Files
doormanserver/doormen/doormen.go
T

139 lines
3.6 KiB
Go

package doormen
import (
"encoding/json"
"errors"
"fmt"
"gopkg.in/mgo.v2/bson"
"math/big"
"strconv"
"time"
"github.com/didiercrunch/doorman/shared"
)
type DoormanValue struct {
Name string `json:"name"`
Probability *big.Rat `json:"probability"`
}
type DoormanId struct {
Id bson.ObjectId `json:"id,omitempty" bson:"_id"`
Name string `json:"name" bson:"name"`
}
func (wId *DoormanId) AsJson() string {
if wId.Id == "" {
return `{}`
}
return fmt.Sprintf(`{"%v":"%v"}`, wId.Id.Hex(), wId.Name)
}
type DoormanDefinition struct {
Id bson.ObjectId `bson:"_id"`
Name string `bson:"name"`
Values []*DoormanValue `bson:"values"`
OwnerEmails []string `bson:"emails"`
}
func NewDoormanDefinition(name string, ownerEmails ...string) *DoormanDefinition {
return &DoormanDefinition{Id: bson.NewObjectId(), Name: name, OwnerEmails: ownerEmails}
}
// a way to quickly create doormen in tests. do not use in real code. will
// panic if a doorman is wrongly specify
func QuickNewDoormanDefinition(name string, probs ...string) *DoormanDefinition {
ret := NewDoormanDefinition(name, "natasha@bigtits.com")
for i, prob := range probs {
r := new(big.Rat)
_, err := fmt.Sscan(prob, r)
if err != nil {
panic(err)
}
ret.Values = append(ret.Values, &DoormanValue{"T" + strconv.Itoa(i), r})
}
if err := ret.Validate("natasha@bigtits.com"); err != nil {
panic(err)
}
return ret
}
func (dmd *DoormanDefinition) ValidateDoormanValueNames() error {
m := make(map[string]bool)
for _, w := range dmd.Values {
if name := w.Name; name == "" {
return errors.New("doorman value cannot be empty")
} else {
m[name] = true
}
}
if len(m) != len(dmd.Values) {
return errors.New("doorman value names must be unique within a doorman")
}
return nil
}
func (dmd *DoormanDefinition) AsWriteAccess(email string) bool {
for _, email_ := range dmd.OwnerEmails {
if email_ == email {
return true
}
}
return false
}
func (dmd *DoormanDefinition) ValidateDoormanValueProbabilities() error {
sum, zero, one := big.NewRat(0, 1), big.NewRat(0, 1), big.NewRat(1, 1)
for _, w := range dmd.Values {
if p := w.Probability; p.Cmp(zero) < 0 || p.Cmp(one) > 0 {
return errors.New(fmt.Sprintf("doorman value %v is out of range", p))
} else {
sum = new(big.Rat).Add(sum, p)
}
}
if sum.Cmp(one) != 0 {
return errors.New("the sum of the probability must be 1")
}
return nil
}
func (dmd *DoormanDefinition) Validate(author string) (err error) {
switch {
case dmd.Name == "":
err = errors.New("name cannot be empty")
case len(dmd.Values) < 2:
err = errors.New("need at least 2 values")
case dmd.ValidateDoormanValueNames() != nil:
err = dmd.ValidateDoormanValueNames()
case dmd.ValidateDoormanValueProbabilities() != nil:
err = dmd.ValidateDoormanValueProbabilities()
case len(dmd.OwnerEmails) < 1:
err = errors.New("A doorman needs at least one owner specify as 'email'.")
case !dmd.AsWriteAccess(author):
err = errors.New(fmt.Sprintf("'%s' is not allow to edit this doorman.", author))
}
return
}
func (dmd *DoormanDefinition) CanBeUpdatedBy(dmd2 *DoormanDefinition) error {
if dmd.Name != dmd2.Name {
return errors.New("cannot change doorman name")
}
if len(dmd.Values) != len(dmd2.Values) {
return errors.New("cannot change the number of cases in doorman")
}
return nil
}
func (dmd *DoormanDefinition) AsDoormanUpdatePayload() ([]byte, error) {
wu := &shared.DoormanUpdater{Id: dmd.Id.Hex()}
wu.Timestamp = time.Now().Unix()
wu.Probabilities = make([]*big.Rat, len(dmd.Values))
for i, value := range dmd.Values {
wu.Probabilities[i] = value.Probability
}
return json.Marshal(wu)
}