package staticfileserver

import (
	"bytes"
	"html/template"
	"path/filepath"

	"edge-infra.dev/config/components/pxe"
)

var (
	volumeMountPoint = "/opt/boot"
	livePath         = volumeMountPoint + "/live"
)

// template locations
var (
	deploymentTemplate = "deployment.template"
	configMapTemplate  = "configmap.template"

	templateDir = "static-file-server"

	deploymentTemplateGlob = filepath.Join(templateDir, deploymentTemplate)
	configMapTemplateGlob  = filepath.Join(templateDir, configMapTemplate)
)

// ScaleParams contains the configuration required to update replica counts
type ScaleParams struct {
	Replicas int32
}

// ConfigParams contains the configuration required to update the
// static-file-server directory
type ConfigParams struct {
	Directory string
}

// ScaledDownDeployment returns a scaled down static-file-server deployment with
// 0 replicas
func ScaledDownDeployment() ([]byte, error) {
	return scaledDeployment(0)
}

// ScaledUpDeployment returns a scaled up static-file-server deployment with
// 1 replica
func ScaledUpDeployment() ([]byte, error) {
	return scaledDeployment(1)
}

// scaledDeployment returns the static-file-server manifest scaled to the
// desired number of replicas
func scaledDeployment(desired int32) ([]byte, error) {
	tmpl, err := template.New("").
		Delims("<<", ">>").
		ParseFS(pxe.TemplateFS, deploymentTemplateGlob)
	if err != nil {
		return nil, err
	}

	params := ScaleParams{
		Replicas: desired,
	}

	var rendered bytes.Buffer
	if err := tmpl.ExecuteTemplate(&rendered, deploymentTemplate, params); err != nil {
		return nil, err
	}

	return rendered.Bytes(), nil
}

// ConfigMap returns the static-file-server-config configmap manifest
func ConfigMap() ([]byte, error) {
	tmpl, err := template.New("").
		Delims("<<", ">>").
		ParseFS(pxe.TemplateFS, configMapTemplateGlob)
	if err != nil {
		return nil, err
	}

	params := ConfigParams{
		Directory: livePath,
	}

	var rendered bytes.Buffer
	if err := tmpl.ExecuteTemplate(&rendered, configMapTemplate, params); err != nil {
		return nil, err
	}

	return rendered.Bytes(), nil
}