import { Injectable } from '@nestjs/common';

import {
  BOOKING_LIST_TABS,
  mapStatusCountsToTabs,
} from '../bookings/booking-list-tabs.config';
import type { OverviewRangeQuery } from './dto/overview-query.dto';
import type { OverviewResponseDto } from './dto/overview-response.dto';
import type {
  OverviewBillingTabDto,
  OverviewBookingsTabDto,
  OverviewClearanceTabDto,
  OverviewContractsTabDto,
  OverviewCustomersTabDto,
  OverviewFleetTabDto,
  OverviewOperationsTabDto,
  OverviewStaffTabDto,
} from './dto/overview-tab-response.dto';
import {
  OVERVIEW_RANGE_DAYS,
  mapContractStatusCountsToPipeline,
} from './overview.constants';
import { OverviewRepository } from './overview.repository';

@Injectable()
export class OverviewService {
  constructor(private readonly overviewRepository: OverviewRepository) {}

  private mapStatusCounts(statusCounts: Record<string, number>) {
    const pipelineTabs = mapStatusCountsToTabs(statusCounts);
    const bookingsByPipeline = BOOKING_LIST_TABS.filter(
      (tab) => tab.key !== 'all',
    ).map((tab) => ({
      stage: tab.key,
      count: pipelineTabs[tab.key],
    }));

    const bookingsByStatus = Object.entries(statusCounts)
      .map(([status, count]) => ({ status, count }))
      .sort((a, b) => b.count - a.count);

    return { bookingsByPipeline, bookingsByStatus };
  }

  async getDashboard(
    range: OverviewRangeQuery = '30d',
    dirs?: string[],
  ): Promise<OverviewResponseDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      bookingKpis,
      contractKpis,
      operationsKpis,
      customerKpis,
      billingKpis,
      staffKpis,
      bookingTrend,
      statusCounts,
      paymentTrend,
      current,
      previous,
      revenueByDirection,
      revenueByFreightType,
      previousPaymentTrend,
      tonsTrend,
      revenueFlows,
      bookingHeatmap,
    ] = await Promise.all([
      this.overviewRepository.getBookingKpis(dirs),
      this.overviewRepository.getContractKpis(dirs),
      this.overviewRepository.getOperationsKpis(),
      this.overviewRepository.getCustomerKpis(),
      this.overviewRepository.getBillingKpis(dirs),
      this.overviewRepository.getStaffKpis(),
      this.overviewRepository.getBookingTrend(days, dirs),
      this.overviewRepository.getStatusCounts(dirs),
      this.overviewRepository.getPaymentTrend(days, dirs),
      this.overviewRepository.getPeriodTotals(days, 0, dirs),
      this.overviewRepository.getPeriodTotals(days, days, dirs),
      this.overviewRepository.getRevenueByDirection(days, dirs),
      this.overviewRepository.getRevenueByFreightType(days, dirs),
      this.overviewRepository.getPaymentTrend(days, dirs, days),
      this.overviewRepository.getTonsTrend(days, dirs),
      this.overviewRepository.getRevenueFlows(days, dirs),
      this.overviewRepository.getBookingHeatmap(days, dirs),
    ]);

    const { bookingsByPipeline, bookingsByStatus } =
      this.mapStatusCounts(statusCounts);

    return {
      kpis: {
        bookings: bookingKpis,
        contracts: contractKpis,
        operations: operationsKpis,
        customers: customerKpis,
        billing: billingKpis,
        staff: staffKpis,
      },
      bookingTrend,
      bookingsByStatus,
      bookingsByPipeline,
      paymentTrend,
      current,
      previous,
      revenueByDirection,
      revenueByFreightType,
      previousPaymentTrend,
      tonsTrend,
      revenueFlows,
      bookingHeatmap,
      generatedAt: new Date().toISOString(),
    };
  }

  async getBookingsTab(
    range: OverviewRangeQuery = '30d',
    dirs?: string[],
  ): Promise<OverviewBookingsTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      kpis,
      bookingTrend,
      statusCounts,
      bookingsByFreightType,
      bookingsByCurrency,
      recentBookings,
    ] = await Promise.all([
      this.overviewRepository.getBookingKpis(dirs),
      this.overviewRepository.getBookingTrend(days, dirs),
      this.overviewRepository.getStatusCounts(dirs),
      this.overviewRepository.getBookingsByFreightType(dirs),
      this.overviewRepository.getBookingsByCurrency(dirs),
      this.overviewRepository.getRecentBookings(8, dirs),
    ]);

