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

package fan

import (
_	"context"
_	"encoding/json"
	"fmt"
_	"gopkg.in/yaml.v3"
	"net/url"
_	"path/filepath"
	"decl/internal/data"
	"decl/internal/resource"
	"decl/internal/folio"
_	"os"
_	"io"
	"log/slog"
)

type Package struct {
	PackageType resource.PackageType `yaml:"type" json:"type"`
}

func NewPackage() *Package {
	return &Package{ PackageType: resource.SystemPackageType }
}

func init() {
	folio.DocumentRegistry.ConverterTypes.Register([]string{"package"}, func(u *url.URL) data.Converter {
		p := NewPackage()
		packageType := u.Query().Get("type")
		if len(packageType) > 0 {
			p.PackageType = resource.PackageType(packageType)
		}
		return p
	})

}

func (p *Package) Type() data.TypeName { return "package" }

func (p *Package) Extract(sourceResource data.Resource, filter data.ElementSelector) (document data.Document, err error) {
	slog.Info("fan.Package.Extract()", "package", p) 

	installedPackages := make([]*resource.Package, 0, 100)
	cmd := p.PackageType.NewReadPackagesCommand()
	if cmd == nil {
		return document, fmt.Errorf("%w: %s", resource.ErrUnsupportedPackageType, p.PackageType)
	}

	var out []byte
	if out, err = cmd.Execute(p); err == nil {
		slog.Info("fan.Package.Extract()", "output", out)
		if err = cmd.Extractor(out, &installedPackages); err == nil {
			document = folio.DocumentRegistry.NewDocument("file://-")
			for _, pkg := range installedPackages {
				if pkg == nil {
					pkg = resource.NewPackage()
				}
				if _, err = document.NewResource(pkg.URI()); err != nil {
					return
				}
			}
		}
	}
	slog.Info("fan.Package.Extract()", "output", out, "error", err)
	return
}

func (p *Package) Emit(document data.Document, filter data.ElementSelector) (resourceTarget data.Resource, err error) {
	return nil, data.ErrUnsupportedConversion
}

func (p *Package) Close() error {
	return nil
}