| 1 | // SPDX-License-Identifier: AGPL-3.0-or-later |
| 2 | |
| 3 | package review |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "fmt" |
| 8 | |
| 9 | "github.com/jackc/pgx/v5/pgtype" |
| 10 | |
| 11 | pullsdb "github.com/tenseleyFlow/shithub/internal/pulls/sqlc" |
| 12 | repogit "github.com/tenseleyFlow/shithub/internal/repos/git" |
| 13 | ) |
| 14 | |
| 15 | // RemapAllForPR re-anchors every non-draft review comment on a PR |
| 16 | // against the new (base, head) snapshot. For each comment we do a |
| 17 | // content-aware check: |
| 18 | // |
| 19 | // 1. Read the line text at (original_commit_sha, file_path, |
| 20 | // original_line). This is what the comment was written against. |
| 21 | // 2. Read the same line number in the new blob (newHeadOID for |
| 22 | // side=right; newBaseOID for side=left). |
| 23 | // 3. If the bytes are identical → keep current_position = original_line. |
| 24 | // If not → current_position = NULL (outdated). The comment still |
| 25 | // renders in the conversation timeline; the Files tab hides it |
| 26 | // until the user clicks "Show outdated." |
| 27 | // |
| 28 | // This is the conservative v1 mapper. Lines that have been re-indented, |
| 29 | // shifted by an insertion above, or merely had a comma added all |
| 30 | // outdate — that's the right default. The spec calls out |
| 31 | // `git blame --porcelain` as a richer mapper for rebase-heavy PRs; |
| 32 | // add that when the simple presence check proves too aggressive. |
| 33 | // |
| 34 | // Idempotent: re-running converges on the same answer. |
| 35 | func RemapAllForPR(ctx context.Context, deps Deps, gitDir string, prID int64, newBaseOID, newHeadOID string) error { |
| 36 | if newBaseOID == "" || newHeadOID == "" { |
| 37 | return nil |
| 38 | } |
| 39 | q := pullsdb.New() |
| 40 | rows, err := q.ListNonDraftCommentsForPositionMap(ctx, deps.Pool, prID) |
| 41 | if err != nil { |
| 42 | return fmt.Errorf("position map list: %w", err) |
| 43 | } |
| 44 | if len(rows) == 0 { |
| 45 | return nil |
| 46 | } |
| 47 | |
| 48 | // Per-(ref, path) blob cache so we read each blob at most once per |
| 49 | // PR, regardless of how many comments anchor into it. |
| 50 | type blobKey struct { |
| 51 | ref string |
| 52 | path string |
| 53 | } |
| 54 | cache := map[blobKey][]byte{} |
| 55 | loadBlob := func(ref, path string) []byte { |
| 56 | k := blobKey{ref, path} |
| 57 | if b, ok := cache[k]; ok { |
| 58 | return b |
| 59 | } |
| 60 | // We don't bother mapping files > 1 MiB; those comments outdate. |
| 61 | const maxBytes = 1 << 20 |
| 62 | blob, err := repogit.ReadBlobBytes(ctx, gitDir, ref, path, maxBytes) |
| 63 | if err != nil { |
| 64 | cache[k] = nil |
| 65 | return nil |
| 66 | } |
| 67 | cache[k] = blob |
| 68 | return blob |
| 69 | } |
| 70 | |
| 71 | for _, c := range rows { |
| 72 | newRef := newHeadOID |
| 73 | if c.Side == pullsdb.PrReviewSideLeft { |
| 74 | newRef = newBaseOID |
| 75 | } |
| 76 | original := loadBlob(c.OriginalCommitSha, c.FilePath) |
| 77 | current := loadBlob(newRef, c.FilePath) |
| 78 | |
| 79 | var newPos pgtype.Int4 |
| 80 | if line, ok := lineAt(original, int(c.OriginalLine)); ok { |
| 81 | if cur, ok := lineAt(current, int(c.OriginalLine)); ok && bytesEqual(line, cur) { |
| 82 | newPos = pgtype.Int4{Int32: c.OriginalLine, Valid: true} |
| 83 | } |
| 84 | } |
| 85 | if err := q.SetPRReviewCommentCurrentPosition(ctx, deps.Pool, pullsdb.SetPRReviewCommentCurrentPositionParams{ |
| 86 | ID: c.ID, |
| 87 | CurrentPosition: newPos, |
| 88 | }); err != nil { |
| 89 | return fmt.Errorf("position map update: %w", err) |
| 90 | } |
| 91 | } |
| 92 | return nil |
| 93 | } |
| 94 | |
| 95 | // lineAt returns the bytes of line N (1-indexed) in blob, excluding |
| 96 | // the trailing newline. Returns (nil, false) when the blob is nil/empty |
| 97 | // or N is out of range. |
| 98 | func lineAt(blob []byte, n int) ([]byte, bool) { |
| 99 | if blob == nil || n < 1 { |
| 100 | return nil, false |
| 101 | } |
| 102 | start, line := 0, 1 |
| 103 | for i := 0; i < len(blob); i++ { |
| 104 | if blob[i] == '\n' { |
| 105 | if line == n { |
| 106 | return blob[start:i], true |
| 107 | } |
| 108 | line++ |
| 109 | start = i + 1 |
| 110 | } |
| 111 | } |
| 112 | // Trailing line without terminator. |
| 113 | if line == n && start < len(blob) { |
| 114 | return blob[start:], true |
| 115 | } |
| 116 | return nil, false |
| 117 | } |
| 118 | |
| 119 | // bytesEqual is a tiny escape hatch so the test fixtures stay readable. |
| 120 | // `bytes.Equal` would do, but pulling the whole package in for one call |
| 121 | // adds noise to the position-map dependency graph. |
| 122 | func bytesEqual(a, b []byte) bool { |
| 123 | if len(a) != len(b) { |
| 124 | return false |
| 125 | } |
| 126 | for i := range a { |
| 127 | if a[i] != b[i] { |
| 128 | return false |
| 129 | } |
| 130 | } |
| 131 | return true |
| 132 | } |
| 133 |