package dialer

import (
	"context"
	"net"
	"net/netip"
	"time"

	C "github.com/sagernet/sing-box/constant"
	E "github.com/sagernet/sing/common/exceptions"
	M "github.com/sagernet/sing/common/metadata"
	N "github.com/sagernet/sing/common/network"
)

func DialSerialNetwork(ctx context.Context, dialer N.Dialer, network string, destination M.Socksaddr, destinationAddresses []netip.Addr, strategy *C.NetworkStrategy, interfaceType []C.InterfaceType, fallbackInterfaceType []C.InterfaceType, fallbackDelay time.Duration) (net.Conn, error) {
	if len(destinationAddresses) == 0 {
		if !destination.IsIP() {
			panic("invalid usage")
		}
		destinationAddresses = []netip.Addr{destination.Addr}
	}
	if parallelDialer, isParallel := dialer.(ParallelNetworkDialer); isParallel {
		return parallelDialer.DialParallelNetwork(ctx, network, destination, destinationAddresses, strategy, interfaceType, fallbackInterfaceType, fallbackDelay)
	}
	var errors []error
	if parallelDialer, isParallel := dialer.(ParallelInterfaceDialer); isParallel {
		for _, address := range destinationAddresses {
			conn, err := parallelDialer.DialParallelInterface(ctx, network, M.SocksaddrFrom(address, destination.Port), strategy, interfaceType, fallbackInterfaceType, fallbackDelay)
			if err == nil {
				return conn, nil
			}
			errors = append(errors, err)
		}
	} else {
		for _, address := range destinationAddresses {
			conn, err := dialer.DialContext(ctx, network, M.SocksaddrFrom(address, destination.Port))
			if err == nil {
				return conn, nil
			}
			errors = append(errors, err)
		}
	}
	return nil, E.Errors(errors...)
}

func DialParallelNetwork(ctx context.Context, dialer ParallelInterfaceDialer, network string, destination M.Socksaddr, destinationAddresses []netip.Addr, preferIPv6 bool, strategy *C.NetworkStrategy, interfaceType []C.InterfaceType, fallbackInterfaceType []C.InterfaceType, fallbackDelay time.Duration) (net.Conn, error) {
	if len(destinationAddresses) == 0 {
		if !destination.IsIP() {
			panic("invalid usage")
		}
		destinationAddresses = []netip.Addr{destination.Addr}
	}
	return N.DialParallel(ctx, &networkStrategyDialer{
		ParallelInterfaceDialer: dialer,
		strategy:                strategy,
		interfaceType:           interfaceType,
		fallbackInterfaceType:   fallbackInterfaceType,
		fallbackDelay:           fallbackDelay,
	}, network, destination, destinationAddresses, preferIPv6, fallbackDelay)
}

type networkStrategyDialer struct {
	ParallelInterfaceDialer
	strategy              *C.NetworkStrategy
	interfaceType         []C.InterfaceType
	fallbackInterfaceType []C.InterfaceType
	fallbackDelay         time.Duration
}

func (d *networkStrategyDialer) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
	return d.DialParallelInterface(ctx, network, destination, d.strategy, d.interfaceType, d.fallbackInterfaceType, d.fallbackDelay)
}

func ListenSerialNetworkPacket(ctx context.Context, dialer N.Dialer, destination M.Socksaddr, destinationAddresses []netip.Addr, strategy *C.NetworkStrategy, interfaceType []C.InterfaceType, fallbackInterfaceType []C.InterfaceType, fallbackDelay time.Duration) (net.PacketConn, netip.Addr, error) {
	if len(destinationAddresses) == 0 {
		if !destination.IsIP() {
			panic("invalid usage")
		}
		destinationAddresses = []netip.Addr{destination.Addr}
	}
	if parallelDialer, isParallel := dialer.(ParallelNetworkDialer); isParallel {
		return parallelDialer.ListenSerialNetworkPacket(ctx, destination, destinationAddresses, strategy, interfaceType, fallbackInterfaceType, fallbackDelay)
	}
	var errors []error
	if parallelDialer, isParallel := dialer.(ParallelInterfaceDialer); isParallel {
		for _, address := range destinationAddresses {
			conn, err := parallelDialer.ListenSerialInterfacePacket(ctx, M.SocksaddrFrom(address, destination.Port), strategy, interfaceType, fallbackInterfaceType, fallbackDelay)
			if err == nil {
				return conn, address, nil
			}
			errors = append(errors, err)
		}
	} else {
		for _, address := range destinationAddresses {
			conn, err := dialer.ListenPacket(ctx, M.SocksaddrFrom(address, destination.Port))
			if err == nil {
				return conn, address, nil
			}
			errors = append(errors, err)
		}
	}
	return nil, netip.Addr{}, E.Errors(errors...)
}