app.py

# ============================================
# IMPORT LIBRARIES
# ============================================

import json
from pathlib import Path

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow

# ============================================
# CREATE FLASK APP
# ============================================

app = Flask(__name__)

# ============================================
# DATABASE CONFIGURATION
# ============================================

app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///dhammapada.db"
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

# ============================================
# INITIALIZE EXTENSIONS
# ============================================

db = SQLAlchemy(app)
ma = Marshmallow(app)

BASE_DIR = Path(__file__).resolve().parent
DHAMMAPADA_JSON_PATH = BASE_DIR / "dhammapada.json"

# ============================================
# DATABASE MODELS
# ============================================

class Chapter(db.Model):
    """
    Chapter table represents a chapter of Dhammapada.
    """

    id = db.Column(db.Integer, primary_key=True)
    number = db.Column(db.Integer, nullable=False, unique=True)
    title = db.Column(db.String(200), nullable=False)
    verses = db.relationship("Verse", backref="chapter", lazy=True)


class Verse(db.Model):
    """
    Verse table stores each verse text.
    """

    id = db.Column(db.Integer, primary_key=True)
    verse_number = db.Column(db.Integer, nullable=False)
    text = db.Column(db.Text, nullable=False)
    chapter_id = db.Column(db.Integer, db.ForeignKey("chapter.id"), nullable=False)


# ============================================
# MARSHMALLOW SCHEMA
# ============================================

class VerseSchema(ma.SQLAlchemyAutoSchema):

    class Meta:
        model = Verse
        load_instance = True


class ChapterSchema(ma.SQLAlchemyAutoSchema):

    verses = ma.Nested(VerseSchema, many=True)

    class Meta:
        model = Chapter
        load_instance = True


chapter_schema = ChapterSchema()
chapters_schema = ChapterSchema(many=True)

verse_schema = VerseSchema()
verses_schema = VerseSchema(many=True)


# ============================================
# DATA IMPORT
# ============================================

def import_dhammapada(json_path=DHAMMAPADA_JSON_PATH):
    """
    Import chapters and verses from a JSON file.
    """

    with json_path.open("r", encoding="utf-8") as file:
        data = json.load(file)

    chapters = data.get("chapters", [])

    for chapter_data in chapters:
        chapter = Chapter(
            number=chapter_data["number"],
            title=chapter_data["title"],
        )
        db.session.add(chapter)
        db.session.flush()

        verses = [
            Verse(
                verse_number=verse_data["verse_number"],
                text=verse_data["text"],
                chapter_id=chapter.id,
            )
            for verse_data in chapter_data.get("verses", [])
        ]
        db.session.add_all(verses)

    db.session.commit()


# ============================================
# API ROUTES (ONLY GET)
# ============================================

@app.route("/")
def home():
    chapters = Chapter.query.order_by(Chapter.number).all()
    return chapters_schema.jsonify(chapters)


@app.route("/chapters")
def get_chapters():
    chapters = Chapter.query.order_by(Chapter.number).all()
    return chapters_schema.jsonify(chapters)


@app.route("/chapters/<int:id>")
def get_chapter(id):
    chapter = Chapter.query.get_or_404(id)
    return chapter_schema.jsonify(chapter)


@app.route("/verses")
def get_verses():
    verses = Verse.query.order_by(Verse.chapter_id, Verse.verse_number).all()
    return verses_schema.jsonify(verses)


@app.route("/verses/<int:id>")
def get_verse(id):
    verse = Verse.query.get_or_404(id)
    return verse_schema.jsonify(verse)


@app.route("/chapters/<int:chapter_id>/verses")
def get_chapter_verses(chapter_id):
    verses = Verse.query.filter_by(chapter_id=chapter_id).order_by(Verse.verse_number).all()
    return verses_schema.jsonify(verses)


# ============================================
# CREATE DATABASE
# ============================================

with app.app_context():
    db.create_all()

    if Chapter.query.count() == 0:
        import_dhammapada()


# ============================================
# RUN SERVER
# ============================================

if __name__ == "__main__":
    app.run(debug=True)