package sandbox

import (
	"net"

	"github.com/docker/libnetwork/types"
)

// Sandbox represents a network sandbox, identified by a specific key.  It
// holds a list of Interfaces, routes etc, and more can be added dynamically.
type Sandbox interface {
	// The path where the network namespace is mounted.
	Key() string

	// The collection of Interface previously added with the AddInterface
	// method. Note that this doesn't incude network interfaces added in any
	// other way (such as the default loopback interface which are automatically
	// created on creation of a sandbox).
	Interfaces() []*Interface

	// Add an existing Interface to this sandbox. The operation will rename
	// from the Interface SrcName to DstName as it moves, and reconfigure the
	// interface according to the specified settings. The caller is expected
	// to only provide a prefix for DstName. The AddInterface api will auto-generate
	// an appropriate suffix for the DstName to disambiguate.
	AddInterface(*Interface) error

	// Remove an interface from the sandbox by renaming to original name
	// and moving it out of the sandbox.
	RemoveInterface(*Interface) error

	// Set default IPv4 gateway for the sandbox
	SetGateway(gw net.IP) error

	// Set default IPv6 gateway for the sandbox
	SetGatewayIPv6(gw net.IP) error

	// Unset the previously set default IPv4 gateway in the sandbox
	UnsetGateway() error

	// Unset the previously set default IPv6 gateway in the sandbox
	UnsetGatewayIPv6() error

	// Add a static route to the sandbox.
	AddStaticRoute(*types.StaticRoute) error

	// Remove a static route from the sandbox.
	RemoveStaticRoute(*types.StaticRoute) error

	// Destroy the sandbox
	Destroy() error
}

// Info represents all possible information that
// the driver wants to place in the sandbox which includes
// interfaces, routes and gateway
type Info struct {
	Interfaces []*Interface

	// IPv4 gateway for the sandbox.
	Gateway net.IP

	// IPv6 gateway for the sandbox.
	GatewayIPv6 net.IP

	// Additional static routes for the sandbox.  (Note that directly
	// connected routes are stored on the particular interface they refer to.)
	StaticRoutes []*types.StaticRoute

	// TODO: Add ip tables etc.
}

// Interface represents the settings and identity of a network device. It is
// used as a return type for Network.Link, and it is common practice for the
// caller to use this information when moving interface SrcName from host
// namespace to DstName in a different net namespace with the appropriate
// network settings.
type Interface struct {
	// The name of the interface in the origin network namespace.
	SrcName string

	// The name that will be assigned to the interface once moves inside a
	// network namespace. When the caller passes in a DstName, it is only
	// expected to pass a prefix. The name will modified with an appropriately
	// auto-generated suffix.
	DstName string

	// IPv4 address for the interface.
	Address *net.IPNet

	// IPv6 address for the interface.
	AddressIPv6 *net.IPNet

	// IP routes for the interface.
	Routes []*net.IPNet
}

// GetCopy returns a copy of this Interface structure
func (i *Interface) GetCopy() *Interface {
	copiedRoutes := make([]*net.IPNet, len(i.Routes))

	for index := range i.Routes {
		copiedRoutes[index] = types.GetIPNetCopy(i.Routes[index])
	}

	return &Interface{
		SrcName:     i.SrcName,
		DstName:     i.DstName,
		Address:     types.GetIPNetCopy(i.Address),
		AddressIPv6: types.GetIPNetCopy(i.AddressIPv6),
		Routes:      copiedRoutes,
	}
}

// Equal checks if this instance of Interface is equal to the passed one
func (i *Interface) Equal(o *Interface) bool {
	if i == o {
		return true
	}

	if o == nil {
		return false
	}

	if i.SrcName != o.SrcName || i.DstName != o.DstName {
		return false
	}

	if !types.CompareIPNet(i.Address, o.Address) {
		return false
	}

	if !types.CompareIPNet(i.AddressIPv6, o.AddressIPv6) {
		return false
	}

	if len(i.Routes) != len(o.Routes) {
		return false
	}

	for index := range i.Routes {
		if !types.CompareIPNet(i.Routes[index], o.Routes[index]) {
			return false
		}
	}

	return true
}

// GetCopy returns a copy of this SandboxInfo structure
func (s *Info) GetCopy() *Info {
	list := make([]*Interface, len(s.Interfaces))
	for i, iface := range s.Interfaces {
		list[i] = iface.GetCopy()
	}
	gw := types.GetIPCopy(s.Gateway)
	gw6 := types.GetIPCopy(s.GatewayIPv6)

	routes := make([]*types.StaticRoute, len(s.StaticRoutes))
	for i, r := range s.StaticRoutes {
		routes[i] = r.GetCopy()
	}

	return &Info{Interfaces: list,
		Gateway:      gw,
		GatewayIPv6:  gw6,
		StaticRoutes: routes}
}

// Equal checks if this instance of SandboxInfo is equal to the passed one
func (s *Info) Equal(o *Info) bool {
	if s == o {
		return true
	}

	if o == nil {
		return false
	}

	if !s.Gateway.Equal(o.Gateway) {
		return false
	}

	if !s.GatewayIPv6.Equal(o.GatewayIPv6) {
		return false
	}

	if (s.Interfaces == nil && o.Interfaces != nil) ||
		(s.Interfaces != nil && o.Interfaces == nil) ||
		(len(s.Interfaces) != len(o.Interfaces)) {
		return false
	}

	// Note: At the moment, the two lists must be in the same order
	for i := 0; i < len(s.Interfaces); i++ {
		if !s.Interfaces[i].Equal(o.Interfaces[i]) {
			return false
		}
	}

	for index := range s.StaticRoutes {
		ss := s.StaticRoutes[index]
		oo := o.StaticRoutes[index]
		if !types.CompareIPNet(ss.Destination, oo.Destination) {
			return false
		}
		if !ss.NextHop.Equal(oo.NextHop) {
			return false
		}
	}

	return true

}