Added discrepancy management for duplicate seats

apps/edr-passenger-api/src/modules/seats/duplicate-seats.dto.ts

@@ -0,0 +1,33 @@
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+import { IsArray, IsDateString, IsOptional, IsUUID } from 'class-validator';
+
+export class GetDuplicateSeatsQuery {
+  @ApiProperty({ example: '2026-07-17', description: 'Schedule date (YYYY-MM-DD)' })
+  @IsDateString()
+  date: string;
+
+  @ApiPropertyOptional({ description: 'Filter to a specific schedule ID' })
+  @IsOptional()
+  @IsUUID()
+  scheduleId?: string;
+}
+
+export class ResolveDuplicatesDto {
+  @ApiProperty({
+    description: 'BookingSeat IDs of the duplicate bookings to reassign',
+    type: [String],
+    example: ['uuid-booking-seat-1', 'uuid-booking-seat-2'],
+  })
+  @IsArray()
+  @IsUUID(undefined, { each: true })
+  bookingSeatIds: string[];
+
+  @ApiProperty({
+    description: 'Coach IDs to source replacement seats from (searched in order; first available seat per coach is used)',
+    type: [String],
+    example: ['uuid-coach-1', 'uuid-coach-2'],
+  })
+  @IsArray()
+  @IsUUID(undefined, { each: true })
+  coachIds: string[];
+}

apps/edr-passenger-api/src/modules/seats/seats.controller.ts

@@ -17,9 +17,11 @@ import {
   ApiParam,
   ApiQuery,
   ApiResponse,
+  ApiBody,
 } from "@nestjs/swagger";
 import { SeatsService } from "./seats.service";
 import { HoldSeatsDto, ReleaseHoldDto } from "./seats.dto";
+import { GetDuplicateSeatsQuery, ResolveDuplicatesDto } from "./duplicate-seats.dto";
 import { JwtGuard } from "../../common/jwt.guard";
 import { PassengerStaff } from "../../common/passenger-guards";
 import { PASSENGER_PERMS } from "../../seed/passenger-permissions.registry";
@@ -306,4 +308,90 @@ This makes it clear which segment of the route each seat is held for, enabling s
   ) {
     return this.service.importSeatsCSV(body.scheduleId, body.csv, body.commit);
   }
+
+  // ── Duplicate seat management (backoffice) ────────────────────────────────
+
+  @Get("duplicates")
+  @UseGuards(JwtGuard)
+  @ApiBearerAuth("JWT-auth")
+  @ApiOperation({
+    summary: "List duplicate seat assignments by schedule date",
+    description:
+      "Returns all schedules on the given date that have bookings sharing " +
+      "the same seat, grouped by coach. Each coach entry includes the duplicate " +
+      "groups (with full booking info) and the list of currently available seats " +
+      "that can be used for reassignment.",
+  })
+  @ApiQuery({ name: "date", example: "2026-07-17", description: "Schedule date (YYYY-MM-DD)" })
+  @ApiQuery({ name: "scheduleId", required: false, description: "Filter to a specific schedule" })
+  @ApiResponse({
+    status: 200,
+    description: "Duplicate seat report grouped by schedule → coach",
+    schema: {
+      example: {
+        date: "2026-07-17",
+        totalDuplicates: 1,
+        schedules: [{
+          scheduleId: "uuid",
+          departureAt: "2026-07-17T06:00:00.000Z",
+          origin: "Addis Ababa",
+          destination: "Dire Dawa",
+          coaches: [{
+            coachId: "uuid",
+            coachNumber: "C1",
+            coachTypeName: "SBC",
+            duplicates: [{
+              seatId: "uuid",
+              seatNumber: "12A",
+              leg: 1,
+              bookings: [
+                { bookingSeatId: "uuid", bookingId: "uuid", bookingRef: "ATPC9F", passengerName: "Abebe", contactPhone: "+251911000000", createdAt: "2026-07-16T10:00:00.000Z" },
+                { bookingSeatId: "uuid", bookingId: "uuid", bookingRef: "XYZ123", passengerName: "Kebede", contactPhone: "+251922000000", createdAt: "2026-07-16T11:00:00.000Z" },
+              ],
+            }],
+            availableSeats: [
+              { seatId: "uuid", seatNumber: "14B" },
+              { seatId: "uuid", seatNumber: "15A" },
+            ],
+          }],
+        }],
+      },
+    },
+  })
+  getDuplicateSeats(@Query() query: GetDuplicateSeatsQuery) {
+    return this.service.getDuplicateSeats(query.date, query.scheduleId);
+  }
+
+  @Post("duplicates/resolve")
+  @UseGuards(JwtGuard)
+  @ApiBearerAuth("JWT-auth")
+  @ApiOperation({
+    summary: "Auto-assign duplicate bookings to seats in selected coaches",
+    description:
+      "Staff selects which duplicate BookingSeat IDs to fix and which coaches to pull replacement seats from. " +
+      "The system automatically picks the first available (non-blocked, non-occupied) seat in the given coaches " +
+      "for each booking, updates BookingSeat + Ticket + JourneySegment atomically so the seatmap reflects the " +
+      "change immediately, then sends an SMS notification to the passenger. " +
+      "Coaches are searched in the order provided; seats within each coach are assigned by row then column.",
+  })
+  @ApiBody({ type: ResolveDuplicatesDto })
+  @ApiResponse({
+    status: 200,
+    description: "Resolution summary — resolved count, unresolved count, per-booking results",
+    schema: {
+      example: {
+        resolved: 2,
+        unresolved: 0,
+        results: [
+          { bookingRef: "XYZ123", oldSeatNumber: "1A", newSeatNumber: "14B", contactPhone: "+251922000000" },
+          { bookingRef: "ABC456", oldSeatNumber: "1A", newSeatNumber: "15A", contactPhone: "+251933000000" },
+        ],
+      },
+    },
+  })
+  @ApiResponse({ status: 400, description: "Booking not in CONFIRMED/BOARDED status" })
+  @ApiResponse({ status: 404, description: "BookingSeat ID not found" })
+  resolveDuplicateSeats(@Body() dto: ResolveDuplicatesDto) {
+    return this.service.resolveDuplicateSeats(dto.bookingSeatIds, dto.coachIds);
+  }
 }

apps/edr-passenger-api/src/modules/seats/seats.module.ts

@@ -5,9 +5,10 @@ import { SeatsService } from './seats.service';
 import { SegmentsModule } from '../segments/segments.module';
 import { SystemConfigModule } from '../system-config/system-config.module';
 import { AuditModule } from '../../common/audit.module';
+import { NotificationsModule } from '../notifications/notifications.module';
 
