Add code activity graph to project widget

Signed-off-by: Sebastian Martinez <sebastinez@me.com>

src/commit.ts

@@ -17,7 +17,6 @@ export interface GroupedCommitsHistory {
 }
 
 export interface Author {
-  avatar: string;
   email: string;
   name: string;
 }
@@ -54,8 +53,10 @@ export interface CommitHeader {
 
 // A set of commits grouped by time.
 export interface CommitGroup {
-  time: string;
+  date: string;
+  time: number;
   commits: CommitMetadata[];
+  week: number;
 }
 
 export interface CommitStats {
@@ -112,8 +113,10 @@ export function groupCommits(commits: { header: CommitHeader; context: CommitCon
 
       if (isNewDay) {
         groupedCommits.push({
-          time: formatGroupTime(time),
+          date: formatGroupTime(time),
+          time,
           commits: [],
+          week: 0
         });
         groupDate = date;
       }
@@ -128,3 +131,61 @@ export function groupCommits(commits: { header: CommitHeader; context: CommitCon
 export const formatCommitTime = (t: number): string => {
   return new Date(t * 1000).toUTCString();
 };
+
+export function groupCommitsByWeek(commits: CommitMetadata[]): CommitGroup[] {
+  const groupedCommits: CommitGroup[] = [];
+  let groupDate: Date | undefined = undefined;
+
+  if (commits.length === 0) {
+    return [];
+  }
+
+  commits = commits.sort((a, b) => {
+    if (a.header.committerTime > b.header.committerTime) {
+      return -1;
+    } else if (a.header.committerTime < b.header.committerTime) {
+      return 1;
+    }
+
+    return 0;
+  });
+
+  // A accumulator that increments by the amount of weeks between weekly commit groups
+  let weekAccumulator = Math.floor(getDaysPassed(new Date(commits[0].header.committerTime * 1000), new Date()) / 7);
+
+  // Loops over all commits and stores them by week with some additional metadata in groupedCommits.
+  for (const commit of commits) {
+    const time = commit.header.committerTime * 1000;
+    const date = new Date(time);
+    const isNewWeek =
+      !groupedCommits.length ||
+      !groupDate ||
+      getDaysPassed(date, groupDate) > 7 ||
+      date.getFullYear() < groupDate.getFullYear();
+
+    if (isNewWeek) {
+      let daysPassed = 0;
+      if (groupDate) {
+        daysPassed = getDaysPassed(date, groupDate);
+      }
+      groupedCommits.push({
+        date: formatGroupTime(time),
+        time,
+        commits: [],
+        week: Math.floor(daysPassed / 7) + weekAccumulator
+      });
+      groupDate = date;
+      weekAccumulator += Math.floor(daysPassed / 7);
+    }
+    groupedCommits[groupedCommits.length - 1].commits.push(commit);
+  }
+
+  return groupedCommits;
+}
+
+// Get amount of days passed between two dates
+function getDaysPassed(from: Date, to: Date): number {
+  return Math.floor(
+    (to.getTime() - from.getTime()) / (24 * 60 * 60 * 1000)
+  );
+}