| 1 | // SPDX-License-Identifier: AGPL-3.0-or-later |
| 2 | |
| 3 | package pulls |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "errors" |
| 8 | "fmt" |
| 9 | "strconv" |
| 10 | "strings" |
| 11 | "time" |
| 12 | |
| 13 | "github.com/jackc/pgx/v5/pgtype" |
| 14 | |
| 15 | "github.com/tenseleyFlow/shithub/internal/issues" |
| 16 | issuesdb "github.com/tenseleyFlow/shithub/internal/issues/sqlc" |
| 17 | "github.com/tenseleyFlow/shithub/internal/pulls/review" |
| 18 | pullsdb "github.com/tenseleyFlow/shithub/internal/pulls/sqlc" |
| 19 | repogit "github.com/tenseleyFlow/shithub/internal/repos/git" |
| 20 | usersdb "github.com/tenseleyFlow/shithub/internal/users/sqlc" |
| 21 | ) |
| 22 | |
| 23 | // MergeParams describes a merge request. |
| 24 | type MergeParams struct { |
| 25 | PRID int64 |
| 26 | ActorUserID int64 |
| 27 | GitDir string |
| 28 | Method string // "merge" | "squash" | "rebase" |
| 29 | Subject string // optional override; falls back to "<title> (#<number>)" |
| 30 | Body string |
| 31 | WorktreesDir string // optional, defaults to <gitDir>/.tmp-worktrees |
| 32 | Now func() time.Time |
| 33 | } |
| 34 | |
| 35 | // Merge performs the requested merge inside a temp worktree: |
| 36 | // |
| 37 | // 1. Lock the pull_requests row (FOR UPDATE) to serialize concurrent |
| 38 | // attempts. The transaction holds for the whole job to keep the |
| 39 | // lock until the DB state reflects the merge. |
| 40 | // 2. Validate state: not merged, not closed, mergeable_state == clean, |
| 41 | // method allowed by the repo config. |
| 42 | // 3. Resolve identity (author = PR author for squash, merger otherwise; |
| 43 | // committer = merger). |
| 44 | // 4. Run repogit.PerformMerge against the bare repo. |
| 45 | // 5. Persist merge_commit_sha + merged_at + flip the issue to closed |
| 46 | // with state_reason='completed'. |
| 47 | // 6. Auto-close linked issues parsed from PR body + commit messages. |
| 48 | // 7. Emit a `merged` timeline event. |
| 49 | func Merge(ctx context.Context, deps Deps, p MergeParams) error { |
| 50 | if p.Now == nil { |
| 51 | p.Now = time.Now |
| 52 | } |
| 53 | |
| 54 | // Begin the locking tx. Holding the row lock through the whole |
| 55 | // merge prevents two attempts both winning at the worktree level. |
| 56 | tx, err := deps.Pool.Begin(ctx) |
| 57 | if err != nil { |
| 58 | return err |
| 59 | } |
| 60 | committed := false |
| 61 | defer func() { |
| 62 | if !committed { |
| 63 | _ = tx.Rollback(ctx) |
| 64 | } |
| 65 | }() |
| 66 | |
| 67 | q := pullsdb.New() |
| 68 | pr, err := q.LockPullRequestForMerge(ctx, tx, p.PRID) |
| 69 | if err != nil { |
| 70 | return ErrPRNotFound |
| 71 | } |
| 72 | if pr.MergedAt.Valid { |
| 73 | return ErrAlreadyMerged |
| 74 | } |
| 75 | // Issue side: must still be open + mergeable. |
| 76 | iq := issuesdb.New() |
| 77 | issue, err := iq.GetIssueByID(ctx, tx, p.PRID) |
| 78 | if err != nil { |
| 79 | return err |
| 80 | } |
| 81 | if issue.State != issuesdb.IssueStateOpen { |
| 82 | return ErrAlreadyClosed |
| 83 | } |
| 84 | if pr.MergeableState != pullsdb.PrMergeableStateClean { |
| 85 | return ErrMergeBlocked |
| 86 | } |
| 87 | |
| 88 | // Belt-and-braces: re-evaluate the review gate inside the row |
| 89 | // lock so a `request_changes` submitted between the last |
| 90 | // Mergeability tick and this merge attempt is still honored. |
| 91 | // Spec pitfall: required-review bypass via direct API. |
| 92 | gate, err := review.Evaluate(ctx, deps.Pool, review.GateInputs{ |
| 93 | RepoID: issue.RepoID, |
