package caddyhugo

import (
	"encoding/base64"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"path"
	"path/filepath"
	"strings"

	"git.stephensearles.com/stephen/caddy-hugo2/assets"
	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
	"github.com/spf13/afero"
)

func (ch *CaddyHugo) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
	if !ch.Match(r) {
		p := path.Join(ch.Dir, "public", r.URL.Path)
		http.ServeFile(w, r, p)
		return nil
	}

	if ch.Comments != nil && strings.HasSuffix(r.URL.Path, "/comments") {
		docName := docNameFromCommentRequest(r)
		err := ch.Comments.ServeComments(docName, w, r)
		if err != nil {
			return fmt.Errorf("couldn't load comments:", err)
		}

		return nil
	}

	if r.URL.Path == "/login" {
		return ch.commentsLogin(r, w)
	}

	if strings.HasPrefix(r.URL.Path, "/hugo/publish") {
		err := ch.Publish()
		if err != nil {
			return err
		}

		http.Redirect(w, r, "/", http.StatusFound)
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/simplemde.css") {
		w.Write(assets.MustAsset("simplemde/dist/simplemde.min.css"))
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/simplemde.js") {
		w.Write(assets.MustAsset("simplemde/debug/simplemde.js"))
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/vue.js") {
		w.Write(assets.MustAsset("js/vue.js"))
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/moment.js") {
		w.Write(assets.MustAsset("js/moment.js"))
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/font-awesome.css") {
		w.Write(assets.MustAsset("css/font-awesome.min.css"))
		return nil
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/admin") {
		return ch.Admin().ServeHTTP(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/author") {
		return ch.AuthorHome().ServeHTTP(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/edit/") {
		return ch.Edit().ServeHTTP(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/draft/") {
		return ch.serveDraft(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/media") {
		return ch.serveMediaPage(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/upload") {
		return ch.uploadMedia(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/media/") {
		return ch.serveMedia(w, r)
	}
	if strings.HasPrefix(r.URL.Path, "/hugo/fs/") {
		printTree(afero.NewOsFs(), w, ch.Dir)
		return nil
	}

	return next.ServeHTTP(w, r)
}

func (ch *CaddyHugo) ServeNewContent(w http.ResponseWriter, r *http.Request) error {
	name := r.FormValue("name")
	ctype := r.FormValue("type")

	filename, err := ch.NewContent(name, ctype)
	if err != nil {
		fmt.Println("error creating new content:", err)
		return err
	}

	// serve redirect
	http.Redirect(w, r, filepath.Join("/hugo/edit/", "content", filename), http.StatusFound)
	return nil
}

func (ch *CaddyHugo) Auth(r *http.Request) bool {
	// this is handled upstream by the caddy configuration
	return true
}

func (ch *CaddyHugo) Match(r *http.Request) bool {
	if strings.HasPrefix(r.URL.Path, "/media/") {
		return true
	}

	if strings.HasSuffix(r.URL.Path, "/comments") {
		return true
	}

	if r.URL.Path == "/login" {
		return true
	}

	if r.URL.Path == "/hugo" {
		return true
	}

	return strings.HasPrefix(r.URL.Path, "/hugo/")
}

func (ch *CaddyHugo) Admin() caddyhttp.Handler {
	return caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
		err := ch.adminTmpl.Execute(w, ch.TmplData(r, nil))
		if err != nil {
			fmt.Println(err)
			return err
		}

		return nil

	})
}

func (ch *CaddyHugo) AuthorHome() caddyhttp.Handler {
	return caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
		td := ch.TmplData(r, nil)
		err := ch.authorTmpl.Execute(w, td)
		if err != nil {
			fmt.Println(err)
			return err
		}

		return nil
	})
}

func (ch *CaddyHugo) Edit() caddyhttp.Handler {
	return caddyhttp.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
		if r.URL.Path == "/hugo/edit/new" {
			return ch.ServeNewContent(w, r)
		}

		if r.Header.Get("Upgrade") == "websocket" {
			return ch.DeltaWebsocket(w, r)
		}

		doc, err := ch.editSession(docNameFromEditRequest(r))
		if err != nil {
			fmt.Println(err)
			http.Error(w, err.Error(), http.StatusNotFound)
			return err
		}

