Implement contributors graph (#27882)

Continuation of #25439. Fixes #847

Before:
<img width="1296" alt="image"
src="https://github.com/go-gitea/gitea/assets/32161460/24571ac8-b254-43c9-b178-97340f0dc8a9">

----
After:
<img width="1296" alt="image"
src="https://github.com/go-gitea/gitea/assets/32161460/c60b2459-9d10-4d42-8d83-d5ef0f45bf94">

---
#### Overview
This is the implementation of a requested feature: Contributors graph
(#847)

It makes Activity page a multi-tab page and adds a new tab called
Contributors. Contributors tab shows the contribution graphs over time
since the repository existed. It also shows per user contribution graphs
for top 100 contributors. Top 100 is calculated based on the selected
contribution type (commits, additions or deletions).

---
#### Demo
(The demo is a bit old but still a good example to show off the main
features)

<video src="https://github.com/go-gitea/gitea/assets/32161460/9f68103f-8145-4cc2-94bc-5546daae7014" controls width="320" height="240">
  <a href="https://github.com/go-gitea/gitea/assets/32161460/9f68103f-8145-4cc2-94bc-5546daae7014">Download</a>
</video>


#### Features:

- Select contribution type (commits, additions or deletions)
- See overall and per user contribution graphs for the selected
contribution type
- Zoom and pan on graphs to see them in detail
- See top 100 contributors based on the selected contribution type and
selected time range
- Go directly to users' profile by clicking their name if they are
registered gitea users
- Cache the results so that when the same repository is visited again
fetching data will be faster


---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: hiifong <i@hiif.ong>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: yp05327 <576951401@qq.com>

options/locale/locale_en-US.ini

@@ -1912,6 +1912,8 @@ wiki.page_name_desc = Enter a name for this Wiki page. Some special names are: '
 wiki.original_git_entry_tooltip = View original Git file instead of using friendly link.
 
 activity = Activity
+activity.navbar.pulse = Pulse
+activity.navbar.contributors = Contributors
 activity.period.filter_label = Period:
 activity.period.daily = 1 day
 activity.period.halfweekly = 3 days
@@ -1977,6 +1979,16 @@ activity.git_stats_and_deletions = and
 activity.git_stats_deletion_1 = %d deletion
 activity.git_stats_deletion_n = %d deletions
 
+contributors = Contributors
+contributors.contribution_type.filter_label = Contribution type:
+contributors.contribution_type.commits = Commits
+contributors.contribution_type.additions = Additions
+contributors.contribution_type.deletions = Deletions
+contributors.loading_title = Loading contributions...
+contributors.loading_title_failed = Could not load contributions
+contributors.loading_info = This might take a bit…
+contributors.component_failed_to_load = An unexpected error happened.
+
 search = Search
 search.search_repo = Search repository
 search.type.tooltip = Search type

package.json

@@ -18,8 +18,12 @@
     "add-asset-webpack-plugin": "2.0.1",
     "ansi_up": "6.0.2",
     "asciinema-player": "3.6.3",
+    "chart.js": "4.3.0",
+    "chartjs-adapter-dayjs-4": "1.0.4",
+    "chartjs-plugin-zoom": "2.0.1",
     "clippie": "4.0.6",
     "css-loader": "6.10.0",
+    "dayjs": "1.11.10",
     "dropzone": "6.0.0-beta.2",
     "easymde": "2.18.0",
     "esbuild-loader": "4.0.3",
@@ -46,6 +50,7 @@
     "uint8-to-base64": "0.2.0",
     "vue": "3.4.18",
     "vue-bar-graph": "2.0.0",
+    "vue-chartjs": "5.3.0",
     "vue-loader": "17.4.2",
     "vue3-calendar-heatmap": "2.0.5",
     "webpack": "5.90.1",

routers/web/repo/activity.go

@@ -22,6 +22,8 @@ func Activity(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.activity")
 	ctx.Data["PageIsActivity"] = true
 
+	ctx.Data["PageIsPulse"] = true
+
 	ctx.Data["Period"] = ctx.Params("period")
 
 	timeUntil := time.Now()

routers/web/repo/contributors.go

@@ -0,0 +1,44 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"errors"
+	"net/http"
+
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+	contributors_service "code.gitea.io/gitea/services/repository"
+)
+
+const (
+	tplContributors base.TplName = "repo/activity"
+)
+
+// Contributors render the page to show repository contributors graph
+func Contributors(ctx *context.Context) {
+	ctx.Data["Title"] = ctx.Tr("repo.contributors")
+
+	ctx.Data["PageIsActivity"] = true
+	ctx.Data["PageIsContributors"] = true
+
+	ctx.PageData["contributionType"] = "commits"
+
+	ctx.PageData["repoLink"] = ctx.Repo.RepoLink
+
+	ctx.HTML(http.StatusOK, tplContributors)
+}
+
+// ContributorsData renders JSON of contributors along with their weekly commit statistics
+func ContributorsData(ctx *context.Context) {
+	if contributorStats, err := contributors_service.GetContributorStats(ctx, ctx.Cache, ctx.Repo.Repository, ctx.Repo.CommitID); err != nil {
+		if errors.Is(err, contributors_service.ErrAwaitGeneration) {
+			ctx.Status(http.StatusAccepted)
+			return
+		}
+		ctx.ServerError("GetContributorStats", err)
+	} else {
+		ctx.JSON(http.StatusOK, contributorStats)
+	}
+}

routers/web/web.go

@@ -1392,6 +1392,10 @@ func registerRoutes(m *web.Route) {
 		m.Group("/activity", func() {
 			m.Get("", repo.Activity)
 			m.Get("/{period}", repo.Activity)
+			m.Group("/contributors", func() {
+				m.Get("", repo.Contributors)
+				m.Get("/data", repo.ContributorsData)
+			})
 		}, context.RepoRef(), repo.MustBeNotEmpty, context.RequireRepoReaderOr(unit.TypePullRequests, unit.TypeIssues, unit.TypeReleases))
 
 		m.Group("/activity_author_data", func() {