1// SPDX-License-Identifier: AGPL-3.0-or-later
2
3package web
4
5import (
6 "context"
7 "net/http"
8
9 "github.com/a-h/templ"
10
11 "bnema.dev/ermite/internal/domain"
12 "bnema.dev/ermite/internal/ports"
13)
14
15// compare shows a branch against the default branch of the repository: the
16// commits it is ahead by and, for the owner, the form that opens a merge
17// request.
18//
19// The API has no "diff between two branches" call outside a merge request, so
20// the page shows the diff only when it is exact without one: the branch is
21// ahead by a single commit that sits on the tip of the target (that commit's
22// own diff is then the whole change). Otherwise it lists the commits, which
23// link to their own diffs, and says the whole diff comes with the merge
24// request.
25func (s *Server) compare(ctx context.Context, r *http.Request) (templ.Component, int, error) {
26 d, err := s.loadRepo(ctx, r.PathValue("repo"))
27 if err != nil {
28 return nil, 0, err
29 }
30 src, rest, ok := resolveRef(d.branches, r.PathValue("rest"))
31 if !ok || rest != "" || d.head == nil {
32 return nil, 0, errNotFound
33 }
34 tgt := *d.head
35 name := d.name()
36
37 p := ComparePage{
38 Source: visibleText(src.ShortName), Target: visibleText(tgt.ShortName),
39 SourceHref: repoHref(name, "tree", src.ShortName), TargetHref: repoHref(name, "tree", tgt.ShortName),
40 CLI: Clone{ID: "cli-create", Lines: []string{
41 "ermite mr create " + shellWord(name) + " --source " + shellWord(src.ShortName) + " --title <title>",
42 }},
43 }
44
45 same := src.ShortName == tgt.ShortName
46 var ahead []domain.Commit
47 exact, behind := false, false
48 if same {
49 p.Note = "this is the default branch: there is nothing to compare it with."
50 p.AheadText = "0 commits"
51 } else {
52 var comparison ports.CompareResult
53 comparison, err = s.cfg.MergeRequests.Compare(ctx, principal(ctx), d.repo.Name, tgt.CommitID, src.CommitID)
54 ahead, exact, behind = comparison.Ahead, comparison.Exact, comparison.Behind
55 if err != nil {
56 return nil, 0, err
57 }
58 now := s.cfg.Now()
59 for _, c := range ahead {
60 p.Ahead = append(p.Ahead, commitRow(name, c, now))
61 }
62 p.AheadText = plural(len(ahead), "commit", "commits")
63 if !exact {
64 p.AheadText += " or more"
65 }
66 switch {
67 case !exact:
68 p.Note = "the branch left " + p.Target + " too long ago to tell where: only the newest commits are listed."
69 case len(ahead) == 0:
70 p.Note = "nothing to merge: " + p.Target + " already has every commit of " + p.Source + "."
71 case behind:
72 p.Note = p.Target + " has moved on since the branch started: a merge request can only be merged after " +
73 p.Source + " is rebased on " + p.Target + " and pushed again."
74 }
75 }
76
77 // The exact diff: one commit on top of the tip of the target.
78 if exact && !behind && len(ahead) == 1 {
79 res, err := s.getCommit(ctx, d.repo.Name, ahead[0].ID.String())
80 if err != nil {
81 return nil, 0, err
82 }
83 p.HasDiff = true
84 p.Files = s.hl.files(ctx, res.Diff.Files)
85 contextGaps(p.Files, res.Diff.Files, repoHref(d.name(), "context", res.Commit.ID.String()))
86 p.NFiles, p.Adds, p.Dels = res.Stats.FilesChanged, res.Stats.Additions, res.Stats.Deletions
87 if n := diffNote(res.Diff, len(p.Files), p.NFiles); n != "" {
88 p.Note = n
89 }
90 lines, invisible := diffLines(p.Files)
91 p.Invisible = invisible
92 self := repoHref(name, "compare", src.ShortName)
93 p.DiffView = newDiffView(r, lines, self+"?view=unified", self+"?view=split")
94 } else if len(ahead) > 1 && exact {
95 if p.Note == "" {
96 p.Note = "the whole diff of the branch is on its merge request; each commit links to its own."
97 }
98 }
99
100 // An open request for the same pair, or the form to open one.
101 var existing *domain.MergeRequest
102 if !same {
103 existing, err = s.openRequestFor(ctx, d.repo.Name, src.ShortName, tgt.ShortName)
104 if err != nil {
105 return nil, 0, err
106 }
107 }
108 switch {
109 case existing != nil:
110 p.Existing = &Link{Label: "#" + itoa(int(existing.Number)) + " " + visibleText(existing.Title.String()), Href: mrHref(name, existing.Number)}
111 case SignedIn(ctx) && !same && len(ahead) > 0:
112 title := ""
113 if len(ahead) == 1 {
114 title = ahead[0].Summary
115 } else {
116 title = ahead[len(ahead)-1].Summary
117 }
118 p.Create = &CreateForm{
119 Action: mrBase(name), Source: src.ShortName, Target: tgt.ShortName,
120 Title: cutRunes(title, 120),
121 }
122 }
123
124 l := s.repoLayout(ctx, d, "merge-requests")
125 l.Title = "compare " + p.Source + " · " + name + " · " + s.instance
126 pinRef(&l, target{rev: src.CommitID.String(), name: src.ShortName})
127 l.Crumbs[0].Current = false
128 l.Crumbs = append(l.Crumbs,
129 Crumb{Label: "merge requests", Href: mrBase(name)},
130 Crumb{Label: "compare", Current: false},
131 Crumb{Label: p.Source, Current: true},
132 )
133 l.HasRail = true
134 return Compare(l, p), http.StatusOK, nil
135}
136
137// openRequestFor finds the open merge request with this source and target.
138func (s *Server) openRequestFor(ctx context.Context, repo domain.RepoName, source, target string) (*domain.MergeRequest, error) {
139 token := ""
140 for range maxOpenPages {
141 res, err := s.cfg.MergeRequests.List(ctx, principal(ctx), repo, ports.ListMergeRequestsParams{
142 State: domain.MRStateOpen, PageSize: pageSize, PageToken: token,
143 })
144 if err != nil {
145 return nil, err
146 }
147 for i := range res.MergeRequests {
148 if m := &res.MergeRequests[i]; m.Source == source && m.Target == target {
149 return m, nil
150 }
151 }
152 if token = res.NextPageToken; token == "" {
153 break
154 }
155 }
156 return nil, nil
157}
158
159// cutRunes shortens s to at most n characters.
160func cutRunes(s string, n int) string {
161 r := []rune(s)
162 if len(r) <= n {
163 return s
164 }
165 return string(r[:n])
166}