| 94 | BaseRef: pr.BaseRef, |
| 95 | PRIssueID: p.PRID, |
| 96 | }, int64FromPg(issue.AuthorUserID)) |
| 97 | if err != nil { |
| 98 | return fmt.Errorf("review gate: %w", err) |
| 99 | } |
| 100 | if !gate.Satisfied { |
| 101 | return ErrMergeBlocked |
| 102 | } |
| 103 | |
| 104 | // Identity for the new commit. Author email rules per spec: |
| 105 | // merge — author = committer = merger |
| 106 | // squash — author = PR author; committer = merger |
| 107 | // rebase — author preserved; committer = merger (handled by |
| 108 | // repogit.PerformMerge via env) |
| 109 | uq := usersdb.New() |
| 110 | mergerName, mergerEmail, err := identityFor(ctx, tx, uq, p.ActorUserID) |
| 111 | if err != nil { |
| 112 | return err |
| 113 | } |
| 114 | authorName, authorEmail := mergerName, mergerEmail |
| 115 | if p.Method == "squash" && issue.AuthorUserID.Valid { |
| 116 | an, ae, err := identityFor(ctx, tx, uq, issue.AuthorUserID.Int64) |
| 117 | if err == nil { |
| 118 | authorName, authorEmail = an, ae |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | subject := strings.TrimSpace(p.Subject) |
| 123 | if subject == "" { |
| 124 | subject = issue.Title + " (#" + strconv.FormatInt(issue.Number, 10) + ")" |
| 125 | } |
| 126 | |
| 127 | // Run the merge against the bare repo. PerformMerge cleans up the |
| 128 | // worktree on every exit path. |
| 129 | mergeRes, err := repogit.PerformMerge(ctx, repogit.MergeOptions{ |
| 130 | GitDir: p.GitDir, |
| 131 | BaseRef: "refs/heads/" + pr.BaseRef, |
| 132 | BaseOID: pr.BaseOid, |
| 133 | HeadOID: pr.HeadOid, |
| 134 | Method: p.Method, |
| 135 | AuthorName: authorName, |
| 136 | AuthorEmail: authorEmail, |
| 137 | CommitterName: mergerName, |
| 138 | CommitterEmail: mergerEmail, |
| 139 | When: p.Now(), |
| 140 | Subject: subject, |
| 141 | Body: p.Body, |
| 142 | WorktreesDir: p.WorktreesDir, |
| 143 | }) |
| 144 | if err != nil { |
| 145 | return fmt.Errorf("perform merge: %w", err) |
| 146 | } |
| 147 | |
| 148 | if err := q.SetPullRequestMerged(ctx, tx, pullsdb.SetPullRequestMergedParams{ |
| 149 | IssueID: p.PRID, |
| 150 | MergedByUserID: pgtype.Int8{Int64: p.ActorUserID, Valid: p.ActorUserID != 0}, |
| 151 | MergeCommitSha: pgtype.Text{String: mergeRes.MergedOID, Valid: true}, |
| 152 | MergeMethod: pullsdb.NullPrMergeMethod{PrMergeMethod: pullsdb.PrMergeMethod(p.Method), Valid: true}, |
| 153 | BaseOidAtMerge: pgtype.Text{String: pr.BaseOid, Valid: true}, |
| 154 | HeadOidAtMerge: pgtype.Text{String: pr.HeadOid, Valid: true}, |
| 155 | }); err != nil { |
| 156 | return err |
| 157 | } |
| 158 | |
| 159 | // Close the issue side with state_reason=completed. |
| 160 | if err := iq.SetIssueState(ctx, tx, issuesdb.SetIssueStateParams{ |
| 161 | ID: p.PRID, |
| 162 | State: issuesdb.IssueStateClosed, |
| 163 | StateReason: issuesdb.NullIssueStateReason{IssueStateReason: issuesdb.IssueStateReasonCompleted, Valid: true}, |
| 164 | ClosedByUserID: pgtype.Int8{Int64: p.ActorUserID, Valid: p.ActorUserID != 0}, |
| 165 | }); err != nil { |
| 166 | return err |
| 167 | } |
| 168 | |
| 169 | // `merged` timeline event. |
| 170 | if _, err := iq.InsertIssueEvent(ctx, tx, issuesdb.InsertIssueEventParams{ |
| 171 | IssueID: p.PRID, |
| 172 | ActorUserID: pgtype.Int8{Int64: p.ActorUserID, Valid: p.ActorUserID != 0}, |
| 173 | Kind: "merged", |
| 174 | Meta: []byte(fmt.Sprintf(`{"method":%q,"commit":%q}`, p.Method, mergeRes.MergedOID)), |
| 175 | }); err != nil { |
| 176 | return err |
| 177 | } |
| 178 | |
