import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import { LedgerCurrency, LedgerDirection, LedgerSourceType, Prisma } from '@prisma/client';
import { PrismaService } from '../../prisma/prisma.service';
import { TableService } from '../admin-table/table.service';
import { LedgerService } from '../accounting/ledger.service';
import { SmsService } from '../sms/sms.service';
import type { TableQueryDto } from '../admin-table/table-query.dto';

/**
 * Financial documents ("اسناد مالی") — legacy views/finical/*, served by
 * CashController (`POST cash/table`, `POST cash`, `PUT cash/{id}`,
 * `GET cash/{id}`, `DELETE cash/{id}`).
 *
 * A legacy "cash" row IS a ledger entry: a customer repayment recorded as melted
 * gold, a transfer, a cheque or cash. The four legacy `type` codes map onto the
 * existing LedgerSourceType enum:
 *
 *   1 آب شده  -> REPAYMENT_MELTED_GOLD  (karat-normalized: value * ayar / 750)
 *   2 حواله   -> REPAYMENT_TRANSFER
 *   3 چک      -> REPAYMENT_CHEQUE
 *   4 پولی    -> REPAYMENT_CASH         (normalized via the gold price per gram)
 *
 * Posting delegates to LedgerService, which owns the karat and price-per-gram
 * conversions and the confirm/balance rules. Re-implementing them here would let
 * the admin path drift from the customer-facing one.
 */
const TYPE_BY_CODE: Record<number, LedgerSourceType> = {
  1: LedgerSourceType.REPAYMENT_MELTED_GOLD,
  2: LedgerSourceType.REPAYMENT_TRANSFER,
  3: LedgerSourceType.REPAYMENT_CHEQUE,
  4: LedgerSourceType.REPAYMENT_CASH,
};

/** The instrument name LedgerService.postGoldRepayment expects. */
const INSTRUMENT_BY_TYPE: Record<string, 'MELTED_GOLD' | 'TRANSFER' | 'CHEQUE' | 'CASH'> = {
  REPAYMENT_MELTED_GOLD: 'MELTED_GOLD',
  REPAYMENT_TRANSFER: 'TRANSFER',
  REPAYMENT_CHEQUE: 'CHEQUE',
  REPAYMENT_CASH: 'CASH',
};

const CODE_BY_TYPE: Partial<Record<LedgerSourceType, number>> = {
  REPAYMENT_MELTED_GOLD: 1,
  REPAYMENT_TRANSFER: 2,
  REPAYMENT_CHEQUE: 3,
  REPAYMENT_CASH: 4,
};

const TYPE_LABELS: Record<LedgerSourceType, string> = {
  ORDER_STOCK: 'سفارش',
  ORDER_PRE_ORDER: 'سفارش ساختنی',
  REPAYMENT_MELTED_GOLD: 'آب شده',
  REPAYMENT_TRANSFER: 'حواله',
  REPAYMENT_CHEQUE: 'چک',
  REPAYMENT_CASH: 'پولی',
  WALLET_BONUS: 'هدیه کیف پول',
  ADJUSTMENT: 'اصلاح',
};

@Injectable()
export class AdminDocumentsService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly table: TableService,
    private readonly ledger: LedgerService,
    private readonly sms: SmsService,
  ) {}

  private static readonly ALLOWED = [
    'id',
    'sourceType',
    'currency',
    'direction',
    'amount',
    'confirmed',
    'createdAt',
    'karatPerMille',
    'labName',
    'customer.fullName',
    // legacy filter keys
    'type_str',
    'ayar',
    'lab',
    'caj',
  ];

  private static readonly FIELD_ALIASES: Record<string, string> = {
    type_str: 'sourceType',
    ayar: 'karatPerMille',
    lab: 'labName',
    caj: 'createdAt',
    uaj: 'createdAt',
    'customer.name': 'customer.fullName',
    value: 'amount',
    price: 'priceRial',
    original_value: 'originalValue',
    account_name: 'accountName',
    bank_name: 'bankName',
    to: 'transferTo',
    recive_date: 'receivedAt',
    price_per_gram: 'pricePerGramRialAtEntry',
    ang: 'hallmark',
  };

