// Handlers pour les mises à jour de paquets apt.
// Supporte : host Proxmox, un LXC spécifique, ou tous les LXC.
// La sortie est streamée ligne par ligne via WebSocket.
package api

import (
	"fmt"
	"net/http"
	"time"

	"git.geronzi.fr/proxmoxPanel/core/backend/internal/audit"
	"git.geronzi.fr/proxmoxPanel/core/backend/internal/crypto"
	"git.geronzi.fr/proxmoxPanel/core/backend/internal/db"
	"git.geronzi.fr/proxmoxPanel/core/backend/internal/ssh"
	"git.geronzi.fr/proxmoxPanel/core/backend/internal/websocket"
	"github.com/go-chi/chi/v5"
	"math/rand"
)

// UpdatesHandler contient les handlers de mises à jour.
type UpdatesHandler struct {
	db          *db.DB
	sshPool     *ssh.Pool
	hub         *websocket.Hub
	auditLogger *audit.Logger
	encryptor   *crypto.Encryptor
}

// NewUpdatesHandler crée un UpdatesHandler.
func NewUpdatesHandler(database *db.DB, sshPool *ssh.Pool, hub *websocket.Hub, auditLog *audit.Logger, enc *crypto.Encryptor) *UpdatesHandler {
	return &UpdatesHandler{
		db:          database,
		sshPool:     sshPool,
		hub:         hub,
		auditLogger: auditLog,
		encryptor:   enc,
	}
}

// RunUpdate lance une mise à jour apt sur la cible spécifiée.
// POST /api/updates/run
// Body: { "target": "host" | "lxc:100" | "all" }
func (h *UpdatesHandler) RunUpdate(w http.ResponseWriter, r *http.Request) {
	claims := GetClaims(r)

	var body struct {
		Target string `json:"target"`
	}
	if err := decodeJSON(r, &body); err != nil || body.Target == "" {
		JSONError(w, "Paramètre 'target' requis (host, lxc:ID, ou all)", http.StatusBadRequest)
		return
	}

	// Récupérer les credentials SSH depuis les settings
	sshHost, _, _ := h.db.GetSetting("ssh_host")
	sshUser, _, _ := h.db.GetSetting("ssh_username")
	encryptedPass, _, _ := h.db.GetSetting("ssh_password")
	sshPass, _ := h.encryptor.Decrypt(encryptedPass)
	if sshHost == "" || sshUser == "" || sshPass == "" {
		JSONError(w, "SSH non configuré", http.StatusServiceUnavailable)
		return
	}

	// Générer un ID de job unique
	jobID := generateJobID()

	// Enregistrer le job en base
	h.db.Exec(`
		INSERT INTO update_history (job_id, target, status, started_by) VALUES (?, ?, 'running', ?)
	`, jobID, body.Target, claims.UserID)

	h.auditLogger.Log(&claims.UserID, claims.Username, "update_start", body.Target, nil, clientIP(r))

	// Lancer la mise à jour en arrière-plan
	go h.executeUpdate(jobID, body.Target, sshHost, sshUser, sshPass, claims.UserID)

	JSONResponse(w, http.StatusAccepted, map[string]string{
		"job_id":  jobID,
		"message": "Mise à jour démarrée",
	})
}

// GetHistory retourne l'historique des mises à jour.
// GET /api/updates/history
func (h *UpdatesHandler) GetHistory(w http.ResponseWriter, r *http.Request) {
	rows, err := h.db.Query(`
		SELECT job_id, target, status, output, started_at, finished_at
		FROM update_history
		ORDER BY started_at DESC
		LIMIT 50
	`)
	if err != nil {
		JSONError(w, "Erreur lecture historique", http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	type entry struct {
		JobID      string  `json:"job_id"`
		Target     string  `json:"target"`
		Status     string  `json:"status"`
		Output     string  `json:"output"`
		StartedAt  string  `json:"started_at"`
		FinishedAt *string `json:"finished_at,omitempty"`
	}

	var entries []entry
	for rows.Next() {
		var e entry
		var finishedAt *string
		rows.Scan(&e.JobID, &e.Target, &e.Status, &e.Output, &e.StartedAt, &finishedAt)
		e.FinishedAt = finishedAt
		entries = append(entries, e)
	}

