package main

import (
	"encoding/json"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"strings"
	"text/template"
)

var countries = map[string]country{}
var lawsByCC = map[string]map[string]law{}

func main() {
	text, _ := ioutil.ReadFile("countries.json")
	err := json.Unmarshal(text, &countries)
	if err != nil {
		log.Fatal("search.json", err)
	}

	lawFiles, err := ioutil.ReadDir("laws")
	if err != nil {
		log.Fatal(err)
	}
	for _, file := range lawFiles {
		text, err := ioutil.ReadFile("laws/" + file.Name())
		if err != nil {
			log.Fatal(file.Name(), err)
		}
		var laws []law
		err = json.Unmarshal([]byte(text), &laws)
		if err != nil {
			log.Fatal(file.Name(), err)
		}
		cc := strings.SplitN(file.Name(), ".", 2)[0]
		lawsByCC[cc] = map[string]law{}
		for _, law := range laws {
			if law.Redir != "" {
				lawsByCC[cc][law.Redir] = law
			}
		}
	}
	http.HandleFunc("/", handler)
	println("listening on 8000")
	log.Fatal(http.ListenAndServe(":8000", nil))
}

var tpl, _ = template.New("").Funcs(template.FuncMap{
	"ToUpper": strings.ToUpper,
}).ParseGlob("views/*")

func handler(w http.ResponseWriter, r *http.Request) {
	if r.Host == "lex.surf" || r.Host == "lex.localhost" {
		if r.URL.Path != "/" {
			w.WriteHeader(http.StatusNotFound)
			w.Write([]byte("page not found"))
			return
		}
		err := tpl.ExecuteTemplate(w, "index.html", map[string]any{
			"Countries": countries,
			"Domain":    r.Host,
		})
		if err != nil {
			log.Fatal(err)
		}
		return
	}

	parts := strings.SplitN(r.Host, ".", 2)
	if len(parts) != 2 {
		w.Write([]byte("unknown host"))
		return
	}
	cc := parts[0]
	host := parts[1]
	key := strings.TrimLeft(r.URL.Path, "/")
	if len(key) > 0 {
		val, ok := lawsByCC[cc][key]
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			w.Write([]byte("unknown law"))
			return
		}
		http.Redirect(w, r, val.Url, 302)
	} else {
		query := r.URL.Query().Get("q")
		if query != "" {
			country, ok := countries[cc]
			if !ok {
				w.WriteHeader(http.StatusNotFound)
				w.Write([]byte("search not implemented for this country"))
				return
			}
			if country.HasPlaceholder() {
				http.Redirect(w, r, strings.Replace(country.SearchURL, "%s", url.QueryEscape(query), 1), 302)
				return
			} else {
				w.WriteHeader(http.StatusBadRequest)
			}
		}
		_, hasJSONLaws := lawsByCC[cc]
		err := tpl.ExecuteTemplate(w, "search.html", map[string]any{
			"TLD":         cc,
			"Domain":      host,
			"Country":     countries[cc],
			"HasJSONLaws": hasJSONLaws,
		})
		if err != nil {
			log.Fatal(err)
		}
	}
}

type law struct {
	Url   string
	Title string
	Abbr  string
	Redir string
}

type country struct {
	Name      string
	SearchURL string `json:"search_url"`
}

func (c country) HasPlaceholder() bool {
	return strings.Contains(c.SearchURL, "%s")
}