package main

import (
	"embed"
	"errors"
	"flag"
	"fmt"
	"html/template"
	"io"
	"net/http"
	"net/url"
	"strings"

	_ "embed"
)

var (
	intf = flag.String("i", "", "interface")
	port = flag.Uint("p", 80, "port")
)

var (
	//go:embed templates/*
	TemplateFS embed.FS

	//go:embed static/*
	StaticFS embed.FS

	Templates *template.Template
)

func main() {
	flag.Parse()

	ParseBookmarks()

	if tmpl, err := template.New("homepage").ParseFS(TemplateFS, "templates/*"); err == nil {
		Templates = tmpl
	} else {
		panic(err)
	}

	http.HandleFunc("/", handler)
	http.HandleFunc("/search", search)
	http.HandleFunc("/style.css", style)
	http.HandleFunc("/icons.ttf", icons)
	if err := http.ListenAndServe(fmt.Sprintf("%s:%d", *intf, *port), nil); err != nil {
		panic(err)
	}
}

func handler(w http.ResponseWriter, r *http.Request) {
	data := &TmplData{
		text:      GetText(r),
		Bookmarks: Bookmarks,
		Settings:  DefaultSettings,
	}

	if err := Templates.ExecuteTemplate(w, "index.html", data); err != nil {
		panic(err)
	}
}

func style(w http.ResponseWriter, r *http.Request) {
	file, err := TemplateFS.Open("templates/style.css")
	if err != nil {
		fmt.Println(err)
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	defer file.Close()

	w.Header().Add("Content-Type", "text/css")

	if err := Templates.ExecuteTemplate(w, "style.css", DefaultSettings); err != nil {
		panic(err)
	}
}

func icons(w http.ResponseWriter, r *http.Request) {
	file, err := StaticFS.Open("static/icons.ttf")
	if err != nil {
		fmt.Println(err)
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	defer file.Close()

	w.Header().Add("Content-Type", "font/ttf")

	io.Copy(w, file)
}

func search(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	query := r.Form.Get("query")

	if uri, err := ParseURI(query); err == nil {
		// url
		w.Header().Add("Location", uri.String())
		w.WriteHeader(http.StatusMovedPermanently)
	} else {
		// search string
		w.Header().Add("Location", fmt.Sprintf("https://duckduckgo.com/?q=%s", query))
		w.WriteHeader(http.StatusMovedPermanently)
	}
}

func ParseURI(uri string) (*url.URL, error) {
	if !strings.HasPrefix(uri, "http://") && !strings.HasPrefix(uri, "https://") {
		uri = "https://" + uri
	}
	ret, err := url.ParseRequestURI(uri)
	if err != nil {
		return nil, err
	}

	splits := strings.Split(ret.Hostname(), ".")
	if len(splits) <= 1 {
		return nil, errors.New("hostname doesn't have a TLD")
	}

	if _, ok := TLDs[splits[len(splits)-1]]; !ok {
		return nil, errors.New("invalid top level domain")
	}

	return ret, nil
}