financial-viewer/app/src/main/java/com/financialviewer/ui/LoanDetailsActivity.kt

package com.financialviewer.ui

import android.annotation.SuppressLint
import android.app.Activity
import android.content.Intent
import android.icu.util.Calendar
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.TextView
import android.widget.Toast
import androidx.activity.OnBackPressedCallback
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.financialviewer.R
import com.financialviewer.data.LoanMonthlyDetails
import com.financialviewer.db.Loan
import com.financialviewer.repository.LoanRepository
import com.financialviewer.ui.adapter.LoanDetailsAdapter
import com.financialviewer.utils.calculateNextInterest
import com.financialviewer.utils.calculateNextPrincipal
import com.financialviewer.utils.calculateNextRemaining
import com.financialviewer.utils.convertDoubleToString
import com.financialviewer.utils.convertInputStringToDouble
import com.financialviewer.utils.convertStringToDouble
import com.financialviewer.utils.getNextMonth
import kotlinx.coroutines.launch

class LoanDetailsActivity: AppCompatActivity() {
    private lateinit var loanRepository: LoanRepository
    private lateinit var loanDetailsAdapter: LoanDetailsAdapter
    private var remainingUpdated: Boolean = false
    private var sumInterest: Double = 0.0

    @SuppressLint("SetTextI18n")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_loan_details)

        loanRepository = LoanRepository(this)

        val loanId = intent.getStringExtra("loanId") ?: "R1"

        val titleTextView: TextView = findViewById(R.id.loanTitle)
        val paymentTextView: TextView = findViewById(R.id.payment)
        val remainingTextView: TextView = findViewById(R.id.remaining)
        val rateTextView: TextView = findViewById(R.id.rate)
        val sumInterestTextView: TextView = findViewById(R.id.sumInterest)

        lifecycleScope.launch {
            val loan = loanRepository.getLoanById(loanId)
            if (loan != null) {
                titleTextView.text = loan.title
                remainingTextView.text = "当前欠款：" + loan.remainingLoan
                paymentTextView.text = "月供： " + loan.payment
                rateTextView.text =  "利率：" + loan.rate

                val recyclerView: RecyclerView = findViewById(R.id.recyclerView)
                recyclerView.layoutManager = LinearLayoutManager(this@LoanDetailsActivity)
                loanDetailsAdapter = LoanDetailsAdapter(generateMonthlyDetails(loan))
                recyclerView.adapter = loanDetailsAdapter

                sumInterestTextView.text = "预计还需支付利息：" + convertDoubleToString(sumInterest)
            }
        }

        val refreshButton: Button = findViewById(R.id.refresh)
        refreshButton.setOnClickListener {
            lifecycleScope.launch {
                val loan = loanRepository.getLoanById(loanId)
                if (loan != null) {
                    loanDetailsAdapter.updateLoanDetailsList(generateMonthlyDetails(loan))
                    sumInterestTextView.text = "预计还需支付利息：" + convertDoubleToString(sumInterest)
                }
            }
        }

        val specialRepaymentButton: Button = findViewById(R.id.specialRepayment)
        specialRepaymentButton.setOnClickListener {
            // 创建一个EditText作为输入框
            val input = EditText(this@LoanDetailsActivity)

            // 创建并显示AlertDialog
            val dialog = AlertDialog.Builder(this@LoanDetailsActivity)
                .setTitle("提前还款金额")
                .setView(input) // 将EditText添加到对话框
                .setPositiveButton("Confirm") { _, _ ->
                    // 获取用户输入并更新TextView的内容
                    val inputString = input.text.toString()
                    try {
                        val inputDouble = convertInputStringToDouble(inputString) // 成功转换
                        lifecycleScope.launch {
                            val loan = loanRepository.getLoanById(loanId)

                            if (loan != null) {
                                val newRemainingLoan = convertStringToDouble(loan.remainingLoan) - inputDouble
                                remainingTextView.text = "当前欠款：" + convertDoubleToString(newRemainingLoan)

                                loan.remainingLoan = convertDoubleToString(newRemainingLoan)
                                loanRepository.updateLoan(loan)
                                remainingUpdated = true
                            }
                        }
                    } catch (e: NumberFormatException) {
                        // 如果输入不是有效的数字，弹出错误提示
                        Toast.makeText(this@LoanDetailsActivity, "Invalid input. Please enter a valid number.", Toast.LENGTH_SHORT).show()
                    }

                }
                .setNegativeButton("Cancel", null)
                .create()

            dialog.show()
        }

        onBackPressedDispatcher.addCallback(this, object: OnBackPressedCallback(true) {
            override fun handleOnBackPressed() {
                if (remainingUpdated) {
                    val resultIntent = Intent().apply {
                        putExtra("loanId", loanId)
                    }
                    setResult(Activity.RESULT_OK, resultIntent)
                }
                finish()
            }
        })
    }

    private fun generateMonthlyDetails(loan: Loan): MutableList<LoanMonthlyDetails> {
        sumInterest = 0.0
        val monthlyDetails: MutableList<LoanMonthlyDetails> = mutableListOf()
        val now = Calendar.getInstance()
        var currentYear = now.get(Calendar.YEAR)
        var currentMonth = now.get(Calendar.MONTH) + 1
        var base = convertStringToDouble(loan.remainingLoan)
        var remaining = 1.0
        while (remaining > 0) {
            val month = getNextMonth(currentYear, currentMonth)
            currentYear = month.split(".")[1].toInt()
            currentMonth = month.split(".")[0].toInt()

            val interest = calculateNextInterest(loan, base)
            var principal = calculateNextPrincipal(loan, base)
            remaining = calculateNextRemaining(loan, base)

            if (remaining < 0) {
                remaining = 0.0
                principal = base
            }
            base = remaining

            monthlyDetails.add(LoanMonthlyDetails(
                month,
                convertDoubleToString(interest),
                convertDoubleToString(principal),
                convertDoubleToString(remaining)
            ))
            sumInterest += interest
        }
        return monthlyDetails
    }
}