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

package resource

import (
	"context"
	"fmt"
	"gopkg.in/yaml.v3"
	"encoding/json"
	_ "log"
	"net/url"
	_ "os"
	_ "os/exec"
_	"strings"
	"io"
	"gitea.rosskeen.house/rosskeen.house/machine"
	"decl/internal/codec"
	"decl/internal/command"
	"decl/internal/data"
	"decl/internal/folio"
	"errors"
	"log/slog"
)

const (
	ExecTypeName TypeName = "exec"
)

type Exec struct {
	*Common `yaml:",inline" json:",inline"`
	stater machine.Stater `yaml:"-" json:"-"`
	Id     string `yaml:"id,omitempty" json:"id,omitempty"`
	CreateTemplate *command.Command `yaml:"create,omitempty" json:"create,omitempty"`
	ReadTemplate *command.Command `yaml:"read,omitempty" json:"read,omitempty"`
	UpdateTemplate *command.Command `yaml:"update,omitempty" json:"update,omitempty"`
	DeleteTemplate *command.Command `yaml:"delete,omitempty" json:"delete,omitempty"`

	Resources data.ResourceMapper `yaml:"-" json:"-"`
}

func init() {
	folio.DocumentRegistry.ResourceTypes.Register([]string{"exec"}, func(u *url.URL) (res data.Resource) {
		x := NewExec()
		res = x
		if u != nil {
			uri := folio.CastParsedURI(u)
			if ri, ok := res.(data.ResourceInitializer); ok {
				if err := ri.Init(uri); err != nil {
					panic(err)
				}
			} else {
				if err := x.SetParsedURI(uri); err != nil {
					panic(err)
				}
			}
		}
                return
	})
}

func NewExec() *Exec {
	e := &Exec{ Common: NewCommon(ExecTypeName, true) }
	return e
}

func (x *Exec) SetResourceMapper(resources data.ResourceMapper) {
	x.Resources = resources
}

func (x *Exec) Clone() data.Resource {
	return &Exec {
		Common: x.Common.Clone(),
		Id: x.Id,
		CreateTemplate: x.CreateTemplate,
		ReadTemplate: x.ReadTemplate,
		UpdateTemplate: x.UpdateTemplate,
		DeleteTemplate: x.DeleteTemplate,
	}
}

func (x *Exec) StateMachine() machine.Stater {
	if x.stater == nil {
		x.stater = ProcessMachine(x)
	}
	return x.stater
}

func (x *Exec) URI() string {
	return fmt.Sprintf("exec://%s", x.Id)
}

func (x *Exec) Init(u data.URIParser) (err error) {
	if u == nil {
		u = folio.URI(x.URI()).Parse()
	}
	err = x.SetParsedURI(u)
	x.Id = x.Common.Path
	return
}

func (x *Exec) SetParsedURI(uri data.URIParser) (err error) {
	err = x.Common.SetParsedURI(uri)
	x.Id = x.Common.Path
	return
}

func (x *Exec) Validate() (err error) {
	var execJson []byte
	if execJson, err = x.JSON(); err == nil {
		s := NewSchema(x.Type())
		err = s.Validate(string(execJson))
	}
	return err
}

func (x *Exec) Apply() error {
	return nil
}

func (x *Exec) Notify(m *machine.EventMessage) {
	ctx := context.Background()
        slog.Info("Notify()", "exec", x, "m", m)
	switch m.On {
	case machine.ENTERSTATEEVENT:
		switch m.Dest {
		case "start_read":
			if _, readErr := x.Read(ctx); readErr == nil {
				if triggerErr := x.StateMachine().Trigger("state_read"); triggerErr == nil {
					return
				} else {
					x.State = "absent"
					panic(triggerErr)
				}
			} else {
				x.State = "absent"
				if ! errors.Is(readErr, ErrResourceStateAbsent) {
					panic(readErr)
				}
			}
		case "start_create":
			if e := x.Create(ctx); e == nil {
				if triggerErr := x.stater.Trigger("created"); triggerErr == nil {
					return
				}
			}
		case "start_delete":
			if deleteErr := x.Delete(ctx); deleteErr == nil {
				if triggerErr := x.StateMachine().Trigger("deleted"); triggerErr == nil {
					return
				} else {
					x.State = "present"
					panic(triggerErr)
				}
			} else {
				x.State = "present"
				panic(deleteErr)
			}
		case "absent":
			x.State = "absent"
		case "present", "created", "read":
			x.State = "present"
		}
	case machine.EXITSTATEEVENT:
	}
}

func (x *Exec) Load(docData []byte, f codec.Format) (err error) {
	err = f.StringDecoder(string(docData)).Decode(x)
	return
}

func (x *Exec) LoadReader(r io.ReadCloser, f codec.Format) (err error) {
	err = f.Decoder(r).Decode(x)
	return
}

func (x *Exec) LoadString(docData string, f codec.Format) (err error) {
	err = f.StringDecoder(docData).Decode(x)
	return
}

func (x *Exec) LoadDecl(yamlResourceDeclaration string) error {
	return x.LoadString(yamlResourceDeclaration, codec.FormatYaml)
}

func (x *Exec) JSON() ([]byte, error) {
	return json.Marshal(x)
}

func (x *Exec) Type() string { return "exec" }

func (x *Exec) Create(ctx context.Context) (err error) {
	x.CreateTemplate.Defaults()
	_, err = x.CreateTemplate.Execute(x)
	slog.Info("Exec.Create()", "resource", x, "error", err)
	return err
}

func (x *Exec) Read(ctx context.Context) ([]byte, error) {
	if x.ReadTemplate != nil {
		x.ReadTemplate.Defaults()
	}
	return yaml.Marshal(x)
}
func (x *Exec) Update(ctx context.Context) (err error) {
	return
}

func (x *Exec) Delete(ctx context.Context) (err error) {
	return
}