1/** Complete dependency validation for current Team task snapshots. */

2

3import type { TeamTaskId, TeamTaskSnapshot } from './types.ts'

4

5/** Task dependency relation rejected by the shared graph validator. */

6export type TeamTaskGraphViolation = 'missing' | 'duplicate' | 'cycle'

7

8/** Package-private task dependency failure retained for command error mapping. */

9export class TeamTaskGraphError extends Error {

10 /**

11 * @param message - concrete invalid dependency relation.

12 * @param violation - stable relation category used by Team commands.

13 */

14 constructor(message: string, readonly violation: TeamTaskGraphViolation) {

15 super(message)

16 this.name = 'TeamTaskGraphError'

17 }

18}

19

20/**

21 * Validate the complete active task graph after replacing one candidate snapshot.

22 * @param current - current task snapshots before the candidate event.

23 * @param candidate - new or next-revision task snapshot.

24 * @throws {TeamTaskGraphError} when an active dependency is missing, duplicated, self-referential, or cyclic.

25 */

26export function assertTaskGraphCandidate(

27 current: readonly TeamTaskSnapshot[],

28 candidate: TeamTaskSnapshot,

29): void {

30 const tasks = new Map(current.map(task => [task.id, task]))

31 tasks.set(candidate.id, candidate)

32

33 for (const task of tasks.values()) {

34 if (task.status === 'deleted') continue

35 const seen = new Set<TeamTaskId>()

36 for (const blockerId of task.blockedBy) {

37 if (blockerId === task.id) {

38 throw new TeamTaskGraphError(`team task "${task.id}" cannot block itself`, 'cycle')

39 }

40 if (seen.has(blockerId)) {

41 throw new TeamTaskGraphError(`team task "${task.id}" repeats blocker "${blockerId}"`, 'duplicate')

42 }

43 const blocker = tasks.get(blockerId)

44 if (blocker === undefined || blocker.status === 'deleted') {

45 throw new TeamTaskGraphError(

46 `blocker task "${blockerId}" for "${task.id}" is missing or deleted`,

47 'missing',

48 )

49 }

50 seen.add(blockerId)

51 }

52 }

53

54 const visiting = new Set<TeamTaskId>()

55 const visited = new Set<TeamTaskId>()

56 const visit = (id: TeamTaskId): void => {

57 if (visiting.has(id)) {

58 throw new TeamTaskGraphError(`task dependency cycle includes "${id}"`, 'cycle')

59 }

60 if (visited.has(id)) return

61 const task = tasks.get(id)

62 if (task === undefined || task.status === 'deleted') return

63 visiting.add(id)

64 for (const blockerId of task.blockedBy) visit(blockerId)

65 visiting.delete(id)

66 visited.add(id)

67 }

68 for (const task of tasks.values()) visit(task.id)

69}