| 179 | // Auto-close linked issues. Linked = Closes/Fixes/Resolves #N in |
| 180 | // the PR body + each commit message. Best-effort; don't fail the |
| 181 | // merge if the close fails. |
| 182 | linked := parseLinkedIssues(issue.Body) |
| 183 | for _, c := range fetchCommitsForLinkScan(ctx, tx, p.PRID) { |
| 184 | linked = append(linked, parseLinkedIssues(c)...) |
| 185 | } |
| 186 | closed := map[int64]bool{} |
| 187 | for _, num := range linked { |
| 188 | if num == issue.Number { |
| 189 | continue // self-reference |
| 190 | } |
| 191 | target, err := iq.GetIssueByNumber(ctx, tx, issuesdb.GetIssueByNumberParams{ |
| 192 | RepoID: issue.RepoID, Number: num, |
| 193 | }) |
| 194 | if err != nil || target.Kind != issuesdb.IssueKindIssue || target.State != issuesdb.IssueStateOpen { |
| 195 | continue |
| 196 | } |
| 197 | if closed[target.ID] { |
| 198 | continue |
| 199 | } |
| 200 | closed[target.ID] = true |
| 201 | _ = iq.SetIssueState(ctx, tx, issuesdb.SetIssueStateParams{ |
| 202 | ID: target.ID, |
| 203 | State: issuesdb.IssueStateClosed, |
| 204 | StateReason: issuesdb.NullIssueStateReason{IssueStateReason: issuesdb.IssueStateReasonCompleted, Valid: true}, |
| 205 | ClosedByUserID: pgtype.Int8{Int64: p.ActorUserID, Valid: p.ActorUserID != 0}, |
| 206 | }) |
| 207 | _, _ = iq.InsertIssueEvent(ctx, tx, issuesdb.InsertIssueEventParams{ |
| 208 | IssueID: target.ID, |
| 209 | ActorUserID: pgtype.Int8{Int64: p.ActorUserID, Valid: p.ActorUserID != 0}, |
| 210 | Kind: "closed", |
| 211 | Meta: []byte(fmt.Sprintf(`{"closed_by_pr":%d}`, p.PRID)), |
| 212 | }) |
| 213 | } |
| 214 | |
| 215 | if err := tx.Commit(ctx); err != nil { |
| 216 | return err |
| 217 | } |
| 218 | committed = true |
| 219 | return nil |
| 220 | } |
| 221 | |
| 222 | // identityFor reads the user's display + primary verified email for |
| 223 | // commit identity. Falls back to a synthesised noreply on missing data |
| 224 | // rather than failing the merge — privacy/noreply emails ship post-MVP. |
| 225 | func identityFor(ctx context.Context, db pullsdb.DBTX, uq *usersdb.Queries, userID int64) (name, email string, err error) { |
| 226 | user, err := uq.GetUserByID(ctx, db, userID) |
| 227 | if err != nil { |
| 228 | return "", "", err |
| 229 | } |
| 230 | display := strings.TrimSpace(user.DisplayName) |
| 231 | if display == "" { |
| 232 | display = user.Username |
| 233 | } |
| 234 | addr := user.Username + "@noreply.shithub.local" |
| 235 | if user.PrimaryEmailID.Valid { |
| 236 | em, err := uq.GetUserEmailByID(ctx, db, user.PrimaryEmailID.Int64) |
| 237 | if err == nil && em.Verified { |
| 238 | addr = string(em.Email) |
| 239 | } |
| 240 | } |
| 241 | return display, addr, nil |
| 242 | } |
| 243 | |
| 244 | // fetchCommitsForLinkScan returns the head-side commit messages so the |
| 245 | // linked-issue parser can scan body + subject. Best-effort — returns |
| 246 | // an empty slice on error. |
| 247 | func fetchCommitsForLinkScan(ctx context.Context, db pullsdb.DBTX, prID int64) []string { |
| 248 | rows, err := pullsdb.New().ListPullRequestCommits(ctx, db, prID) |
| 249 | if err != nil { |
| 250 | return nil |
| 251 | } |
| 252 | out := make([]string, 0, len(rows)) |
| 253 | for _, r := range rows { |
| 254 | out = append(out, r.Subject+"\n\n"+r.Body) |
| 255 | } |
| 256 | return out |
| 257 | } |
| 258 | |
| 259 | // Compile-time check that issues' typed errors are still in scope so |
| 260 | // EditPR's wrapping continues to work after refactors. |
| 261 | var _ = errors.Is(issues.ErrEmptyTitle, issues.ErrEmptyTitle) |
| 262 |