aego/modules/savegame/module.go

package savegame

import (
	"strings"

	"aego/contracts/persistence"
	"aego/contracts/scriptevents"
	"aego/core/log"
	"aego/engine"
	"aego/engine/module"
	"aego/format/aetext"
	"aego/save"
	"aego/schema"
)

const (
	ID             = "save"
	SystemStep     = ID + ".step"
	ScriptModule   = "aego/save"
	EventSave      = "OnSave"
	EventLoad      = "OnLoad"
	MarkerName     = "save.Persist"
	SlotCheckpoint = "checkpoint"
	SlotAutosave   = "autosave"
)

type Persist struct {
	NoTransform bool `aego:"noTransform"`
	NoEnabled   bool `aego:"noEnabled"`
}

type Events struct {
	Save scriptevents.EventID
	Load scriptevents.EventID
}

type Result struct {
	Slot string
	Load bool
	Err  error
}

type Module struct {
	ev       Events
	sections []module.OwnedSection
	game     string
	eng      *engine.Engine
	log      *log.ChannelLogger
	global   aetext.Node
	pending  *save.Doc
	unknown  []save.Section
	playtime float64
	autosave float64
	last     Result
	rev      uint64
}

func New() *Module {
	return &Module{ev: Events{Save: scriptevents.NoEvent, Load: scriptevents.NoEvent}}
}

func (*Module) Info() module.Info {
	return module.Info{ID: ID, Version: engine.Version, Requires: []string{"script", "spawn"}, Builtin: true, DisplayName: "Saving", DocsOrder: 80, DocsIcon: "comp.persist"}
}

func (m *Module) Register(r *module.Registry) error {
	registerDocs(r)
	if err := module.Component[Persist](r, schema.Name(MarkerName),
		schema.Doc("Persist saves the node's transform and enabled flag in save games."),
		schema.FieldDoc("noTransform", "Leaves the transform out of save games, for nodes whose position comes from elsewhere."),
		schema.FieldDoc("noEnabled", "Leaves the enabled flag out of save games.")).
		Category("Engine").Display("Persist").Icon("comp.persist").Err(); err != nil {
		return err
	}
	m.ev.Save = r.ScriptEvent(scriptevents.Event{Name: EventSave,
		Doc: "OnSave runs on every script that has it while a game is saved; write values with save.Put*."})
	m.ev.Load = r.ScriptEvent(scriptevents.Event{Name: EventLoad,
		Doc: "OnLoad runs after Ready on every script that has it when a saved game is loaded; read values with save.Get*."})
	r.System(engine.SystemDesc{ID: SystemStep, Phase: engine.PhaseAnimation, Scope: engine.ScopePlay, Pause: engine.PauseAlways, System: step{}})
	if r.Bindings() != nil {
		installScript(r.ScriptModule(ScriptModule), m)
	}
	r.Finalize(func(r *module.Registry) error {
		m.sections = r.SaveSections()
		var games []string
		for _, info := range r.GameModules() {
			games = append(games, info.ID+"@"+info.Version)
		}
		m.game = strings.Join(games, ",")
		return nil
	})
	return nil
}

func (m *Module) Init(ctx *module.InitContext) error {
	m.eng = ctx.Engine
	lg := ctx.Log
	if lg == nil {
		lg = log.Nop()
	}
	m.log = lg.With(log.Channel(ID))
	return nil
}

func (m *Module) logger() *log.ChannelLogger {
	if m.log == nil {
		m.log = log.Nop().With(log.Channel(ID))
	}
	return m.log
}

func (m *Module) AttachWorld(ctx *module.AttachContext) error {
	if !ctx.Play || ctx.World == nil || ctx.Scene == nil {
		return nil
	}
	s := NewService(m, ctx.World, ctx.Scene)
	ctx.World.SetService(persistence.ServiceID, s)
	if doc := m.pending; doc != nil {
		m.pending = nil
		m.finish(Result{Slot: doc.Meta.Name, Load: true, Err: s.Apply(doc)})
	}
	return nil
}

func (*Module) DetachWorld(ctx *module.AttachContext) {
	if ctx.Play && ctx.World != nil {
		ctx.World.RemoveService(persistence.ServiceID)
	}
}

func (m *Module) finish(r Result) {
	m.last = r
	m.rev++
	what := "saved"
	if r.Load {
		what = "loaded"
	}
	if r.Err != nil {
		m.logger().Error("cannot "+strings.TrimSuffix(what, "d")+" the game", log.F("slot", r.Slot), log.F("err", r.Err.Error()))
		return
	}
	m.logger().Info("game "+what, log.F("slot", r.Slot))
}

func (m *Module) Last() (Result, uint64) {
	return m.last, m.rev
}

func (m *Module) Playtime() float64 {
	return m.playtime
}

func (m *Module) Global(key string) (aetext.Value, bool) {
	return m.global.Field(key)
}

func (m *Module) SetGlobal(key string, v aetext.Value) {
	m.global.SetField(key, v)
}

func (m *Module) store() *save.Store {
	if m.eng == nil {
		return nil
	}
	st, _ := engine.Service[*save.Store](m.eng, persistence.StoreID)
	return st
}

func (m *Module) encode(st *save.Store, slot string, doc *save.Doc) {
	run := func() {
		err := st.Write(slot, save.Encode(doc), nil)
		done := func() { m.finish(Result{Slot: slot, Err: err}) }
		if m.eng != nil {
			m.eng.Jobs().OnMain(done)
			return
		}
		done()
	}
	if m.eng != nil {
		m.eng.Jobs().Submit(run)
		return
	}
	run()
}

func Of(w *engine.World) *Service {
	s, _ := engine.ServiceOf[*Service](w, persistence.ServiceID)
	return s
}

type step struct{}

func (step) Run(ctx *engine.Context) {
	if s := Of(ctx.World); s != nil {
		s.Step(ctx.Dt, ctx.Unscaled)
	}
}