package cvss

import (
  // "encoding/json"
  "regexp"
  "strings"
)

// CVSS 2.0 vector.
type v2Vector []v2Metric

// Convert vector to string.
func (v v2Vector) String() string {
  // convert to slice of metrics
  metrics := []v2Metric(v)

  // build vector
  r := make([]string, len(metrics))
  for i, m := range(metrics) {
    r[i] = m.String()
  }

  // build and return string
  return strings.Join(r, "/")
}

// Return CVSS version.
func (v2Vector) Version() Version {
  return V20
}

// Return metrics in this vector.
func (v v2Vector) Metrics() []Metric {
  // build result
  r := make([]Metric, len(v))
  for i, m := range(v) {
    r[i] = m
  }

  // return result
  return r
}

// Return numerical scores for this vector.
func (v v2Vector) Scores() (v2Scores, error) {
  return newV2Scores(v)
}

// Create CVSS 2.0 vector from string.
func newV2Vector(s string) (v2Vector, error) {
  strs := strings.Split(s, "/")
  r := make([]v2Metric, len(strs))

  // walk metric strings
  for i, ms := range(strs) {
    // convert string to vector
    m, err := getV2Metric(ms)
    if err != nil {
      return nil, err
    }

    // add to results
    r[i] = m
  }

  // build and return vector
  return v2Vector(r), nil
}

// // Unmarshal CVSS 2.0 vector from JSON string.
// func (me *v2Vector) UnmarshalJSON(b []byte) error {
//   // decode string, check for error
//   var s string
//   if err := json.Unmarshal(b, &s); err != nil {
//     return err
//   }
// 
//   // parse vector, check for error
//   r, err := newV2Vector(s)
//   if err != nil {
//     // return error
//     return err
//   }
// 
//   // save result, return success
//   *me = r
//   return nil
// }

var v2MetricRe = "(?:" + strings.Join([]string {
  "(?:AV:[NAL])",
  "(?:AC:[LMH])",
  "(?:Au:[MSN])",
  "(?:C:[NPC])",
  "(?:I:[NPC])",
  "(?:A:[NPC])",
  "(?:E:(?:ND|U|POC|F|H))",
  "(?:RL:(?:OF|TF|W|U|ND))",
  "(?:RC:(?:UC|UR|C|ND))",
  "(?:CDP:(?:N|L|LM|MH|H|ND))",
  "(?:TD:(?:N|L|M|H|ND))",
  "(?:CR:(?:L|M|H|ND))",
  "(?:IR:(?:L|M|H|ND))",
}, "|") + ")"

var v2VecRe = regexp.MustCompile(
  "\\A" + v2MetricRe + "(?:/" + v2MetricRe + ")*\\z",
)

// Is the given string a CVSS v2 vector string?
func isV2VectorString(s string) bool {
  return len(s) > 0 && v2VecRe.MatchString(s)
}