Government Service Query Classifier

An automaton-based chatbot that classifies Sri Lankan government service queries using a Deterministic Finite Automaton (DFA). Supports English, Sinhala, and Tamil languages.

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Quick Start

1. Clone the Repository

git clone https://github.com/AdithaBuwaneka/Automata.git
cd Automata

2. Install Dependencies

pip install -r requirements.txt

3. Run the Application

python app.py

4. Open in Browser

http://127.0.0.1:5000

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Automata Theory Assignment

This project demonstrates the practical application of automata theory to solve a nationally relevant problem in Sri Lanka - classifying citizen queries about government services.

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DFA Design

Formal Definition

Component	Definition
Alphabet (Σ)	Keywords in English, Sinhala, Tamil
States (Q)	{q0, q1, q2, q3, q4, q5, q6, q7, q8, q9, q10, q11, q12, q_reject}
Start State (q₀)	q0
Accepting States (F)	{q1, q2, q3, q4, q5, q6, q7, q8, q9, q10, q11, q12}
Transition Function (δ)	Keyword-based state transitions

State Diagram

                              ┌─────────┐
                              │   q0    │ (START)
                              └────┬────┘
                                   │
         ┌──────────┬──────────┬───┴───┬──────────┬──────────┐
         ▼          ▼          ▼       ▼          ▼          ▼
    ┌─────────┐┌─────────┐┌─────────┐     ┌─────────┐┌─────────┐
    │   q1    ││   q2    ││   q3    │ ... │  q12    ││q_reject │
    │   NIC   ││PASSPORT ││  BIRTH  │     │ HEALTH  ││ REJECT  │
    │ ACCEPT  ││ ACCEPT  ││ ACCEPT  │     │ ACCEPT  ││ REJECT  │
    └─────────┘└─────────┘└─────────┘     └─────────┘└─────────┘

Government Services (Accepting States)

State	Service	Sinhala	Tamil
q1	NIC Services	ජාතික හැඳුනුම්පත්	தேசிய அடையாள அட்டை
q2	Passport	ගමන් බලපත්‍රය	கடவுச்சீட்டு
q3	Birth Certificate	උප්පැන්න සහතිකය	பிறப்புச் சான்றிதழ்
q4	Death Certificate	මරණ සහතිකය	இறப்புச் சான்றிதழ்
q5	Marriage Certificate	විවාහ සහතිකය	திருமணச் சான்றிதழ்
q6	Driving License	රියදුරු බලපත්‍රය	ஓட்டுநர் உரிமம்
q7	Vehicle Registration	වාහන ලියාපදිංචිය	வாகன பதிவு
q8	Tax Services	බදු සේවා	வரி சேவைகள்
q9	Pension	විශ්‍රාම වැටුප්	ஓய்வூதியம்
q10	Samurdhi/Welfare	සමෘද්ධි	சமுர்தி
q11	Education	අධ්‍යාපනය	கல்வி
q12	Health Services	සෞඛ්‍ය සේවා	சுகாதார சேவைகள்

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Project Structure

Automata/
├── app.py                    # Flask backend server
├── automaton.py              # DFA implementation (pure Python)
├── test_automaton.py         # Test cases for all languages
├── requirements.txt          # Python dependencies
├── README.md                 # Documentation
├── .gitignore                # Git ignore rules
├── templates/
│   └── index.html            # Chat interface
└── static/
    ├── css/
    │   └── style.css         # Sri Lankan theme styling
    └── js/
        └── app.js            # Frontend logic

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How to Use

Web Interface

1. Open http://127.0.0.1:5000 in your browser
2. Select your language (English / Sinhala / Tamil)
3. Type your query or click quick action buttons
4. View the DFA state transition and classification result

Example Queries

English:

How to apply for NIC?
Passport renewal process
Birth certificate application
Driving license renewal

Sinhala (සිංහල):

හැඳුනුම්පත ගන්න ඕනේ
ගමන් බලපත්‍රය අලුත් කරන්න
උප්පැන්න සහතිකය
රියදුරු බලපත්‍රය

Tamil (தமிழ்):

அடையாள அட்டை வேண்டும்
கடவுச்சீட்டு புதுப்பித்தல்
பிறப்புச் சான்றிதழ்
ஓட்டுநர் உரிமம்

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Running Tests

Run the test suite to verify DFA functionality:

python test_automaton.py

Expected Output:

• 71 test cases across English, Sinhala, and Tamil
• 67 ACCEPT outcomes (correctly classified)
• 4 REJECT outcomes (unrelated queries)

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API Endpoints

Endpoint	Method	Description
/	GET	Main chat interface
/api/classify	POST	Classify a query
/api/services	GET	List all services
/api/diagram	GET	Get DFA diagram
/api/greet	POST	Handle greetings

Example API Call

Request:

curl -X POST http://127.0.0.1:5000/api/classify \
  -H "Content-Type: application/json" \
  -d "{\"query\": \"NIC application\", \"language\": \"en\"}"

Response:

{
  "query": "NIC application",
  "state": "q1",
  "state_name": "NIC_SERVICES",
  "is_accepted": true,
  "status": "ACCEPT",
  "transition": "δ(q0, 'nic') → q1",
  "service": {
    "name": "NIC Services",
    "office": "Department of Registration of Persons",
    "website": "www.drp.gov.lk"
  }
}

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Technologies Used

Technology	Purpose
Python 3	Backend logic
Flask	Web framework
HTML5/CSS3	Frontend interface
JavaScript	Client-side logic
Pure Python DFA	Automaton implementation

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Features

• Pure Python DFA - No external automaton libraries
• Trilingual Support - English, Sinhala, Tamil
• Real-time Visualization - Live DFA state updates
• ACCEPT/REJECT Display - Clear classification status
• Service Information - Office details, required documents, websites
• Responsive Design - Works on desktop and mobile

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Assignment Checklist

• Problem Definition with national relevance
• Automata Design (DFA with 14 states)
• State Diagram with transitions
• Python Implementation (Pure Python + Flask)
• ACCEPT/REJECT outcomes
• Trilingual support (EN/SI/TA)
• Test cases (71 tests)
• Web interface demonstration

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License

This project is created for educational purposes as part of an Automata Theory assignment.