 @Module({
-  imports: [SegmentsModule, HttpModule, SystemConfigModule, AuditModule],
+  imports: [SegmentsModule, HttpModule, SystemConfigModule, AuditModule, NotificationsModule],
   controllers: [SeatsController],
   providers: [SeatsService],
   exports: [SeatsService],

apps/edr-passenger-api/src/modules/seats/seats.service.ts

@@ -5,6 +5,7 @@ import { Cron, CronExpression } from '@nestjs/schedule';
 import { SegmentsService } from '../segments/segments.service';
 import { SystemConfigService, CONFIG_KEYS } from '../system-config/system-config.service';
 import { AuditService } from '../../common/audit.service';
+import { SmsClientService } from '../notifications/sms-client.service';
 import { computePaymentDeadline } from '../../common/utils/payment-deadline.utils';
 import { checkDirectionConflict } from '../../common/utils/journey-direction.utils';
 
@@ -17,6 +18,7 @@ export class SeatsService {
     private segmentsService: SegmentsService,
     private systemConfig: SystemConfigService,
     private auditService: AuditService,
+    private sms: SmsClientService,
   ) {}
 
   async getSeatMap(scheduleId: string, coachTypeId?: string, journeyDirection?: JourneyDirection, originStationId?: string, destinationStationId?: string) {
@@ -960,4 +962,416 @@ export class SeatsService {
       skippedSeatIds: Array.from(skippedSeatIds), // kept for logging/API compat; no DB writes needed
     };
   }
+
+  // ─────────────────────────────────────────────────────────────────────────
+  // Duplicate-seat management (backoffice)
+  // ─────────────────────────────────────────────────────────────────────────
+
+  async getDuplicateSeats(date: string, scheduleId?: string) {
+    const dayStart = new Date(`${date}T00:00:00.000Z`);
+    const dayEnd   = new Date(`${date}T23:59:59.999Z`);
+
+    const schedules = await this.prisma.trainSchedule.findMany({
+      where: {
+        departureAt: { gte: dayStart, lte: dayEnd },
+        ...(scheduleId ? { id: scheduleId } : {}),
+      },
+      orderBy: { departureAt: 'asc' },
+      include: {
+        originStation:      { select: { name: true } },
+        destinationStation: { select: { name: true } },
+        coachAssignments: {
+          orderBy: { positionNumber: 'asc' },
+          include: {
+            coach: {
+              include: {
+                coachType: { select: { name: true } },
+                seats: {
+                  orderBy: [{ row: 'asc' }, { col: 'asc' }],
+                  select: { id: true, seatNumber: true, status: true, coachId: true },
+                },
+              },
+            },
+          },
+        },
+      },
+    });
+
+    const result = [];
+
+    for (const schedule of schedules) {
+      // All confirmed BookingSeat rows for this schedule
+      const bookingSeats = await this.prisma.bookingSeat.findMany({
+        where: {
+          OR: [
+            { scheduleId: schedule.id },
+            { scheduleId: null, booking: { scheduleId: schedule.id } },
+          ],
+          booking: { status: { in: ['CONFIRMED', 'BOARDED'] } },
+        },
+        select: {
+          id: true, seatId: true, scheduleId: true, leg: true, passengerName: true,
+          seat: { select: { coachId: true } },
+          booking: {
+            select: {
+              id: true, bookingRef: true, scheduleId: true,
+              createdAt: true, contactPhone: true,
+            },
+          },
+        },
+      });
+
+      // Seats occupied by any confirmed journey on this schedule (source of truth)
+      const journeySegments = await this.prisma.journeySegment.findMany({
+        where: {
+          scheduleId: schedule.id,
+          seatId:     { not: null },
+          journey:    { status: { in: ['CONFIRMED', 'PENDING_PAYMENT'] } },
+        },
+        select: { seatId: true },
+      });
+      const occupiedIds = new Set(journeySegments.map(js => js.seatId!));
+
+      // Group BookingSeat rows by (seatId::leg) to detect duplicates
+      type BS = (typeof bookingSeats)[number];
+      const groups = new Map<string, BS[]>();
+      for (const bs of bookingSeats) {
+        const key = `${bs.seatId}::${bs.leg}`;
+        if (!groups.has(key)) groups.set(key, []);
+        groups.get(key)!.push(bs);
+      }
+
+      // All seats held by any confirmed BookingSeat — union of JourneySegment-based
+      // occupancy AND BookingSeat-based occupancy so that seats whose JourneySegments
+      // are missing (e.g. created via enhanced-seats path without bookingId) are still
+      // excluded from the available list.
+      const bookedSeatIds = new Set<string>([
+        ...occupiedIds,
+        ...bookingSeats.map(bs => bs.seatId).filter((id): id is string => id !== null && id !== undefined),
+      ]);
+
+      const coachReports = [];
+
+      for (const assignment of schedule.coachAssignments) {
+        const coach = assignment.coach;
+
+        // Duplicate groups whose seat belongs to this coach
+        const duplicates = [];
+        for (const [key, group] of groups) {
+          if (group.length <= 1) continue;
+          if (group[0].seat.coachId !== coach.id) continue;
+          const [seatId] = key.split('::');
+          const seat = coach.seats.find(s => s.id === seatId);
+          duplicates.push({
+            seatId,
+            seatNumber: seat?.seatNumber ?? seatId,
+            leg: group[0].leg,
+            bookings: group.map(bs => ({
+              bookingSeatId:  bs.id,
+              bookingId:      bs.booking.id,
+              bookingRef:     bs.booking.bookingRef,
+              passengerName:  bs.passengerName,
+              contactPhone:   bs.booking.contactPhone,
+              createdAt:      bs.booking.createdAt,
+            })),
+          });
+        }
+
+        // Free seats in this coach — excludes BLOCKED, all confirmed BookingSeat
+        // assignments, and all confirmed JourneySegment occupancies.
+        const availableSeats = coach.seats
+          .filter(s =>
