package frontend

import (
	"embed"
	"io"
	"io/fs"
	"net/http"
	"sync"

	"dynatron.me/x/blasphem/pkg/blas"
	"dynatron.me/x/blasphem/pkg/blas/core"
	"dynatron.me/x/blasphem/pkg/components"

	"github.com/labstack/echo/v4"
)

const FrontendKey = "frontend"

//go:embed frontend/hass_frontend
var root embed.FS

type Frontend struct {
	fsHandler echo.HandlerFunc
	rootFS    fs.FS

	routeInstall sync.Once
}

func (fe *Frontend) InstallRoutes(e *echo.Echo) {
	fe.routeInstall.Do(func() {
		e.GET("/*", fe.fsHandler)
		e.GET("/auth/authorize", fe.AliasHandler("authorize.html"))
	})
}

func (fe *Frontend) AliasHandler(toFile string) echo.HandlerFunc {
	return func(c echo.Context) error {
		file, err := fe.rootFS.Open(toFile)
		if err != nil {
			return err
		}
		defer file.Close()

		b, err := io.ReadAll(file)
		if err != nil {
			return err
		}

		return c.HTML(http.StatusOK, string(b))
	}
}

func (*Frontend) Shutdown() {}

func Setup(_ core.Core) (components.Component, error) {
	fe := &Frontend{}
	var err error

	fe.rootFS, err = fs.Sub(root, "frontend/hass_frontend")
	if err != nil {
		return nil, err
	}

	fe.fsHandler = echo.StaticDirectoryHandler(fe.rootFS, false)

	return fe, nil
}

func init() {
	blas.Register(FrontendKey, Setup)
}