feat: import settings on login page

app/src/main/java/ani/dantotsu/home/LoginFragment.kt

@@ -1,14 +1,25 @@
 package ani.dantotsu.home
 
+import android.app.AlertDialog
+import android.content.Intent
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.TextView
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.documentfile.provider.DocumentFile
 import androidx.fragment.app.Fragment
 import ani.dantotsu.R
 import ani.dantotsu.connections.anilist.Anilist
 import ani.dantotsu.databinding.FragmentLoginBinding
 import ani.dantotsu.openLinkInBrowser
+import ani.dantotsu.settings.saving.internal.PreferenceKeystore
+import ani.dantotsu.settings.saving.internal.PreferencePackager
+import ani.dantotsu.statusBarHeight
+import ani.dantotsu.toast
+import com.google.android.material.textfield.TextInputEditText
+import eltos.simpledialogfragment.SimpleDialog
 
 class LoginFragment : Fragment() {
 
@@ -21,6 +32,9 @@ class LoginFragment : Fragment() {
         savedInstanceState: Bundle?
     ): View {
         _binding = FragmentLoginBinding.inflate(layoutInflater, container, false)
+        val layoutParams = binding.importSettingsButton.layoutParams as ViewGroup.MarginLayoutParams
+        layoutParams.topMargin += statusBarHeight
+        binding.importSettingsButton.layoutParams = layoutParams
         return binding.root
     }
 
@@ -29,5 +43,89 @@ class LoginFragment : Fragment() {
         binding.loginDiscord.setOnClickListener { openLinkInBrowser(getString(R.string.discord)) }
         binding.loginGithub.setOnClickListener { openLinkInBrowser(getString(R.string.github)) }
         binding.loginTelegram.setOnClickListener { openLinkInBrowser(getString(R.string.telegram)) }
+
+        val openDocumentLauncher = registerForActivityResult(ActivityResultContracts.OpenDocument()) { uri ->
+            if (uri != null) {
+                try {
+                    val jsonString = requireActivity().contentResolver.openInputStream(uri)?.readBytes()
+                        ?: throw Exception("Error reading file")
+                    val name = DocumentFile.fromSingleUri(requireActivity(), uri)?.name ?: "settings"
+                    //.sani is encrypted, .ani is not
+                    if (name.endsWith(".sani")) {
+                        passwordAlertDialog() { password ->
+                            if (password != null) {
+                                val salt = jsonString.copyOfRange(0, 16)
+                                val encrypted = jsonString.copyOfRange(16, jsonString.size)
+                                val decryptedJson = PreferenceKeystore.decryptWithPassword(
+                                    password,
+                                    encrypted,
+                                    salt
+                                )
+                                if(PreferencePackager.unpack(decryptedJson))
+                                    println("Settings imported")
+                                    restartApp()
+                            } else {
+                                toast("Password cannot be empty")
+                            }
+                        }
+                    } else {
+                        val decryptedJson = jsonString.toString(Charsets.UTF_8)
+                        if(PreferencePackager.unpack(decryptedJson))
+                            restartApp()
+                    }
+                } catch (e: Exception) {
+                    e.printStackTrace()
+                    toast("Error importing settings")
+                }
+            }
+        }
+
+        binding.importSettingsButton.setOnClickListener {
+            openDocumentLauncher.launch(arrayOf("*/*"))
+        }
     }
+
+    private fun passwordAlertDialog(callback: (CharArray?) -> Unit) {
+        val password = CharArray(16).apply { fill('0') }
+
+        // Inflate the dialog layout
+        val dialogView = LayoutInflater.from(requireActivity()).inflate(R.layout.dialog_user_agent, null)
+        dialogView.findViewById<TextInputEditText>(R.id.userAgentTextBox)?.hint = "Password"
+        val subtitleTextView = dialogView.findViewById<TextView>(R.id.subtitle)
+        subtitleTextView?.visibility = View.VISIBLE
+        subtitleTextView?.text = "Enter your password to decrypt the file"
+
+        val dialog = AlertDialog.Builder(requireActivity(), R.style.MyPopup)
+            .setTitle("Enter Password")
+            .setView(dialogView)
+            .setPositiveButton("OK", null)
+            .setNegativeButton("Cancel") { dialog, _ ->
+                password.fill('0')
+                dialog.dismiss()
+                callback(null)
+            }
+            .create()
+
+        dialog.window?.setDimAmount(0.8f)
+        dialog.show()
+
+        // Override the positive button here
+        dialog.getButton(AlertDialog.BUTTON_POSITIVE).setOnClickListener {
+            val editText = dialog.findViewById<TextInputEditText>(R.id.userAgentTextBox)
+            if (editText?.text?.isNotBlank() == true) {
+                editText.text?.toString()?.trim()?.toCharArray(password)
+                dialog.dismiss()
+                callback(password)
+            } else {
+                toast("Password cannot be empty")
+            }
+        }
+    }
+
+    private fun restartApp() {
+        val intent = Intent(requireActivity(), requireActivity().javaClass)
+        requireActivity().finish()
+        startActivity(intent)
+    }
+
 }