+            (s.status as string) !== 'BLOCKED' &&
+            !s.seatNumber.startsWith('-') &&
+            !bookedSeatIds.has(s.id),
+          )
+          .map(s => ({ seatId: s.id, seatNumber: s.seatNumber }));
+
+        coachReports.push({
+          coachId:       coach.id,
+          coachNumber:   coach.number,
+          coachTypeName: coach.coachType.name,
+          duplicates,
+          availableSeats,
+        });
+      }
+
+      if (coachReports.some(c => c.duplicates.length > 0)) {
+        result.push({
+          scheduleId:  schedule.id,
+          departureAt: schedule.departureAt,
+          origin:      schedule.originStation.name,
+          destination: schedule.destinationStation.name,
+          coaches:     coachReports,
+        });
+      }
+    }
+
+    const totalDuplicates = result.reduce(
+      (sum, s) => sum + s.coaches.reduce((cs, c) => cs + c.duplicates.length, 0),
+      0,
+    );
+
+    return { date, schedules: result, totalDuplicates };
+  }
+
+  async resolveDuplicateSeats(bookingSeatIds: string[], coachIds: string[]) {
+    if (bookingSeatIds.length === 0) return { resolved: 0, unresolved: 0, results: [] };
+
+    // Load BookingSeat rows with full booking + schedule context
+    const bookingSeats = await this.prisma.bookingSeat.findMany({
+      where: { id: { in: bookingSeatIds } },
+      select: {
+        id: true, seatId: true, leg: true, scheduleId: true,
+        seat: { select: { seatNumber: true } },
+        booking: {
+          select: {
+            id: true, bookingRef: true, scheduleId: true,
+            status: true, contactPhone: true, passengerId: true,
+            totalMinor: true, currency: true,
+            originStationId: true, destinationStationId: true,
+            schedule: {
+              select: {
+                originStationId:      true,
+                destinationStationId: true,
+                originStation:        { select: { name: true } },
+                destinationStation:   { select: { name: true } },
+                departureAt:          true,
+              },
+            },
+          },
+        },
+      },
+    });
+
+    if (bookingSeats.length !== bookingSeatIds.length) {
+      const found   = new Set(bookingSeats.map(bs => bs.id));
+      const missing = bookingSeatIds.filter(id => !found.has(id));
+      throw new NotFoundException(`BookingSeat(s) not found: ${missing.join(', ')}`);
+    }
+
+    const invalid = bookingSeats.filter(bs => !['CONFIRMED', 'BOARDED'].includes(bs.booking.status));
+    if (invalid.length > 0) {
+      throw new BadRequestException(
+        `Bookings must be CONFIRMED or BOARDED: ${invalid.map(bs => bs.booking.bookingRef).join(', ')}`,
+      );
+    }
+
+    // Load all non-blocked, non-removed seats from the selected coaches (ordered for deterministic pick)
+    const coachSeats = await this.prisma.seat.findMany({
+      where: {
+        coachId:    { in: coachIds },
+        status:     { not: 'BLOCKED' },
+        NOT: { seatNumber: { startsWith: '-' } },
+      },
+      select: { id: true, seatNumber: true, coachId: true, row: true, col: true },
+      orderBy: [{ coachId: 'asc' }, { row: 'asc' }, { col: 'asc' }],
+    });
+
+    // Build occupied-seat sets per schedule from confirmed JourneySegments
+    const scheduleIds = [
+      ...new Set(
+        bookingSeats
+          .map(bs => bs.scheduleId ?? bs.booking.scheduleId)
+          .filter((id): id is string => id !== null && id !== undefined),
+      ),
+    ];
+
+    const occupiedBySchedule = new Map<string, Set<string>>();
+    await Promise.all(
+      scheduleIds.map(async scheduleId => {
+        const segments = await this.prisma.journeySegment.findMany({
+          where: {
+            scheduleId,
+            seatId:  { not: null },
+            journey: { status: { in: ['CONFIRMED', 'PENDING_PAYMENT', 'BOARDED'] } },
+          },
+          select: { seatId: true },
+        });
+        occupiedBySchedule.set(scheduleId, new Set(segments.map(s => s.seatId!)));
+      }),
+    );
+
+    // Track seats assigned within this batch to prevent double-assignment
+    const assignedInBatch = new Set<string>();
+
+    const results:    { bookingRef: string; oldSeatNumber: string; newSeatNumber: string; contactPhone: string | null }[] = [];
+    const unresolved: { bookingRef: string; reason: string }[] = [];
+
+    for (const bs of bookingSeats) {
+      const scheduleId = (bs.scheduleId ?? bs.booking.scheduleId)!;
+      const occupied   = occupiedBySchedule.get(scheduleId) ?? new Set<string>();
+
+      // Pick the first available seat across the selected coaches
+      const newSeat = coachSeats.find(
+        seat =>
+          !occupied.has(seat.id) &&
+          !assignedInBatch.has(seat.id) &&
+          seat.id !== bs.seatId,
+      );
+
+      if (!newSeat) {
+        unresolved.push({
+          bookingRef: bs.booking.bookingRef,
+          reason:     'No available seat found in selected coaches',
+        });
+        this.logger.warn(
+          `Duplicate resolve: no seat available for ${bs.booking.bookingRef} (schedule ${scheduleId})`,
+        );
+        continue;
+      }
+
+      await this.prisma.$transaction(async tx => {
+        // 1. Change the seat on the booking and ticket.
+        await tx.bookingSeat.update({
+          where: { id: bs.id },
+          data:  { seatId: newSeat.id, seatLabelSnapshot: newSeat.seatNumber },
+        });
+        await tx.ticket.updateMany({
+          where: { bookingId: bs.booking.id, seatId: bs.seatId, leg: bs.leg },
+          data:  { seatId: newSeat.id },
+        });
+
+        // 2. Point the existing JourneySegments to the new seat.
+        //    The Journey is already linked to this booking via bookingId;
+        //    just update the seatId in its hop rows for this schedule.
+        const journey = await tx.journey.findFirst({
+          where:  { bookingId: bs.booking.id },
+          select: { id: true },
