package vm

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"net/http"

	"forgejo.digital-droplets.de/philschlo/proxui/platform/cluster"
	"forgejo.digital-droplets.de/philschlo/proxui/platform/jobs"
	"forgejo.digital-droplets.de/philschlo/proxui/platform/proxmox"

	"proxui/backend/internal/auth"
	"proxui/backend/internal/rbac"
)

type ClusterRepository interface {
	GetCluster(ctx context.Context, id string) (cluster.Cluster, bool, error)
}

type PowerClient interface {
	PowerVM(ctx context.Context, node string, vmid int, action string) (string, error)
}

type PowerClientFactory func(cluster.Cluster) (PowerClient, error)

type TaskEnqueuer interface {
	EnqueueProxmoxTaskPoll(ctx context.Context, payload jobs.ProxmoxTaskPollPayload) error
}

type PowerAuditWriter interface {
	WriteVMPowerAudit(ctx context.Context, event VMPowerAuditEvent) error
}

type VMPowerAuditEvent struct {
	TenantID  string
	ProfileID string
	Action    string
	VMID      string
	ClusterID string
	Node      string
	UPID      string
}

type PowerDependencies struct {
	Clusters      ClusterRepository
	ClientFactory PowerClientFactory
	Tasks         TaskEnqueuer
	Audit         PowerAuditWriter
}

func (h Handler) StartVM(w http.ResponseWriter, r *http.Request) {
	h.powerVM(w, r, "start", "running")
}

func (h Handler) StopVM(w http.ResponseWriter, r *http.Request) {
	h.powerVM(w, r, "stop", "stopped")
}

func (h Handler) RebootVM(w http.ResponseWriter, r *http.Request) {
	h.powerVM(w, r, "reboot", "running")
}

func (h Handler) powerVM(w http.ResponseWriter, r *http.Request, action string, successStatus string) {
	if h.power.Clusters == nil || h.power.ClientFactory == nil || h.power.Tasks == nil || h.power.Audit == nil {
		writeError(w, http.StatusServiceUnavailable, "vm_power_not_configured")
		return
	}

	principal, ok := auth.PrincipalFromRequest(r)
	if !ok {
		writeError(w, http.StatusUnauthorized, "unauthorized")
		return
	}

	vmID := r.PathValue("vmID")
	if vmID == "" {
		writeError(w, http.StatusBadRequest, "vm_id_required")
		return
	}

	vm, found, err := h.repository.GetVM(r.Context(), principal.Subject, vmID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "vm_get_failed")
		return
	}
	if !found {
		writeError(w, http.StatusNotFound, "vm_not_found")
		return
	}
	if !rbac.Can(rbac.Role(vm.MembershipRole), rbac.ActionVMPower) {
		writeError(w, http.StatusForbidden, "forbidden")
		return
	}

	cluster, found, err := h.power.Clusters.GetCluster(r.Context(), vm.ClusterID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "cluster_get_failed")
		return
	}
	if !found {
		writeError(w, http.StatusBadGateway, "cluster_not_found")
		return
	}

	client, err := h.power.ClientFactory(cluster)
	if err != nil {
		writeError(w, http.StatusBadGateway, "proxmox_client_failed")
		return
	}

	upid, err := client.PowerVM(r.Context(), vm.Node, vm.ProxmoxVMID, action)
	if err != nil {
		writeError(w, http.StatusBadGateway, "proxmox_power_failed")
		return
	}

	auditAction := "vm.power." + action
	if err := h.power.Tasks.EnqueueProxmoxTaskPoll(r.Context(), jobs.ProxmoxTaskPollPayload{
		ClusterID:     vm.ClusterID,
		Node:          vm.Node,
		UPID:          upid,
		TargetType:    "vm",
		TargetID:      vm.ID,
		TenantID:      vm.TenantID,
		ProfileID:     principal.Subject,
		Action:        auditAction,
		SuccessStatus: successStatus,
	}); err != nil {
		writeError(w, http.StatusInternalServerError, "task_enqueue_failed")
		return
	}

	if err := h.power.Audit.WriteVMPowerAudit(r.Context(), VMPowerAuditEvent{
		TenantID:  vm.TenantID,
		ProfileID: principal.Subject,
		Action:    auditAction,
		VMID:      vm.ID,
		ClusterID: vm.ClusterID,
		Node:      vm.Node,
		UPID:      upid,
	}); err != nil {
		writeError(w, http.StatusInternalServerError, "audit_write_failed")
		return
	}

	writeJSON(w, http.StatusAccepted, map[string]string{
		"upid":   upid,
		"status": "queued",
	})
}

func DefaultPowerClientFactory(cluster cluster.Cluster) (PowerClient, error) {
	return proxmox.NewClient(cluster)
}

type SQLPowerAuditWriter struct {
	db *sql.DB
}

func NewSQLPowerAuditWriter(db *sql.DB) SQLPowerAuditWriter {
	return SQLPowerAuditWriter{db: db}
}

func (w SQLPowerAuditWriter) WriteVMPowerAudit(ctx context.Context, event VMPowerAuditEvent) error {
	metadata, err := json.Marshal(map[string]any{
		"cluster_id": event.ClusterID,
		"node":       event.Node,
		"upid":       event.UPID,
	})
	if err != nil {
		return err
	}

	_, err = w.db.ExecContext(ctx, `
		insert into public.audit_log (
			tenant_id,
			profile_id,
			action,
			target_type,
			target_id,
			metadata
		)
		values ($1, $2, $3, 'vm', $4, $5::jsonb)
	`, event.TenantID, event.ProfileID, event.Action, event.VMID, string(metadata))
	if err != nil {
		return fmt.Errorf("insert power audit: %w", err)
	}
	return nil
}