  /** Legacy `POST cash/table` — the documents grid. */
  async list(query: TableQueryDto) {
    this.table.assertNotExport(query);

    const mapField = (f?: string) => (f ? (AdminDocumentsService.FIELD_ALIASES[f] ?? f) : f);
    const aliased: TableQueryDto = {
      ...query,
      filters: (query.filters ?? []).map((f) => {
        const mapped = { ...f, field: mapField(f.field) };
        if (mapped.field === 'sourceType' && mapped.value !== undefined) {
          mapped.value = TYPE_BY_CODE[Number(mapped.value)] ?? mapped.value;
        }
        if (mapped.field === 'confirmed' && mapped.value !== undefined) {
          mapped.value = String(mapped.value) === '1';
        }
        return mapped;
      }),
      order: query.order
        ? `${query.order.startsWith('-') ? '-' : '+'}${mapField(query.order.replace(/^[+-]/, ''))}`
        : undefined,
    };

    const { where, orderBy, skip, take, page, limit } = this.table.build(aliased, {
      searchable: ['note', 'customer.fullName', 'labName'],
      allowed: AdminDocumentsService.ALLOWED,
      defaultOrderBy: { createdAt: 'desc' },
    });

    // The grid is the REPAYMENT document list; order-generated debt entries are
    // not documents an operator files, so they are excluded as legacy's separate
    // `cash` table naturally did.
    const scoped: Prisma.LedgerEntryWhereInput = {
      AND: [
        where as Prisma.LedgerEntryWhereInput,
        { sourceType: { in: Object.values(TYPE_BY_CODE) } },
      ],
    };

    const [rows, total] = await Promise.all([
      this.prisma.ledgerEntry.findMany({
        where: scoped,
        orderBy: orderBy as Prisma.LedgerEntryOrderByWithRelationInput,
        skip,
        take,
        include: { customer: true, postedByAdminUser: true },
      }),
      this.prisma.ledgerEntry.count({ where: scoped }),
    ]);

    return this.table.respond(rows.map((r) => this.toRow(r)), total, query, page, limit);
  }

  /** Legacy field names preserved so the ported table model binds unchanged. */
  private toRow(
    e: Prisma.LedgerEntryGetPayload<{ include: { customer: true; postedByAdminUser: true } }>,
  ) {
    return {
      id: e.id,
      type: CODE_BY_TYPE[e.sourceType] ?? null,
      type_str: TYPE_LABELS[e.sourceType],
      sourceType: e.sourceType,
      currency: e.currency,
      direction: e.direction,
      // legacy `value` is the normalized final weight, `original_value` the raw one
      value: e.amount,
      original_value: e.originalValue,
      price: e.priceRial,
      price_per_gram: e.pricePerGramRialAtEntry,
      ayar: e.karatPerMille,
      lab: e.labName,
      ang: e.hallmark,
      account_name: e.accountName,
      bank_name: e.bankName,
      to: e.transferTo,
      recive_date: e.receivedAt,
      note: e.note,
      // legacy grid renders `confirmed` through a slot using 0/1
      confirmed: e.confirmed ? 1 : 0,
      confirmedAt: e.confirmedAt,
      customer: {
        id: e.customer.id,
        name: e.customer.fullName,
        // D0 — real name parts
        fname: e.customer.firstName ?? e.customer.fullName,
        lname: e.customer.lastName ?? '',
        mobile: e.customer.mobile,
      },
      posted_by: e.postedByAdminUser ? e.postedByAdminUser.fullName : null,
      caj: e.createdAt,
      uaj: e.createdAt,
    };
  }

  /** Legacy `GET cash/{id}`. */
  async findOne(id: string) {
    const e = await this.prisma.ledgerEntry.findUnique({
      where: { id },
      include: { customer: true, postedByAdminUser: true },
    });
    if (!e) throw new NotFoundException('سند یافت نشد');
    return this.toRow(e);
  }

  /**
   * Legacy `POST cash` — file a repayment document.
   *
   * The gram/karat/price conversions are LedgerService's job; this method only
   * translates the legacy form shape and attaches the instrument metadata.
   */
  async create(data: Record<string, unknown>, actorAdminUserId: string) {
    const typeCode = Number(data.type ?? 2);
    const sourceType = TYPE_BY_CODE[typeCode];
    if (!sourceType) throw new BadRequestException('نوع سند نامعتبر است');

    const customerId = String(data.customer_id ?? '');
    if (!customerId) throw new BadRequestException('مشتری انتخاب نشده است');

    // LedgerService takes the legacy instrument name and the RAW figure, then
    // applies the karat / price-per-gram conversion itself.
    const instrument = INSTRUMENT_BY_TYPE[sourceType];

