Fix code quality issues and refactor password generation

app/src/main/java/cz/bugsy/passwordzebra/MainActivity.kt

@@ -7,7 +7,8 @@ import android.os.Bundle
 import android.widget.Button
 import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
-import kotlin.random.Random
+
+private const val KEY_PASSWORD = "password"
 
 class MainActivity : AppCompatActivity() {
 
@@ -37,8 +38,12 @@ class MainActivity : AppCompatActivity() {
             generatePassword()
         }
 
-        // Initially generate a password
+        // Restore password after rotation, otherwise generate a new one
-        generatePassword()
+        if (savedInstanceState != null) {
+            passwordTextView.text = savedInstanceState.getString(KEY_PASSWORD, "")
+        } else {
+            generatePassword()
+        }
 
         // Set click listener to copy password to clipboard
         passwordTextView.setOnClickListener {
@@ -46,98 +51,40 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        outState.putString(KEY_PASSWORD, passwordTextView.text.toString())
+    }
+
     private fun generatePassword() {
         val passwordLength = passwordLengthPicker.value
         val password = generateRandomWords(passwordLength)
-
         passwordTextView.text = password
     }
 
     private fun generateRandomWords(numWords: Int): String {
-        val syllables = arrayOf(
-            "ing","er","a","ly","ed","i","es","re","tion","in","e","con","y","ter","ex","al","de","com",
-            "o","di","en","an","ty","ry","u","ti","ri","be","per","to","pro","ac","ad","ar","ers","ment",
-            "or","tions","ble","der","ma","na","si","un","at","dis","ca","cal","man","ap","po","sion","vi",
-            "el","est","la","lar","pa","ture","for","is","mer","pe","ra","so","ta","as","col","fi","ful",
-            "ger","low","ni","par","son","tle","day","ny","pen","pre","tive","car","ci","mo","on","ous",
-            "pi","se","ten","tor","ver","ber","can","dy","et","it","mu","no","ple","cu","fac","fer","gen",
-            "ic","land","light","ob","of","pos","tain","den","ings","mag","ments","set","some","sub","sur",
-            "ters","tu","af","au","cy","fa","im","li","lo","men","min","mon","op","out","rec","ro","sen",
-            "side","tal","tic","ties","ward","age","ba","but","cit","cle","co","cov","da","dif","ence",
-            "ern","eve","hap","ies","ket","lec","main","mar","mis","my","nal","ness","ning","n't","nu","oc",
-            "pres","sup","te","ted","tem","tin","tri","tro","up","va","ven","vis","am","bor","by","cat",
-            "cent","ev","gan","gle","head","high","il","lu","me","nore","part","por","read","rep","su",
-            "tend","ther","ton","try","um","uer","way","ate","bet","bles","bod","cap","cial","cir","cor",
-            "coun","cus","dan","dle","ef","end","ent","ered","fin","form","go","har","ish","lands","let",
-            "long","mat","meas","mem","mul","ner","play","ples","ply","port","press","sat","sec","ser",
-            "south","sun","the","ting","tra","tures","val","var","vid","wil","win","won","work","act","ag",
-            "air","als","bat","bi","cate","cen","char","come","cul","ders","east","fect","fish","fix","gi",
-            "grand","great","heav","ho","hunt","ion","its","jo","lat","lead","lect","lent","less","lin",
-            "mal","mi","mil","moth","near","nel","net","new","one","point","prac","ral","rect","ried",
-            "round","row","sa","sand","self","sent","ship","sim","sions","sis","sons","stand","sug","tel",
-            "tom","tors","tract","tray","us","vel","west","where","writing","er","i","y","ter","al","ed",
-            "es","e","tion","re","o","oth","ry","de","ver","ex","en","di","bout","com","ple","u","con",
-            "per","un","der","tle","ber","ty","num","peo","ble","af","ers","mer","wa","ment","pro","ar",
-            "ma","ri","sen","ture","fer","dif","pa","tions","ther","fore","est","fa","la","ei","not","si",
-            "ent","ven","ev","ac","ca","fol","ful","na","tain","ning","col","par","dis","ern","ny","cit",
-            "po","cal","mu","moth","pic","im","coun","mon","pe","lar","por","fi","bers","sec","ap","stud",
-            "ad","tween","gan","bod","tence","ward","hap","nev","ure","mem","ters","cov","ger","nit"
-            // Add more syllables as needed
-        )
-
-        val random = Random.Default
-
         return buildString {
             repeat(numWords) {
-                append(generateRandomWord(syllables, random))
+                append(PasswordGenerator.generateRandomWord())
                 append(" ")  // Add space between words
             }
         }.let { password ->
             // Check if the switch for adding special characters is checked
             if (switchSpecialChars.isChecked) {
-                addSpecialCharacters(password)
+                PasswordGenerator.addSpecialCharacters(password)
             } else {
                 password
             }
         }.trim() // Remove trailing space
     }
 