+        });
+
+        if (!journey) {
+          // No Journey/JourneySegment for this booking (e.g. duplicate that was never
+          // processed by finalizePaymentSuccess). Create them now using the same logic,
+          // scoped to the booking's origin→destination leg so the seatmap shows BOOKED
+          // only for the correct range of stops.
+          const originId = bs.booking.originStationId ?? bs.booking.schedule?.originStationId;
+          const destId   = bs.booking.destinationStationId ?? bs.booking.schedule?.destinationStationId;
+
+          const stopTimes = await tx.tripStopTime.findMany({
+            where:   { scheduleId },
+            orderBy: { sequence: 'asc' },
+            select:  { stationId: true },
+          });
+
+          const originIdx = originId ? stopTimes.findIndex(s => s.stationId === originId) : 0;
+          const destIdx   = destId   ? stopTimes.findIndex(s => s.stationId === destId)   : stopTimes.length - 1;
+          const fromIdx   = originIdx >= 0 ? originIdx : 0;
+          const toIdx     = destIdx   >= 0 ? destIdx   : stopTimes.length - 1;
+
+          const newJourney = await tx.journey.create({
+            data: {
+              passengerId: bs.booking.passengerId,
+              bookingId:   bs.booking.id,
+              status:      'CONFIRMED',
+              totalMinor:  bs.booking.totalMinor,
+              currency:    bs.booking.currency,
+            } as any,
+          });
+
+          const segments = [];
+          for (let i = fromIdx; i < toIdx; i++) {
+            segments.push({
+              journeyId:          newJourney.id,
+              scheduleId,
+              segmentOrder:       i - fromIdx,
+              seatId:             newSeat.id,
+              coachId:            newSeat.coachId,
+              departureStationId: stopTimes[i].stationId,
+              arrivalStationId:   stopTimes[i + 1].stationId,
+            });
+          }
+          if (segments.length > 0) {
+            await tx.journeySegment.createMany({ data: segments, skipDuplicates: true });
+          }
+          this.logger.log(
+            `No Journey for ${bs.booking.bookingRef} — created Journey + ${segments.length} segment(s) for seat ${newSeat.seatNumber}`,
+          );
+          return;
+        }
+
+        const { count } = await tx.journeySegment.updateMany({
+          where: { journeyId: journey.id, scheduleId, seatId: bs.seatId },
+          data:  { seatId: newSeat.id },
+        });
+
+        // Journey exists but had no segments (e.g. booking confirmed via a path
+        // that skipped JourneySegment creation). Create them now for the new seat
+        // so the seatmap reflects BOOKED.
+        if (count === 0) {
+          const originId = bs.booking.originStationId ?? bs.booking.schedule?.originStationId;
+          const destId   = bs.booking.destinationStationId ?? bs.booking.schedule?.destinationStationId;
+          const stopTimes = await tx.tripStopTime.findMany({
+            where:   { scheduleId },
+            orderBy: { sequence: 'asc' },
+            select:  { stationId: true },
+          });
+          const originIdx = originId ? stopTimes.findIndex(s => s.stationId === originId) : 0;
+          const destIdx   = destId   ? stopTimes.findIndex(s => s.stationId === destId)   : stopTimes.length - 1;
+          const fromIdx   = originIdx >= 0 ? originIdx : 0;
+          const toIdx     = destIdx   >= 0 ? destIdx   : stopTimes.length - 1;
+          const segments  = [];
+          for (let i = fromIdx; i < toIdx; i++) {
+            segments.push({
+              journeyId:          journey.id,
+              scheduleId,
+              segmentOrder:       i - fromIdx,
+              seatId:             newSeat.id,
+              coachId:            newSeat.coachId,
+              departureStationId: stopTimes[i].stationId,
+              arrivalStationId:   stopTimes[i + 1].stationId,
+            });
+          }
+          if (segments.length > 0) {
+            await tx.journeySegment.createMany({ data: segments, skipDuplicates: true });
+          }
+          this.logger.log(
+            `Seat reassigned: ${bs.booking.bookingRef} ` +
+            `${bs.seat?.seatNumber ?? bs.seatId} → ${newSeat.seatNumber} ` +
+            `(0 existing segments — created ${segments.length} new hop(s))`,
+          );
+        } else {
+          this.logger.log(
+            `Seat reassigned: ${bs.booking.bookingRef} ` +
+            `${bs.seat?.seatNumber ?? bs.seatId} → ${newSeat.seatNumber} ` +
+            `(${count} segment hop(s) updated)`,
+          );
+        }
+      });
+
+      // Mark as taken so the next booking in this batch doesn't get the same seat
+      assignedInBatch.add(newSeat.id);
+      occupied.add(newSeat.id);
+
+      const oldSeatNumber = bs.seat?.seatNumber ?? '?';
+      const origin        = bs.booking.schedule?.originStation?.name ?? '';
+      const dest          = bs.booking.schedule?.destinationStation?.name ?? '';
+
+      if (bs.booking.contactPhone) {
+        const message =
+          `EDR: Your booking ${bs.booking.bookingRef} (${origin} → ${dest}): ` +
+          `your seat has been changed from seat ${oldSeatNumber} to seat ${newSeat.seatNumber}. ` +
+          `We apologize for any inconvenience.`;
+        await this.sms.sendSms({ to: bs.booking.contactPhone, message }).catch(() => null);
+      }
+
+      this.logger.log(
+        `Duplicate resolved: ${bs.booking.bookingRef} seat ${oldSeatNumber} → ${newSeat.seatNumber}`,
+      );
+
+      results.push({
+        bookingRef:    bs.booking.bookingRef,
+        oldSeatNumber,
+        newSeatNumber: newSeat.seatNumber,
+        contactPhone:  bs.booking.contactPhone,
+      });
+    }
+
+    return {
+      resolved:          results.length,
+      unresolved:        unresolved.length,
+      results,
+      ...(unresolved.length > 0 ? { unresolvedDetails: unresolved } : {}),
+    };
+  }
 }

