module-ify homepage

1 files changed, 116 insertions, 0 deletions

diff --git a/src/util/wiki-data.js b/src/util/wiki-data.js
index e4142c85..2527a4b3 100644
--- a/src/util/wiki-data.js
+++ b/src/util/wiki-data.js
@@ -159,3 +159,119 @@ export function getTrackCover(track, {to}) {
         return to('media.trackCover', track.album.directory, track.directory);
     }
 }
+
+// Big-ass homepage row functions
+
+export function getNewAdditions(numAlbums, {wikiData}) {
+    const { albumData } = wikiData;
+
+    // Sort al8ums, in descending order of priority, 8y...
+    //
+    // * D8te of addition to the wiki (descending).
+    // * Major releases first.
+    // * D8te of release (descending).
+    //
+    // Major releases go first to 8etter ensure they show up in the list (and
+    // are usually at the start of the final output for a given d8 of release
+    // too).
+    const sortedAlbums = albumData.filter(album => album.isListedOnHomepage).sort((a, b) => {
+        if (a.dateAdded > b.dateAdded) return -1;
+        if (a.dateAdded < b.dateAdded) return 1;
+        if (a.isMajorRelease && !b.isMajorRelease) return -1;
+        if (!a.isMajorRelease && b.isMajorRelease) return 1;
+        if (a.date > b.date) return -1;
+        if (a.date < b.date) return 1;
+    });
+
+    // When multiple al8ums are added to the wiki at a time, we want to show
+    // all of them 8efore pulling al8ums from the next (earlier) date. We also
+    // want to show a diverse selection of al8ums - with limited space, we'd
+    // rather not show only the latest al8ums, if those happen to all 8e
+    // closely rel8ted!
+    //
+    // Specifically, we're concerned with avoiding too much overlap amongst
+    // the primary (first/top-most) group. We do this 8y collecting every
+    // primary group present amongst the al8ums for a given d8 into one
+    // (ordered) array, initially sorted (inherently) 8y latest al8um from
+    // the group. Then we cycle over the array, adding one al8um from each
+    // group until all the al8ums from that release d8 have 8een added (or
+    // we've met the total target num8er of al8ums). Once we've added all the
+    // al8ums for a given group, it's struck from the array (so the groups
+    // with the most additions on one d8 will have their oldest releases
+    // collected more towards the end of the list).
+
+    const albums = [];
+
+    let i = 0;
+    outerLoop: while (i < sortedAlbums.length) {
+        // 8uild up a list of groups and their al8ums 8y order of decending
+        // release, iter8ting until we're on a different d8. (We use a map for
+        // indexing so we don't have to iter8te through the entire array each
+        // time we access one of its entries. This is 8asically unnecessary
+        // since this will never 8e an expensive enough task for that to
+        // matter.... 8ut it's nicer code. BBBB) )
+        const currentDate = sortedAlbums[i].dateAdded;
+        const groupMap = new Map();
+        const groupArray = [];
+        for (let album; (album = sortedAlbums[i]) && +album.dateAdded === +currentDate; i++) {
+            const primaryGroup = album.groups[0];
+            if (groupMap.has(primaryGroup)) {
+                groupMap.get(primaryGroup).push(album);
+            } else {
+                const entry = [album]
+                groupMap.set(primaryGroup, entry);
+                groupArray.push(entry);
+            }
+        }
+
+        // Then cycle over that sorted array, adding one al8um from each to
+        // the main array until we've run out or have met the target num8er
+        // of al8ums.
+        while (groupArray.length) {
+            let j = 0;
+            while (j < groupArray.length) {
+                const entry = groupArray[j];
+                const album = entry.shift();
+                albums.push(album);
+
+
+                // This is the only time we ever add anything to the main al8um
+                // list, so it's also the only place we need to check if we've
+                // met the target length.
+                if (albums.length === numAlbums) {
+                    // If we've met it, 8r8k out of the outer loop - we're done
+                    // here!
+                    break outerLoop;
+                }
+
+                if (entry.length) {
+                    j++;
+                } else {
+                    groupArray.splice(j, 1);
+                }
+            }
+        }
+    }
+
+    // Finally, do some quick mapping shenanigans to 8etter display the result
+    // in a grid. (This should pro8a8ly 8e a separ8te, shared function, 8ut
+    // whatevs.)
+    return albums.map(album => ({large: album.isMajorRelease, item: album}));
+}
+
+export function getNewReleases(numReleases, {wikiData}) {
+    const { albumData } = wikiData;
+
+    const latestFirst = albumData.filter(album => album.isListedOnHomepage).reverse();
+    const majorReleases = latestFirst.filter(album => album.isMajorRelease);
+    majorReleases.splice(1);
+
+    const otherReleases = latestFirst
+        .filter(album => !majorReleases.includes(album))
+        .slice(0, numReleases - majorReleases.length);
+
+    return [
+        ...majorReleases.map(album => ({large: true, item: album})),
+        ...otherReleases.map(album => ({large: false, item: album}))
+    ];
+}