Add Android app implementation with core features

Co-authored-by: Kenearos <86194771+Kenearos@users.noreply.github.com>

android-app/app/src/main/java/com/dienstplan/nrw/ResultsActivity.kt

@@ -0,0 +1,102 @@
+package com.dienstplan.nrw
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.appcompat.app.AppCompatActivity
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+import com.dienstplan.nrw.data.DutyDataStore
+import com.dienstplan.nrw.data.PayrollCalculator
+import com.dienstplan.nrw.databinding.ActivityResultsBinding
+import com.dienstplan.nrw.databinding.ItemResultBinding
+import com.dienstplan.nrw.model.PayrollResult
+
+class ResultsActivity : AppCompatActivity() {
+    
+    private lateinit var binding: ActivityResultsBinding
+    private lateinit var adapter: ResultsAdapter
+    private var year: Int = 0
+    private var month: Int = 0
+    
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityResultsBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+        
+        year = intent.getIntExtra("year", 0)
+        month = intent.getIntExtra("month", 0)
+        
+        if (year == 0 || month == 0) {
+            finish()
+            return
+        }
+        
+        setupUI()
+        calculateAndDisplayResults()
+    }
+    
+    private fun setupUI() {
+        val monthName = getMonthName(month)
+        binding.tvSelectedMonth.text = String.format("%s %d", monthName, year)
+        
+        adapter = ResultsAdapter()
+        binding.rvResults.layoutManager = LinearLayoutManager(this)
+        binding.rvResults.adapter = adapter
+    }
+    
+    private fun calculateAndDisplayResults() {
+        val duties = DutyDataStore.getDutiesForMonth(year, month)
+        val calculator = PayrollCalculator()
+        val results = calculator.calculatePayroll(duties, year, month)
+        
+        adapter.submitList(results)
+    }
+    
+    private fun getMonthName(month: Int): String {
+        val months = resources.getStringArray(R.array.months)
+        return if (month in 1..12) months[month - 1] else ""
+    }
+}
+
+class ResultsAdapter : RecyclerView.Adapter<ResultsAdapter.ViewHolder>() {
+    
+    private var results = listOf<PayrollResult>()
+    
+    fun submitList(newResults: List<PayrollResult>) {
+        results = newResults
+        notifyDataSetChanged()
+    }
+    
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
+        val binding = ItemResultBinding.inflate(
+            LayoutInflater.from(parent.context),
+            parent,
+            false
+        )
+        return ViewHolder(binding)
+    }
+    
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+        holder.bind(results[position])
+    }
+    
+    override fun getItemCount() = results.size
+    
+    class ViewHolder(
+        private val binding: ItemResultBinding
+    ) : RecyclerView.ViewHolder(binding.root) {
+        
+        fun bind(result: PayrollResult) {
+            binding.tvEmployeeName.text = result.employeeName
+            binding.tvWTUnits.text = String.format("%.2f", result.wtUnits)
+            binding.tvWEFriday.text = String.format("%.2f", result.weFriday)
+            binding.tvWEOther.text = String.format("%.2f", result.weOther)
+            binding.tvWETotal.text = String.format("%.2f", result.weTotal)
+            binding.tvThresholdReached.text = if (result.thresholdReached) "JA" else "NEIN"
+            binding.tvPayoutWT.text = String.format("%.2f €", result.payoutWT)
+            binding.tvPayoutWE.text = String.format("%.2f €", result.payoutWE)
+            binding.tvPayoutTotal.text = String.format("%.2f €", result.payoutTotal)
+        }
+    }
+}