import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import { DataSource } from 'typeorm';
import { isT1TransportFileCode, type Freight } from '@edr/types';

import { FilesService } from '../files/files.service';
import { Booking } from '../bookings/entities/booking.entity';
import { TrainSchedule } from '../train-schedules/entities/train-schedule.entity';
import {
  ClearanceIncident,
  IncidentType,
} from './entities/clearance-incident.entity';
import { ClearanceMilestoneService } from './clearance-milestone.service';
import {
  persistExportTransportUploads,
  persistT1TransportUploads,
} from './phased-clearance.util';

/**
 * Maps a GL post-booking document `code` to the milestone it auto-completes when
 * uploaded (doc §11.3/§12.2 — doc-triggered milestones). Uploading the document
 * marks the milestone done so the timeline advances without a separate click.
 */
const DOC_CODE_TO_MILESTONE: Record<string, string> = {
  release_order: 'RELEASE_ORDER_SECURED', // export — GL DJ
  delivery_order: 'DO_COLLECTED', // import — GL DJ
  // t1_transport_document intentionally NOT doc-triggered: T1_CLOSED completes only
  // when GL Ethiopia accepts the T1 set after the train arrives (closeT1).
  import_release: 'IMPORT_RELEASE_GRANTED', // import — GL ET
  full_in_interchange: 'OFFLOADED', // export — GL DJ
  final_declaration: 'IMPORT_PROCESS_COMPLETED', // import — GL ET
  export_transport_document: 'EXPORT_TRANSPORT_ISSUED', // export — GL ET post-allocation
};

/**
 * Operational Global Logistics actions that hang off a shipment booking after GL
 * creates it: station routing, damage/incident reporting, and the phased GL
 * document uploads (Release Order, Delivery Order, T1, etc.) that advance
 * doc-triggered milestones. See docs/new-doc.md §11–§13, gap matrix #14/#16/#18.
 */
@Injectable()
export class GlOperationsService {
  constructor(
    private readonly dataSource: DataSource,
    private readonly filesService: FilesService,
    private readonly milestoneService: ClearanceMilestoneService,
  ) {}

  private get bookings() {
    return this.dataSource.getRepository(Booking);
  }

  private get incidents() {
    return this.dataSource.getRepository(ClearanceIncident);
  }

  private async getBooking(bookingId: string): Promise<Booking> {
    const booking = await this.bookings.findOne({ where: { id: bookingId } });
    if (!booking) throw new NotFoundException(`Booking ${bookingId} not found`);
    return booking;
  }

  /**
   * Route a shipment to an origin station and (optionally) bind a GL staff user
   * to it (GL US-02). Setting both moves the shipment to that station's queue.
   */
  async assignStation(
    bookingId: string,
    input: { stationYardId: string; staffId?: string },
  ): Promise<Booking> {
    const booking = await this.getBooking(bookingId);
    booking.glStationYardId = input.stationYardId;
    if (input.staffId) {
      booking.glAssignedStaffId = input.staffId;
      booking.glAssignedAt = new Date();
    }
    return this.bookings.save(booking);
  }

  /** Log a cargo exception (seal broken, container damaged, etc.) with photos. */
  async reportIncident(
    bookingId: string,
    input: {
      incidentType: IncidentType;
      description: string;
      files: Express.Multer.File[];
    },
    userId?: string,
  ): Promise<ClearanceIncident> {
    await this.getBooking(bookingId);
    if (!input.description?.trim()) {
      throw new BadRequestException('A description is required for an incident report.');
    }
    const photoFileIds: string[] = [];
    for (const file of input.files ?? []) {
      const record = await this.filesService.upload({
        resourceId: bookingId,
        resource: 'bookings',
        code: 'incident_photo',
        file,
      });
      photoFileIds.push(record.id);
    }
    const incident = this.incidents.create({
      bookingId,
      incidentType: input.incidentType,
      description: input.description.trim(),
      photoFileIds,
      reportedByUserId: userId ?? null,
      reportedAt: new Date(),
    });
    return this.incidents.save(incident);
  }

  async listIncidents(bookingId: string): Promise<ClearanceIncident[]> {
    return this.incidents.find({
      where: { bookingId },
      order: { reportedAt: 'DESC' },
    });
  }

  /**
   * Customer uploads the duty/tax payment slip after GL advised the amount. The
   * slip attaches to the booking and doc-triggers DUTY_TAX_PAID (§11.3 #7).
   */
  async uploadDutySlip(
    bookingId: string,
    file: Express.Multer.File,
  ): Promise<{ milestoneCompleted: boolean }> {
    await this.getBooking(bookingId);
    if (!file) throw new BadRequestException('No payment slip uploaded');
    await this.filesService.upsertByCode({
      resourceId: bookingId,
      resource: 'bookings',
      code: 'duty_tax_receipt',
      file,
    });
    await this.milestoneService.completeByDocTrigger({ bookingId }, 'DUTY_TAX_PAID');
    return { milestoneCompleted: true };
  }

  /**
   * GL uploads a post-booking operational document (DO, RO, T1, import release,
   * interchange…). The file attaches to the booking; if the code maps to a
   * doc-triggered milestone, that milestone auto-completes.
   */
  async uploadDocuments(
    bookingId: string,
    files: Express.Multer.File[],
  ): Promise<{ uploaded: number; completedMilestones: string[] }> {
    await this.getBooking(bookingId);
    if (!files?.length) throw new BadRequestException('No documents uploaded');

    const completedMilestones: string[] = [];
    for (const file of files) {
      await this.filesService.upsertByCode({
        resourceId: bookingId,
        resource: 'bookings',
        code: file.fieldname,
        file,
      });
      const milestoneCode = DOC_CODE_TO_MILESTONE[file.fieldname];
      if (milestoneCode) {
        await this.milestoneService.completeByDocTrigger({ bookingId }, milestoneCode);
        completedMilestones.push(milestoneCode);
      }
    }
    return { uploaded: files.length, completedMilestones };
  }

