// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

// The resource package handles CRUD operations on resources and YAML (de)serialization
package resource

import (
	_ "encoding/json"
	_ "fmt"
	_ "gopkg.in/yaml.v3"
	"gitea.rosskeen.house/rosskeen.house/machine"
	"decl/internal/data"
	"errors"
)


var (
	ErrInvalidResourceURI error = errors.New("Invalid resource URI")
	ErrResourceStateAbsent = errors.New("Resource state absent")
	ErrUnableToFindResource = errors.New("Unable to find resource - not loaded")
)

type ResourceReference string
/*
type ResourceSelector func(r *Declaration) bool

type Resource interface {
	Type() string
	StateMachine() machine.Stater
	URI() string
	SetURI(string) error
	UseConfig(config ConfigurationValueGetter)
	ResolveId(context.Context) string
	ResourceLoader
	StateTransformer
	ResourceReader
	ResourceValidator
	Clone() Resource
	SetResourceMapper(resources ResourceMapper)
}

type ContentReader interface {
	ContentReaderStream() (*transport.Reader, error)
}

type ContentWriter interface {
	ContentWriterStream() (*transport.Writer, error)
}

type ContentReadWriter interface {
	ContentReader
	ContentWriter
}

type ResourceValidator interface {
	Validate() error
}

type ResourceCreator interface {
	Create(context.Context) error
}

type ResourceReader interface {
	Read(context.Context) ([]byte, error)
}

type ResourceUpdater interface {
	Update(context.Context) error
}

type ResourceDeleter interface {
	Delete(context.Context) error
}

type ResourceDecoder struct {
}

type ResourceCrudder struct {
	ResourceCreator
	ResourceReader
	ResourceUpdater
	ResourceDeleter
}
*/

func NewResource(uri string) data.Resource {
	r, e := ResourceTypes.New(uri)
	if e == nil {
		return r
	}
	return nil
}

/*

// Return a Content ReadWriter for the resource referred to.
func (r ResourceReference) Lookup(look data.ResourceMapper) data.ContentReadWriter {
	slog.Info("ResourceReference.Lookup()", "resourcereference", r, "resourcemapper", look)
	if look != nil {
		if v,ok := look.Get(string(r)); ok {
			return v.(data.ContentReadWriter)
		}
	}
	return r
}

func (r ResourceReference) Dereference(look data.ResourceMapper) data.Resource {
	slog.Info("ResourceReference.Dereference()", "resourcereference", r, "resourcemapper", look)
	if look != nil {
		if v,ok := look.Get(string(r)); ok {
			return v.(*Declaration).Attributes
		}
	}
	return nil
}

func (r ResourceReference) Parse() *url.URL {
	u, e := url.Parse(string(r))
	if e == nil {
		return u
	}
	return nil
}

func (r ResourceReference) Exists() bool {
	return transport.ExistsURI(string(r))
}

func (r ResourceReference) ContentReaderStream() (*transport.Reader, error) {
	return transport.NewReaderURI(string(r))
}

func (r ResourceReference) ContentWriterStream() (*transport.Writer, error) {
	return transport.NewWriterURI(string(r))
}
*/

func StorageMachine(sub machine.Subscriber) machine.Stater {
// start_destroy -> absent -> start_create -> present -> start_destroy
	stater := machine.New("unknown")
	stater.AddStates("unkonwn", "absent", "start_create", "present", "start_delete", "start_read", "start_update", "start_stat")

	stater.AddTransition("create", machine.States("unknown", "absent"), "start_create")
	if e := stater.AddSubscription("create", sub); e != nil {
		return nil
	}

	stater.AddTransition("created", machine.States("start_create"), "present")
	if e := stater.AddSubscription("created", sub); e != nil {
		return nil
	}
	stater.AddTransition("exists", machine.States("unknown", "absent", "start_stat"), "present")
	if e := stater.AddSubscription("exists", sub); e != nil {
		return nil
	}

	stater.AddTransition("notexists", machine.States("*"), "absent")
	if e := stater.AddSubscription("notexists", sub); e != nil {
		return nil
	}

	stater.AddTransition("read", machine.States("*"), "start_read")
	if e := stater.AddSubscription("read", sub); e != nil {
		return nil
	}

	stater.AddTransition("state_read", machine.States("start_read"), "present")

	stater.AddTransition("stat", machine.States("*"), "start_stat")
	if e := stater.AddSubscription("stat", sub); e != nil {
		return nil
	}

	stater.AddTransition("update", machine.States("*"), "start_update")
	if e := stater.AddSubscription("update", sub); e != nil {
		return nil
	}

	stater.AddTransition("updated", machine.States("start_update"), "present")

	stater.AddTransition("delete", machine.States("*"), "start_delete")
	if e := stater.AddSubscription("delete", sub); e != nil {
		return nil
	}

	stater.AddTransition("deleted", machine.States("start_delete"), "absent")
	if e := stater.AddSubscription("deleted", sub); e != nil {
		return nil
	}

	return stater
}

func ProcessMachine(sub machine.Subscriber) machine.Stater {
// "enum": [ "created", "restarting", "running", "paused", "exited", "dead" ]
	stater := machine.New("unknown")
	stater.AddStates("unkonwn", "absent", "start_create", "present", "created", "restarting", "running", "paused", "exited", "dead", "start_delete", "start_read", "start_update")
	stater.AddTransition("create", machine.States("unknown", "absent"), "start_create")
	if e := stater.AddSubscription("create", sub); e != nil {
		return nil
	}
	stater.AddTransition("created", machine.States("start_create"), "present")
	if e := stater.AddSubscription("created", sub); e != nil {
		return nil
	}
	stater.AddTransition("exists", machine.States("unknown", "absent"), "present")
	if e := stater.AddSubscription("exists", sub); e != nil {
		return nil
	}
	stater.AddTransition("notexists", machine.States("*"), "absent")
	if e := stater.AddSubscription("notexists", sub); e != nil {
		return nil
	}
	stater.AddTransition("read", machine.States("*"), "start_read")
	if e := stater.AddSubscription("read", sub); e != nil {
		return nil
	}
	stater.AddTransition("state_read", machine.States("start_read"), "present")
	stater.AddTransition("update", machine.States("*"), "start_update")
	if e := stater.AddSubscription("update", sub); e != nil {
		return nil
	}

	stater.AddTransition("stat", machine.States("*"), "start_stat")
	if e := stater.AddSubscription("stat", sub); e != nil {
		return nil
	}

	stater.AddTransition("updated", machine.States("start_update"), "present")
	stater.AddTransition("delete", machine.States("*"), "start_delete")
	if e := stater.AddSubscription("delete", sub); e != nil {
		return nil
	}
	stater.AddTransition("deleted", machine.States("start_delete"), "absent")
	if e := stater.AddSubscription("deleted", sub); e != nil {
		return nil
	}
	return stater
}