appconfig

type Change struct {
	Path string
	Old  any
	New  any
}

type Entry struct {
	Version int64
	At      time.Time
	Actor   string // "user:<id>", "key:<name>", "function:<db>/<name>", …
	Kind    string // KindSet or KindRollback
	// RolledBackTo is the version a rollback restored.
	RolledBackTo int64
	Changes      []Change
	// Values are the stored values after the change: what a rollback to this version restores.
	Values map[string]any
}

type Input struct {
	Set   map[string]any
	Reset []string
}

type InvalidError struct{ Problems []Problem }

type MemStore struct {
	// contains filtered or unexported fields
}

type Problem struct{ Path, Reason string }

type Result struct {
	Version int64
	// Changed is false when the change left every value as it was; no version is made then.
	Changed bool
	Changes []Change
}

type Service struct {
	Store  Store
	Config *registry.AppConfig
	Now    func() time.Time // defaults to time.Now
}

type State struct {
	Version   int64
	Values    map[string]any
	UpdatedAt time.Time
	UpdatedBy string
}

type Store interface {
	// AppConfigState returns the current state; version 0 with no values when none was saved.
	AppConfigState(ctx context.Context) (State, error)
	// SaveAppConfig replaces the state with next when the stored version is expected
	// (ErrConflict otherwise), records the entry, and removes entries of versions up to
	// pruneTo that are older than pruneBefore.
	SaveAppConfig(ctx context.Context, expected int64, next State, entry Entry, pruneTo int64, pruneBefore time.Time) error
	// AppConfigHistory returns entries, newest first.
	AppConfigHistory(ctx context.Context, limit int) ([]Entry, error)
	// AppConfigEntry returns one version's entry, or ErrNoVersion.
	AppConfigEntry(ctx context.Context, version int64) (Entry, error)
}

type View struct {
	Version int64
	// Values is every key with its effective value: the default, or what was set.
	Values map[string]any
	// Overrides are the values that differ from their defaults, nested.
	Overrides map[string]any
	// Invalid are stored values that no longer satisfy the declaration (after a
	// deploy): they are ignored, so their keys read as defaults, until fixed or reset.
	Invalid   []Problem
	UpdatedAt time.Time
	UpdatedBy string
}