  /**
   * T1 transit-document lifecycle state for an import shipment booking. Wagon
   * allocation opens the upload window; train departure locks it; train arrival
   * lets GL Ethiopia close (accept) the T1 set.
   */
  async t1State(bookingId: string): Promise<Freight.ClearanceT1State> {
    const booking = await this.getBooking(bookingId);
    const milestones = await this.milestoneService.listForBooking(bookingId);

    const wagonMilestone = milestones.find((m) => m.milestoneCode === 'WAGON_ALLOCATED');
    const wagonAllocated =
      wagonMilestone?.status === 'COMPLETED' ||
      booking.schedulingStatus === 'SCHEDULED' ||
      booking.schedulingStatus === 'DISPATCHED' ||
      Boolean(booking.trainScheduleId);

    let schedule: TrainSchedule | null = null;
    if (booking.trainScheduleId) {
      schedule = await this.dataSource
        .getRepository(TrainSchedule)
        .findOne({ where: { id: booking.trainScheduleId } });
    }

    const closedMilestone = milestones.find(
      (m) => m.milestoneCode === 'T1_CLOSED' && m.status === 'COMPLETED',
    );

    return {
      bookingId,
      wagonAllocated,
      trainDepartedAt: schedule?.actualDepartureAt
        ? new Date(schedule.actualDepartureAt).toISOString()
        : null,
      trainArrivedAt: schedule?.actualArrivalAt
        ? new Date(schedule.actualArrivalAt).toISOString()
        : null,
      closed: Boolean(closedMilestone),
      closedAt: closedMilestone?.triggeredAt
        ? new Date(closedMilestone.triggeredAt).toISOString()
        : null,
    };
  }

  /**
   * GL Djibouti uploads T1 transport documents (multi-file) after wagon allocation.
   * Replaces the previous batch; locked once the train departs or T1 is closed.
   */
  async uploadT1Documents(
    bookingId: string,
    files: Express.Multer.File[],
  ): Promise<{ uploaded: number }> {
    const booking = await this.getBooking(bookingId);
    if (booking.tradeDirection !== 'IMPORT') {
      throw new BadRequestException('T1 transport documents apply to import shipments only.');
    }

    const state = await this.t1State(bookingId);
    if (!state.wagonAllocated) {
      throw new BadRequestException(
        'Wagons must be allocated before T1 transport documents can be uploaded.',
      );
    }
    if (state.closed) {
      throw new BadRequestException('T1 has been closed by GL Ethiopia — documents are final.');
    }
    if (state.trainDepartedAt) {
      throw new BadRequestException(
        'The train has departed — T1 transport documents can no longer be changed.',
      );
    }

    await persistT1TransportUploads(this.filesService, bookingId, files);
    return { uploaded: files.length };
  }

  /**
   * GL Ethiopia closes (accepts) the T1 document set once the train has arrived.
   * Completes the T1_CLOSED milestone; the document set becomes final.
   */
  async closeT1(
    bookingId: string,
    userId?: string,
  ): Promise<Freight.ClearanceT1State> {
    const booking = await this.getBooking(bookingId);
    if (booking.tradeDirection !== 'IMPORT') {
      throw new BadRequestException('T1 closure applies to import shipments only.');
    }

    const state = await this.t1State(bookingId);
    if (state.closed) return state;
    if (!state.trainArrivedAt) {
      throw new BadRequestException(
        'The train has not arrived yet — T1 can be closed only after arrival.',
      );
    }

    const files = await this.filesService.findByResource(bookingId, 'bookings');
    const hasT1 = files.some((f) => isT1TransportFileCode(f.code));
    if (!hasT1) {
      throw new BadRequestException(
        'No T1 transport documents on file — GL Djibouti must upload them first.',
      );
    }

    await this.milestoneService.completeForBooking(bookingId, 'T1_CLOSED', userId);
    return this.t1State(bookingId);
  }

  /**
   * GL ET uploads export transport document after wagon allocation (export ONE_TIME).
   */
  async uploadTransportDocument(
    bookingId: string,
    files: Express.Multer.File[],
  ): Promise<{ uploaded: boolean; milestoneCompleted: boolean }> {
    const booking = await this.getBooking(bookingId);
    if (booking.tradeDirection !== 'EXPORT') {
      throw new BadRequestException('Transport document upload applies to export shipments only.');
    }

    const milestones = await this.milestoneService.listForBooking(bookingId);
    const wagonAllocated = milestones.find((m) => m.milestoneCode === 'WAGON_ALLOCATED');
    const wagonDone =
      wagonAllocated?.status === 'COMPLETED' || booking.schedulingStatus === 'SCHEDULED';
    if (!wagonDone) {
      throw new BadRequestException(
        'Wagon must be allocated before the transport document can be uploaded.',
      );
    }

    if (files.length === 0) {
      throw new BadRequestException('No transit permit documents uploaded');
    }

    await persistExportTransportUploads(this.filesService, bookingId, files);

    if (wagonAllocated && wagonAllocated.status !== 'COMPLETED') {
      await this.milestoneService.completeForBooking(bookingId, 'WAGON_ALLOCATED');
    }

    await this.milestoneService.completeByDocTrigger(
      { bookingId },
      'EXPORT_TRANSPORT_ISSUED',
    );

    return { uploaded: true, milestoneCompleted: true };
  }
}