package main

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

const staticPrefix = "/static/"

type NavTree struct {
	name string
	path string
	children []NavTree
	hasIndex bool
	selected bool
}

func stripPath(caminho string) string {
	caminho = path.Clean(caminho)
	return "/" + path.Join(strings.Split(caminho, "/")[1:]...)
}

func rootTree(root string, goal string) (NavTree, string) {
	nav := NavTree{}
	nav.name = path.Base(root)
	nav.path = root
	nav.selected = false
	
	index := ""

	if !strings.HasPrefix(goal, root) {
		return nav, index
	}
	
	nav.selected = true

	filepath.Walk(root, func(current string, info os.FileInfo, err error) error {
		if info.Name() == ".index" {
			index = current
		}
		
		if current == root || info.Name()[0] == '.'  {
			return nil
		}
		
		rec, idx := rootTree(current, goal)
		if idx != "" {
			index = idx
		}
		
		nav.children = append(nav.children, rec)

		if info.IsDir() {
			return filepath.SkipDir
		} else {
			return nil
		}
	})

	return nav, index
}

func RenderList(children []NavTree) string {
	deleg := ""
	ul := "<ul>"
	for _, s := range children {
		u, d := s.Render()
		ul += u
		deleg += d
	}
	ul += "</ul>"
	ul += deleg
	return ul
}

func (v *NavTree) Render() (string, string) {
	li := "<li><a href=\"" + stripPath(v.path) + "\">"
	if v.selected {
		li += "<span class=\"nav-intended\">"
	} else {
		li += "<span class=\"nav-not-intended\">"
	}
	li += v.name
	li += "</span></a></li>"
	
	deleg := ""

	if len(v.children) > 0 {
		deleg += RenderList(v.children)
	}
	
	return li, deleg
}

func build(request *http.Request) (string, int) {
	code := 200
	root := request.Host
	postLoc := path.Join(root, request.URL.Path)
	
	if strings.HasPrefix(request.URL.Path, staticPrefix) {
		staticLoc := path.Join(root, request.URL.Path[len(staticPrefix):])
		static, err0 := ioutil.ReadFile(staticLoc)
		if err0 != nil {
			return "Path not  found", 404
		}
		
		return string(static), 200
	}
	
	tr, idx := rootTree(root, postLoc)
	template, err0 := ioutil.ReadFile(idx)
	if err0 != nil {
		return "No template in tree", 500
	}

	final := string(template)
	
	post, err1 := ioutil.ReadFile(postLoc)
	if err1 != nil {
		viewLoc := path.Join(root, request.URL.Path, ".view")
		
		view, err1_0 := ioutil.ReadFile(viewLoc)
		if err1_0 != nil {
			return "Path not found", 404
		}
		post = view
	}

	final = strings.Replace(string(template), "{{ post }}", string(post), -1)
	final = strings.Replace(string(final), "{{ nav }}", RenderList(tr.children), -1)
	
	return final, code
}

func handler(w http.ResponseWriter, r *http.Request) {
	content, code := build(r)

	w.WriteHeader(code)
	w.Write([]byte(content))
}

func main() {
	http.HandleFunc("/", handler)
	http.ListenAndServe(":8080", nil)
}