package app

import (
	"fmt"
	"strings"
	"time"
)

func buildTransportClientFromCreate(body TransportClientCreateRequest) (TransportClient, error) {
	id := sanitizeID(body.ID)
	if id == "" {
		return TransportClient{}, fmt.Errorf("invalid id")
	}
	kind := normalizeTransportKind(body.Kind)
	if kind == "" {
		return TransportClient{}, fmt.Errorf("kind must be singbox|dnstt|phoenix")
	}
	enabled := true
	if body.Enabled != nil {
		enabled = *body.Enabled
	}
	name := strings.TrimSpace(body.Name)
	if name == "" {
		name = id
	}
	ifaceID := normalizeTransportIfaceID(body.IfaceID)

	client := TransportClient{
		ID:           id,
		Name:         name,
		Kind:         kind,
		Enabled:      enabled,
		Status:       TransportClientDown,
		IfaceID:      ifaceID,
		RoutingTable: transportRoutingTableForID(id),
		Capabilities: defaultTransportCapabilities(kind),
		Config:       cloneMap(body.Config),
		UpdatedAt:    time.Now().UTC().Format(time.RFC3339),
		Runtime: TransportClientRuntime{
			Backend:        "",
			AllowedActions: []string{"provision", "start", "stop", "restart"},
			LastExitCode:   0,
		},
	}
	if normCfg, _ := normalizeTransportClientConfig(client.Kind, client.Config); normCfg != nil || client.Config != nil {
		client.Config = normCfg
	}
	client.Runtime.Backend = selectTransportBackend(client).ID()
	client.Health = TransportClientHealth{
		LastCheck: client.UpdatedAt,
	}
	return client, nil
}

func normalizeTransportKind(k TransportClientKind) TransportClientKind {
	switch strings.ToLower(strings.TrimSpace(string(k))) {
	case string(TransportClientSingBox):
		return TransportClientSingBox
	case string(TransportClientDNSTT):
		return TransportClientDNSTT
	case string(TransportClientPhoenix):
		return TransportClientPhoenix
	default:
		return ""
	}
}

func defaultTransportCapabilities(kind TransportClientKind) []string {
	switch kind {
	case TransportClientSingBox:
		return []string{"tcp", "udp", "dns_tunnel"}
	case TransportClientDNSTT:
		return []string{"tcp", "dns_tunnel"}
	case TransportClientPhoenix:
		return []string{"tcp", "udp", "ssh_tunnel"}
	default:
		return nil
	}
}