// Module viewServices — gestion des services systemd via systemctl.
// Dépôt indépendant : https://git.geronzi.fr/proxmoxPanel/viewServices
package viewservices

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"

	"git.geronzi.fr/proxmoxPanel/core/backend/modules"
	"github.com/go-chi/chi/v5"
)

// ServicesModule gère les opérations systemctl sur le host et les LXC.
type ServicesModule struct{}

// New crée un ServicesModule.
func New() *ServicesModule { return &ServicesModule{} }

func (m *ServicesModule) ID() string { return "viewServices" }

// Register enregistre les routes du module dans le CORE.
func (m *ServicesModule) Register(r modules.Registry) error {
	r.RegisterNavItem(modules.NavItemDef{
		ID:       "viewServices",
		Href:     "/viewServices/services.html",
		Icon:     "lnid-gear-2",
		Color:    "#fb923c",
		LabelKey: "nav.services",
	})
	r.RegisterRoute("GET", "/api/services", m.listServices(r), false)
	r.RegisterRoute("GET", "/api/services/{name}/status", m.serviceStatus(r), false)
	r.RegisterRoute("POST", "/api/services/{name}/{action}", m.serviceAction(r), true)
	return nil
}

// ServiceEntry représente un service systemd dans la liste.
type ServiceEntry struct {
	Name        string `json:"name"`
	LoadState   string `json:"load_state"`
	ActiveState string `json:"active_state"`
	SubState    string `json:"sub_state"`
	Description string `json:"description"`
}

// listServices retourne la liste des services systemd d'une cible.
// GET /api/services?target=host|lxc:ID
func (m *ServicesModule) listServices(r modules.Registry) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		target := req.URL.Query().Get("target")
		if target == "" {
			target = "host"
		}

		out, err := r.RunOnTarget(target, "systemctl list-units --type=service --all --no-legend --plain --no-pager 2>/dev/null")
		if err != nil {
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusInternalServerError)
			json.NewEncoder(w).Encode(map[string]string{"error": "Erreur commande SSH : " + err.Error()})
			return
		}

		services := parseServiceList(out)
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(services)
	}
}

// parseServiceList parse la sortie de systemctl list-units.
func parseServiceList(output string) []ServiceEntry {
	var services []ServiceEntry
	for _, line := range strings.Split(output, "\n") {
		line = strings.TrimSpace(line)
		if line == "" || strings.HasPrefix(line, "UNIT") || strings.HasPrefix(line, "Legend") ||
			strings.HasPrefix(line, "To show") || strings.HasPrefix(line, "Pass") {
			continue
		}
		line = strings.TrimPrefix(line, "● ")
		line = strings.TrimPrefix(line, "  ")

		fields := strings.Fields(line)
		if len(fields) < 4 {
			continue
		}
		name := strings.TrimSuffix(fields[0], ".service")
		desc := ""
		if len(fields) >= 5 {
			desc = strings.Join(fields[4:], " ")
		}
		services = append(services, ServiceEntry{
			Name:        name,
			LoadState:   fields[1],
			ActiveState: fields[2],
			SubState:    fields[3],
			Description: desc,
		})
	}
	return services
}

// serviceStatus retourne le statut détaillé d'un service.
// GET /api/services/{name}/status?target=host|lxc:ID
func (m *ServicesModule) serviceStatus(r modules.Registry) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		name := chi.URLParam(req, "name")
		target := req.URL.Query().Get("target")
		if target == "" {
			target = "host"
		}

		out, _ := r.RunOnTarget(target, fmt.Sprintf("systemctl status %s --no-pager 2>&1", name))

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]string{"output": out})
	}
}

// serviceAction exécute une action (start/stop/restart/reload) sur un service.
// POST /api/services/{name}/{action}
// Body: { "target": "host" | "lxc:ID" }
func (m *ServicesModule) serviceAction(r modules.Registry) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		name := chi.URLParam(req, "name")
		action := chi.URLParam(req, "action")

		// Valider l'action pour éviter l'injection de commandes
		allowed := map[string]bool{
			"start": true, "stop": true, "restart": true,
			"reload": true, "enable": true, "disable": true,
		}
		if !allowed[action] {
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(http.StatusBadRequest)
			json.NewEncoder(w).Encode(map[string]string{"error": "Action invalide"})
			return
		}

		var body struct {
			Target string `json:"target"`
		}
		if err := json.NewDecoder(req.Body).Decode(&body); err != nil || body.Target == "" {
			body.Target = "host"
		}

		out, err := r.RunOnTarget(body.Target, fmt.Sprintf("systemctl %s %s 2>&1", action, name))

		w.Header().Set("Content-Type", "application/json")
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			json.NewEncoder(w).Encode(map[string]string{
				"error":  fmt.Sprintf("Erreur action %s sur %s : %v", action, name, err),
				"output": out,
			})
			return
		}

		json.NewEncoder(w).Encode(map[string]string{
			"message": fmt.Sprintf("Action « %s » exécutée sur %s", action, name),
			"output":  out,
		})
	}
}