package com.mapbox.mapboxsdk.testapp.activity.fragment

import android.os.Bundle
import android.support.v4.app.Fragment
import android.support.v4.app.FragmentManager
import android.support.v4.app.FragmentStatePagerAdapter
import android.support.v7.app.AppCompatActivity
import com.mapbox.mapboxsdk.camera.CameraPosition
import com.mapbox.mapboxsdk.geometry.LatLng
import com.mapbox.mapboxsdk.maps.MapboxMapOptions
import com.mapbox.mapboxsdk.maps.Style
import com.mapbox.mapboxsdk.maps.SupportMapFragment
import com.mapbox.mapboxsdk.testapp.R
import kotlinx.android.synthetic.main.activity_viewpager.*

/**
 * Test activity showcasing using the Android SDK ViewPager API to show MapFragments.
 */
class ViewPagerActivity : AppCompatActivity() {

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_viewpager)
    viewPager.adapter = MapFragmentAdapter(supportFragmentManager)
  }

  override fun onRestoreInstanceState(savedInstanceState: Bundle) {
    super.onRestoreInstanceState(savedInstanceState)
    val currentPosition = viewPager.currentItem
    val offscreenLimit = viewPager.offscreenPageLimit
    for (i in currentPosition - offscreenLimit..currentPosition + offscreenLimit) {
      if (i < 0 || i > viewPager.adapter?.count ?: 0) {
        continue
      }
      val mapFragment = viewPager.adapter?.instantiateItem(viewPager, i) as SupportMapFragment
      mapFragment.getMapAsync(i)
    }
  }

  internal class MapFragmentAdapter(fragmentManager: FragmentManager) : FragmentStatePagerAdapter(fragmentManager) {

    override fun getCount(): Int {
      return NUM_ITEMS
    }

    override fun getItem(position: Int): Fragment? {
      val options = MapboxMapOptions()
      options.textureMode(true)
      options.camera(
        CameraPosition.Builder()
          .zoom(3.0)
          .target(
            when (position) {
              0 -> {
                LatLng(34.920526, 102.634774)
              }
              1 -> {
                LatLng(62.326440, 92.764913)
              }
              2 -> {
                LatLng(-25.007786, 133.623852)
              }
              3 -> {
                LatLng(62.326440, 92.764913)
              }
              else -> {
                LatLng(34.920526, 102.634774)
              }
            }
          )
          .build())

      val fragment = SupportMapFragment.newInstance(options)
      fragment.getMapAsync(position)
      return fragment
    }

    override fun getPageTitle(position: Int): CharSequence? {
      return "Page $position"
    }

    companion object {
      private const val NUM_ITEMS = 5
    }
  }
}

fun SupportMapFragment.getMapAsync(index: Int) {
  this.getMapAsync {
    it.setStyle(
      when (index) {
        0 -> Style.MAPBOX_STREETS
        1 -> Style.DARK
        2 -> Style.SATELLITE
        3 -> Style.LIGHT
        4 -> Style.TRAFFIC_NIGHT
        else -> Style.MAPBOX_STREETS
      }
    )
  }
}