govote/voting/quorum/quorum.go

package quorum

import (
	"fmt"
	"strings"
)

type Quorum uint8

const (
  Simple Quorum = iota
  OneFifth
  OneQuarter
  OneThird
  OneHalf
  TwoFifths
  TwoThirds
  ThreeQuarters
  ThreeFifths
  FourFifths
  Unanimous
)

func ValidQuorums() []Quorum {
  return []Quorum{
    Simple,
    OneFifth, OneQuarter, OneThird, OneHalf,
    TwoThirds, TwoFifths,
    ThreeQuarters, ThreeFifths,
    FourFifths,
  }
}

func FromString(s string) (Quorum, error) {
  for _, q := range ValidQuorums() {
    if strings.ToUpper(q.String()) == strings.ToUpper(s) {
      return q, nil
    } 
  }
  return Simple, fmt.Errorf("inalid quorum: %s", s)
}

func (q Quorum) String() string {
  switch q {
  case Simple:
    return "SIMPLE"
  case OneFifth:
    return "1/5"
  case OneQuarter:
    return "1/4"
  case OneThird:
    return "1/3"
  case OneHalf:
    return "1/2"
  case TwoThirds:
    return "2/3"
  case TwoFifths:
    return "2/5"
  case ThreeQuarters:
    return "3/4"
  case ThreeFifths:
    return "3/5"
  case FourFifths:
    return "4/5"
  case Unanimous:
    return "ALL"
  default:
    panic("this code should never be reached")
  }
}

func (q Quorum) IsSatisfied(possibleVotes, totalVotes int) bool {
  if totalVotes == 0 {
    return false
  }
  switch q {
  case Simple:
    return true
  case OneFifth:
    return totalVotes * 5 >= possibleVotes
  case OneQuarter:
    return totalVotes * 4 >= possibleVotes
  case OneThird:
    return totalVotes * 3 >= possibleVotes
  case OneHalf:
    return totalVotes * 2 >= possibleVotes
  case TwoThirds:
    return totalVotes * 3 >= possibleVotes * 2
  case TwoFifths:
    return totalVotes * 5 >= possibleVotes * 2
  case ThreeQuarters:
    return totalVotes * 4 >= possibleVotes * 3
  case ThreeFifths:
    return totalVotes * 5 >= possibleVotes * 3
  case FourFifths:
    return totalVotes * 5 >= possibleVotes * 4
  case Unanimous:
    return totalVotes >= possibleVotes
  default:
    panic("this code should never be reached⚜️")
  }
  return false
}