package main

import (
	"fmt"
	"html/template"
	"log"
	"net/http"
	"os"
)

type Page struct {
	Title string
	Body  []byte
}

func loadPage(title string) (*Page, error) {
	body, err := os.ReadFile(title + ".txt")
	if err != nil {
		return nil, err
	}
	return &Page{Title: title, Body: body}, nil
}

func (p *Page) savePage() error {
	filename := p.Title + ".txt"
	return os.WriteFile(filename, p.Body, 0600)
}

func viewHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/view/"):]
	page, err := loadPage(title)
	if err != nil {
		fmt.Fprintf(w, "<h1>ERROR</h1><p>%s not found!</p>", title)
	} else {
		fmt.Fprintf(w, "<h1>%s</h1><p>%s</p>", page.Title, string(page.Body))
	}
}

func saveHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/save/"):]
	p := &Page{Title: title, Body: []byte(r.FormValue("body"))}
	p.savePage()
	http.Redirect(w, r, "/view/"+title, http.StatusFound)

}

func editHandler(w http.ResponseWriter, r *http.Request) {
	title := r.URL.Path[len("/edit/"):]
	page, err := loadPage(title)
	if err != nil {
		page = &Page{Title: title}
	}
	t, _ := template.ParseFiles("edit.html")
	t.Execute(w, page)
}

func main() {
	http.HandleFunc("/view/", viewHandler)
	http.HandleFunc("/save/", saveHandler)
	http.HandleFunc("/edit/", editHandler)
	log.Fatal(http.ListenAndServe(":8080", nil))
}