package filemanager

import (
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strings"

	humanize "github.com/dustin/go-humanize"
	"github.com/hacdias/caddy-filemanager/config"
)

// FileInfo contains the information about a particular file or directory
type FileInfo struct {
	os.FileInfo
	URL         string
	Path        string // Relative path to Caddyfile
	VirtualPath string // Relative path to u.FileSystem
	Mimetype    string
	Content     []byte
	Type        string
	UserAllowed bool // Indicates if the user has enough permissions
}

// GetInfo gets the file information and, in case of error, returns the
// respective HTTP error code
func GetInfo(url *url.URL, c *config.Config, u *config.User) (*FileInfo, int, error) {
	var err error

	i := &FileInfo{URL: url.Path}
	i.VirtualPath = strings.Replace(url.Path, c.BaseURL, "", 1)
	i.VirtualPath = strings.TrimPrefix(i.VirtualPath, "/")
	i.VirtualPath = "/" + i.VirtualPath

	i.Path = u.Scope + i.VirtualPath
	i.Path = strings.Replace(i.Path, "\\", "/", -1)
	i.Path = filepath.Clean(i.Path)

	i.FileInfo, err = os.Stat(i.Path)
	if err != nil {
		code := http.StatusInternalServerError

		switch {
		case os.IsPermission(err):
			code = http.StatusForbidden
		case os.IsNotExist(err):
			code = http.StatusGone
		case os.IsExist(err):
			code = http.StatusGone
		}

		return i, code, err
	}

	return i, 0, nil
}

func (i *FileInfo) Read() error {
	var err error
	i.Content, err = ioutil.ReadFile(i.Path)
	if err != nil {
		return err
	}
	i.Mimetype = http.DetectContentType(i.Content)
	i.Type = SimplifyMimeType(i.Mimetype)
	return nil
}

func (i FileInfo) StringifyContent() string {
	return string(i.Content)
}

// HumanSize returns the size of the file as a human-readable string
// in IEC format (i.e. power of 2 or base 1024).
func (i FileInfo) HumanSize() string {
	return humanize.IBytes(uint64(i.Size()))
}

// HumanModTime returns the modified time of the file as a human-readable string.
func (i FileInfo) HumanModTime(format string) string {
	return i.ModTime().Format(format)
}

func (i *FileInfo) ServeHTTP(w http.ResponseWriter, r *http.Request, c *config.Config, u *config.User) (int, error) {
	if i.IsDir() {
		return i.serveListing(w, r, c, u)
	}

	return i.serveSingleFile(w, r, c, u)
}

func (i *FileInfo) serveSingleFile(w http.ResponseWriter, r *http.Request, c *config.Config, u *config.User) (int, error) {
	err := i.Read()
	if err != nil {
		code := http.StatusInternalServerError

		switch {
		case os.IsPermission(err):
			code = http.StatusForbidden
		case os.IsNotExist(err):
			code = http.StatusGone
		case os.IsExist(err):
			code = http.StatusGone
		}

		return code, err
	}

	if i.Type == "blob" {
		http.Redirect(
			w, r,
			c.AddrPath+r.URL.Path+"?download=true",
			http.StatusTemporaryRedirect,
		)
		return 0, nil
	}

	p := &page{
		pageInfo: &pageInfo{
			Name:   i.Name(),
			Path:   i.VirtualPath,
			IsDir:  false,
			Data:   i,
			User:   u,
			Config: c,
		},
	}

	if (canBeEdited(i.Name()) || i.Type == "text") && u.AllowEdit {
		p.Data, err = i.GetEditor()
		if err != nil {
			return http.StatusInternalServerError, err
		}

		return p.PrintAsHTML(w, "frontmatter", "editor")
	}

	return p.PrintAsHTML(w, "single")
}

func SimplifyMimeType(name string) string {
	if strings.HasPrefix(name, "video") {
		return "video"
	}

	if strings.HasPrefix(name, "audio") {
		return "audio"
	}

	if strings.HasPrefix(name, "image") {
		return "image"
	}

	if strings.HasPrefix(name, "text") {
		return "text"
	}

	if strings.HasPrefix(name, "application/javascript") {
		return "text"
	}

	return "blob"
}