package main

import (
	"dns_service/settings"
	"dns_service/utils"
	"embed"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path"

	"github.com/joho/godotenv"
)

func Settings(w http.ResponseWriter, req *http.Request) {
	if req.Method == "GET" {
		resp_settings, err := settings.GetSettings()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		jsondata, err := json.Marshal(resp_settings)
		if err != nil {
			http.Error(w, "Error json marshal settings", http.StatusInternalServerError)
			return
		}
		w.Header().Add("Content-Type", "application/json")
		fmt.Fprintf(w, "%s", string(jsondata))
	} else if req.Method == "POST" {
		new_settings := make(map[string]any)
		decoder := json.NewDecoder(req.Body)
		decoder.Decode(&new_settings)
		old_settings, err := settings.GetSettings()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		resp_settings, err := settings.SetSettings(new_settings, old_settings)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		jsondata, err := json.Marshal(resp_settings)
		if err != nil {
			http.Error(w, "Error json marshal settings", http.StatusInternalServerError)
			return
		}
		w.Header().Add("Content-Type", "application/json")
		fmt.Println(new_settings, old_settings, resp_settings)
		fmt.Fprintf(w, "%s", string(jsondata))
	}
}

func SettingsFile(w http.ResponseWriter, req *http.Request) {
	if req.Method == "GET" {
		data, e := os.ReadFile(os.Getenv("DNSMASQ_CONFIG"))
		if e != nil {
			panic(e)
		}
		w.Header().Add("Content-Type", "text/plain")
		fmt.Fprintf(w, "%s", string(data))
	} else if req.Method == "POST" {
		bodyBytes, err := io.ReadAll(req.Body)
		if err != nil {
			http.Error(w, "Error reading request body", http.StatusBadRequest)
			return
		}
		err = os.WriteFile(os.Getenv("DNSMASQ_CONFIG"), bodyBytes, 0644)
		if err != nil {
			http.Error(w, "Error writing dnsmasq config file", http.StatusInternalServerError)
			return
		}
		fmt.Println(string(bodyBytes))
		utils.RestartDnsmasq()
		exec.Command("rc", "restart", "dnsmasq").Run()
		w.Header().Add("Content-Type", "text/plain")
		fmt.Fprintf(w, "%s", string(bodyBytes))
	}
}

//go:embed frontend/*
var frontend embed.FS

func spaHandler(fs http.FileSystem) http.Handler {
	fileServer := http.FileServer(fs)
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Println("/frontend" + r.URL.Path)
		r.URL.Path = "/frontend" + path.Clean(r.URL.Path)
		if _, err := fs.Open(path.Clean(r.URL.Path)); err != nil {
			r.URL.Path = "/"
		}
		fileServer.ServeHTTP(w, r)
	})
}

func main() {
	err := godotenv.Load("/etc/dns_service/dns_service.conf")
	if err != nil {
		log.Fatal("Error loading .env file")
	}

	http.Handle("/", spaHandler(http.FS(frontend)))
	http.HandleFunc("/api/settings", Settings)
	http.HandleFunc("/api/settings/file", SettingsFile)

	if os.Getenv("ENABLE_TLS") == "true" {
		http.ListenAndServeTLS(
			os.Getenv("SERVER_ADDRESS")+":"+os.Getenv("SERVER_PORT"),
			os.Getenv("CERT_FILE"),
			os.Getenv("KEY_FILE"),
			nil,
		)
	} else {
		http.ListenAndServe(
			os.Getenv("SERVER_ADDRESS")+":"+os.Getenv("SERVER_PORT"),
			nil,
		)
	}
}