main.py

import os
from datetime import datetime, timezone

from flask import Flask, jsonify, request
from flask_cors import CORS
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate

# ---------------------------------------------------------------------------
# Config
# ---------------------------------------------------------------------------
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = os.getenv(
    "DATABASE_URL", "sqlite:///dev.db"
)
# Railway Postgres URLs start with postgres:// — SQLAlchemy 1.4+ needs postgresql://
if app.config["SQLALCHEMY_DATABASE_URI"].startswith("postgres://"):
    app.config["SQLALCHEMY_DATABASE_URI"] = app.config[
        "SQLALCHEMY_DATABASE_URI"
    ].replace("postgres://", "postgresql://", 1)

app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "change-me-in-production")

CORS(app)
db = SQLAlchemy(app)
migrate = Migrate(app, db)

# ---------------------------------------------------------------------------
# Models
# ---------------------------------------------------------------------------
class Item(db.Model):
    __tablename__ = "items"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(120), nullable=False)
    description = db.Column(db.Text, default="")
    created_at = db.Column(db.DateTime, default=lambda: datetime.now(timezone.utc))
    updated_at = db.Column(
        db.DateTime,
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    def to_dict(self):
        return {
            "id": self.id,
            "name": self.name,
            "description": self.description,
            "created_at": self.created_at.isoformat(),
            "updated_at": self.updated_at.isoformat(),
        }


# ---------------------------------------------------------------------------
# Auto-create tables (no migration needed for quick start)
# ---------------------------------------------------------------------------
with app.app_context():
    db.create_all()

# ---------------------------------------------------------------------------
# Error handlers
# ---------------------------------------------------------------------------
@app.errorhandler(404)
def not_found(e):
    return jsonify({"error": "Resource not found"}), 404


@app.errorhandler(400)
def bad_request(e):
    return jsonify({"error": str(e)}), 400


@app.errorhandler(500)
def internal_error(e):
    return jsonify({"error": "Internal server error"}), 500


# ---------------------------------------------------------------------------
# Health / Root
# ---------------------------------------------------------------------------
@app.get("/")
def root():
    return jsonify({
        "service": "Flask REST API Boilerplate",
        "status": "running",
        "endpoints": {
            "health": "/health",
            "items": "/api/items",
            "item": "/api/items/<id>",
        },
    })


@app.get("/health")
def health():
    return jsonify({"status": "healthy", "timestamp": datetime.now(timezone.utc).isoformat()})


# ---------------------------------------------------------------------------
# CRUD  —  /api/items
# ---------------------------------------------------------------------------
@app.get("/api/items")
def list_items():
    page = request.args.get("page", 1, type=int)
    per_page = request.args.get("per_page", 20, type=int)
    per_page = min(per_page, 100)

    pagination = Item.query.order_by(Item.created_at.desc()).paginate(
        page=page, per_page=per_page, error_out=False
    )
    return jsonify({
        "items": [i.to_dict() for i in pagination.items],
        "total": pagination.total,
        "page": pagination.page,
        "pages": pagination.pages,
    })


@app.post("/api/items")
def create_item():
    data = request.get_json(silent=True) or {}
    if not data.get("name"):
        return jsonify({"error": "Field 'name' is required"}), 400

    item = Item(name=data["name"], description=data.get("description", ""))
    db.session.add(item)
    db.session.commit()
    return jsonify(item.to_dict()), 201


@app.get("/api/items/<int:item_id>")
def get_item(item_id):
    item = db.session.get(Item, item_id)
    if not item:
        return jsonify({"error": "Item not found"}), 404
    return jsonify(item.to_dict())


@app.put("/api/items/<int:item_id>")
def update_item(item_id):
    item = db.session.get(Item, item_id)
    if not item:
        return jsonify({"error": "Item not found"}), 404

    data = request.get_json(silent=True) or {}
    if "name" in data:
        item.name = data["name"]
    if "description" in data:
        item.description = data["description"]

    db.session.commit()
    return jsonify(item.to_dict())


@app.delete("/api/items/<int:item_id>")
def delete_item(item_id):
    item = db.session.get(Item, item_id)
    if not item:
        return jsonify({"error": "Item not found"}), 404

    db.session.delete(item)
    db.session.commit()
    return jsonify({"message": "Deleted", "id": item_id})


# ---------------------------------------------------------------------------
# Run
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    port = int(os.getenv("PORT", 8080))
    app.run(host="0.0.0.0", port=port, debug=os.getenv("FLASK_DEBUG", "0") == "1")