logic for waste calculations

[cch5ng]

• [ ] brainstorm of how it should work (behavior to the user); biz requirements

first pass

• after user completes shopping trip they should signal

  • what they bought

  • when they bought it

• then user should get some notification when a food item is about to expire (1-2 days before)

• [ ] analysis of what needs to happen in order to implement; missing info (technical requirements)

first pass

• storing date/time that a list item was purchased

• determine when to start the countdown timer for notification (what should be the trigger)

• determine how to map the list item name to the amount of time until food expiration occurs

• determine which resource to use to make rules for food expiration timeline (by food type); not sure how to find a free resource

• determine notification formats (push notification, email, or SMS)

• scheduling

  • try first using cron job interfacing with node

  • potentially query on the hour to check which notifications are next due

  • need to think a little bit more about how to schedule notifications so that they are not considered annoying (opt out)

---

considerations

• how to store times in database

• how to handle different time zones

• how to track a user's local time zone (where/how to input that)

  • is it simplest to use geolocation? or require user input on registration

  • what is the simplest way to get it? US state; how about internationally

  • this probably affects UI like where can the user review and edit this info later

• also think there has to be something like scheduled notifications and how to implement this

  • something like celery/node-celery?

  • or node with cron jobs?

[cch5ng]

resc

• how to store date/time in db

  • https://dba.stackexchange.com/questions/150158/preferred-way-to-store-datetime

  • https://stackoverflow.com/questions/44965545/best-practices-with-saving-datetime-timezone-info-in-database-when-data-is-dep

  • https://medium.com/@vivekmadurai/how-to-deal-with-date-and-time-across-time-zones-39b1bd747f35

  • https://www.postgresqltutorial.com/postgresql-timestamp/

  • https://www.iana.org/time-zones

• get user time zone

  • https://stackoverflow.com/questions/13/determine-a-users-timezone

• push notifications

  • https://developer.mozilla.org/en-US/docs/Web/API/Push_API

  • https://developers.google.com/web/ilt/pwa/introduction-to-push-notifications

• service worker in react application

  • https://create-react-app.dev/docs/making-a-progressive-web-app/

    • I'm not using CRA currently but this probably gives some example/pattern

• cron jobs with node

  • https://scotch.io/tutorials/nodejs-cron-jobs-by-examples

  • https://medium.com/javascript-in-plain-english/how-to-schedule-cron-jobs-in-node-js-897215e2e5d3

[cch5ng]

UI consideration: probably to user it is simplest if during the shopping session, every time they check an item as purchased, this should be the time that the start date/time gets saved (db) to count down to the expiration notification event... otherwise need to add another button for completed list purchase but that looks redundant visually

[cch5ng]

logistics

set db server timezone; America/Los_Angeles

[cch5ng]

010719

• [ ] store timezones as constants file

• [ ] write a script, want to store an array of strings (db timezones)

• [ ] implement UI where user can set their time zone (react select)

• [ ] need to figure out how

  • store the times to expiration

  • mapping shopping items to correct time to expire (by section? by item name?)

  • want to make a rough implementation

  • want to create a couple simple tests

  • right now focus on US time zones for now

    • start on local time zone, then expand out to different US time zones

[cch5ng]

010920/011320

• [x] sketch out the flow for how to get the timestamp for item purchased into BE

• [x] choose a rough data source for when foods typically expire

  • https://www.fda.gov/media/101389/download
  • could also create a dummy file with fake times for testing purposes but want to define the data format
  • how to determin whether the person stores food item in refrigerator vs freezer
  • ask HN about how you get data; how do you know if the data is free
  • do you ask permission to use it in a non profit sense
  • do you always hire on experts so you are consulting on that data

• [x] update data file to add a hard coded numeric field for how much to increment to the expiration date

• [x] choose the initial method to map between a list item and the line/rule for when that item should expire

  • think about how to enhance mapping because it will be hard to ever have an exact match or even a close match with the data file field names, they are too clinical

• [ ] initially use section setting to determine the expiration length category

• [ ] sketch out the flow for how the timing of notifications would work

  • at some point want to look at the resource for push notification settings (customizations for when notifications are delivered, etc)

• [ ] start to test out notifications

  • start to test using cron job
  • maybe create some dummy time offsets like 3-5 min
  • one notification type, email, should be simple enough
  • how to calculate the list of deadlines (should the deadline be stored in the db or just the expiration time length)

• [ ] later on test different time zones (US)

  • verify that I'm able to retrieve a line item timestamp for a user in a different timezone and convert the timestamp to their timezone

• [x] user settings for local timezone

  • (done) db
  • (done) api
    • post/create
    • get
    • put
  • (done) FE
    • UI (not sure if it is just browser/vm but the responsiveness of the react select element feels slow)
    • axn
    • request

• (fri) need to start doing research on how to set up push notifications (in particular service worker in react context)

• (fri) research to figure out how to map a food item to a category of expiration date; maybe something a long the line of how google search works (it is not always guaranteed to be an exact match so how to find the best match); do a little digging to understand the relationship b/t ML and text searching

  • https://www.searchenginejournal.com/how-search-engines-use-machine-learning/224451/

[cch5ng]

resc

• research on notifications and UX (user preferences)

  • https://blog.hubspot.com/marketing/push-notification-types

  • I like the notifications options samples by Breaking News

• resource on sms api (most cost $)

  • https://rapidapi.com/blog/sms-apis-send-texts/

[cch5ng]

010920 > 310

X-(fixed) some issue with setting comp useEffect; the timing seems off where the form field gets overwritten by useState call; need to figure out if my syntax with useEffect needs to change (try to look at definition of 2nd param again)

check how I handled this in the other form for retrieving either shopping list or template list

[cch5ng]

012320 > 350

X-(done) write up some tests to check out the logic in the map_expiration_dates.js file

[cch5ng]

012720 > 330

• [ ] view that allows user to do matching test

  • rethink this; timing for when the mapping should happen and more logistics about how the mapping should be saved on BE

• [ ] view overlay that reminds user to do matching test

---

resc

UX or examples on different notification types; use like model for how to remind user they should set up the mapping between sample shopping list and the list item expiration date matches

https://www.nngroup.com/articles/indicators-validations-notifications/

[cch5ng]

013120 > 1218

(012920 > 353)

need to debug issues on ExpirationMapTest;

• fix the logic for handling checkboxes; if user changes a checkbox from disabled (checked) to enabled, then this should somehow trigger the mapping logic (?)

  • think about this, is it done at single row level or is it done at batch level; and how to avoid doing calculations for items that did not change?

• (done) implement event handler when user wants to override a mapping (?) and set a different food expiration category

• (done) add button and form submit handler

• (done) fix inputChangeHandler() - only call expirationDateMapper1() on form submit/btn click

• (done) getExpirationCategory() check if it works

• (done) also revisit I think in the console there might have been some issue with the exports in the map_expiration_dates.js file (after the fix, check if import works and also check how this affects the unit tests)

value prop on select should not be null; not sure where in the code this might be getting set; it should be "none"