    const { bookingsByPipeline, bookingsByStatus } =
      this.mapStatusCounts(statusCounts);

    return {
      kpis,
      bookingTrend,
      bookingsByStatus,
      bookingsByPipeline,
      bookingsByFreightType,
      bookingsByCurrency,
      recentBookings: recentBookings.map((row) => ({
        ...row,
        createdAt: row.createdAt.toISOString(),
      })),
      generatedAt: new Date().toISOString(),
    };
  }

  async getContractsTab(
    range: OverviewRangeQuery = '30d',
    dirs?: string[],
  ): Promise<OverviewContractsTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      kpis,
      contractTrend,
      statusCounts,
      contractsByKind,
      contractsByFreightType,
      recentContracts,
    ] = await Promise.all([
      this.overviewRepository.getContractKpis(dirs),
      this.overviewRepository.getContractTrend(days, dirs),
      this.overviewRepository.getContractStatusCounts(dirs),
      this.overviewRepository.getContractsByKind(dirs),
      this.overviewRepository.getContractsByFreightType(dirs),
      this.overviewRepository.getRecentContracts(8, dirs),
    ]);

    const contractsByStatus = Object.entries(statusCounts)
      .map(([status, count]) => ({ status, count }))
      .sort((a, b) => b.count - a.count);
    const contractsByPipeline = mapContractStatusCountsToPipeline(statusCounts);

    return {
      kpis,
      contractTrend,
      contractsByStatus,
      contractsByPipeline,
      contractsByKind,
      contractsByFreightType,
      recentContracts: recentContracts.map((row) => ({
        ...row,
        validUntil: row.validUntil ? row.validUntil.toISOString() : null,
        createdAt: row.createdAt.toISOString(),
      })),
      generatedAt: new Date().toISOString(),
    };
  }

  async getBillingTab(
    range: OverviewRangeQuery = '30d',
    dirs?: string[],
  ): Promise<OverviewBillingTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [kpis, paymentTrend, paymentsByStatus, paymentsByMethod, revenueByCurrency] =
      await Promise.all([
        this.overviewRepository.getBillingKpis(dirs),
        this.overviewRepository.getPaymentTrend(days, dirs),
        this.overviewRepository.getPaymentsByStatus(dirs),
        this.overviewRepository.getPaymentsByMethod(dirs),
        this.overviewRepository.getRevenueByCurrency(dirs),
      ]);

    return {
      kpis,
      paymentTrend,
      paymentsByStatus,
      paymentsByMethod,
      revenueByCurrency,
      generatedAt: new Date().toISOString(),
    };
  }

  async getOperationsTab(
    range: OverviewRangeQuery = '30d',
  ): Promise<OverviewOperationsTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      kpis,
      departureTrend,
      scheduleStatusBreakdown,
      wagonsByType,
      wagonsByYard,
      containersBySize,
      cargoTonnageByType,
      trainStatusBreakdown,
      wagonStatusBreakdown,
      containerStatusBreakdown,
      cargoStatusBreakdown,
      bookingsByPort,
      bookingStatusByPort,
      trainLoads,
    ] = await Promise.all([
      this.overviewRepository.getOperationsKpis(),
      this.overviewRepository.getDepartureTrend(days),
      this.overviewRepository.getScheduleStatusBreakdown(),
      this.overviewRepository.getWagonsByType(),
      this.overviewRepository.getWagonsByYard(8),
      this.overviewRepository.getContainersBySize(),
      this.overviewRepository.getCargoTonnageByType(8),
      this.overviewRepository.getTrainStatusBreakdown(),
      this.overviewRepository.getWagonStatusBreakdown(),
      this.overviewRepository.getContainerStatusBreakdown(),
      this.overviewRepository.getCargoStatusBreakdown(),
      this.overviewRepository.getBookingsByPort(days),
      this.overviewRepository.getBookingStatusByPort(days),
      this.overviewRepository.getTrainLoads(8),
    ]);

    return {
      kpis,
      departureTrend,
      scheduleStatusBreakdown,
      wagonsByType,
      wagonsByYard,
      containersBySize,
      cargoTonnageByType,
      trainStatusBreakdown,
      wagonStatusBreakdown,
      containerStatusBreakdown,
      cargoStatusBreakdown,
      bookingsByPort,
      bookingStatusByPort,
      trainLoads,
      generatedAt: new Date().toISOString(),
    };
  }

