Allow to mark files in a PR as viewed (#19007)

Users can now mark files in PRs as viewed, resulting in them not being shown again by default when they reopen the PR again.

services/gitdiff/gitdiff.go

@@ -22,6 +22,7 @@ import (
 
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/models/db"
+	pull_model "code.gitea.io/gitea/models/pull"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/analyze"
 	"code.gitea.io/gitea/modules/charset"
@@ -602,25 +603,27 @@ func (diffSection *DiffSection) GetComputedInlineDiffFor(diffLine *DiffLine) Dif
 
 // DiffFile represents a file diff.
 type DiffFile struct {
-	Name                    string
-	OldName                 string
-	Index                   int
-	Addition, Deletion      int
-	Type                    DiffFileType
-	IsCreated               bool
-	IsDeleted               bool
-	IsBin                   bool
-	IsLFSFile               bool
-	IsRenamed               bool
-	IsAmbiguous             bool
-	IsSubmodule             bool
-	Sections                []*DiffSection
-	IsIncomplete            bool
-	IsIncompleteLineTooLong bool
-	IsProtected             bool
-	IsGenerated             bool
-	IsVendored              bool
-	Language                string
+	Name                      string
+	OldName                   string
+	Index                     int
+	Addition, Deletion        int
+	Type                      DiffFileType
+	IsCreated                 bool
+	IsDeleted                 bool
+	IsBin                     bool
+	IsLFSFile                 bool
+	IsRenamed                 bool
+	IsAmbiguous               bool
+	IsSubmodule               bool
+	Sections                  []*DiffSection
+	IsIncomplete              bool
+	IsIncompleteLineTooLong   bool
+	IsProtected               bool
+	IsGenerated               bool
+	IsVendored                bool
+	IsViewed                  bool // User specific
+	HasChangedSinceLastReview bool // User specific
+	Language                  string
 }
 
 // GetType returns type of diff file.
@@ -663,6 +666,18 @@ func (diffFile *DiffFile) GetTailSection(gitRepo *git.Repository, leftCommitID,
 	return tailSection
 }
 
+// GetDiffFileName returns the name of the diff file, or its old name in case it was deleted
+func (diffFile *DiffFile) GetDiffFileName() string {
+	if diffFile.Name == "" {
+		return diffFile.OldName
+	}
+	return diffFile.Name
+}
+
+func (diffFile *DiffFile) ShouldBeHidden() bool {
+	return diffFile.IsGenerated || diffFile.IsViewed
+}
+
 func getCommitFileLineCount(commit *git.Commit, filePath string) int {
 	blob, err := commit.GetBlobByPath(filePath)
 	if err != nil {
@@ -677,10 +692,12 @@ func getCommitFileLineCount(commit *git.Commit, filePath string) int {
 
 // Diff represents a difference between two git trees.
 type Diff struct {
-	Start, End                             string
-	NumFiles, TotalAddition, TotalDeletion int
-	Files                                  []*DiffFile
-	IsIncomplete                           bool
+	Start, End                   string
+	NumFiles                     int
+	TotalAddition, TotalDeletion int
+	Files                        []*DiffFile
+	IsIncomplete                 bool
+	NumViewedFiles               int // user-specific
 }
 
 // LoadComments loads comments into each line
@@ -1497,6 +1514,70 @@ func GetDiff(gitRepo *git.Repository, opts *DiffOptions, files ...string) (*Diff
 	return diff, nil
 }
 
+// SyncAndGetUserSpecificDiff is like GetDiff, except that user specific data such as which files the given user has already viewed on the given PR will also be set
+// Additionally, the database asynchronously is updated if files have changed since the last review
+func SyncAndGetUserSpecificDiff(ctx context.Context, userID int64, pull *models.PullRequest, gitRepo *git.Repository, opts *DiffOptions, files ...string) (*Diff, error) {
+	diff, err := GetDiff(gitRepo, opts, files...)
+	if err != nil {
+		return nil, err
+	}
+	review, err := pull_model.GetNewestReviewState(ctx, userID, pull.ID)
+	if err != nil || review == nil || review.UpdatedFiles == nil {
+		return diff, err
+	}
+
+	latestCommit := opts.AfterCommitID
+	if latestCommit == "" {
+		latestCommit = pull.HeadBranch // opts.AfterCommitID is preferred because it handles PRs from forks correctly and the branch name doesn't
+	}
+
+	changedFiles, err := gitRepo.GetFilesChangedBetween(review.CommitSHA, latestCommit)
+	if err != nil {
+		return diff, err
+	}
+
+	filesChangedSinceLastDiff := make(map[string]pull_model.ViewedState)
+outer:
+	for _, diffFile := range diff.Files {
+		fileViewedState := review.UpdatedFiles[diffFile.GetDiffFileName()]
+
+		// Check whether it was previously detected that the file has changed since the last review
+		if fileViewedState == pull_model.HasChanged {
+			diffFile.HasChangedSinceLastReview = true
+			continue
+		}
+
+		filename := diffFile.GetDiffFileName()
+
+		// Check explicitly whether the file has changed since the last review
+		for _, changedFile := range changedFiles {
+			diffFile.HasChangedSinceLastReview = filename == changedFile
+			if diffFile.HasChangedSinceLastReview {
+				filesChangedSinceLastDiff[filename] = pull_model.HasChanged
+				continue outer // We don't want to check if the file is viewed here as that would fold the file, which is in this case unwanted
+			}
+		}
+		// Check whether the file has already been viewed
+		if fileViewedState == pull_model.Viewed {
+			diffFile.IsViewed = true
+			diff.NumViewedFiles++
+		}
+	}
+
+	// Explicitly store files that have changed in the database, if any is present at all.
+	// This has the benefit that the "Has Changed" attribute will be present as long as the user does not explicitly mark this file as viewed, so it will even survive a page reload after marking another file as viewed.
+	// On the other hand, this means that even if a commit reverting an unseen change is committed, the file will still be seen as changed.
+	if len(filesChangedSinceLastDiff) > 0 {
+		err := pull_model.UpdateReviewState(ctx, review.UserID, review.PullID, review.CommitSHA, filesChangedSinceLastDiff)
+		if err != nil {
+			log.Warn("Could not update review for user %d, pull %d, commit %s and the changed files %v: %v", review.UserID, review.PullID, review.CommitSHA, filesChangedSinceLastDiff, err)
+			return nil, err
+		}
+	}
+
+	return diff, err
+}
+
 // CommentAsDiff returns c.Patch as *Diff
 func CommentAsDiff(c *models.Comment) (*Diff, error) {
 	diff, err := ParsePatch(setting.Git.MaxGitDiffLines,