNumber} — ${o.customer.fullName}`);
    for (const c of customers) m.set(c.id, `${c.fullName} (${c.mobile})`);
    for (const p of products) m.set(p.id, p.title);
    return m;
  }

  async retry(id: string) {
    const row = await this.prisma.accountingOutbox.findUnique({ where: { id } });
    if (!row) throw new NotFoundException('ردیف پیدا نشد');
    if (row.status === 'SENT' || row.status === 'SENDING') throw new BadRequestException('این ردیف قابل تلاش دوباره نیست');
    return this.prisma.accountingOutbox.update({
      where: { id },
      data: { status: 'PENDING', nextAttemptAt: new Date(), attempts: row.status === 'PENDING' ? row.attempts : 0 },
    });
  }

  async resolve(id: string, adminId: string, note?: string) {
    const row = await this.prisma.accountingOutbox.findUnique({ where: { id } });
    if (!row) throw new NotFoundException('ردیف پیدا نشد');
    if (row.status === 'SENDING') throw new BadRequestException('در حال ارسال است');
    return this.prisma.accountingOutbox.update({
      where: { id },
      data: { status: 'RESOLVED', resolvedById: adminId, lastError: note ? `حل‌شده: ${note}` : row.lastError },
    });
  }

  // ── issues ──────────────────────────────────────────────────────────

  async issues(q: Record<string, unknown>) {
    const where: Prisma.AccountingIssueWhereInput = q.resolved === '1' ? { resolvedAt: { not: null } } : { resolvedAt: null };
    const p = page(q.page);
    const l = limit(q.limit);
    const [rows, total] = await Promise.all([
      this.prisma.accountingIssue.findMany({ where, orderBy: { updatedAt: 'desc' }, skip: (p - 1) * l, take: l }),
      this.prisma.accountingIssue.count({ where }),
    ]);
    return { rows, total, page: p, limit: l };
  }

  resolveIssue(id: string) {
    return this.prisma.accountingIssue.update({ where: { id }, data: { resolvedAt: new Date() } });
  }

  // ── links ───────────────────────────────────────────────────────────

  async links(q: Record<string, unknown>) {
    const config = await this.config.get();
    const where: Prisma.AccountingLinkWhereInput = {};
    if (q.entityType === 'CUSTOMER' || q.entityType === 'PRODUCT') where.entityType = q.entityType;
    where.provider = isProviderName(q.provider) ? q.provider : config.provider === 'none' ? undefined : config.provider;
    if (typeof q.entityId === 'string' && q.entityId) where.entityId = q.entityId;
    if (typeof q.q === 'string' && q.q.trim()) {
      where.OR = [{ externalCode: { contains: q.q.trim() } }, { externalName: { contains: q.q.trim() } }];
    }
    const p = page(q.page);
    const l = limit(q.limit);
    const [rows, total] = await Promise.all([
      this.prisma.accountingLink.findMany({ where, orderBy: { createdAt: 'desc' }, skip: (p - 1) * l, take: l }),
      this.prisma.accountingLink.count({ where }),
    ]);
    return { rows, total, page: p, limit: l };
  }

  async manualLink(body: Record<string, unknown>) {
    const config = await this.config.get();
    if (config.provider === 'none') throw new BadRequestException('نرم‌افزار حسابداری انتخاب نشده است');
    const provider = config.provider as ProviderName;
    const entityType = body.entityType === 'PRODUCT' ? AccountingEntityType.PRODUCT : AccountingEntityType.CUSTOMER;
    const entityId = String(body.entityId ?? '').trim();
    const externalCode = String(body.externalCode ?? '').trim();
    if (!entityId || !externalCode) throw new BadRequestException('شناسه و کد حسابداری الزامی است');

    const exists =
      entityType === 'CUSTOMER'
        ? await this.prisma.customer.findUnique({ where: { id: entityId }, select: { id: true } })
        : await this.prisma.product.findUnique({ where: { id: entityId }, select: { id: true } });
    if (!exists) throw new NotFoundException('ردیف اپ پیدا نشد');