-    private fun generateRandomWord(syllables: Array<String>, random: Random): String {
-        return buildString {
-            repeat(random.nextInt(2, 4)) {
-                append(syllables[random.nextInt(syllables.size)])
-            }
-        }
-    }
-
     private fun copyToClipboard(text: String, clipboardManager: ClipboardManager) {
-
+        val clipData = if (switchWithoutSpaces.isChecked) {
-        val clipData = if (switchWithoutSpaces.isChecked)
+            val textNoSpaces = text.filter { !it.isWhitespace() }
-        { val textNoSpaces = text.filter { !it.isWhitespace() }
+            ClipData.newPlainText("Password", textNoSpaces)
-        ClipData.newPlainText("Password", textNoSpaces)
         } else {
             ClipData.newPlainText("Password", text)
         }
         clipboardManager.setPrimaryClip(clipData)
     }
-
-    private fun addSpecialCharacters(password: String): String {
-        // Insert special character, uppercase character, and digit at random positions within the password
-        val specialChars = listOf('$', ',', '.', '#', '@', '!', '%', '&')
-        val random = Random.Default
-
-        val index = random.nextInt(0, password.length + 1)
-        val specialChar = specialChars[random.nextInt(specialChars.size)]
-
-        val uppercaseChar = ('A'..'Z').random() // Generate random uppercase character
-        val digit = random.nextInt(0, 10) // Generate random digit (number)
-
-        val newPassword = StringBuilder(password)
-        newPassword.insert(index, specialChar)
-        newPassword.insert(random.nextInt(0, newPassword.length + 1), uppercaseChar)
-        newPassword.insert(random.nextInt(0, newPassword.length + 1), digit.toString())
-
-        //return password.substring(0, index) + specialChar + password.substring(index)
-        return newPassword.toString()
-    }
 }

