package app

import (
	"encoding/json"
	"io"
	"net/http"
	"strings"
)

// ---------------------------------------------------------------------
// EN: `handleDNSSmartdnsService` is an HTTP handler for dns smartdns service.
// RU: `handleDNSSmartdnsService` - HTTP-обработчик для dns smartdns service.
// ---------------------------------------------------------------------
func handleDNSSmartdnsService(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var body struct {
		Action string `json:"action"`
	}
	if r.Body != nil {
		defer r.Body.Close()
		_ = json.NewDecoder(io.LimitReader(r.Body, 1<<20)).Decode(&body)
	}

	action := strings.ToLower(strings.TrimSpace(body.Action))
	if action == "" {
		action = "restart"
	}
	switch action {
	case "start", "stop", "restart":
	default:
		http.Error(w, "unknown action", http.StatusBadRequest)
		return
	}

	res := runSmartdnsUnitAction(action)
	mode := loadDNSMode()
	rt := smartDNSRuntimeSnapshot()
	writeJSON(w, http.StatusOK, map[string]any{
		"ok":              res.OK,
		"message":         res.Message,
		"exitCode":        res.ExitCode,
		"stdout":          res.Stdout,
		"stderr":          res.Stderr,
		"unit_state":      smartdnsUnitState(),
		"via_smartdns":    mode.ViaSmartDNS,
		"smartdns_addr":   mode.SmartDNSAddr,
		"mode":            mode.Mode,
		"runtime_nftset":  rt.Enabled,
		"wildcard_source": rt.WildcardSource,
	})
}

// ---------------------------------------------------------------------
// EN: `handleSmartdnsService` is an HTTP handler for smartdns service.
// RU: `handleSmartdnsService` - HTTP-обработчик для smartdns service.
// ---------------------------------------------------------------------
func handleSmartdnsService(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodGet:
		writeJSON(w, http.StatusOK, map[string]string{"state": smartdnsUnitState()})
	case http.MethodPost:
		var body struct {
			Action string `json:"action"`
		}
		if r.Body != nil {
			defer r.Body.Close()
			_ = json.NewDecoder(io.LimitReader(r.Body, 1<<20)).Decode(&body)
		}

		action := strings.ToLower(strings.TrimSpace(body.Action))
		if action == "" {
			action = "restart"
		}
		switch action {
		case "start", "stop", "restart":
		default:
			http.Error(w, "unknown action", http.StatusBadRequest)
			return
		}
		writeJSON(w, http.StatusOK, runSmartdnsUnitAction(action))
	default:
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
	}
}