    const taken = await this.prisma.accountingLink.findUnique({
      where: { provider_entityType_externalCode: { provider, entityType, externalCode } },
    });
    if (taken && taken.entityId !== entityId) throw new BadRequestException('این کد به ردیف دیگری لینک است');

    return this.prisma.accountingLink.upsert({
      where: { provider_entityType_entityId: { provider, entityType, entityId } },
      update: { externalCode, origin: 'MANUAL', syncedAt: new Date() },
      create: { provider, entityType, entityId, externalCode, origin: 'MANUAL', externalName: (body.externalName as string) || null },
    });
  }

  async unlink(id: string) {
    await this.prisma.accountingLink.delete({ where: { id } }).catch(() => {
      throw new NotFoundException('لینک پیدا نشد');
    });
    return { success: true };
  }

  // ── per-row panels ──────────────────────────────────────────────────

  async customer(id: string) {
    const config = await this.config.get();
    const c = await this.prisma.customer.findUnique({
      where: { id },
      select: {
        id: true,
        goldDebtGrams: true,
        fiatDebtRial: true,
        accountingGoldBalance: true,
        accountingRialBalance: true,
        accountingBalanceAt: true,
      },
    });
    if (!c) throw new NotFoundException('مشتری یافت نشد');
    const link =
      config.provider === 'none'
        ? null
        : await this.prisma.accountingLink.findUnique({
            where: { provider_entityType_entityId: { provider: config.provider, entityType: 'CUSTOMER', entityId: id } },
          });
    const fresh = link ? await this.sync.customerBalance(id) : null;
    const jobs = await this.prisma.accountingOutbox.findMany({
      where: { entityId: id, kind: 'CUSTOMER_PUSH' },
      orderBy: { createdAt: 'desc' },
      take: 5,
    });
    return {
      provider: config.provider,
      link,
      internal: { gold: c.goldDebtGrams, rial: c.fiatDebtRial },
      accounting: fresh
        ? { gold: fresh.gold, rial: fresh.rial, at: fresh.at }
        : c.accountingBalanceAt
          ? { gold: c.accountingGoldBalance, rial: c.accountingRialBalance, at: c.accountingBalanceAt }
          : null,
      jobs,
    };
  }

  async productsStatus(idsCsv: string) {
    const ids = String(idsCsv ?? '')
      .split(',')
      .map((s) => s.trim())
      .filter(Boolean)
      .slice(0, 500);
    const config = await this.config.get();
    if (ids.length === 0) return {};
    const [products, links] = await Promise.all([
      this.prisma.product.findMany({
        where: { id: { in: ids } },
        select: {
          id: true,
          accountingStockWeight: true,
          accountingStockCount: true,
          accountingStockAt: true,
          _count: { select: { images: true } },
        },
      }),
      config.provider === 'none'
        ? []
        : this.prisma.accountingLink.findMany({ where: { provider: config.provider, entityType: 'PRODUCT', entityId: { in: ids } } }),
    ]);
    const linkBy = new Map(links.map((l) => [l.entityId, l]));
    return Object.fromEntries(
      products.map((p) => {
        const l = linkBy.get(p.id);
        return [
          p.id,
          {
            linked: !!l,
            locked: !!l && config.features.products,
            code: l?.externalCode ?? null,
            origin: l?.origin ?? null,
            stockWeight: p.accountingStockWeight,
            stockCount: p.accountingStockCount,
            stockAt: p.accountingStockAt,
            hasImage: p._count.images > 0,
          },
        ];
      }),
    );
  }

  async movement(q: Record<string, unknown>) {
    const a = await this.config.active();
    if (!a) throw new BadRequestException('اتصال حسابداری فعال نیست');
    const to = parseJalali(q.to as string) ?? toJalali(new Date());
    const from = parseJalali(q.from as string) ?? toJalali(new Date(Date.now() - 30 * 24 * 3600 * 1000));
    const rows = await a.provider.getKarSakhteMovement(a.settings, from, to);
    return { provider: a.provider.label, scope: a.provider.capabilities.movementScope, rows };
  }
}