apps/edr-passenger-web/backoffice/src/app/discrepancy/layout.tsx

@@ -0,0 +1,5 @@
+import DashboardLayout from '../dashboard/layout';
+
+export default function DiscrepancyLayout({ children }: { children: React.ReactNode }) {
+  return <DashboardLayout>{children}</DashboardLayout>;
+}

apps/edr-passenger-web/backoffice/src/app/discrepancy/page.tsx

@@ -0,0 +1,519 @@
+'use client';
+
+import { useState } from 'react';
+import { useQuery, useMutation } from '@tanstack/react-query';
+import { Search, Layers, ChevronDown, ChevronUp, CheckSquare, Square, AlertCircle, CheckCircle2, X, Loader2 } from 'lucide-react';
+import { seatsApi } from '@/lib/api';
+import { formatDateTime } from '@/lib/utils';
+
+// ── Types ─────────────────────────────────────────────────────────────────
+
+interface DuplicateBooking {
+  bookingSeatId: string;
+  bookingId: string;
+  bookingRef: string;
+  passengerName: string;
+  contactPhone: string | null;
+  createdAt: string;
+}
+
+interface DuplicateSeatGroup {
+  seatId: string;
+  seatNumber: string;
+  leg: number;
+  bookings: DuplicateBooking[];
+}
+
+interface AvailableSeat {
+  seatId: string;
+  seatNumber: string;
+}
+
+interface CoachReport {
+  coachId: string;
+  coachNumber: string;
+  coachTypeName: string;
+  duplicates: DuplicateSeatGroup[];
+  availableSeats: AvailableSeat[];
+}
+
+interface ScheduleReport {
+  scheduleId: string;
+  origin: string;
+  destination: string;
+  departureAt: string;
+  coaches: CoachReport[];
+}
+
+interface DuplicatesResponse {
+  date: string;
+  schedules: ScheduleReport[];
+  totalDuplicates: number;
+}
+
+// ── Helpers ───────────────────────────────────────────────────────────────
+
+function today() {
+  return new Date().toISOString().slice(0, 10);
+}
+
+function scheduleDuplicateCount(s: ScheduleReport) {
+  return s.coaches.reduce((sum, c) => sum + c.duplicates.length, 0);
+}
+
+// ── Resolve modal ─────────────────────────────────────────────────────────
+
+interface ResolveModalProps {
+  schedule: ScheduleReport;
+  coach: CoachReport;
+  onClose: () => void;
+  onSuccess: () => void;
+}
+
+function ResolveModal({ schedule, coach, onClose, onSuccess }: ResolveModalProps) {
+  // Default: pre-select all-but-first passenger in every duplicate group
+  const defaultSelected = new Set<string>(
+    coach.duplicates.flatMap(g => g.bookings.slice(1).map(b => b.bookingSeatId)),
+  );
+  const [selectedSeats, setSelectedSeats] = useState<Set<string>>(defaultSelected);
+
+  // Coaches that have at least one available seat (pre-select all)
+  const coachesWithSeats = schedule.coaches.filter(c => c.availableSeats.length > 0);
+  const [selectedCoachIds, setSelectedCoachIds] = useState<Set<string>>(
+    new Set(coachesWithSeats.map(c => c.coachId)),
+  );
+
+  const [successMsg, setSuccessMsg] = useState<string | null>(null);
+  const [errorMsg, setErrorMsg] = useState<string | null>(null);
+
+  const mutation = useMutation({
+    mutationFn: (data: { bookingSeatIds: string[]; coachIds: string[] }) =>
+      seatsApi.resolveDuplicates(data),
+    onSuccess: (res) => {
+      setSuccessMsg(
+        `${res.resolved ?? 0} passenger(s) successfully reassigned.` +
+        (res.unresolved > 0 ? ` ${res.unresolved} could not be resolved (no available seat).` : ''),
+      );
+      setErrorMsg(null);
+      onSuccess();
+    },
+    onError: (err: any) => {
+      setErrorMsg(err?.response?.data?.message ?? 'Failed to resolve duplicates.');
+    },
+  });
+
+  function toggleBookingSeat(id: string) {
+    setSelectedSeats(prev => {
+      const next = new Set(prev);
+      next.has(id) ? next.delete(id) : next.add(id);
+      return next;
+    });
+  }
+
+  function toggleCoach(id: string) {
+    setSelectedCoachIds(prev => {
+      const next = new Set(prev);
+      next.has(id) ? next.delete(id) : next.add(id);
+      return next;
+    });
+  }
+
+  function handleAssign() {
+    setErrorMsg(null);
+    if (selectedSeats.size === 0) {
+      setErrorMsg('Select at least one passenger to reassign.');
+      return;
+    }
+    if (selectedCoachIds.size === 0) {
+      setErrorMsg('Select at least one coach to source the replacement seat from.');
+      return;
+    }
+    mutation.mutate({
+      bookingSeatIds: [...selectedSeats],
+      coachIds:       [...selectedCoachIds],
+    });
+  }
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4">
+      <div className="w-full max-w-2xl max-h-[90vh] overflow-y-auto rounded-xl bg-white dark:bg-gray-900 shadow-2xl flex flex-col">
+
+        {/* Header */}
+        <div className="flex items-center justify-between px-6 py-4 border-b border-gray-200 dark:border-gray-700">
+          <div>
+            <h2 className="text-lg font-semibold text-gray-900 dark:text-white">
+              Resolve Duplicates — {coach.coachNumber}
+            </h2>
+            <p className="text-sm text-gray-500 dark:text-gray-400">
+              {schedule.origin} → {schedule.destination} · {formatDateTime(schedule.departureAt)}
+            </p>
+          </div>
+          <button onClick={onClose} className="p-1 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800">
+            <X className="w-5 h-5 text-gray-500" />
+          </button>
+        </div>
+
+        <div className="flex-1 overflow-y-auto px-6 py-5 space-y-6">
+
+          {/* Duplicate seat groups */}
+          <div className="space-y-4">
+            <h3 className="text-sm font-semibold text-gray-700 dark:text-gray-300 uppercase tracking-wide">
+              Duplicate seat assignments
+            </h3>
+            <p className="text-xs text-gray-500 dark:text-gray-400">
+              Check the passengers you want to reassign to a new seat. Unchecked passengers keep their current seat.
+            </p>
+
+            {coach.duplicates.map(group => (
+              <div
+                key={`${group.seatId}-${group.leg}`}
+                className="rounded-lg border border-orange-200 dark:border-orange-800 bg-orange-50 dark:bg-orange-950/30 p-4"
+              >
+                <div className="flex items-center gap-2 mb-3">
+                  <AlertCircle className="w-4 h-4 text-orange-500 shrink-0" />
+                  <span className="text-sm font-medium text-orange-800 dark:text-orange-300">
+                    Seat {group.seatNumber} — {group.bookings.length} passengers assigned
+                  </span>
+                </div>
+                <div className="space-y-2">
+                  {group.bookings.map((b, idx) => {
+                    const checked = selectedSeats.has(b.bookingSeatId);
+                    return (
+                      <label
+                        key={b.bookingSeatId}
+                        className="flex items-start gap-3 cursor-pointer rounded-lg px-3 py-2 hover:bg-orange-100 dark:hover:bg-orange-900/30 transition-colors"
+                      >
+                        <input
+                          type="checkbox"
+                          checked={checked}
+                          onChange={() => toggleBookingSeat(b.bookingSeatId)}
+                          className="mt-0.5 h-4 w-4 rounded border-gray-300 text-blue-600 focus:ring-blue-500"
+                        />
+                        <div className="flex-1 min-w-0">
+                          <div className="flex items-center gap-2 flex-wrap">
