args... still needs charset minimums (how?)

pwgenerator/funcs_genopts.go

@@ -2,12 +2,86 @@ package pwgenerator
 
 import (
 	"strings"
+
+	"r00t2.io/goutils/multierr"
 )
 
 // Generate generates a list of passwords for a GenOpts.
 func (o *GenOpts) Generate() (passwords []string, err error) {
 
-	// TODO
+	var passwds []string = make([]string, o.Count)
+	var charset CharSet = o.Chars()
+	var errs *multierr.MultiError = multierr.NewMultiError(nil)
+
+	if o.Count == 0 {
+		o.Count = DefCount
+	}
+	if o.LengthMax == 0 {
+		o.LengthMax = DefMaxLen
+	}
+
+	for idx, _ := range passwds {
+		if passwds[idx], err = o.generatePassword(charset); err != nil {
+			errs.AddError(err)
+			err = nil
+		}
+	}
+
+	passwords = passwds
+
+	if !errs.IsEmpty() {
+		err = errs
+	}
+
+	return
+}
+
+// generatePassword generates a single password from CharSet c.
+func (o *GenOpts) generatePassword(c CharSet) (password string, err error) {
+
+	var maxMin uint
+	var trueMinLen uint
+	var passLenGap uint
+	var passLen int
+	var passAlloc []rune
+
+	// Sanity checks/error conditions.
+	maxMin = o.CountUpper + o.CountLower + o.CountSymbols + o.CountExtended
+	if maxMin > o.LengthMax {
+		err = ErrTooSmall
+		return
+	}
+	if o.LengthMin > o.LengthMax {
+		err = ErrSwitchedLenLimits
+		return
+	}
+
+	// Defaults.
+	trueMinLen = o.LengthMin
+	if trueMinLen == 0 {
+		trueMinLen = DefMinLin
+	}
+
+	// Get a fixed password length...
+	passLenGap = o.LengthMax - trueMinLen
+	if passLen, err = saferRandInt(int(passLenGap)); err != nil {
+		return
+	}
+	passLen = passLen + int(trueMinLen) // (We need to re-add; it was subtracted above to get a zero-shifted number for start in saferRandInt.)
+	// And make the rune slice of that length.
+	passAlloc = make([]rune, passLen)
+
+	for _, idx := range passAlloc {
+		var char Char
+
+		if char, err = c.RandChar(); err != nil {
+			return
+		}
+
+		passAlloc[idx] = rune(char)
+	}
+
+	password = string(passAlloc)
 
 	return
 }
@@ -35,6 +109,8 @@ func (o *GenOpts) Chars() (chars CharSet) {
 		chars = append(chars, extendedSymbols...)
 	}
 
+	// TODO: Count* fields
+
 	return
 }