app/src/main/java/cz/bugsy/passwordzebra/PasswordGenerator.kt

@@ -0,0 +1,64 @@
+package cz.bugsy.passwordzebra
+
+import kotlin.random.Random
+
+internal object PasswordGenerator {
+
+    private val defaultRandom = Random.Default
+
+    private val syllables = arrayOf(
+        "ing","er","a","ly","ed","i","es","re","tion","in","e","con","y","ter","ex","al","de","com",
+        "o","di","en","an","ty","ry","u","ti","ri","be","per","to","pro","ac","ad","ar","ers","ment",
+        "or","tions","ble","der","ma","na","si","un","at","dis","ca","cal","man","ap","po","sion","vi",
+        "el","est","la","lar","pa","ture","for","is","mer","pe","ra","so","ta","as","col","fi","ful",
+        "ger","low","ni","par","son","tle","day","ny","pen","pre","tive","car","ci","mo","on","ous",
+        "pi","se","ten","tor","ver","ber","can","dy","et","it","mu","no","ple","cu","fac","fer","gen",
+        "ic","land","light","ob","of","pos","tain","den","ings","mag","ments","set","some","sub","sur",
+        "ters","tu","af","au","cy","fa","im","li","lo","men","min","mon","op","out","rec","ro","sen",
+        "side","tal","tic","ties","ward","age","ba","but","cit","cle","co","cov","da","dif","ence",
+        "ern","eve","hap","ies","ket","lec","main","mar","mis","my","nal","ness","ning","n't","nu","oc",
+        "pres","sup","te","ted","tem","tin","tri","tro","up","va","ven","vis","am","bor","by","cat",
+        "cent","ev","gan","gle","head","high","il","lu","me","nore","part","por","read","rep","su",
+        "tend","ther","ton","try","um","uer","way","ate","bet","bles","bod","cap","cial","cir","cor",
+        "coun","cus","dan","dle","ef","end","ent","ered","fin","form","go","har","ish","lands","let",
+        "long","mat","meas","mem","mul","ner","play","ples","ply","port","press","sat","sec","ser",
+        "south","sun","the","ting","tra","tures","val","var","vid","wil","win","won","work","act","ag",
+        "air","als","bat","bi","cate","cen","char","come","cul","ders","east","fect","fish","fix","gi",
+        "grand","great","heav","ho","hunt","ion","its","jo","lat","lead","lect","lent","less","lin",
+        "mal","mi","mil","moth","near","nel","net","new","one","point","prac","ral","rect","ried",
+        "round","row","sa","sand","self","sent","ship","sim","sions","sis","sons","stand","sug","tel",
+        "tom","tors","tract","tray","us","vel","west","where","writing","er","i","y","ter","al","ed",
+        "es","e","tion","re","o","oth","ry","de","ver","ex","en","di","bout","com","ple","u","con",
+        "per","un","der","tle","ber","ty","num","peo","ble","af","ers","mer","wa","ment","pro","ar",
+        "ma","ri","sen","ture","fer","dif","pa","tions","ther","fore","est","fa","la","ei","not","si",
+        "ent","ven","ev","ac","ca","fol","ful","na","tain","ning","col","par","dis","ern","ny","cit",
+        "po","cal","mu","moth","pic","im","coun","mon","pe","lar","por","fi","bers","sec","ap","stud",
+        "ad","tween","gan","bod","tence","ward","hap","nev","ure","mem","ters","cov","ger","nit"
+        // Add more syllables as needed
+    )
+
+    fun generateRandomWord(random: Random = defaultRandom): String {
+        return buildString {
+            repeat(random.nextInt(2, 4)) {
+                append(syllables[random.nextInt(syllables.size)])
+            }
+        }
+    }
+
+    fun addSpecialCharacters(password: String, random: Random = defaultRandom): String {
+        // Insert special character, uppercase character, and digit at random positions within the password
+        val specialChars = listOf('$', ',', '.', '#', '@', '!', '%', '&')
+
+        val index = random.nextInt(0, password.length + 1)
+        val specialChar = specialChars[random.nextInt(specialChars.size)]
+        val uppercaseChar = ('A'..'Z').random(random)
+        val digit = random.nextInt(0, 10)
+
+        val newPassword = StringBuilder(password)
+        newPassword.insert(index, specialChar)
+        newPassword.insert(random.nextInt(0, newPassword.length + 1), uppercaseChar)
+        newPassword.insert(random.nextInt(0, newPassword.length + 1), digit.toString())
+
+        return newPassword.toString()
+    }
+}

app/src/main/java/cz/bugsy/passwordzebra/PasswordZebra.kt

@@ -2,11 +2,16 @@ package cz.bugsy.passwordzebra
 
 import android.app.Application
 import com.google.android.material.color.DynamicColors
+import com.google.android.material.color.DynamicColorsOptions
 
 class PasswordZebra : Application() {
     override fun onCreate() {
         // Apply dynamic color
-        //DynamicColors.applyToActivitiesIfAvailable(this)
+        DynamicColors.applyToActivitiesIfAvailable(
-        DynamicColors.applyToActivitiesIfAvailable(this, R.style.AppTheme_Overlay)
+            this,
+            DynamicColorsOptions.Builder()
+                .setThemeOverlay(R.style.AppTheme_Overlay)
+                .build()
+        )
     }
 }

app/src/main/res/layout-land/activity_main.xml

@@ -4,8 +4,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity"
-    tools:layout_editor_absoluteX="0dp"
+>
-    tools:layout_editor_absoluteY="2dp">
 
     <TextView
         android:id="@+id/passwordTextView"

app/src/main/res/layout/activity_main.xml

@@ -4,8 +4,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity"
-    tools:layout_editor_absoluteX="0dp"
+>
-    tools:layout_editor_absoluteY="2dp">
 
     <TextView
         android:id="@+id/passwordTextView"
@@ -156,7 +155,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="vertical"
-        app:layout_constraintGuide_begin="364dp" />
+        app:layout_constraintGuide_percent="0.92" />
 
 
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values-night/themes.xml

@@ -15,7 +15,7 @@
 
         <!-- navigation bar = bottom bar with navigation buttons -->
         <item name="android:navigationBarColor">@android:color/transparent</item>
-        <item name="android:windowLightNavigationBar">true</item>
+        <item name="android:windowLightNavigationBar">false</item>
         <item name="android:windowTranslucentNavigation">false</item>
 
