3 files changed, 108 insertions, 78 deletions

diff --git a/src/index.html b/src/index.html
index cb7a781..feefbd8 100644
--- a/src/index.html
+++ b/src/index.html
@@ -95,17 +95,57 @@
                             </div>
                         </div>
                         <div class="entropy-container hidden">
-                            <label for="entropy" class="col-sm-2 control-label">Entropy</label>
-                            <div class="col-sm-10">
-                                <input id="entropy" class="entropy form-control" placeholder="Accepts binary, base 6, 6-sided dice, base 10, hexadecimal">
-                                <span class="help-block">
-                                    <div class="text-danger">
-                                    This is an advanced feature.
-                                    Your mnemonic may be insecure if this feature is used incorrectly.
-                                    <a href="#entropy-notes">Read more</a>
+                            <div class="form-group">
+                                <label for="entropy" class="col-sm-2 control-label">Entropy</label>
+                                <div class="col-sm-10">
+                                    <input id="entropy" class="entropy form-control" placeholder="Accepts binary, base 6, 6-sided dice, base 10, hexadecimal">
+                                    <span class="help-block">
+                                        <div class="text-danger">
+                                        This is an advanced feature.
+                                        Your mnemonic may be insecure if this feature is used incorrectly.
+                                        <a href="#entropy-notes">Read more</a>
+                                        </div>
+                                   </span>
+                                </div>
+                            </div>
+                            <div class="entropy-feedback">
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Filtered</label>
+                                    <div class="filtered col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Type</label>
+                                    <div class="type col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Strength</label>
+                                    <div class="strength col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Event Count</label>
+                                    <div class="event-count col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Bits Per Event</label>
+                                    <div class="bits-per-event col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Bits</label>
+                                    <div class="bits col-sm-10 form-control-static"></div>
+                                </div>
+                                <div class="form-group">
+                                    <label class="col-sm-2 control-label">Mnemonic Length</label>
+                                    <div class="col-sm-10">
+                                        <select class="mnemonic-length form-control">
+                                            <option value="raw">From entropy length</option>
+                                            <option value="12">12 Words</option>
+                                            <option value="15">15 Words</option>
+                                            <option value="18">18 Words</option>
+                                            <option value="21">21 Words</option>
+                                            <option value="24">24 Words</option>
+                                        </select>
                                     </div>
-                                    <div class="text-danger entropy-error"></div>
-                               </span>
+                                </div>
                             </div>
                         </div>
                         <div class="form-group">
diff --git a/src/js/entropy.js b/src/js/entropy.js
index db4051b..cd9b375 100644
--- a/src/js/entropy.js
+++ b/src/js/entropy.js
@@ -96,40 +96,6 @@ window.Entropy = new (function() {
                 base: base,
             };
         }
-        // Pull leading zeros off
-        var leadingZeros = [];
-        while (base.ints[0] == "0") {
-            leadingZeros.push("0");
-            base.ints.shift();
-        }
-        // Convert leading zeros to binary equivalent
-        var numBinLeadingZeros = Math.floor(Math.log2(base.asInt) * leadingZeros.length);
-        var binLeadingZeros = "";
-        for (var i=0; i<numBinLeadingZeros; i++) {
-            binLeadingZeros += "0";
-        }
-        // Handle entropy of zero
-        if (base.ints.length == 0) {
-            return {
-                binaryStr: binLeadingZeros,
-                cleanStr: leadingZeros.join(""),
-                base: base,
-            }
-        }
-        // If the first integer is small, it must be padded with zeros.
-        // Otherwise the chance of the first bit being 1 is 100%, which is
-        // obviously incorrect.
-        // This is not perfect for unusual bases, so is only done for bases
-        // of 2^n, eg octal or hexadecimal
-        if (base.asInt == 16) {
-            var firstInt = base.ints[0];
-            var firstIntBits = firstInt.toString(2).length;
-            var maxFirstIntBits = (base.asInt-1).toString(2).length;
-            var missingFirstIntBits = maxFirstIntBits - firstIntBits;
-            for (var i=0; i<missingFirstIntBits; i++) {
-                binLeadingZeros += "0";
-            }
-        }
         // Convert base.ints to BigInteger.
         // Due to using unusual bases, eg cards of base52, this is not as simple as
         // using BigInteger.parse()
@@ -140,8 +106,17 @@ window.Entropy = new (function() {
             var additionalEntropy = BigInteger.parse(base.asInt).pow(power).multiply(thisInt);
             entropyInt = entropyInt.add(additionalEntropy);
         }
-        // Convert entropy to different formats
-        var entropyBin = binLeadingZeros + entropyInt.toString(2);
+        // Convert entropy to binary
+        var entropyBin = entropyInt.toString(2);
+        // If the first integer is small, it must be padded with zeros.
+        // Otherwise the chance of the first bit being 1 is 100%, which is
+        // obviously incorrect.
+        // This is not perfect for non-2^n bases.
+        var expectedBits = Math.floor(base.parts.length * Math.log2(base.asInt));
+        while (entropyBin.length < expectedBits) {
+            entropyBin = "0" + entropyBin;
+        }
+        // Supply a 'filtered' entropy string for display purposes
         var entropyClean = base.parts.join("");
         if (base.asInt == 52) {
             entropyClean = base.parts.join(" ").toUpperCase();
diff --git a/src/js/index.js b/src/js/index.js
index 45db7b1..45f378d 100644
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -24,7 +24,14 @@
     DOM.useEntropy = $(".use-entropy");
     DOM.entropyContainer = $(".entropy-container");
     DOM.entropy = $(".entropy");
-    DOM.entropyError = $(".entropy-error");
+    DOM.entropyFeedback = $(".entropy-feedback");
+    DOM.entropyFiltered = DOM.entropyFeedback.find(".filtered");
+    DOM.entropyType = DOM.entropyFeedback.find(".type");
+    DOM.entropyStrength = DOM.entropyFeedback.find(".strength");
+    DOM.entropyEventCount = DOM.entropyFeedback.find(".event-count");
+    DOM.entropyBits = DOM.entropyFeedback.find(".bits");
+    DOM.entropyBitsPerEvent = DOM.entropyFeedback.find(".bits-per-event");
+    DOM.entropyMnemonicLength = DOM.entropyFeedback.find(".mnemonic-length");
     DOM.phrase = $(".phrase");
     DOM.passphrase = $(".passphrase");
     DOM.generateContainer = $(".generate-container");
@@ -153,7 +160,7 @@
         // If blank entropy, clear mnemonic, addresses, errors
         if (DOM.entropy.val().trim().length == 0) {
             clearDisplay();
-            hideEntropyError();
+            hideEntropyFeedback();
             DOM.phrase.val("");
             showValidationError("Blank entropy");
             return;
@@ -727,7 +734,7 @@
     }
 
