/*
 * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
 * SPDX-License-Identifier: GPL-3.0-only
 */

package dev.msfjarvis.aps.ui.crypto

import android.content.Intent
import android.os.Bundle
import android.view.Menu
import android.view.MenuItem
import androidx.lifecycle.lifecycleScope
import com.github.michaelbull.result.runCatching
import dagger.hilt.android.AndroidEntryPoint
import dev.msfjarvis.aps.R
import dev.msfjarvis.aps.data.crypto.CryptoRepository
import dev.msfjarvis.aps.data.passfile.PasswordEntry
import dev.msfjarvis.aps.data.password.FieldItem
import dev.msfjarvis.aps.databinding.DecryptLayoutBinding
import dev.msfjarvis.aps.ui.adapters.FieldItemAdapter
import dev.msfjarvis.aps.util.extensions.isErr
import dev.msfjarvis.aps.util.extensions.unsafeLazy
import dev.msfjarvis.aps.util.extensions.viewBinding
import dev.msfjarvis.aps.util.settings.PreferenceKeys
import java.io.ByteArrayOutputStream
import java.io.File
import javax.inject.Inject
import kotlin.time.Duration
import kotlin.time.ExperimentalTime
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.delay
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.flow.collectLatest
import kotlinx.coroutines.flow.onEach
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext

@AndroidEntryPoint
class DecryptActivityV2 : BasePgpActivity() {

  private val binding by viewBinding(DecryptLayoutBinding::inflate)
  @Inject lateinit var passwordEntryFactory: PasswordEntry.Factory
  @Inject lateinit var repository: CryptoRepository
  private val relativeParentPath by unsafeLazy { getParentPath(fullPath, repoPath) }

  private var passwordEntry: PasswordEntry? = null
  private var retries = 0

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    supportActionBar?.setDisplayHomeAsUpEnabled(true)
    title = name
    with(binding) {
      setContentView(root)
      passwordCategory.text = relativeParentPath
      passwordFile.text = name
      passwordFile.setOnLongClickListener {
        copyTextToClipboard(name)
        true
      }
    }
    decrypt(isError = false)
  }

  override fun onCreateOptionsMenu(menu: Menu): Boolean {
    menuInflater.inflate(R.menu.pgp_handler, menu)
    passwordEntry?.let { entry ->
      menu.findItem(R.id.edit_password).isVisible = true
      if (!entry.password.isNullOrBlank()) {
        menu.findItem(R.id.share_password_as_plaintext).isVisible = true
        menu.findItem(R.id.copy_password).isVisible = true
      }
    }
    return true
  }

  override fun onOptionsItemSelected(item: MenuItem): Boolean {
    when (item.itemId) {
      android.R.id.home -> onBackPressed()
      R.id.edit_password -> editPassword()
      R.id.share_password_as_plaintext -> shareAsPlaintext()
      R.id.copy_password -> copyPasswordToClipboard(passwordEntry?.password)
      else -> return super.onOptionsItemSelected(item)
    }
    return true
  }

  /**
   * Automatically finishes the activity 60 seconds after decryption succeeded to prevent
   * information leaks from stale activities.
   */
  @OptIn(ExperimentalTime::class)
  private fun startAutoDismissTimer() {
    lifecycleScope.launch {
      delay(Duration.seconds(60))
      finish()
    }
  }

  /**
   * Edit the current password and hide all the fields populated by encrypted data so that when the
   * result triggers they can be repopulated with new data.
   */
  private fun editPassword() {
    val intent = Intent(this, PasswordCreationActivityV2::class.java)
    intent.putExtra("FILE_PATH", relativeParentPath)
    intent.putExtra("REPO_PATH", repoPath)
    intent.putExtra(PasswordCreationActivityV2.EXTRA_FILE_NAME, name)
    intent.putExtra(PasswordCreationActivityV2.EXTRA_PASSWORD, passwordEntry?.password)
    intent.putExtra(
      PasswordCreationActivityV2.EXTRA_EXTRA_CONTENT,
      passwordEntry?.extraContentString
    )
    intent.putExtra(PasswordCreationActivityV2.EXTRA_EDITING, true)
    startActivity(intent)
    finish()
  }

  private fun shareAsPlaintext() {
    val sendIntent =
      Intent().apply {
        action = Intent.ACTION_SEND
        putExtra(Intent.EXTRA_TEXT, passwordEntry?.password)
        type = "text/plain"
      }
    // Always show a picker to give the user a chance to cancel
    startActivity(
      Intent.createChooser(sendIntent, resources.getText(R.string.send_plaintext_password_to))
    )
  }

  private fun decrypt(isError: Boolean) {
    if (retries < MAX_RETRIES) {
      retries += 1
    } else {
      finish()
    }
    val dialog = PasswordDialog()
    if (isError) {
      dialog.setError()
    }
    lifecycleScope.launch(Dispatchers.Main) {
      dialog.password.collectLatest { value ->
        if (value != null) {
          if (runCatching { decrypt(value) }.isErr()) {
            decrypt(isError = true)
          }
        }
      }
    }
    dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
  }

  private suspend fun decrypt(password: String) {
    val message = withContext(Dispatchers.IO) { File(fullPath).readBytes().inputStream() }
    val result =
      withContext(Dispatchers.IO) {
        val outputStream = ByteArrayOutputStream()
        repository.decrypt(
          password,
          message,
          outputStream,
        )
        outputStream
      }
    require(result.size() != 0) { "Incorrect password" }
    startAutoDismissTimer()

    val entry = passwordEntryFactory.create(lifecycleScope, result.toByteArray())
    passwordEntry = entry
    createPasswordUi(entry)
  }

  private suspend fun createPasswordUi(entry: PasswordEntry) =
    withContext(Dispatchers.Main) {
      val showPassword = settings.getBoolean(PreferenceKeys.SHOW_PASSWORD, true)
      invalidateOptionsMenu()

      val items = arrayListOf<FieldItem>()
      if (!entry.password.isNullOrBlank()) {
        items.add(FieldItem.createPasswordField(entry.password!!))
      }

      if (entry.hasTotp()) {
        items.add(FieldItem.createOtpField(entry.totp.value))
      }

      if (!entry.username.isNullOrBlank()) {
        items.add(FieldItem.createUsernameField(entry.username!!))
      }

      entry.extraContent.forEach { (key, value) ->
        items.add(FieldItem(key, value, FieldItem.ActionType.COPY))
      }

      val adapter = FieldItemAdapter(items, showPassword) { text -> copyTextToClipboard(text) }
      binding.recyclerView.adapter = adapter

      if (entry.hasTotp()) {
        lifecycleScope.launch {
          entry
            .totp
            .onEach { code -> withContext(Dispatchers.Main) { adapter.updateOTPCode(code) } }
            .collect()
        }
      }
    }

  private companion object {
    private const val MAX_RETRIES = 3
  }
}