from flask import Blueprint, request, jsonify, make_response, render_template
from app.core.models import Subnet, Server, App
from app.core.extensions import db
import csv
import io
import datetime

bp = Blueprint("importexport", __name__, url_prefix="/import-export")

MODEL_MAP = {"subnet": Subnet, "server": Server, "app": App}


@bp.route("/export/<model_name>", methods=["GET"])
def export_model(model_name):
    if model_name not in MODEL_MAP:
        return jsonify({"error": "Invalid model name"}), 400

    model = MODEL_MAP[model_name]
    instances = model.query.all()

    # Create a CSV file in memory
    output = io.StringIO()
    writer = csv.writer(output)

    # Get column names from model
    columns = [column.name for column in model.__table__.columns]
    writer.writerow(columns)

    # Write data
    for instance in instances:
        row = [getattr(instance, column) for column in columns]
        writer.writerow(row)

    # Create response
    timestamp = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
    filename = f"{model_name}_{timestamp}.csv"

    response = make_response(output.getvalue())
    response.headers["Content-Disposition"] = f"attachment; filename={filename}"
    response.headers["Content-type"] = "text/csv"

    return response


@bp.route("/import/<model_name>", methods=["GET", "POST"])
def import_model(model_name):
    if model_name not in MODEL_MAP:
        return jsonify({"error": "Invalid model name"}), 400

    model = MODEL_MAP[model_name]

    if request.method == "GET":
        # Show import form
        return render_template("import_form.html", model_name=model_name)

    # Process CSV upload
    if "file" not in request.files:
        return jsonify({"error": "No file part"}), 400

    file = request.files["file"]
    if file.filename == "":
        return jsonify({"error": "No selected file"}), 400

    if not file.filename.endswith(".csv"):
        return jsonify({"error": "File must be CSV format"}), 400

    try:
        # Read CSV
        stream = io.StringIO(file.stream.read().decode("UTF8"), newline=None)
        csv_reader = csv.reader(stream)

        # Get headers
        headers = next(csv_reader)

        # Validate required columns
        required_columns = [
            col.name
            for col in model.__table__.columns
            if not col.nullable and col.name != "id"
        ]

        for col in required_columns:
            if col not in headers:
                return jsonify({"error": f"Required column {col} missing"}), 400

        # Process rows
        imported = 0
        for row in csv_reader:
            data = dict(zip(headers, row))

            # Remove id to create new record
            if "id" in data:
                del data["id"]

            # Create new instance
            instance = model(**data)
            db.session.add(instance)
            imported += 1

        db.session.commit()
        return jsonify({"success": f"Imported {imported} records successfully"})

    except Exception as e:
        db.session.rollback()
        return jsonify({"error": str(e)}), 500