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

package dev.msfjarvis.aps.util.totp

import android.net.Uri
import javax.inject.Inject

/** [Uri] backed TOTP URL parser. */
class UriTotpFinder @Inject constructor() : TotpFinder {

  override fun findSecret(content: String): String? {
    content.split("\n".toRegex()).forEach { line ->
      if (line.startsWith(TOTP_FIELDS[0])) {
        return Uri.parse(line).getQueryParameter("secret")
      }
      if (line.startsWith(TOTP_FIELDS[1], ignoreCase = true)) {
        return line.split(": *".toRegex(), 2).toTypedArray()[1]
      }
    }
    return null
  }

  override fun findDigits(content: String): String {
    content.split("\n".toRegex()).forEach { line ->
      if (line.startsWith(TOTP_FIELDS[0]) && Uri.parse(line).getQueryParameter("digits") != null) {
        return Uri.parse(line).getQueryParameter("digits")!!
      }
    }
    return "6"
  }

  override fun findPeriod(content: String): Long {
    content.split("\n".toRegex()).forEach { line ->
      if (line.startsWith(TOTP_FIELDS[0]) && Uri.parse(line).getQueryParameter("period") != null) {
        val period = Uri.parse(line).getQueryParameter("period")!!.toLongOrNull()
        if (period != null && period > 0) return period
      }
    }
    return 30
  }

  override fun findAlgorithm(content: String): String {
    content.split("\n".toRegex()).forEach { line ->
      if (line.startsWith(TOTP_FIELDS[0]) && Uri.parse(line).getQueryParameter("algorithm") != null
      ) {
        return Uri.parse(line).getQueryParameter("algorithm")!!
      }
    }
    return "sha1"
  }

  companion object {

    val TOTP_FIELDS = arrayOf("otpauth://totp", "totp:")
  }
}