	JSONResponse(w, http.StatusOK, entries)
}

// WebSocketUpdate ouvre un WebSocket pour suivre un job de mise à jour en temps réel.
// GET /ws/updates/{jobId}
func (h *UpdatesHandler) WebSocketUpdate(w http.ResponseWriter, r *http.Request) {
	conn, err := upgrader.Upgrade(w, r, nil)
	if err != nil {
		return
	}

	claims := GetClaims(r)
	var userID int64
	if claims != nil {
		userID = claims.UserID
	}

	jobID := chi.URLParam(r, "jobId")
	wsClient := h.hub.NewClient(conn, userID)
	wsClient.Subscribe("update:" + jobID)
}

// executeUpdate exécute la commande apt et streame la sortie via WebSocket.
func (h *UpdatesHandler) executeUpdate(jobID, target, sshHost, sshUser, sshPass string, userID int64) {
	outputChan := make(chan string, 100)
	var command string

	switch {
	case target == "host":
		command = "DEBIAN_FRONTEND=noninteractive apt-get update && DEBIAN_FRONTEND=noninteractive apt-get full-upgrade -y"

	case len(target) > 4 && target[:4] == "lxc:":
		lxcID := target[4:]
		command = fmt.Sprintf(
			"pct exec %s -- bash -c 'DEBIAN_FRONTEND=noninteractive apt-get update && DEBIAN_FRONTEND=noninteractive apt-get full-upgrade -y'",
			lxcID,
		)

	case target == "all":
		command = `for ct in $(pct list | awk 'NR>1 {print $1}'); do
			echo "=== LXC $ct ==="
			pct exec $ct -- bash -c 'DEBIAN_FRONTEND=noninteractive apt-get update -qq && DEBIAN_FRONTEND=noninteractive apt-get full-upgrade -y' 2>/dev/null || echo "SKIP LXC $ct"
		done`

	default:
		h.db.Exec(`UPDATE update_history SET status='error', output=?, finished_at=CURRENT_TIMESTAMP WHERE job_id=?`,
			"Cible invalide : "+target, jobID)
		return
	}

	// Lancer le streaming SSH
	err := h.sshPool.StreamCommand(sshHost, sshUser, sshPass, command, outputChan)
	if err != nil {
		h.db.Exec(`UPDATE update_history SET status='error', output=?, finished_at=CURRENT_TIMESTAMP WHERE job_id=?`,
			"Erreur SSH : "+err.Error(), jobID)
		h.hub.Publish("update:"+jobID, "update_error", map[string]string{"error": err.Error()})
		return
	}

	// Collecter la sortie et la publier ligne par ligne
	var fullOutput string
	for chunk := range outputChan {
		fullOutput += chunk
		h.hub.Publish("update:"+jobID, "update_output", map[string]string{"chunk": chunk})
	}

	// Finaliser le job
	h.db.Exec(`UPDATE update_history SET status='success', output=?, finished_at=CURRENT_TIMESTAMP WHERE job_id=?`,
		fullOutput, jobID)
	h.hub.Publish("update:"+jobID, "update_done", map[string]string{"job_id": jobID})
}

// generateJobID génère un identifiant unique pour un job de mise à jour.
func generateJobID() string {
	const chars = "abcdefghijklmnopqrstuvwxyz0123456789"
	b := make([]byte, 8)
	for i := range b {
		b[i] = chars[rand.Intn(len(chars))]
	}
	return fmt.Sprintf("%d-%s", time.Now().Unix(), string(b))
}