burnchart/README.md

#GitHub Burndown Chart
##Rework in Progress

[ ![Codeship Status for radekstepan/github-burndown-chart](https://www.codeship.io/projects/d69f4420-e5b0-0130-bbae-1632ddfb80f8/status?branch=rework)](https://www.codeship.io/projects/5855)

##Project Charter

The app is to display a burndown chart from a set of GitHub issues in a milestone.

If we can, do all processing and storage on the client which makes the app run for "free" on `gh-pages` etc.

Show:

* Upcoming issues by size.
* Issues closed today.
* For each issue show other tags and assignee (avatar).
* Number of working days left.
* To whom open issues still belong.
* Projected ship date (project running late/not).
* For each user/avatar what is their % progress and number of open/closed issues.
* Heat: if we are struck/very productive for a period of time, colorize the chart line.
* For milestones with no due date, show an estimate as to when it will probably be finished.

Allow:

* Toggle non working days.
* Have a print view.
* Customization of the theme (own logo/colors etc.).

Configure:

* Repos for users/orgs.
* Private api keys.
* Non working days.
* Label pattern to determine size (?).
* How often to poll for updates (limited by GH API).

Be:

* Responsive.
* As lightweight as possible (do we need Backbone/jQuery?).
* Well documented and modularized.
* Handling upstream API downtimes.
* Testing the algo by way of using the proxy service to fake responses.
* Handling daylight savings et al.

Usage envisaged in these three scenarios:

1. Use the `gh-pages` branch of this repo to connect and visualize a public repo.
    * App requesting a static JSON config file, merging with LocalStorage.
1. Deploy the app on a static server elsewhere with custom `config`.
    * App requesting a static JSON config file, merging with LocalStorage.
1. Proxy requests through a service to not disclose private api keys publicly.
    * Proxy app wrapping a request with API credentials. When requesting the config file we get the file dynamically stating which URL to use to make requests. API keys are scrubbed from the JSON file. When someone makes a request to us, wrap their request (only GET requests to specific endpoints!) and pipe the response back.
    * All this works as a Connect Middleware.
    * Also, make this cache responses for a given amount of time (poll time). This way people concerned with a big amount of requests can share the same resource.

##Design

###Initialization

1. Get [milestones](http://developer.github.com/v3/issues/milestones/#list-milestones-for-a-repository) and determine which one is ending the soonest.
1. For this milestone get both [open & closed](http://developer.github.com/v3/issues/#list-issues-for-a-repository) issues (can span [multiple pages](http://developer.github.com/v3/#pagination)).
1. Filter out issues not matching our pattern. For those that do keep tally and insert them to a map of days. Keep track of issue ids of open and closed issues.
1. Determine what the average velocity per day needs to be.
1. Go from the front (milestone creation date) to the back (milestone due date) day by day.
    1. For each day that has an entry in the map, add them to the end array (for actual).
    1. For expected just keep reducing the total by velocity every day.
1. Profit.

###Poll

Assuming it is quicker to get issue events and update existing data than it is to get all the issue over again.

1. Get [changes](http://developer.github.com/v3/activity/events/#list-issue-events-for-a-repository) to tickets doing pagination if need be up to the last check time.
1. If events are closed/opened ones that ref an issue in our milestone & matching pattern then update/add to our collections.