+                            <span className="text-sm font-medium text-gray-900 dark:text-white">
+                              {b.passengerName || '—'}
+                            </span>
+                            <span className="text-xs font-mono bg-gray-100 dark:bg-gray-800 text-gray-600 dark:text-gray-400 px-1.5 py-0.5 rounded">
+                              {b.bookingRef}
+                            </span>
+                            {idx === 0 && (
+                              <span className="text-xs bg-green-100 dark:bg-green-900/30 text-green-700 dark:text-green-400 px-1.5 py-0.5 rounded">
+                                earliest
+                              </span>
+                            )}
+                          </div>
+                          <div className="text-xs text-gray-500 dark:text-gray-400 mt-0.5">
+                            {b.contactPhone ?? 'No phone'} · Booked {formatDateTime(b.createdAt)}
+                          </div>
+                        </div>
+                      </label>
+                    );
+                  })}
+                </div>
+              </div>
+            ))}
+          </div>
+
+          {/* Coach selection */}
+          <div className="space-y-3">
+            <h3 className="text-sm font-semibold text-gray-700 dark:text-gray-300 uppercase tracking-wide">
+              Reassign to seats in
+            </h3>
+            <p className="text-xs text-gray-500 dark:text-gray-400">
+              The system picks the first available seat in the selected coaches.
+            </p>
+            <div className="space-y-2">
+              {coachesWithSeats.length === 0 ? (
+                <p className="text-sm text-red-500">No coaches have available seats on this schedule.</p>
+              ) : (
+                coachesWithSeats.map(c => (
+                  <label
+                    key={c.coachId}
+                    className="flex items-center gap-3 cursor-pointer rounded-lg border border-gray-200 dark:border-gray-700 px-3 py-2 hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
+                  >
+                    <input
+                      type="checkbox"
+                      checked={selectedCoachIds.has(c.coachId)}
+                      onChange={() => toggleCoach(c.coachId)}
+                      className="h-4 w-4 rounded border-gray-300 text-blue-600 focus:ring-blue-500"
+                    />
+                    <div className="flex-1">
+                      <span className="text-sm font-medium text-gray-900 dark:text-white">
+                        {c.coachNumber}
+                      </span>
+                      <span className="text-xs text-gray-500 dark:text-gray-400 ml-2">
+                        {c.coachTypeName}
+                      </span>
+                    </div>
+                    <span className="text-xs text-green-600 dark:text-green-400 font-medium">
+                      {c.availableSeats.length} available
+                    </span>
+                  </label>
+                ))
+              )}
+            </div>
+          </div>
+
+          {/* Feedback */}
+          {errorMsg && (
+            <div className="flex items-start gap-2 rounded-lg bg-red-50 dark:bg-red-950/30 border border-red-200 dark:border-red-800 px-4 py-3">
+              <AlertCircle className="w-4 h-4 text-red-500 shrink-0 mt-0.5" />
+              <p className="text-sm text-red-700 dark:text-red-400">{errorMsg}</p>
+            </div>
+          )}
+          {successMsg && (
+            <div className="flex items-start gap-2 rounded-lg bg-green-50 dark:bg-green-950/30 border border-green-200 dark:border-green-800 px-4 py-3">
+              <CheckCircle2 className="w-4 h-4 text-green-500 shrink-0 mt-0.5" />
+              <p className="text-sm text-green-700 dark:text-green-400">{successMsg}</p>
+            </div>
+          )}
+        </div>
+
+        {/* Footer */}
+        <div className="flex items-center justify-between px-6 py-4 border-t border-gray-200 dark:border-gray-700 gap-3">
+          <button
+            onClick={onClose}
+            className="px-4 py-2 text-sm rounded-lg border border-gray-300 dark:border-gray-600 text-gray-700 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
+          >
+            {successMsg ? 'Close' : 'Cancel'}
+          </button>
+          {!successMsg && (
+            <button
+              onClick={handleAssign}
+              disabled={mutation.isPending || selectedSeats.size === 0 || selectedCoachIds.size === 0}
+              className="flex items-center gap-2 px-5 py-2 text-sm font-medium rounded-lg bg-blue-600 text-white hover:bg-blue-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+            >
+              {mutation.isPending && <Loader2 className="w-4 h-4 animate-spin" />}
+              Assign {selectedSeats.size > 0 ? `${selectedSeats.size} passenger${selectedSeats.size > 1 ? 's' : ''}` : ''}
+            </button>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+// ── Coach card ────────────────────────────────────────────────────────────
+
+interface CoachCardProps {
+  coach: CoachReport;
+  schedule: ScheduleReport;
+  onResolve: () => void;
+}
+
+function CoachCard({ coach, schedule, onResolve }: CoachCardProps) {
+  const [expanded, setExpanded] = useState(false);
+  const hasDuplicates = coach.duplicates.length > 0;
+
+  return (
+    <div className={`rounded-xl border ${hasDuplicates ? 'border-orange-200 dark:border-orange-800' : 'border-gray-200 dark:border-gray-700'} bg-white dark:bg-gray-900 overflow-hidden`}>
+      {/* Card header */}
+      <div className="flex items-center gap-4 px-5 py-4">
+        <div className="flex-1 min-w-0">
+          <div className="flex items-center gap-2 flex-wrap">
+            <span className="font-semibold text-gray-900 dark:text-white">{coach.coachNumber}</span>
+            <span className="text-sm text-gray-500 dark:text-gray-400">{coach.coachTypeName}</span>
+          </div>
+          <div className="flex items-center gap-3 mt-1 text-xs text-gray-500 dark:text-gray-400">
+            <span>{coach.availableSeats.length} available seats</span>
+            {hasDuplicates && (
+              <span className="flex items-center gap-1 text-orange-600 dark:text-orange-400 font-medium">
+                <AlertCircle className="w-3.5 h-3.5" />
+                {coach.duplicates.length} duplicate{coach.duplicates.length > 1 ? 's' : ''}
+              </span>
+            )}
+          </div>
+        </div>
+
+        <div className="flex items-center gap-2 shrink-0">
+          {hasDuplicates && (
+            <button
+              onClick={onResolve}
+              className="px-3 py-1.5 text-xs font-medium rounded-lg bg-orange-500 text-white hover:bg-orange-600 transition-colors"
+            >
+              Resolve
+            </button>
+          )}
+          {hasDuplicates && (
+            <button
+              onClick={() => setExpanded(v => !v)}
+              className="p-1.5 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 text-gray-500 transition-colors"
+              title={expanded ? 'Collapse' : 'View passengers'}
+            >
+              {expanded ? <ChevronUp className="w-4 h-4" /> : <ChevronDown className="w-4 h-4" />}