     function setMnemonicFromEntropy() {
-        hideEntropyError();
+        hideEntropyFeedback();
         // Get entropy value
         var entropyStr = DOM.entropy.val();
         // Work out minimum base for entropy
@@ -736,30 +743,7 @@
             return;
         }
         // Show entropy details
-        var extraBits = 32 - (entropy.binaryStr.length % 32);
-        var extraChars = Math.ceil(extraBits * Math.log(2) / Math.log(entropy.base.asInt));
-        var words = Math.floor(entropy.binaryStr.length / 32) * 3;
-        var strength = "an extremely weak";
-        if (words >= 3) {
-            strength = "a very weak";
-        }
-        if (words >= 6) {
-            strength = "a weak";
-        }
-        if (words >= 9) {
-            strength = "a strong";
-        }
-        if (words >= 12) {
-            strength = "a very strong";
-        }
-        if (words >= 15) {
-            strength = "an extremely strong";
-        }
-        if (words >= 18) {
-            strength = "an even stronger"
-        }
-        var msg = "Have " + entropy.binaryStr.length + " bits of entropy, " + extraChars + " more " + entropy.base.str + " chars required to generate " + strength + " mnemonic: " + entropy.cleanStr;
-        showEntropyError(msg);
+        showEntropyFeedback(entropy);
         // Discard trailing entropy
         var bitsToUse = Math.floor(entropy.binaryStr.length / 32) * 32;
         var binaryStr = entropy.binaryStr.substring(0, bitsToUse);
@@ -776,13 +760,44 @@
         DOM.phrase.val(phrase);
     }
 
-    function hideEntropyError() {
-        DOM.entropyError.addClass("hidden");
+    function hideEntropyFeedback() {
+        DOM.entropyFeedback.addClass("hidden");
+        DOM.entropyFiltered.text("");
+        DOM.entropyType.text("");
+        DOM.entropyStrength.text("");
+        DOM.entropyEventCount.text("");
+        DOM.entropyBits.text("");
+        DOM.entropyBitsPerEvent.text("");
     }
 
-    function showEntropyError(msg) {
-        DOM.entropyError.text(msg);
-        DOM.entropyError.removeClass("hidden");
+    function showEntropyFeedback(entropy) {
+        var strength = "extremely weak";
+        if (entropy.binaryStr.length >= 64) {
+            strength = "very weak";
+        }
+        if (entropy.binaryStr.length >= 96) {
+            strength = "weak";
+        }
+        if (entropy.binaryStr.length >= 128) {
+            strength = "strong";
+        }
+        if (entropy.binaryStr.length >= 160) {
+            strength = "very strong";
+        }
+        if (entropy.binaryStr.length >= 192) {
+            strength = "extremely strong";
+        }
+        var bitsStr = entropy.binaryStr.length;
+        if (entropy.base.asInt != 2) {
+            bitsStr += " (" + entropy.binaryStr + ")";
+        }
+        DOM.entropyFiltered.text(entropy.cleanStr);
+        DOM.entropyType.text(entropy.base.str);
+        DOM.entropyStrength.text(strength);
+        DOM.entropyEventCount.text(entropy.base.ints.length);
+        DOM.entropyBits.text(bitsStr);
+        DOM.entropyBitsPerEvent.text(Math.log2(entropy.base.asInt).toFixed(2));
+        DOM.entropyFeedback.removeClass("hidden");
     }
 
     var networks = [