package route

import (
	"github.com/sagernet/sing-box/adapter"
	C "github.com/sagernet/sing-box/constant"
	"github.com/sagernet/sing-box/log"
	"github.com/sagernet/sing-box/option"
	tun "github.com/sagernet/sing-tun"
	"github.com/sagernet/sing/common"
	E "github.com/sagernet/sing/common/exceptions"
)

func NewIPRule(router adapter.Router, logger log.ContextLogger, options option.IPRule) (adapter.IPRule, error) {
	switch options.Type {
	case "", C.RuleTypeDefault:
		if !options.DefaultOptions.IsValid() {
			return nil, E.New("missing conditions")
		}
		if common.IsEmpty(options.DefaultOptions.Action) {
			return nil, E.New("missing action")
		}
		return NewDefaultIPRule(router, logger, options.DefaultOptions)
	case C.RuleTypeLogical:
		if !options.LogicalOptions.IsValid() {
			return nil, E.New("missing conditions")
		}
		if common.IsEmpty(options.DefaultOptions.Action) {
			return nil, E.New("missing action")
		}
		return NewLogicalIPRule(router, logger, options.LogicalOptions)
	default:
		return nil, E.New("unknown rule type: ", options.Type)
	}
}

var _ adapter.IPRule = (*DefaultIPRule)(nil)

type DefaultIPRule struct {
	abstractDefaultRule
	action tun.ActionType
}

func NewDefaultIPRule(router adapter.Router, logger log.ContextLogger, options option.DefaultIPRule) (*DefaultIPRule, error) {
	rule := &DefaultIPRule{
		abstractDefaultRule: abstractDefaultRule{
			invert:   options.Invert,
			outbound: options.Outbound,
		},
		action: tun.ActionType(options.Action),
	}
	if len(options.Inbound) > 0 {
		item := NewInboundRule(options.Inbound)
		rule.items = append(rule.items, item)
		rule.allItems = append(rule.allItems, item)
	}
	if options.IPVersion > 0 {
		switch options.IPVersion {
		case 4, 6:
			item := NewIPVersionItem(options.IPVersion == 6)
			rule.items = append(rule.items, item)
			rule.allItems = append(rule.allItems, item)
		default:
			return nil, E.New("invalid ip version: ", options.IPVersion)
		}
	}
	if len(options.Network) > 0 {
		item := NewNetworkItem(options.Network)
		rule.items = append(rule.items, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.Domain) > 0 || len(options.DomainSuffix) > 0 {
		item := NewDomainItem(options.Domain, options.DomainSuffix)
		rule.destinationAddressItems = append(rule.destinationAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.DomainKeyword) > 0 {
		item := NewDomainKeywordItem(options.DomainKeyword)
		rule.destinationAddressItems = append(rule.destinationAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.DomainRegex) > 0 {
		item, err := NewDomainRegexItem(options.DomainRegex)
		if err != nil {
			return nil, E.Cause(err, "domain_regex")
		}
		rule.destinationAddressItems = append(rule.destinationAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.Geosite) > 0 {
		item := NewGeositeItem(router, logger, options.Geosite)
		rule.destinationAddressItems = append(rule.destinationAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.SourceGeoIP) > 0 {
		item := NewGeoIPItem(router, logger, true, options.SourceGeoIP)
		rule.sourceAddressItems = append(rule.sourceAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.SourceIPCIDR) > 0 {
		item, err := NewIPCIDRItem(true, options.SourceIPCIDR)
		if err != nil {
			return nil, E.Cause(err, "source_ipcidr")
		}
		rule.sourceAddressItems = append(rule.sourceAddressItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.SourcePort) > 0 {
		item := NewPortItem(true, options.SourcePort)
		rule.sourcePortItems = append(rule.sourcePortItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.SourcePortRange) > 0 {
		item, err := NewPortRangeItem(true, options.SourcePortRange)
		if err != nil {
			return nil, E.Cause(err, "source_port_range")
		}
		rule.sourcePortItems = append(rule.sourcePortItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.Port) > 0 {
		item := NewPortItem(false, options.Port)
		rule.destinationPortItems = append(rule.destinationPortItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	if len(options.PortRange) > 0 {
		item, err := NewPortRangeItem(false, options.PortRange)
		if err != nil {
			return nil, E.Cause(err, "port_range")
		}
		rule.destinationPortItems = append(rule.destinationPortItems, item)
		rule.allItems = append(rule.allItems, item)
	}
	return rule, nil
}

func (r *DefaultIPRule) Action() tun.ActionType {
	return r.action
}

var _ adapter.IPRule = (*LogicalIPRule)(nil)

type LogicalIPRule struct {
	abstractLogicalRule
	action tun.ActionType
}

func NewLogicalIPRule(router adapter.Router, logger log.ContextLogger, options option.LogicalIPRule) (*LogicalIPRule, error) {
	r := &LogicalIPRule{
		abstractLogicalRule: abstractLogicalRule{
			rules:    make([]adapter.Rule, len(options.Rules)),
			invert:   options.Invert,
			outbound: options.Outbound,
		},
		action: tun.ActionType(options.Action),
	}
	switch options.Mode {
	case C.LogicalTypeAnd:
		r.mode = C.LogicalTypeAnd
	case C.LogicalTypeOr:
		r.mode = C.LogicalTypeOr
	default:
		return nil, E.New("unknown logical mode: ", options.Mode)
	}
	for i, subRule := range options.Rules {
		rule, err := NewDefaultIPRule(router, logger, subRule)
		if err != nil {
			return nil, E.Cause(err, "sub rule[", i, "]")
		}
		r.rules[i] = rule
	}
	return r, nil
}

func (r *LogicalIPRule) Action() tun.ActionType {
	return r.action
}