package kustomize

import (
	"bytes"
	"errors"
	"fmt"
	"html/template"
	"os"
	"path/filepath"

	"git.badhouseplants.net/allanger/shoebill/internal/utils/githelper"
	"github.com/sirupsen/logrus"
	kustomize_types "sigs.k8s.io/kustomize/api/types"
	"sigs.k8s.io/yaml"
)

type Kusmtomize struct {
	Files      []string
	ConfigMaps []string
	Secrets    []string
}

func (k *Kusmtomize) PopulateResources(path string) error {
	// Main sources
	files, err := os.ReadDir(fmt.Sprintf("%s/src", path))
	if err != nil {
		return err
	}
	for _, file := range files {
		if file.Name() != ".gitkeep" && !file.IsDir() {
			k.Files = append(k.Files, fmt.Sprintf("src/%s", file.Name()))
		}
	}
	// Values
	files, err = os.ReadDir(fmt.Sprintf("%s/src/values", path))
	if err != nil {
		return err
	}

	for _, file := range files {
		k.ConfigMaps = append(k.ConfigMaps, fmt.Sprintf("src/values/%s", file.Name()))
	}

	// Secrets
	files, err = os.ReadDir(fmt.Sprintf("%s/src/secrets", path))
	if err != nil {
		return err
	}

	for _, file := range files {
		k.Secrets = append(k.Secrets, fmt.Sprintf("src/secrets/%s", file.Name()))
	}

	return nil
}

func (k *Kusmtomize) SecGeneratorCreate(path string) error {
	logrus.Info("preparing the secret generator file")
	genFileTmpl := `---
apiVersion: viaduct.ai/v1
kind: ksops
metadata:
  name: shoebill-secret-gen
files:
{{- range $val := . }}
  - {{ $val }}
{{- end }}
`

	destFileName := fmt.Sprintf("%s/sec-generator.yaml", path)
	t := template.Must(template.New("tmpl").Parse(genFileTmpl))
	var genFileData bytes.Buffer
	t.Execute(&genFileData, k.Secrets)
	var genFile *os.File
	if _, err := os.Stat(destFileName); err == nil {
		genFile, err := os.Open(destFileName)
		if err != nil {
			return err
		}
		defer genFile.Close()
	} else if errors.Is(err, os.ErrNotExist) {
		genFile, err = os.Create(destFileName)
		if err != nil {
			return nil
		}
		defer genFile.Close()
	} else {
		return err
	}
	if err := os.WriteFile(destFileName, genFileData.Bytes(), os.ModeExclusive); err != nil {
		return nil
	}

	return nil
}

func (k *Kusmtomize) CmGeneratorFromFiles() []kustomize_types.ConfigMapArgs {
	cmGens := []kustomize_types.ConfigMapArgs{}
	for _, cm := range k.ConfigMaps {
		cmName := filepath.Base(cm)
		cmGen := &kustomize_types.ConfigMapArgs{
			GeneratorArgs: kustomize_types.GeneratorArgs{
				Namespace: "flux-system",
				Name:      cmName,
				KvPairSources: kustomize_types.KvPairSources{
					FileSources: []string{cm},
				},
			},
		}
		cmGens = append(cmGens, *cmGen)
	}

	return cmGens
}

func Generate(path string, gh githelper.Githelper) error {
	kustomize := &Kusmtomize{}
	if err := kustomize.PopulateResources(path); err != nil {
		return err
	}

	kustomization := kustomize_types.Kustomization{
		TypeMeta: kustomize_types.TypeMeta{
			Kind:       kustomize_types.KustomizationKind,
			APIVersion: kustomize_types.KustomizationVersion,
		},
		MetaData: &kustomize_types.ObjectMeta{
			Name:      "helm-root",
			Namespace: "flux-system",
		},
		Resources: kustomize.Files,
		GeneratorOptions: &kustomize_types.GeneratorOptions{
			DisableNameSuffixHash: true,
		},
		ConfigMapGenerator: kustomize.CmGeneratorFromFiles(),
	}

	if len(kustomize.Secrets) > 0 {
		kustomization.Generators = []string{"sec-generator.yaml"}
		if err := kustomize.SecGeneratorCreate(path); err != nil {
			return err
		}
	} else {
		if err := os.RemoveAll(fmt.Sprintf("%s/sec-generator.yaml", path)); err != nil {
			return err
		}
	}

	manifest, err := yaml.Marshal(kustomization)
	if err != nil {
		return err
	}
	dstFilePath := path + "/kustomization.yaml"
	var dstFile *os.File
	if _, err = os.Stat(dstFilePath); err == nil {
		dstFile, err = os.Open(dstFilePath)
		if err != nil {
			return err
		}
		defer dstFile.Close()
	} else if errors.Is(err, os.ErrNotExist) {
		dstFile, err = os.Create(dstFilePath)
		if err != nil {
			return nil
		}
		defer dstFile.Close()
	} else {
		return err
	}

	if err := os.WriteFile(dstFilePath, manifest, os.ModeExclusive); err != nil {
		return nil
	}

	if err := gh.AddAllAndCommit(path, "Update the root kustomization"); err != nil {
		return err
	}

	return nil
}