package photo

import (
	"fmt"
	"html/template"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"time"

	"meutel.net/meutel/go-examples/photoblog/admin"
)

const (
	DISPLAY_SIZE = 5 // number of photos displayed on home
)

var (
	PHOTOEXT = [3]string{".jpg", ".jpeg", ".png"}
)

type AppData struct {
	Username string
	Photos   []string
	errors   []error
	messages []string
}

type TimedFile struct {
	Mod  time.Time
	Path string
}

type timeMap []TimedFile

func (m timeMap) Len() int {
	return len(m)
}
func (m timeMap) Less(i, j int) bool {
	return m[i].Mod.After(m[j].Mod)
}
func (m timeMap) Swap(i, j int) {
	m[i], m[j] = m[j], m[i]
}

type PhotoBlog struct {
	*admin.AuthCookie
	Templates *template.Template
	DataDir   *os.File
}

func RedirectHome(res http.ResponseWriter, req *http.Request) {
	// FIXME duplicate admin
	http.Redirect(res, req, "/", http.StatusSeeOther)
}
func IsPhoto(path string) bool {
	for _, ext := range PHOTOEXT {
		if strings.HasSuffix(path, ext) {
			return true
		}
	}
	return false
}

func Latest(photos timeMap) []string {
	latest := make([]string, 0, DISPLAY_SIZE)
	sort.Sort(photos)
	for i, v := range photos {
		if i > DISPLAY_SIZE {
			break
		}
		latest = append(latest, v.Path)
	}
	return latest
}

func (app *PhotoBlog) HomePage(res http.ResponseWriter, req *http.Request) {
	data := AppData{
		Username: app.Username(res, req),
	}
	photos := make([]TimedFile, 0)
	filepath.Walk(app.DataDir.Name(), func(path string, info os.FileInfo, err error) error {
		if !info.IsDir() && IsPhoto(path) {
			photos = append(photos, TimedFile{
				info.ModTime(),
				path,
			})
		}
		return nil
	})
	data.Photos = Latest(photos)
	app.Templates.ExecuteTemplate(res, "home.html", data)
}
func (app *PhotoBlog) UploadPage(res http.ResponseWriter, req *http.Request) {
	if !app.IsLoggedIn(res, req) {
		RedirectHome(res, req)
		return
	}
	data := make(map[string]string)
	switch req.Method {
	case "POST":
		message, err := app.NewPhoto(res, req)
		if err != nil {
			data["error"] = err.Error()
		}
		data["message"] = message
		fallthrough
	case "GET":
		app.Templates.ExecuteTemplate(res, "upload.html", data)
	}
}
func (app *PhotoBlog) NewPhoto(res http.ResponseWriter, req *http.Request) (string, error) {
	file, header, err := req.FormFile("file")
	if err != nil {
		return "", err
	}
	defer file.Close()

	// FIXME check type
	tmpFile, err := os.Create(filepath.Join(app.DataDir.Name(), app.Username(res, req), header.Filename))
	if err != nil {
		return "", err
	}
	defer tmpFile.Close()

	sz, err := io.Copy(tmpFile, file)
	if err != nil {
		return "", err
	}
	return fmt.Sprintf("File uploaded (%d bytes)", sz), nil
}