package request

import (
	"context"
	"fmt"
	"strconv"
	"strings"

	"k8s.io/apiserver/pkg/endpoints/request"

	"github.com/grafana/grafana/pkg/infra/appcontext"
	"github.com/grafana/grafana/pkg/setting"
)

type NamespaceInfo struct {
	// OrgID defined in namespace (1 when using stack ids)
	OrgID int64

	// The cloud stack ID (must match the value in cfg.Settings)
	StackID string

	// The original namespace string regardless the input
	Value string
}

// NamespaceMapper converts an orgID into a namespace
type NamespaceMapper = func(orgId int64) string

// GetNamespaceMapper returns a function that will convert orgIds into a consistent namespace
func GetNamespaceMapper(cfg *setting.Cfg) NamespaceMapper {
	if cfg != nil && cfg.StackID != "" {
		return func(orgId int64) string { return "stack-" + cfg.StackID }
	}
	return func(orgId int64) string {
		if orgId == 1 {
			return "default"
		}
		return fmt.Sprintf("org-%d", orgId)
	}
}

func NamespaceInfoFrom(ctx context.Context, requireOrgID bool) (NamespaceInfo, error) {
	info, err := ParseNamespace(request.NamespaceValue(ctx))
	if err == nil && requireOrgID && info.OrgID < 1 {
		return info, fmt.Errorf("expected valid orgId in namespace")
	}
	return info, err
}

func ParseNamespace(ns string) (NamespaceInfo, error) {
	info := NamespaceInfo{Value: ns, OrgID: -1}
	if ns == "default" {
		info.OrgID = 1
		return info, nil
	}

	if strings.HasPrefix(ns, "org-") {
		id, err := strconv.Atoi(ns[4:])
		if id < 1 {
			return info, fmt.Errorf("invalid org id")
		}
		if id == 1 {
			return info, fmt.Errorf("use default rather than org-1")
		}
		info.OrgID = int64(id)
		return info, err
	}

	if strings.HasPrefix(ns, "stack-") {
		stackIDStr := ns[6:]
		stackID, err := strconv.Atoi(stackIDStr)
		if err != nil || stackID < 1 {
			return info, fmt.Errorf("invalid stack id")
		}
		info.StackID = stackIDStr
		info.OrgID = 1
		return info, nil
	}
	return info, nil
}

func OrgIDForList(ctx context.Context) (int64, error) {
	ns := request.NamespaceValue(ctx)
	if ns == "" {
		user, err := appcontext.User(ctx)
		if user != nil {
			return user.OrgID, err
		}
		return -1, err
	}
	info, err := ParseNamespace(ns)
	return info.OrgID, err
}