package ui

import (
	"bytes"
	"fmt"
	"html/template"
	"io"
	"net/http"
	"path/filepath"
	"sort"

	"git.faercol.me/faercol/http-boot-server/bootserver/helpers"
	"git.faercol.me/faercol/http-boot-server/bootserver/services"
	"github.com/sirupsen/logrus"
)

const UIRoute = "/"

type templateBootOption struct {
	ID       string
	Name     string
	Path     string
	DiskID   string
	Selected bool
}

type templateClient struct {
	ID          string
	Name        string
	BootOptions []templateBootOption
}

type templateData struct {
	Clients []templateClient
}

type UIController struct {
	clientService *services.ClientHandlerService
	l             *logrus.Logger
}

func NewUIController(l *logrus.Logger, service *services.ClientHandlerService) *UIController {
	return &UIController{
		clientService: service,
		l:             l,
	}
}

func (uc *UIController) serveUI(w http.ResponseWriter, r *http.Request) (int, int, error) {
	lp := filepath.Join("templates", "index.html")
	tmpl, err := template.ParseFiles(lp)
	if err != nil {
		return http.StatusInternalServerError, -1, fmt.Errorf("failed to init template: %w", err)
	}
	buf := new(bytes.Buffer)

	clients, err := uc.clientService.GetAllClientConfig()
	if err != nil {
		return http.StatusInternalServerError, -1, fmt.Errorf("failed to get list of clients: %w", err)
	}

	dat := templateData{Clients: []templateClient{}}
	for _, clt := range clients {
		tplBO := []templateBootOption{}
		for id, bo := range clt.Options {
			tplBO = append(tplBO, templateBootOption{
				Name:     bo.Name,
				Path:     bo.Path,
				ID:       id,
				DiskID:   bo.DiskID,
				Selected: id == clt.SelectedOption,
			})
			sort.Slice(tplBO, func(i, j int) bool {
				return tplBO[i].ID < tplBO[j].ID
			})
		}
		dat.Clients = append(dat.Clients, templateClient{
			ID:          clt.ID.String(),
			Name:        clt.Name,
			BootOptions: tplBO,
		})
	}

	if err := tmpl.Execute(buf, dat); err != nil {
		return http.StatusInternalServerError, -1, fmt.Errorf("failed to execute template: %w", err)
	}
	n, err := io.Copy(w, buf)
	if err != nil {
		return http.StatusInternalServerError, int(n), fmt.Errorf("failed to write response; %w", err)
	}

	return http.StatusOK, int(n), nil
}

func (uc *UIController) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.RequestURI != "/" {
		uc.l.Errorf("Unhandled route %q", r.RequestURI)
		helpers.HandleResponse(w, r, http.StatusNotFound, nil, uc.l)
		return
	}
	returncode, contentLength, err := uc.serveUI(w, r)
	if err != nil {
		uc.l.Errorf("Error serving UI: %s", err.Error())
		helpers.HandleResponse(w, r, returncode, nil, uc.l)
	} else {
		helpers.AddToContext(r, returncode, contentLength)
	}
}