package main

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"os/user"
	"path/filepath"

	"varia.zone/snackbar/components"

	"github.com/a-h/templ"
	"github.com/codeclysm/extract/v3"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
)

// App is the application state.
type App struct {
	ctx context.Context
}

// NewApp creates a new application state.
func NewApp() *App {
	return &App{}
}

func (a *App) startup(ctx context.Context) {
	a.ctx = ctx
}

func ensureDataDir(homeDir string) error {
	paths := []string{
		filepath.Join(homeDir, ".local"),
		filepath.Join(homeDir, ".local", "snackbar"),
		filepath.Join(homeDir, ".local", "snackbar", "hugo"),
		filepath.Join(homeDir, ".local", "snackbar", "sites"),
	}

	for _, fpath := range paths {
		if _, err := os.Stat(fpath); err != nil && os.IsNotExist(err) {
			if err := os.Mkdir(fpath, 0764); err != nil {
				return err
			}
		}
	}

	return nil
}

func ensureHugoBin(homeDir string) error {
	hugoVersion := "0.124.1"
	dataDir := filepath.Join(homeDir, ".local", "snackbar")
	hugoDir := filepath.Join(dataDir, "hugo")
	hugoBinPath := filepath.Join(hugoDir, "hugo")
	hugoTarPath := filepath.Join(hugoDir, fmt.Sprintf("hugo-%s.tar.gz", hugoVersion))
	url := fmt.Sprintf("https://github.com/gohugoio/hugo/releases/download/v%s/hugo_extended_%s_linux-amd64.tar.gz", hugoVersion, hugoVersion)

	if _, err := os.Stat(hugoBinPath); err != nil && os.IsNotExist(err) {
		if err := httpGetFile(hugoTarPath, url); err != nil {
			return err
		}
	}

	fpath, err := ioutil.ReadFile(hugoTarPath)
	if err != nil {
		return err
	}
	if err := extract.Gz(context.TODO(), bytes.NewBuffer(fpath), hugoDir, nil); err != nil {
		return err
	}

	return nil
}

func httpGetFile(filepath, url string) error {
	out, err := os.Create(filepath)
	if err != nil {
		return err
	}
	defer out.Close()

	resp, err := http.Get(url)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return err
	}

	_, err = io.Copy(out, resp.Body)
	if err != nil {
		return err
	}

	return nil
}

func initialise(w http.ResponseWriter, r *http.Request) {
	usr, err := user.Current()
	if err != nil {
		w.Write([]byte(fmt.Sprintf("unable to determine user: %s", err)))
	}

	if err := ensureDataDir(usr.HomeDir); err != nil {
		w.Write([]byte(fmt.Sprintf("unable to create data directory: %s", err)))
	}

	if err := ensureHugoBin(usr.HomeDir); err != nil {
		w.Write([]byte(fmt.Sprintf("unable to download hugo binary: %s", err)))
	}

	// TODO: is there a Hugo site already?

	templ.Handler(components.NewSiteInput()).ServeHTTP(w, r)
}

func hugoNewSite(w http.ResponseWriter, r *http.Request) {
	log.Printf("NEW SITE BEING CREATED: %s", r.FormValue("site-name"))
}

// NewRouter creates a new web router.
func NewRouter() *chi.Mux {
	router := chi.NewRouter()

	router.Use(middleware.Logger)
	router.Use(middleware.Recoverer)

	router.Get("/init", initialise)
	router.Post("/hugo/new", hugoNewSite)

	return router
}