+            </button>
+          )}
+        </div>
+      </div>
+
+      {/* Expanded passenger list */}
+      {expanded && hasDuplicates && (
+        <div className="border-t border-gray-100 dark:border-gray-800 divide-y divide-gray-100 dark:divide-gray-800">
+          {coach.duplicates.map(group => (
+            <div key={`${group.seatId}-${group.leg}`} className="px-5 py-3">
+              <p className="text-xs font-semibold text-orange-600 dark:text-orange-400 mb-2">
+                Seat {group.seatNumber} — {group.bookings.length} passengers
+              </p>
+              <div className="space-y-2">
+                {group.bookings.map((b, idx) => (
+                  <div key={b.bookingSeatId} className="flex items-center gap-3 text-sm">
+                    <span className="w-5 h-5 rounded-full bg-gray-100 dark:bg-gray-800 text-gray-600 dark:text-gray-400 text-xs flex items-center justify-center font-medium shrink-0">
+                      {idx + 1}
+                    </span>
+                    <div className="flex-1 min-w-0">
+                      <span className="font-medium text-gray-900 dark:text-white">{b.passengerName || '—'}</span>
+                      <span className="ml-2 text-xs font-mono text-gray-500 dark:text-gray-400">{b.bookingRef}</span>
+                    </div>
+                    <span className="text-xs text-gray-400 dark:text-gray-500 shrink-0">{b.contactPhone ?? '—'}</span>
+                  </div>
+                ))}
+              </div>
+            </div>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
+// ── Main page ─────────────────────────────────────────────────────────────
+
+export default function DiscrepancyPage() {
+  const [date, setDate] = useState(today());
+  const [searchDate, setSearchDate] = useState('');
+  const [resolveTarget, setResolveTarget] = useState<{ schedule: ScheduleReport; coach: CoachReport } | null>(null);
+
+  const { data, isLoading, isError, refetch } = useQuery<DuplicatesResponse>({
+    queryKey: ['seat-duplicates', searchDate],
+    queryFn: () => seatsApi.getDuplicates(searchDate),
+    enabled: !!searchDate,
+  });
+
+  function handleSearch() {
+    if (date) setSearchDate(date);
+  }
+
+  function handleKeyDown(e: React.KeyboardEvent) {
+    if (e.key === 'Enter') handleSearch();
+  }
+
+  return (
+    <div className="p-6 space-y-6 max-w-5xl mx-auto">
+
+      {/* Page header */}
+      <div className="flex items-center gap-3">
+        <div className="p-2 rounded-lg bg-orange-100 dark:bg-orange-950/40">
+          <Layers className="w-6 h-6 text-orange-600 dark:text-orange-400" />
+        </div>
+        <div>
+          <h1 className="text-2xl font-bold text-gray-900 dark:text-white">Seat Discrepancy</h1>
+          <p className="text-sm text-gray-500 dark:text-gray-400">
+            Detect and resolve duplicate seat assignments by schedule date
+          </p>
+        </div>
+      </div>
+
+      {/* Date picker */}
+      <div className="flex items-center gap-3">
+        <input
+          type="date"
+          value={date}
+          onChange={e => setDate(e.target.value)}
+          onKeyDown={handleKeyDown}
+          className="rounded-lg border border-gray-300 dark:border-gray-600 bg-white dark:bg-gray-800 text-gray-900 dark:text-white px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-blue-500"
+        />
+        <button
+          onClick={handleSearch}
+          disabled={!date || isLoading}
+          className="flex items-center gap-2 px-4 py-2 rounded-lg bg-blue-600 text-white text-sm font-medium hover:bg-blue-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+        >
+          {isLoading ? <Loader2 className="w-4 h-4 animate-spin" /> : <Search className="w-4 h-4" />}
+          Search
+        </button>
+      </div>
+
+      {/* Error */}
+      {isError && (
+        <div className="flex items-center gap-2 rounded-lg bg-red-50 dark:bg-red-950/30 border border-red-200 dark:border-red-800 px-4 py-3 text-sm text-red-700 dark:text-red-400">
+          <AlertCircle className="w-4 h-4 shrink-0" />
+          Failed to load duplicate seat data. Please try again.
+        </div>
+      )}
+
+      {/* Summary banner */}
+      {data && (
+        <div className={`rounded-xl border px-5 py-4 flex items-center gap-3 ${
+          data.totalDuplicates > 0
+            ? 'bg-orange-50 dark:bg-orange-950/20 border-orange-200 dark:border-orange-800'
+            : 'bg-green-50 dark:bg-green-950/20 border-green-200 dark:border-green-800'
+        }`}>
+          {data.totalDuplicates > 0 ? (
+            <AlertCircle className="w-5 h-5 text-orange-500 shrink-0" />
+          ) : (
+            <CheckCircle2 className="w-5 h-5 text-green-500 shrink-0" />
+          )}
+          <span className={`text-sm font-medium ${
+            data.totalDuplicates > 0
+              ? 'text-orange-800 dark:text-orange-300'
+              : 'text-green-800 dark:text-green-300'
+          }`}>
+            {data.totalDuplicates > 0
+              ? `${data.totalDuplicates} duplicate seat assignment${data.totalDuplicates > 1 ? 's' : ''} found across ${data.schedules.length} schedule${data.schedules.length > 1 ? 's' : ''} on ${data.date}`
+              : `No duplicate seat assignments found on ${data.date}`}
+          </span>
+        </div>
+      )}
+
+      {/* Results per schedule */}
+      {data?.schedules.map(schedule => (
+        <div key={schedule.scheduleId} className="space-y-3">
+          {/* Schedule header */}
+          <div className="flex items-center justify-between">
+            <div>
+              <h2 className="text-base font-semibold text-gray-900 dark:text-white">
+                {schedule.origin} → {schedule.destination}
+              </h2>
+              <p className="text-xs text-gray-500 dark:text-gray-400">
+                {formatDateTime(schedule.departureAt)} · {scheduleDuplicateCount(schedule)} duplicate{scheduleDuplicateCount(schedule) !== 1 ? 's' : ''}
+              </p>
+            </div>
+          </div>
+
+          {/* Coach cards grid */}
+          <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
+            {schedule.coaches.map(coach => (
+              <CoachCard
+                key={coach.coachId}
+                coach={coach}
+                schedule={schedule}
+                onResolve={() => setResolveTarget({ schedule, coach })}
+              />
+            ))}
+          </div>
+        </div>
+      ))}
+
+      {/* Empty state when searched but no results */}
+      {data && data.schedules.length === 0 && data.totalDuplicates === 0 && searchDate && (
+        <div className="flex flex-col items-center justify-center py-16 text-center">
+          <CheckCircle2 className="w-12 h-12 text-green-400 mb-3" />
+          <p className="text-gray-500 dark:text-gray-400">All seats are correctly assigned for {data.date}</p>
+        </div>
+      )}
+
+      {/* Resolve modal */}
+      {resolveTarget && (
+        <ResolveModal
+          schedule={resolveTarget.schedule}
+          coach={resolveTarget.coach}
+          onClose={() => setResolveTarget(null)}
+          onSuccess={() => {
+            refetch();
+            // Keep modal open to show success message; user closes manually
+          }}
+        />
+      )}
+    </div>
+  );
+}

