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

//
package resource

import (
  "context"
  "fmt"
_ "log"
  "gopkg.in/yaml.v3"
)

type Declaration struct {
  Type string `yaml:"type"`
  Attributes yaml.Node `yaml:"attributes"`
  Implementation Resource `-`
}

type ResourceLoader interface {
  LoadDecl(string) error
}

type StateTransformer interface {
  Apply() error
}

type YamlLoader func(string, any) error

func YamlLoadDecl(yamlFileResourceDeclaration string, resource any) error {
  if err := yaml.Unmarshal([]byte(yamlFileResourceDeclaration), resource); err != nil {
    return err
  }
  return nil
}

func NewDeclaration() *Declaration {
  return &Declaration{}
}

func (d *Declaration) LoadDecl(yamlResourceDeclaration string) error {
  return YamlLoadDecl(yamlResourceDeclaration, d)
}

func (d *Declaration) NewResource() error {
  uri := fmt.Sprintf("%s://", d.Type)
  newResource, err := ResourceTypes.New(uri)
  d.Implementation = newResource
  return err
}

func (d *Declaration) LoadResourceFromYaml() (Resource, error) {
  var errResource error
  if d.Implementation == nil {
    errResource = d.NewResource()
    if errResource != nil {
      return nil, errResource
    }
  }
  d.Attributes.Decode(d.Implementation)
  d.Implementation.ResolveId(context.Background())
  return d.Implementation, errResource
}

func (d *Declaration) UpdateYamlFromResource() error {
  if d.Implementation != nil {
    return d.Attributes.Encode(d.Implementation)
  }
  return nil
}

func (d *Declaration) Resource() Resource {
  return d.Implementation
}

func (d *Declaration) SetURI(uri string) error {
  d.Implementation = NewResource(uri)
  if d.Implementation == nil {
    panic("unknown resource")
  }
  d.Type = d.Implementation.Type()
  d.Implementation.Read(context.Background()) // fix
  return nil
}