    // Which field carries the raw figure depends on the instrument, exactly as
    // the legacy form did: cash posts a Rial price, melted gold posts the
    // pre-normalization weight, transfer/cheque post grams directly.
    const rawValue =
      instrument === 'CASH'
        ? String(data.price ?? 0)
        : instrument === 'MELTED_GOLD'
          ? String(data.original_value ?? data.value ?? 0)
          : String(data.value ?? 0);

    const entry = await this.ledger.postGoldRepayment({
      customerId,
      instrument,
      rawValue,
      karatPerMille: data.ayar ? Number(data.ayar) : undefined,
      pricePerGramRial: data.price_per_gram ? String(data.price_per_gram) : undefined,
      note: (data.note as string) ?? undefined,
      postedByAdminUserId: actorAdminUserId,
    });

    // Attach the instrument metadata the ledger service does not model.
    await this.prisma.ledgerEntry.update({
      where: { id: entry.id },
      data: this.metadataPatch(data),
    });

    return this.findOne(entry.id);
  }

  private metadataPatch(data: Record<string, unknown>): Prisma.LedgerEntryUpdateInput {
    const patch: Prisma.LedgerEntryUpdateInput = {};
    if (data.lab !== undefined) patch.labName = (data.lab as string) || null;
    if (data.ang !== undefined) patch.hallmark = (data.ang as string) || null;
    if (data.account_name !== undefined) patch.accountName = (data.account_name as string) || null;
    if (data.bank_name !== undefined) patch.bankName = (data.bank_name as string) || null;
    if (data.to !== undefined) patch.transferTo = (data.to as string) || null;
    if (data.original_value !== undefined && data.original_value !== null) {
      patch.originalValue = new Prisma.Decimal(String(data.original_value));
    }
    if (data.price !== undefined && data.price !== null) {
      patch.priceRial = new Prisma.Decimal(String(data.price));
    }
    if (data.recive_date) patch.receivedAt = new Date(String(data.recive_date));
    return patch;
  }

  /**
   * Legacy `PUT cash/{id}` — edit a document.
   *
   * Only metadata and the note are editable. Changing the AMOUNT of a confirmed
   * entry would silently rewrite a customer's debt, so that is refused: the
   * correct accounting action is a reversing adjustment, not an edit. Legacy
   * allowed it. Recorded in docs/ADMIN-PORT-PLAN.md.
   */
  async update(id: string, data: Record<string, unknown>) {
    const existing = await this.prisma.ledgerEntry.findUnique({ where: { id } });
    if (!existing) throw new NotFoundException('سند یافت نشد');

    const amountChanged =
      data.value !== undefined && !new Prisma.Decimal(String(data.value)).equals(existing.amount);

    if (existing.confirmed && amountChanged) {
      throw new BadRequestException(
        'مبلغ سند تاییدشده قابل ویرایش نیست، چون بدهی مشتری بر اساس آن محاسبه شده است. برای اصلاح، سند جدید ثبت کنید.',
      );
    }

    const patch = this.metadataPatch(data);
    if (data.note !== undefined) patch.note = (data.note as string) || null;
    if (!existing.confirmed && amountChanged) {
      patch.amount = new Prisma.Decimal(String(data.value));
    }

    await this.prisma.ledgerEntry.update({ where: { id }, data: patch });
    return this.findOne(id);
  }

  /**
   * Legacy `POST cash/confirem/{id}` (legacy's own spelling) — a TOGGLE: the grid
   * shows a tick on an unconfirmed row and a cross on a confirmed one, both
   * calling this same endpoint.
   *
   * Confirming delegates to LedgerService so the customer balance moves through
   * the one code path that owns it. Un-confirming reverses that same amount
   * rather than editing the balance directly, so the two stay consistent.
   */
  async toggleConfirm(id: string, adminUserId: string) {
    const e = await this.prisma.ledgerEntry.findUnique({ where: { id } });
    if (!e) throw new NotFoundException('سند یافت نشد');

    if (!e.confirmed) {
      await this.ledger.confirmEntry(id, adminUserId);
      this.notifyDocumentConfirm(e.customerId, true);
      return this.findOne(id);
    }

    // Un-confirm: undo this entry's effect on the cached balance, then clear the
    // flag. A repayment is a CREDIT against gold debt, so reversing it adds the
    // amount back.
    await this.prisma.$transaction(async (tx) => {
      const delta =
        e.direction === LedgerDirection.CREDIT ? e.amount : e.amount.negated();
      const field =
        e.currency === LedgerCurrency.GOLD_GRAM ? 'goldDebtGrams' : 'fiatDebtRial';

      await tx.customer.update({
        where: { id: e.customerId },
        data: { [field]: { increment: delta } },
      });
      await tx.ledgerEntry.update({
        where: { id },
        data: { confirmed: false, confirmedAt: null },
      });
    });

    this.notifyDocumentConfirm(e.customerId, false);
    return this.findOne(id);
  }