         <item name="colorPrimary">@color/md_theme_dark_primary</item>
@@ -34,7 +34,7 @@
         <item name="colorErrorContainer">@color/md_theme_dark_errorContainer</item>
         <item name="colorOnError">@color/md_theme_dark_onError</item>
         <item name="colorOnErrorContainer">@color/md_theme_dark_onErrorContainer</item>
-        <item name="android:colorBackground">@color/md_theme_dark_onBackground</item>
+        <item name="android:colorBackground">@color/md_theme_dark_background</item>
         <item name="colorSurface">@color/md_theme_dark_surface</item>
         <item name="colorOnSurface">@color/md_theme_dark_onSurface</item>
         <item name="colorSurfaceVariant">@color/md_theme_dark_surfaceVariant</item>

app/src/test/java/cz/bugsy/passwordzebra/PasswordGenerationTest.kt

@@ -0,0 +1,86 @@
+package cz.bugsy.passwordzebra
+
+import org.junit.Assert.*
+import org.junit.Test
+import kotlin.random.Random
+
+class PasswordGenerationTest {
+
+    // generateRandomWord tests
+
+    @Test
+    fun generateRandomWord_returnsNonEmptyString() {
+        val word = PasswordGenerator.generateRandomWord()
+        assertTrue(word.isNotEmpty())
+    }
+
+    @Test
+    fun generateRandomWord_consistsOnlyOfLowercaseLettersOrApostrophe() {
+        repeat(20) {
+            val word = PasswordGenerator.generateRandomWord()
+            assertTrue("Word '$word' contains unexpected characters",
+                word.all { it.isLowerCase() || it == '\'' })
+        }
+    }
+
+    @Test
+    fun generateRandomWord_withSameSeed_returnsSameResult() {
+        val word1 = PasswordGenerator.generateRandomWord(Random(42))
+        val word2 = PasswordGenerator.generateRandomWord(Random(42))
+        assertEquals(word1, word2)
+    }
+
+    @Test
+    fun generateRandomWord_withDifferentSeeds_canReturnDifferentResults() {
+        val words = (1..10).map { PasswordGenerator.generateRandomWord(Random(it.toLong())) }.toSet()
+        assertTrue("Expected multiple distinct words, got: $words", words.size > 1)
+    }
+
+    // addSpecialCharacters tests
+
+    @Test
+    fun addSpecialCharacters_addsExactlyThreeCharacters() {
+        val password = "hello world"
+        val result = PasswordGenerator.addSpecialCharacters(password)
+        assertEquals(password.length + 3, result.length)
+    }
+
+    @Test
+    fun addSpecialCharacters_containsAtLeastOneDigit() {
+        val password = "hello world"
+        val result = PasswordGenerator.addSpecialCharacters(password)
+        assertTrue("Expected a digit in '$result'", result.any { it.isDigit() })
+    }
+
+    @Test
+    fun addSpecialCharacters_containsAtLeastOneUppercaseLetter() {
+        val password = "hello world"
+        val result = PasswordGenerator.addSpecialCharacters(password)
+        assertTrue("Expected an uppercase letter in '$result'", result.any { it.isUpperCase() })
+    }
+
+    @Test
+    fun addSpecialCharacters_containsAtLeastOneSpecialCharacter() {
+        val specialChars = setOf('$', ',', '.', '#', '@', '!', '%', '&')
+        val password = "hello world"
+        val result = PasswordGenerator.addSpecialCharacters(password)
+        assertTrue("Expected a special character in '$result'", result.any { it in specialChars })
+    }
+
+    @Test
+    fun addSpecialCharacters_preservesOriginalCharsAsSubsequence() {
+        val password = "helloworld"
+        val result = PasswordGenerator.addSpecialCharacters(password)
+        var i = 0
+        result.forEach { c -> if (i < password.length && c == password[i]) i++ }
+        assertEquals("Original chars should remain as subsequence in '$result'", password.length, i)
+    }
+
+    @Test
+    fun addSpecialCharacters_withSameSeed_returnsSameResult() {
+        val password = "testpassword"
+        val result1 = PasswordGenerator.addSpecialCharacters(password, Random(99))
+        val result2 = PasswordGenerator.addSpecialCharacters(password, Random(99))
+        assertEquals(result1, result2)
+    }
+}