Files
bloodpressure/app/routes/data.py
T

98 lines
3.9 KiB
Python

import csv
from io import StringIO
from flask import Blueprint, render_template, redirect, request, url_for, flash, stream_with_context
from app.models import Reading, db
from flask_login import login_required, current_user
from datetime import datetime
from app.forms import DeleteForm
from app.insights import parse_range, readings_query, user_timezone
data = Blueprint('data', __name__)
@data.route('/', methods=['GET', 'POST'])
@login_required
def manage_data():
form = DeleteForm()
if request.method == 'POST':
if not form.validate_on_submit():
flash('Your form expired. Please try again.', 'danger')
return redirect(url_for('data.manage_data'))
# Handle CSV file upload
file = request.files.get('file')
if file and file.filename.endswith('.csv'):
try:
payload = file.read(2_000_001)
if len(payload) > 2_000_000:
raise ValueError('CSV must be 2 MB or smaller.')
csv_data = csv.reader(StringIO(payload.decode('utf-8-sig')))
if next(csv_data, None) != ['Timestamp', 'Systolic', 'Diastolic', 'Heart Rate']:
raise ValueError('Use the column headings from a BP Tracker export.')
readings_to_add = []
for line, row in enumerate(csv_data, 2):
timestamp, systolic, diastolic, heart_rate = row
if not (50 <= int(systolic) <= 250 and 30 <= int(diastolic) <= 150 and 30 <= int(heart_rate) <= 200):
raise ValueError(f'Check the measurement values on row {line}.')
readings_to_add.append(Reading(
user_id=current_user.id,
timestamp=datetime.strptime(timestamp, '%Y-%m-%d %H:%M:%S'),
systolic=int(systolic),
diastolic=int(diastolic),
heart_rate=int(heart_rate),
))
db.session.bulk_save_objects(readings_to_add)
db.session.commit()
flash('Data imported successfully!', 'success')
except Exception as e:
db.session.rollback()
flash(f'Error importing data: {str(e)}', 'danger')
else:
flash('Please upload a valid CSV file.', 'danger')
return redirect(url_for('data.manage_data'))
return render_template('data.html', form=form)
@data.route('/export', methods=['GET'])
@login_required
def export_data():
import io
from flask import Response
user_id = current_user.id
selected = None
if any(request.args.get(key) for key in ('start_date', 'end_date', 'days')):
try:
selected = parse_range(request.args, user_timezone(), 30)
except ValueError as error:
return render_template('error.html', message=str(error)), 400
def generate_csv():
"""Stream CSV rows to avoid loading all readings into memory."""
# Write header
output = io.StringIO()
writer = csv.writer(output)
writer.writerow(['Timestamp', 'Systolic', 'Diastolic', 'Heart Rate'])
yield output.getvalue()
output.seek(0)
output.truncate(0)
# Stream readings in chunks using yield_per
readings = readings_query(user_id, selected).order_by(
Reading.timestamp, Reading.id
).yield_per(500)
for reading in readings:
writer.writerow([
reading.timestamp.strftime('%Y-%m-%d %H:%M:%S'),
reading.systolic,
reading.diastolic,
reading.heart_rate,
])
yield output.getvalue()
output.seek(0)
output.truncate(0)
return Response(
stream_with_context(generate_csv()),
mimetype='text/csv',
headers={'Content-Disposition': 'attachment; filename=readings.csv'}
)