package skill

import "time"

// SkillVersion is one immutable snapshot of a Skill at the moment it
// was saved. The skill_versions table is append-only; pruning is by
// retention policy in PruneOldVersions.
//
// Why: edit history with rollback (v3) and the admin pin gate (v3 Phase 4)
// both need a stable snapshot of the skill at a known version. The Snapshot
// field carries the FULL Skill struct so a later restore or pin produces
// the exact agent definition that was saved — system_prompt, tools,
// schedule, every field — not a synthesized partial snapshot.
//
// What: identity (UUID per snapshot) + skill ref + version-string copy +
// the full Skill payload + audit fields (saved_by, saved_at, edit_summary).
//
// Test: see skill_version_test.go for round-trip, list ordering, prune
// retention, and version-by-number disambiguation coverage.
type SkillVersion struct {
	ID          string    // UUID per snapshot (NOT the skill's ID)
	SkillID     string    // FK to skills.id (conceptually; not enforced by GORM)
	Version     string    // Skill.Version at save time (semver)
	Snapshot    Skill     // full Skill struct embedded; serialised as JSON
	SavedBy     string    // caller member ID (or "" for builtin loader / pre-v3)
	SavedAt     time.Time // wall-clock save time
	EditSummary string    // optional human-readable note ("changed model tier", "...")
}