apps/edr-passenger-web/backoffice/src/components/layout/Sidebar.tsx

@@ -37,6 +37,7 @@ import {
   Banknote,
   Activity,
   Smartphone,
+  Layers,
 } from 'lucide-react';
 import { useAuthStore } from '@/lib/auth-store';
 import { cn } from '@/lib/utils';
@@ -65,6 +66,7 @@ const navigationSections: { title: string; items: NavItem[] }[] = [
       { name: 'Tickets',    href: '/tickets',        icon: FileText,  permission: PERMS.tickets.view },
       { name: 'Boarding',   href: '/boarding',       icon: LogIn,     permission: PERMS.tickets.view },
       { name: 'Luggage',        href: '/excess-baggage',  icon: Banknote, permission: PERMS.bookings.view },
+      { name: 'Discrepancy',    href: '/discrepancy',     icon: Layers,   permission: PERMS.seats.manage },
     ]
   },
   {

apps/edr-passenger-web/backoffice/src/lib/api/index.ts

@@ -159,6 +159,10 @@ export const seatsApi = {
   undoRemove: (seatId: string) => apiClient.patch<any>(`/seats/${seatId}/undo-remove`, {}),
   setMaintenance: (seatId: string, reason: string) => apiClient.post<any>(`/seats/${seatId}/maintenance`, { reason }),
   clearMaintenance: (seatId: string) => apiClient.delete(`/seats/${seatId}/maintenance`),
+  getDuplicates: (date: string, scheduleId?: string) =>
+    apiClient.get<any>(`/seats/duplicates?date=${date}${scheduleId ? `&scheduleId=${scheduleId}` : ''}`),
+  resolveDuplicates: (data: { bookingSeatIds: string[]; coachIds: string[] }) =>
+    apiClient.post<any>('/seats/duplicates/resolve', data),
 };
 
 // Payments API