%use dataframe

val apiKey = System.getenv("YOUTUBE_API_KEY")

fun load(path: String): AnyRow = DataRow.read("https://www.googleapis.com/youtube/v3/$path&key=$apiKey")

fun load(path: String, maxPages: Int): AnyFrame {
    val rows = mutableListOf<AnyRow>()
    var pagePath = path
    do {
        val row = load(pagePath)
        rows.add(row)
        val next = row.getValueOrNull<String>("nextPageToken")
        pagePath = path + "&pageToken=" + next
    } while (next != null && rows.size < maxPages)
    return rows.concat()
}

val df = load("search?q=cute%20cats&maxResults=50&part=snippet", 5)
df

val items = df.items.concat()
items

val videos = items.dropNulls { id.videoId }
    .select { id.videoId named "id" and snippet }
    .distinct()
videos

val parsed = videos.parse()

val loaded = parsed.convert { colsAtAnyDepth().colsOf<URL>() }.with { IMG(it, maxHeight = 150) }
    .add("video") { IFRAME("https://www.youtube.com/embed/$id") }

val clean = loaded.move { snippet.channelId and snippet.channelTitle }.under("channel")
    .move { snippet.title and snippet.publishedAt }.toTop()
    .remove { snippet }
clean

val statPages = clean.id.chunked(50).map {
    val ids = it.joinToString("%2C")
    load("videos?part=statistics&id=$ids")
}
statPages

val stats = statPages.items.concat().select { id and statistics.allCols() }.parse()
stats

val joined = clean.join(stats)
joined

val view by column<Int>()

val channels = joined.groupBy { channel }.sortByCount().aggregate {
    viewCount.sum() into view

    val last = maxBy { publishedAt }
    last.title into "last title"
    last.publishedAt into "time"
    last.viewCount into "viewCount"
}.sortByDesc(view).flatten()
channels

%useLatestDescriptors
%use kandy

channels.sortBy { viewCount.desc() }.plot {
    bars {
        x(channelTitle.map { it.take(10) })
        y(viewCount)
    }
}

val growth = joined
    .select { publishedAt and viewCount }
    .sortBy { publishedAt }
    .convert { all() }.toLong()
    .cumSum { viewCount }

growth.plot {
    area {
        x(publishedAt)
        y(viewCount)
    }
}