npm_download_counts.juttle

input npm_package: text -default "juttle" -label "NPM Package";
input start: date -default :2016-01-01: -label "Start Date";
input end:   date -default :today: -label "End Date";

function dayof(date) {
    return Date.format(date, "YYYY-MM-DD");
}

// fetch the data
sub fetch() {
    read http -url 'https://api.npmjs.org/downloads/range/${dayof(start)}:${dayof(end)}/${npm_package}' -timeField "day" -rootPath "downloads"
}

// add a simple title using markdown
sub title() {
    emit -points [{title: '# Download Counts for ${npm_package}'}]
    | view markdown -row 0
}

// Sum up the data by the given interval
sub rollup(interval) {
    reduce -every interval value=sum(downloads) | put name='downloads'
}

// Add a rolling average series
sub trend(interval, window, label) {
    (pass; reduce -every interval -over window value=Math.floor(avg(value)), name=label)
}

sub chart(interval, label, row, col, color) {
    view timechart
        -keyField 'name'
        -series [{name: 'downloads', color: color, geom: 'bars'},
                 {color: '#909552'} ]
        -title 'NPM Downloads per ${label} for ${npm_package}'
        -yScales.primary.label "Download Count"
        -downsample false
        -interval interval
        -row row -col col
}

title;
fetch
| (
    rollup -interval :1d: | trend -interval :1d: -window :28d: -label '28 day trend'
      | chart -interval :1d: -label 'day' -row 1 -col 0 -color '#A4B946';

    rollup -interval :1w: | trend -interval :1w: -window :10w: -label '10 week trend'
      | chart -interval :1w: -label 'week' -row 1 -col 1 -color '#79E0CB';

    rollup -interval :1M:
      | chart -interval :1M: -label 'month' -row 2 -col 0 -color '#666E4C';

    rollup -interval :1y:
      | chart -interval :1y: -label 'year' -row 2 -col 1 -color '#4E8DB8';
  )