  // Legacy CashController::toggleConfiremCash sent an SMS on both outcomes.
  private notifyDocumentConfirm(customerId: string, confirmed: boolean) {
    const text = confirmed
      ? 'هنزا گلد\nسند مالی شما توسط مدیر سیستم تایید شد.'
      : 'هنزا گلد\nسند مالی شما توسط مدیر سیستم رد شد.';

    this.prisma.customer
      .findUnique({ where: { id: customerId }, select: { mobile: true } })
      .then((c) => {
        if (c) this.sms.send(c.mobile, text);
      })
      .catch(() => {});
  }

  /**
   * Legacy `DELETE cash/{id}`.
   *
   * A confirmed entry has already moved the customer's balance; deleting it
   * would leave that balance overstated with no trace. Refused — legacy allowed
   * it. Unconfirmed entries never touched a balance, so they delete cleanly.
   */
  async remove(id: string) {
    const e = await this.prisma.ledgerEntry.findUnique({ where: { id } });
    if (!e) throw new NotFoundException('سند یافت نشد');
    if (e.confirmed) {
      throw new BadRequestException(
        'حذف سند تاییدشده ممکن نیست، چون در تراز مشتری اعمال شده است.',
      );
    }
    await this.prisma.ledgerEntry.delete({ where: { id } });
    return { success: true };
  }

  typeOptions() {
    return Object.entries(TYPE_BY_CODE).map(([code, sourceType]) => ({
      value: Number(code),
      title: TYPE_LABELS[sourceType],
    }));
  }

  // ── Wallet ─────────────────────────────────────────────────────────

  /** Legacy `POST wallet` grid — the list of granted wallet bonuses. */
  async listWallet(query: TableQueryDto) {
    this.table.assertNotExport(query);

    const { where, orderBy, skip, take, page, limit } = this.table.build(query, {
      searchable: ['customer.fullName'],
      allowed: ['id', 'goldGrams', 'grantedAt', 'expiresAt', 'isActive', 'customer.fullName'],
      defaultOrderBy: { grantedAt: 'desc' },
    });

    const [rows, total] = await Promise.all([
      this.prisma.walletBonus.findMany({
        where: where as Prisma.WalletBonusWhereInput,
        orderBy: orderBy as Prisma.WalletBonusOrderByWithRelationInput,
        skip,
        take,
        include: { customer: true },
      }),
      this.prisma.walletBonus.count({ where: where as Prisma.WalletBonusWhereInput }),
    ]);

    return this.table.respond(
      rows.map((w) => ({
        id: w.id,
        value: w.goldGrams,
        grams: w.goldGrams,
        is_active: w.isActive,
        consumed: Boolean(w.consumedAt),
        caj: w.grantedAt,
        expires_at: w.expiresAt,
        customer: {
          id: w.customer.id,
          name: w.customer.fullName,
          mobile: w.customer.mobile,
        },
      })),
      total,
      query,
      page,
      limit,
    );
  }

  /**
   * Legacy `GET /wallet/config` and `/wallet/birthday/config`, plus their POST
   * counterparts — the wallet settings screen (views/manage/wallet.vue).
   * Stored in the Setting key/value table that replaces legacy `config_static`.
   */
  async getSetting(key: string) {
    const row = await this.prisma.setting.findUnique({ where: { key } });
    return row?.value ?? {};
  }

  async setSetting(key: string, value: Record<string, unknown>) {
    const row = await this.prisma.setting.upsert({
      where: { key },
      update: { value: value as Prisma.InputJsonValue },
      create: { key, value: value as Prisma.InputJsonValue },
    });
    return row.value;
  }

  /** The customer picker used by the document form — legacy `GET query/customer`. */
  async queryCustomers() {
    const rows = await this.prisma.customer.findMany({
      where: { isActive: true },
      orderBy: { fullName: 'asc' },
      select: { id: true, fullName: true, firstName: true, lastName: true, mobile: true },
    });
    // D0 — real name parts.
    return rows.map((c) => ({
      id: c.id,
      name: c.fullName,
      fname: c.firstName ?? c.fullName,
      lname: c.lastName ?? '',
      mobile: c.mobile,
    }));
  }
}