package ldap

import (
	goldap "github.com/go-ldap/ldap/v3"
	ber "github.com/nmcclain/asn1-ber"
	"github.com/nmcclain/ldap"
	"goauthentik.io/api"
)

func parseFilterForUser(req api.ApiCoreUsersListRequest, f *ber.Packet, skip bool) (api.ApiCoreUsersListRequest, bool) {
	switch f.Tag {
	case ldap.FilterEqualityMatch:
		return parseFilterForUserSingle(req, f)
	case ldap.FilterAnd:
		for _, child := range f.Children {
			r, s := parseFilterForUser(req, child, skip)
			skip = skip || s
			req = r
		}
		return req, skip
	}
	return req, skip
}

func parseFilterForUserSingle(req api.ApiCoreUsersListRequest, f *ber.Packet) (api.ApiCoreUsersListRequest, bool) {
	// We can only handle key = value pairs here
	if len(f.Children) < 2 {
		return req, false
	}
	k := f.Children[0].Value
	// Ensure key is string
	if _, ok := k.(string); !ok {
		return req, false
	}
	v := f.Children[1].Value
	// Null values are ignored
	if v == nil {
		return req, false
	}
	// Switch on type of the value, then check the key
	switch vv := v.(type) {
	case string:
		switch k {
		case "cn":
			return req.Username(vv), false
		case "name":
		case "displayName":
			return req.Name(vv), false
		case "mail":
			return req.Email(vv), false
		case "member":
			fallthrough
		case "memberOf":
			groupDN, err := goldap.ParseDN(vv)
			if err != nil {
				return req.GroupsByName([]string{vv}), false
			}
			name := groupDN.RDNs[0].Attributes[0].Value
			// If the DN's first ou is virtual-groups, ignore this filter
			if len(groupDN.RDNs) > 1 {
				if groupDN.RDNs[1].Attributes[0].Value == UsersOU || groupDN.RDNs[1].Attributes[0].Value == VirtualGroupsOU {
					// Since we know we're not filtering anything, skip this request
					return req, true
				}
			}
			return req.GroupsByName([]string{name}), false
		}
	// TODO: Support int
	default:
		return req, false
	}
	return req, false
}