// Copyright (C) 2022 Marius Schellenberger

package srv

import (
	"bytes"
	"encoding/xml"
	"net/http"
	"sort"
	"strings"

	"cachefs/pkg/fs"
)

type statusInterceptor struct {
	w      http.ResponseWriter
	status int
}

func (s *statusInterceptor) Header() http.Header {
	return s.w.Header()
}

func (s *statusInterceptor) Write(p []byte) (int, error) {
	return s.w.Write(p)
}

func (s *statusInterceptor) WriteHeader(statusCode int) {
	s.w.WriteHeader(statusCode)
	s.status = statusCode
}

func (s *statusInterceptor) Status() int {
	if s.status == 0 {
		return http.StatusOK
	}
	return s.status
}

type dirContents struct {
	AllPaths []string `xml:"a"`
	Dirs     []string `xml:"-"`
	Files    files    `xml:"-"`
}

type file struct {
	Name   string
	Anchor string
	Status int
}

type files []file

func (f files) Len() int           { return len(f) }
func (f files) Less(i, j int) bool { return f[i].Name < f[j].Name }
func (f files) Swap(i, j int)      { f[i], f[j] = f[j], f[i] }

type responseInterceptor struct {
	buf    bytes.Buffer
	w      http.ResponseWriter
	status int
}

func (r *responseInterceptor) Header() http.Header {
	return r.w.Header()
}

func (r *responseInterceptor) Write(p []byte) (int, error) {
	return r.buf.Write(p)
}

func (r *responseInterceptor) WriteHeader(statusCode int) {
	r.status = statusCode
}

func (r *responseInterceptor) Status() int {
	if r.status == 0 {
		return http.StatusOK
	}
	return r.status
}

func (r *responseInterceptor) GetPaths(path string, fs *fs.FS) (dir dirContents, err error) {
	err = xml.Unmarshal(r.buf.Bytes(), &dir)
	if err != nil {
		return
	}
	path = strings.TrimSuffix(path, "/")
	for _, p := range dir.AllPaths {
		if p[len(p)-1] == '/' {
			dir.Dirs = append(dir.Dirs, p)
		} else {
			dir.Files = append(dir.Files, file{
				Name:   p,
				Anchor: anchor(p),
				Status: fs.CacheStatus(path + "/" + p),
			})
		}
	}
	sort.Strings(dir.Dirs)
	sort.Sort(dir.Files)
	return
}

func anchor(s string) string {
	if i := strings.LastIndex(s, "/"); i > 0 && i+1 < len(s) {
		s = s[i+1:]
	}
	s = strings.ReplaceAll(s, " ", "_")
	return strings.ToLower(s)
}