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Overview

The Catalog service is responsible for managing the event catalog, including event details, venues, and seatmaps. It provides read-only access to event information and seat availability for the ticketing platform. Port: 50001 (external), 5001 (internal)
Database Schema: bc_catalog
Dependencies: PostgreSQL

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Responsibilities

  • Store and retrieve event information (name, description, date, pricing)
  • Manage venue seatmaps with section, row, and seat details
  • Provide event listings and detailed event views
  • Track seat status (available, reserved, sold)
  • Support querying events and seats by various criteria

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API Endpoints

All endpoints are accessed via the EventsController.

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Get All Events

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GET /events
endpoint
Returns a list of all available events without seatmap details.
[HttpGet]
public async Task<IActionResult> GetAllEvents()
{
    var query = new GetAllEventsQuery();
    var result = await _mediator.Send(query);
    return Ok(result);
}
Response: Array of event objects

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Get Event by ID

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GET /events/{id}
endpoint
Returns a specific event by ID without seatmap details.
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id
Guid
required
The unique identifier of the event
[HttpGet("{id}")]
public async Task<IActionResult> GetEvent(Guid id)
{
    var query = new GetEventQuery(id);
    var result = await _mediator.Send(query);
    return result is not null ? Ok(result) : NotFound();
}
Response: Single event object or 404 if not found

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Get Event Seatmap

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GET /events/{id}/seatmap
endpoint
Returns a specific event with its complete seatmap including all seat details.
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id
Guid
required
The unique identifier of the event
[HttpGet("{id}/seatmap")]
public async Task<IActionResult> GetEventSeatmap(Guid id)
{
    var query = new GetEventSeatmapQuery(id);
    var result = await _mediator.Send(query);
    return result is not null ? Ok(result) : NotFound();
}
Response: Event object with nested seat collection

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Domain Models

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Event

Represents a ticketed event with associated seats.
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Id
Guid
Unique event identifier
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Name
string
Event name
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Description
string
Event description
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EventDate
DateTime
Date and time of the event
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BasePrice
decimal
Base ticket price for the event
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Seats
ICollection<Seat>
Collection of all seats for this event
~/workspace/source/services/catalog/src/Domain/Entities/Event.cs
public class Event
{
    public Guid Id { get; set; }
    public string Name { get; set; } = string.Empty;
    public string Description { get; set; } = string.Empty;
    public DateTime EventDate { get; set; }
    public decimal BasePrice { get; set; }
    public ICollection<Seat> Seats { get; set; } = new List<Seat>();

    public bool IsBookable() => EventDate > DateTime.UtcNow && HasAvailableSeats();
    public bool HasAvailableSeats() => Seats.Any(s => s.IsAvailable());
    public int GetAvailableSeatsCount() => Seats.Count(s => s.IsAvailable());
}

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Seat

Represents an individual seat within an event venue.
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Id
Guid
Unique seat identifier
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EventId
Guid
Reference to the parent event
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SectionCode
string
Venue section code (e.g., “A”, “B”, “VIP”)
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RowNumber
int
Row number within the section
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SeatNumber
int
Seat number within the row
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Price
decimal
Price for this specific seat
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Status
string
Current seat status: available, reserved, or sold
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CurrentReservationId
Guid?
ID of the active reservation (if reserved)
~/workspace/source/services/catalog/src/Domain/Entities/Seat.cs
public class Seat
{
    public const string StatusAvailable = "available";
    public const string StatusReserved = "reserved";
    public const string StatusSold = "sold";

    public Guid Id { get; set; }
    public Guid EventId { get; set; }
    public string SectionCode { get; set; } = string.Empty;
    public int RowNumber { get; set; }
    public int SeatNumber { get; set; }
    public decimal Price { get; set; }
    public string Status { get; set; } = StatusAvailable;
    public Guid? CurrentReservationId { get; set; }

    public bool IsAvailable() => Status.Equals(StatusAvailable, StringComparison.OrdinalIgnoreCase);
    public bool CanBeReserved() => IsAvailable();
    public void Reserve() { /* ... */ }
    public void Sell() { /* ... */ }
    public void Release() { /* ... */ }
}

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Configuration

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Database Connection

appsettings.json
{
  "ConnectionStrings": {
    "Default": "Host=postgres;Port=5432;Database=ticketing;Username=postgres;Password=postgres;SearchPath=bc_catalog"
  }
}
The service uses a dedicated PostgreSQL schema (bc_catalog) within the shared ticketing database.

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CORS

Configured to allow requests from the frontend running on http://localhost:3000.

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Use Cases

  • GetAllEvents: Retrieves all events for display in event listings
  • GetEvent: Retrieves a single event’s basic information
  • GetEventSeatmap: Retrieves an event with complete seatmap data for seat selection

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Architecture Notes

  • Uses MediatR for CQRS-style command/query handling
  • Read-only service (no write operations exposed via API)
  • Seat status updates are managed by the Inventory service
  • Infrastructure services registered via AddInfrastructure() extension method

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