🚇 MetroCard Travel Billing System — Geektrust Challenge

A Java console application that simulates a Metro Card travel billing system between CENTRAL and AIRPORT stations.
This project processes travel commands, applies correct fare rules, performs auto-recharge when needed, and prints the final summary exactly as required by the Geektrust problem.

---

📌 Features

• Add balance to MetroCard
• Check-in passengers with correct fare calculation
• Apply 50% discount on return journey
• Auto-recharge MetroCard when balance is insufficient
• Add 2% service fee to station collection during recharge
• Maintain station-level:
  • Total collection
  • Total discount
  • Passenger type summary
• Output formatted exactly as Geektrust expects

---

🏛 Passenger Types & Fares

Passenger Type	Fare
ADULT	200
SENIOR_CITIZEN	100
KID	50

---

🔁 Return Journey Logic

If a passenger travels:

• CENTRAL → AIRPORT
• AIRPORT → CENTRAL

The second trip receives 50% discount.

Example:
Senior Citizen fare = 100
Return fare = 50 (discount 50)

---

⚡ Auto Recharge Logic

If MetroCard balance < required fare:

1. Recharge = (fare - currentBalance)
2. Service Fee = 2% of recharge
3. Service fee is added to station's collection
4. Card balance increases by (recharge + fare deduction)

---

🧾 Input Format

BALANCE <CARD_ID> <AMOUNT>
CHECK_IN <CARD_ID> <PASSENGER_TYPE> <STATION>
PRINT_SUMMARY

Example:

BALANCE MC1 600
CHECK_IN MC1 ADULT CENTRAL
PRINT_SUMMARY

---

📝 Sample Output (Geektrust Format)

TOTAL_COLLECTION CENTRAL <collection> <discount>
PASSENGER_TYPE_SUMMARY
<type1> <count>
<type2> <count>

TOTAL_COLLECTION AIRPORT <collection> <discount>
PASSENGER_TYPE_SUMMARY
<type1> <count>
<type2> <count>

❗ Passenger types with 0 count are NOT printed, based on sample outputs.

---

📂 Project Structure

com.example.geektrust
 ├── Main.java
 ├── enums
 │     ├── PassengerType.java
 │     └── StationType.java
 ├── model
 │     ├── MetroCard.java
 │     └── StationSummary.java
 ├── service
 │     ├── MetroCardService.java
 │     ├── FareService.java
 │     └── StationService.java
 └── processor
       └── CommandProcessor.java

---

▶️ How to Run

1️⃣ Compile the project

./gradlew build

2️⃣ Run the project with input file (VS Code / Terminal)

gradlew run --args="sample_input/input1.txt"

or using Java directly:

java com.example.geektrust.Main sample_input/input1.txt

---

📁 Sample Input

BALANCE MC1 600
BALANCE MC2 500
CHECK_IN MC1 ADULT CENTRAL
CHECK_IN MC1 ADULT AIRPORT
PRINT_SUMMARY

---

🚀 Output Example

TOTAL_COLLECTION CENTRAL 200 0
PASSENGER_TYPE_SUMMARY
ADULT 1

TOTAL_COLLECTION AIRPORT 100 100
PASSENGER_TYPE_SUMMARY
ADULT 1

---

👨‍💻 Author

Pushpak Fasate
MetroCard — Geektrust Java Challenge Implementation

---