app.py

from flask import Flask, render_template, request, jsonify
from database import init_db, get_db
app = Flask(__name__)
with app.app_context():
    init_db()
VALID_STATUS = ["Available", "Issued"]
def error_response(message, status_code=400):
    return jsonify({"success": False, "error": message}), status_code
def success_response(message, data=None, status_code=200):
    response = {
        "success": True,
        "message": message
    }
    if data is not None:
        response["data"] = data
    return jsonify(response), status_code
@app.route("/")
def index():
    return render_template("index.html")
@app.route("/api/books", methods=["GET"])
def get_books():
    query = request.args.get("q", "").strip()
    db = get_db()

    if query:
        books = db.execute(
            """
            SELECT * FROM books
            WHERE title LIKE ?
            OR author LIKE ?
            OR genre LIKE ?
            ORDER BY created_at DESC
            """,
            (f"%{query}%", f"%{query}%", f"%{query}%")
        ).fetchall()
    else:
        books = db.execute(
            "SELECT * FROM books ORDER BY created_at DESC"
        ).fetchall()

    return jsonify([dict(book) for book in books])

@app.route("/api/books", methods=["POST"])
def add_book():
    data = request.get_json()

    if not data:
        return error_response("Invalid JSON data.")

    title = data.get("title", "").strip()
    author = data.get("author", "").strip()
    genre = data.get("genre", "").strip()
    year = str(data.get("year", "")).strip()
    status = data.get("status", "Available").strip()

    if not title or not author:
        return error_response("Title and Author are required.")

    if status not in VALID_STATUS:
        return error_response("Invalid status value.")

    if year and not year.isdigit():
        return error_response("Year must be numeric.")

    db = get_db()

    db.execute(
        """
        INSERT INTO books (title, author, genre, year, status)
        VALUES (?, ?, ?, ?, ?)
        """,
        (title, author, genre, year, status)
    )

    db.commit()

    return success_response("Book added successfully!", status_code=201)

@app.route("/api/books/<int:book_id>", methods=["PUT"])
def update_book(book_id):
    data = request.get_json()

    if not data:
        return error_response("Invalid JSON data.")

    title = data.get("title", "").strip()
    author = data.get("author", "").strip()
    genre = data.get("genre", "").strip()
    year = str(data.get("year", "")).strip()
    status = data.get("status", "Available").strip()

    if not title or not author:
        return error_response("Title and Author are required.")

    if status not in VALID_STATUS:
        return error_response("Invalid status value.")

    if year and not year.isdigit():
        return error_response("Year must be numeric.")

    db = get_db()

    existing_book = db.execute(
        "SELECT * FROM books WHERE id=?",
        (book_id,)
    ).fetchone()

    if not existing_book:
        return error_response("Book not found.", 404)

    db.execute(
        """
        UPDATE books
        SET title=?, author=?, genre=?, year=?, status=?
        WHERE id=?
        """,
        (title, author, genre, year, status, book_id)
    )

    db.commit()

    return success_response("Book updated successfully!")

@app.route("/api/books/<int:book_id>", methods=["DELETE"])
def delete_book(book_id):
    db = get_db()

    existing_book = db.execute(
        "SELECT * FROM books WHERE id=?",
        (book_id,)
    ).fetchone()

    if not existing_book:
        return error_response("Book not found.", 404)

    db.execute(
        "DELETE FROM books WHERE id=?",
        (book_id,)
    )

    db.commit()

    return success_response("Book deleted successfully.")

@app.route("/api/stats", methods=["GET"])
def stats():
    db = get_db()

    total = db.execute(
        "SELECT COUNT(*) FROM books"
    ).fetchone()[0]

    available = db.execute(
        "SELECT COUNT(*) FROM books WHERE status='Available'"
    ).fetchone()[0]
    issued = db.execute(
        "SELECT COUNT(*) FROM books WHERE status='Issued'"
    ).fetchone()[0]
    genres = db.execute(
        """
        SELECT COUNT(DISTINCT genre)
        FROM books
        WHERE genre != ''
        """
    ).fetchone()[0]
    return jsonify({
        "total": total,
        "available": available,
        "issued": issued,
        "genres": genres
    })
if __name__ == "__main__":
    app.run(debug=True)