# jagadish210523-lgtm/railqueue-cascade-engine architecture

> Architecture diagram of the GitHub repository jagadish210523-lgtm/railqueue-cascade-engine, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-09-26). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/jagadish210523-lgtm/railqueue-cascade-engine
- Repository: https://github.com/jagadish210523-lgtm/railqueue-cascade-engine

## Overview

This is a small, single-file railway reservation CLI. The user enters passenger and seat actions; the application creates passenger records, allocates preferred or alternate seats (or queues them), supports cancellation with FIFO promotion, and displays the reservation chart. Train state is restored from and saved to JSON. The README describes a separate main.py, but the provided tree contains only train_ticket.py; the graph follows the sampled source.

Main entry points: [`train_ticket.py`](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py) (Menu and input)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_interface["CLI"]
  node_cli["Menu and input<br/>[train_ticket.py]"]
end

subgraph group_reservation["Reservations"]
  node_passenger["Passenger entity<br/>[train_ticket.py]"]
  node_train["Train controller<br/>[train_ticket.py]"]
  node_booking["Seat booking<br/>[train_ticket.py]"]
  node_cancellation["Cancellation cascade<br/>[train_ticket.py]"]
  node_chart["Reservation chart<br/>[train_ticket.py]"]
end

subgraph group_state["State and storage"]
  node_persistence["JSON persistence<br/>[train_ticket.py]"]
  node_jsonfile[("Train data file")]
end

node_user(("User"))

node_user -->|"enters choices"| node_cli
node_cli -->|"creates passenger"| node_passenger
node_cli -->|"initializes"| node_train
node_cli -->|"requests booking"| node_booking
node_cli -->|"requests cancellation"| node_cancellation
node_cli -->|"requests chart"| node_chart
node_train -->|"loads state"| node_persistence
node_train -->|"generates seats"| node_train
node_booking -->|"saves state"| node_persistence
node_cancellation -->|"saves state"| node_persistence
node_persistence -->|"reads and writes"| node_jsonfile
node_persistence -->|"reconstructs records"| node_passenger
node_passenger -->|"serializes fields"| node_persistence
node_cancellation -->|"promotes queued passenger"| node_train

click node_cli "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_passenger "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_train "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_booking "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_cancellation "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_chart "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"
click node_persistence "https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_cli,node_user toneBlue
class node_passenger,node_train,node_booking,node_cancellation,node_chart toneAmber
class node_persistence,node_jsonfile toneMint
```

## Components

### CLI

- [Menu and input](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`

### Reservations

- [Passenger entity](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`
- [Train controller](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`
- [Seat booking](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`
- [Cancellation cascade](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`
- [Reservation chart](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`

### State and storage

- [JSON persistence](https://github.com/jagadish210523-lgtm/railqueue-cascade-engine/blob/main/train_ticket.py): `train_ticket.py`
- **Train data file**

### Other components

- **User**

## Connections

- User → Menu and input: enters choices
- Menu and input → Passenger entity: creates passenger
- Menu and input → Train controller: initializes
- Menu and input → Seat booking: requests booking
- Menu and input → Cancellation cascade: requests cancellation
- Menu and input → Reservation chart: requests chart
- Train controller → JSON persistence: loads state
- Train controller → Train controller: generates seats
- Seat booking → JSON persistence: saves state
- Cancellation cascade → JSON persistence: saves state
- JSON persistence → Train data file: reads and writes
- JSON persistence → Passenger entity: reconstructs records
- Passenger entity → JSON persistence: serializes fields
- Cancellation cascade → Train controller: promotes queued passenger