package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"html/template"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"path"
	"path/filepath"
	"strings"

	"github.com/gorilla/mux"
)

var config = readConfig("")

type Configuration struct {
	Host     string
	Port     string
	DataPath string
}

// our main function
func main() {

	// Ausgeben der Config-Optionen
	fmt.Println("Host: " + config.Host)
	fmt.Println("Post: " + config.Port)
	fmt.Println("DataPath: " + config.DataPath)

	// DataPath-Verzeichnis anlegen, wenn es noch nicht existiert
	if !directoryExists(config.DataPath) {
		os.MkdirAll(config.DataPath, os.ModePerm)

		// Default Seiten anlegen
		bStartmd, _ := Asset("web/pages/start.md")
		bHilfemd, _ := Asset("web/pages/hilfe.md")
		bPlaygroundmd, _ := Asset("web/pages/playground.md")
		bSidebarmd, _ := Asset("web/pages/sidebar.md")

		err := ioutil.WriteFile(path.Join(config.DataPath, "start.md"), bStartmd, 0644)
		check(err)
		err = ioutil.WriteFile(path.Join(config.DataPath, "sidebar.md"), bSidebarmd, 0644)
		check(err)
		err = ioutil.WriteFile(path.Join(config.DataPath, "hilfe.md"), bHilfemd, 0644)
		check(err)
		err = ioutil.WriteFile(path.Join(config.DataPath, "playground.md"), bPlaygroundmd, 0644)
		check(err)
	}

	router := mux.NewRouter()
	router.HandleFunc("/p/{pagename:.*}", getRawPage).Methods("GET")
	router.HandleFunc("/{pagename:.*}", getHTMLPage).Methods("GET")
	router.HandleFunc("/{pagename:.*}", postHTMLPage).Methods("POST")

	log.Fatal(http.ListenAndServe(":"+config.Port, router))

}

func getHTMLPage(w http.ResponseWriter, r *http.Request) {

	params := mux.Vars(r)

	if strings.HasSuffix(params["pagename"], ".css") {
		//fmt.Println("CSS: " + params["pagename"])
		b, _ := Asset("web/" + params["pagename"])
		w.Header().Set("Content-Type", "text/css")
		w.Write(b)
	} else if strings.HasSuffix(params["pagename"], ".js") {
		//fmt.Println("JS: " + params["pagename"])
		b, _ := Asset("web/" + params["pagename"])
		w.Header().Set("Content-Type", "application/javascript")
		w.Write(b)
	} else {
		// Directory Listing für die Sidebar
		sidebarAusgabe := "  \r\n  \r\n**Inhaltsverzeichnis**  \r\n\r\n"
		filepath.Walk(config.DataPath, func(path string, info os.FileInfo, err error) error {

			tmpPath := strings.Replace(path, "\\", "/", -1)
			tmpPath = strings.Replace(tmpPath, "data", "", -1)
			tmpPathSplit := strings.Split(tmpPath, "/")

			sidebarTABs := ""
			for i, _ := range tmpPathSplit {
				//fmt.Println(i, " => ", string(c))
				if i > 1 {
					sidebarTABs = sidebarTABs + "	"
				}
			}

			if info.Name() != "data" && info.Name() != "start.md" && info.Name() != "sidebar.md" && info.Name() != "hilfe.md" {
				if !strings.HasSuffix(info.Name(), ".md") {
					sidebarAusgabe = sidebarAusgabe + sidebarTABs + "* [" + strings.TrimSuffix(info.Name(), ".md") + "](" + strings.TrimSuffix(tmpPath, ".md") + "/start)  \r\n"
				} else {
					sidebarAusgabe = sidebarAusgabe + sidebarTABs + "* [" + strings.TrimSuffix(info.Name(), ".md") + "](" + strings.TrimSuffix(tmpPath, ".md") + ")  \r\n"
				}
			}

			return nil
		})

		//tmpl := template.Must(template.ParseFiles("./web/index.html"))
		bTmpl, _ := Asset("web/index.html")
		tmpl := template.Must(template.New("tml").Parse(string(bTmpl)))
		data := MarkDownData{
			PageTitle: " ",
			MDText:    "",
			SideBar:   sidebarAusgabe,
		}
		tmpl.Execute(w, data)
	}
}

func getRawPage(w http.ResponseWriter, r *http.Request) {

	params := mux.Vars(r)
	pPageName := params["pagename"] + ".md"
	// Hack für anzeige der start.md wenn / aufgerufen wird
	if pPageName == ".md" {
		pPageName = "start.md"
	}
	pageContent := "Empty"

	//fmt.Println(path.Join(config.DataPath, pPageName))
	b, err := ioutil.ReadFile(path.Join(config.DataPath, pPageName))
	check(err)

	pageContent = string(b)

	json.NewEncoder(w).Encode(pageContent)
}

func postHTMLPage(w http.ResponseWriter, r *http.Request) {

	params := mux.Vars(r)
	pPageName := params["pagename"] + ".md"

	// Verzeichnis erstellen
	dir := path.Dir(pPageName)
	if !directoryExists(path.Join(config.DataPath, dir)) {
		os.MkdirAll(path.Join(config.DataPath, dir), os.ModePerm)
	}

	//{ "MDText":"**test3**" }
	var oBody TPostBody
	json.NewDecoder(r.Body).Decode(&oBody)
	//fmt.Println(oBody)

	f, err := os.Create(path.Join(config.DataPath, pPageName))
	check(err)
	defer f.Close()
	fw := bufio.NewWriter(f)
	_, err = fw.WriteString(oBody.MDText)
	check(err)
	fw.Flush()

	json.NewEncoder(w).Encode("OK")

}

//--------------------------------------------------------------------------
// Typen
//--------------------------------------------------------------------------

type MarkDownData struct {
	PageTitle string
	MDText    string
	SideBar   string
}

type TPostBody struct {
	MDText string
}

//--------------------------------------------------------------------------
// Hilfsfunktionen
//--------------------------------------------------------------------------

func check(e error) {
	if e != nil {
		fmt.Println(e)
	}
}

func fileExists(filename string) bool {
	info, err := os.Stat(filename)
	if os.IsNotExist(err) {
		return false
	}
	return !info.IsDir()
}

func directoryExists(filename string) bool {
	info, err := os.Stat(filename)
	if os.IsNotExist(err) {
		return false
	}
	return info.IsDir()
}

func readConfig(filename string) *Configuration {
	// initialize conf with default values.
	conf := &Configuration{Host: "http://127.0.0.1", Port: "8000", DataPath: "./data"}

	b, err := ioutil.ReadFile("./config.json")
	if err != nil {
		return conf
	}
	if err = json.Unmarshal(b, conf); err != nil {
		return conf
	}
	return conf
}