		err = ch.editTmpl.Execute(w, ch.TmplData(r, doc))
		if err != nil {
			fmt.Println(err)
			return err
		}

		return nil
	})
}

func (ch *CaddyHugo) serveDraft(w http.ResponseWriter, r *http.Request) error {
	pathSegments := strings.SplitN(r.URL.Path, "/", 5)
	if len(pathSegments) < 4 {
		return errors.New("not found")
	}

	encoded := pathSegments[3]

	nameBytes, err := base64.RawURLEncoding.DecodeString(encoded)
	if err != nil {
		return errors.New("not found")
	}

	name := string(nameBytes)

	ch.mtx.Lock()
	defer ch.mtx.Unlock()

	docref, ok := ch.docs[ch.docFilename(name)]
	if !ok {
		return fmt.Errorf("draft not found")
	}

	r.URL.Path = strings.ToLower(r.URL.Path)

	prefix := "/hugo/draft/" + encoded
	r.URL.Path = path.Join("public", r.URL.Path[len(prefix):])

	page := ch.HugoSites.GetContentPage(ch.docFilename(name))
	if page == nil {
		fmt.Fprintf(w, "can't find %q to display a draft", name)
		return fmt.Errorf("draft not found")
	}

	r.URL.Path = page.RelPermalink()
	http.FileServer(aferoHTTP{afero.NewBasePathFs(docref.tmpfs, path.Join(ch.Dir, "public"))}).ServeHTTP(w, r)

	return nil
}

func printTree(fs afero.Fs, w io.Writer, dir string) {
	const (
		Line  = "  │ "
		Tab   = "    "
		Elbow = "  └─"
		Tee   = "  ├─"
	)

	wd, _ := os.Getwd()
	fmt.Fprintln(w, wd)

	if dir == "" {
		dir = "/"
	}

	openDirs := map[string]bool{}
	lastFiles := map[string]string{}

	afero.Walk(fs, dir, filepath.WalkFunc(func(p string, info os.FileInfo, err error) error {
		if strings.HasPrefix(p, "./") {
			p = p[2:]
		}

		openDirs[filepath.Dir(p)] = true
		lastFiles[filepath.Dir(p)] = filepath.Base(p)
		return nil
	}))

	afero.Walk(fs, dir, filepath.WalkFunc(func(p string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		if strings.HasPrefix(p, "./") {
			p = p[2:]
		}

		if filepath.Base(p)[0] == '.' && info.IsDir() {
			return filepath.SkipDir
		}

		entry := Tee

		if lastFiles[filepath.Dir(p)] == filepath.Base(p) {
			openDirs[filepath.Dir(p)] = false
			entry = Elbow
		}

		indent := ""
		dirs := strings.Split(p, string(filepath.Separator))
		dirs = dirs[:len(dirs)-1]
		for i := range dirs {
			if openDirs[filepath.Join(dirs[:i]...)] {
				indent += Line
			} else {
				indent += Tab
			}
		}

		fmt.Fprintf(w, "%s%s %s (%s)\n", indent, entry, filepath.Base(p), p)
		return nil
	}))
}

type aferoHTTP struct {
	afero.Fs
}

func (a aferoHTTP) Open(name string) (http.File, error) {
	af, err := a.Fs.Open(name)
	if os.IsExist(err) {
		err = os.ErrExist
	}
	if os.IsNotExist(err) {
		err = os.ErrNotExist
	}
	return af, err
}

func (ch *CaddyHugo) commentsLogin(r *http.Request, w http.ResponseWriter) error {
	if ch.Comments == nil {
		return nil
	}

	_, ok := ch.Comments.User(r)
	if !ok {
		w.Header().Set("WWW-Authenticate", `Basic realm="Log in with your name and the password. Ask Dan or Stephen for the password."`)
		w.WriteHeader(401)
		fmt.Fprintf(w, "<html><body>Log in with your name and the password. Ask Dan or Stephen for the password. <a href=%q>go back</a></body></html>", r.Referer())
		return nil
	}

	http.Redirect(w, r, r.Referer(), http.StatusFound)

	return nil
}