  /**
   * Rolling stock in depth: wagons and locomotives crossed with type and yard,
   * plus how fast each train set turns around. Feeds the operations and control
   * centre dashboards.
   */
  async getFleetTab(
    range: OverviewRangeQuery = '30d',
  ): Promise<OverviewFleetTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      wagonStatusBreakdown,
      wagonStatusByType,
      wagonStatusByYard,
      locomotiveStatusBreakdown,
      locomotivesByYard,
      locomotivesByType,
      turnaround,
    ] = await Promise.all([
      this.overviewRepository.getWagonStatusBreakdown(),
      this.overviewRepository.getWagonStatusByType(),
      this.overviewRepository.getWagonStatusByYard(),
      this.overviewRepository.getLocomotiveStatusBreakdown(),
      this.overviewRepository.getLocomotivesByYard(),
      this.overviewRepository.getLocomotivesByType(),
      this.overviewRepository.getTrainTurnaround(days, 8),
    ]);

    return {
      wagonStatusBreakdown,
      wagonStatusByType,
      wagonStatusByYard,
      locomotiveStatusBreakdown,
      locomotivesByYard,
      locomotivesByType,
      avgTurnaroundHours: turnaround.avgHours,
      turnaroundByTrain: turnaround.rows,
      generatedAt: new Date().toISOString(),
    };
  }

  /** Document and invoice queues — the GL desks' and marketing's work in progress. */
  async getClearanceTab(): Promise<OverviewClearanceTabDto> {
    const [
      bookingDocumentsByStatus,
      contractDocumentsByStatus,
      invoicesByStatus,
      invoicesByType,
      handoversByMile,
    ] = await Promise.all([
      this.overviewRepository.getBookingDocumentsByStatus(),
      this.overviewRepository.getContractDocumentsByStatus(),
      this.overviewRepository.getInvoicesByStatus(),
      this.overviewRepository.getInvoicesByType(),
      this.overviewRepository.getHandoversByMile(),
    ]);

    return {
      bookingDocumentsByStatus,
      contractDocumentsByStatus,
      invoicesByStatus,
      invoicesByType,
      handoversByMile,
      generatedAt: new Date().toISOString(),
    };
  }

  async getCustomersTab(
    range: OverviewRangeQuery = '30d',
    dirs?: string[],
  ): Promise<OverviewCustomersTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [
      kpis,
      customerGrowthTrend,
      customersByType,
      topCustomersByBookings,
      profilesByTypeStatus,
    ] = await Promise.all([
      this.overviewRepository.getCustomerKpis(),
      this.overviewRepository.getCustomerGrowthTrend(days),
      this.overviewRepository.getCustomersByType(),
      this.overviewRepository.getTopCustomersByBookings(8, dirs),
      this.overviewRepository.getProfilesByTypeStatus(),
    ]);

    return {
      kpis,
      customerGrowthTrend,
      customersByType,
      topCustomersByBookings,
      profilesByTypeStatus,
      generatedAt: new Date().toISOString(),
    };
  }

  async getStaffTab(range: OverviewRangeQuery = '30d'): Promise<OverviewStaffTabDto> {
    const days = OVERVIEW_RANGE_DAYS[range];

    const [kpis, usersByStatus, employeeGrowthTrend, activeUsersBreakdown] =
      await Promise.all([
        this.overviewRepository.getStaffKpis(),
        this.overviewRepository.getUsersByStatus(),
        this.overviewRepository.getEmployeeGrowthTrend(days),
        this.overviewRepository.getActiveUsersBreakdown(),
      ]);

    return {
      kpis,
      usersByStatus,
      employeeGrowthTrend,
      activeUsersBreakdown,
      generatedAt: new Date().toISOString(),
    };
  }
}