package api

import (
	"encoding/json"
	"net/http"
	"os"
	"os/exec"
	"strings"

	"proxmox-router/internal/dns"
)

// handleGetDNSSettings returns the current router DNS configuration.
func (s *Server) handleGetDNSSettings(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}
	settings := s.dnsMgr.GetSettings()
	writeJSON(w, http.StatusOK, settings)
}

// handleSaveDNSSettings updates the router DNS configuration.
func (s *Server) handleSaveDNSSettings(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}

	var req dns.DNSSettings
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if err := s.dnsMgr.SaveSettings(req); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{
		"success":  true,
		"settings": s.dnsMgr.GetSettings(),
	})
}

// handleListDNSStatic returns all static DNS host mappings.
func (s *Server) handleListDNSStatic(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}
	records := s.dnsMgr.ListStaticRecords()
	writeJSON(w, http.StatusOK, records)
}

// handleSaveDNSStatic adds or updates a static DNS record.
func (s *Server) handleSaveDNSStatic(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}

	var rec dns.StaticRecord
	if err := json.NewDecoder(r.Body).Decode(&rec); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if err := s.dnsMgr.SaveStaticRecord(rec); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{
		"success": true,
		"record":  rec,
	})
}

// handleDeleteDNSStatic deletes a static DNS record by ID.
func (s *Server) handleDeleteDNSStatic(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}

	id := r.PathValue("id")
	if id == "" {
		writeError(w, http.StatusBadRequest, "record ID is required")
		return
	}

	if err := s.dnsMgr.DeleteStaticRecord(id); err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{"success": true, "id": id})
}

// handleSetDNSStaticState toggles enabled/disabled state of a static DNS record.
func (s *Server) handleSetDNSStaticState(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}

	id := r.PathValue("id")
	var req struct {
		Disabled bool `json:"disabled"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if err := s.dnsMgr.ToggleStaticRecord(id, req.Disabled); err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{"success": true, "id": id, "disabled": req.Disabled})
}

// handleFlushDNSCache flushes the local DNS cache.
func (s *Server) handleFlushDNSCache(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}

	if err := s.dnsMgr.FlushCache(); err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{"success": true, "message": "DNS cache flushed successfully"})
}

// handleGetDNSStatus returns live DNS forwarder and resolv.conf status.
func (s *Server) handleGetDNSStatus(w http.ResponseWriter, r *http.Request) {
	if s.dnsMgr == nil {
		writeError(w, http.StatusServiceUnavailable, "DNS manager not initialized")
		return
	}
	status := s.dnsMgr.GetStatus()
	writeJSON(w, http.StatusOK, status)
}

// handleGetSystemSettings returns hostname, timezone, and appliance info.
func (s *Server) handleGetSystemSettings(w http.ResponseWriter, r *http.Request) {
	hostname, _ := os.Hostname()

	tz := "UTC"
	if out, err := exec.Command("timedatectl", "show", "--property=Timezone", "--value").Output(); err == nil {
		tz = strings.TrimSpace(string(out))
	} else if data, err := os.ReadFile("/etc/timezone"); err == nil {
		tz = strings.TrimSpace(string(data))
	}

	writeJSON(w, http.StatusOK, map[string]any{
		"hostname": hostname,
		"timezone": tz,
	})
}

// handleSaveSystemSettings updates hostname and/or timezone.
func (s *Server) handleSaveSystemSettings(w http.ResponseWriter, r *http.Request) {
	var req struct {
		Hostname string `json:"hostname"`
		Timezone string `json:"timezone"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if req.Hostname != "" {
		h := strings.TrimSpace(req.Hostname)
		if err := exec.Command("hostnamectl", "set-hostname", h).Run(); err != nil {
			_ = os.WriteFile("/etc/hostname", []byte(h+"\n"), 0644)
		}
	}

	if req.Timezone != "" {
		tz := strings.TrimSpace(req.Timezone)
		_ = exec.Command("timedatectl", "set-timezone", tz).Run()
	}

	curH, _ := os.Hostname()
	writeJSON(w, http.StatusOK, map[string]any{
		"success":  true,
		"hostname": curH,
		"timezone": req.Timezone,
	})
}