Suggested Start/Completed Date for Trackers based on reading history

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -929,7 +929,7 @@ class LibraryPresenter(
                 libraryManga.forEach { manga ->
                     if (manga.date_added == 0L) {
                         val chapters = db.getChapters(manga).executeAsBlocking()
-                        manga.date_added = chapters.minBy { it.date_fetch }?.date_fetch ?: 0L
+                        manga.date_added = chapters.minByOrNull { it.date_fetch }?.date_fetch ?: 0L
                         db.insertManga(manga).executeAsBlocking()
                     }
                     db.resetMangaInfo(manga).executeAsBlocking()

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaDetailsPresenter.kt

@@ -30,6 +30,7 @@ import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.model.toSChapter
 import eu.kanade.tachiyomi.source.model.toSManga
 import eu.kanade.tachiyomi.ui.manga.chapter.ChapterItem
+import eu.kanade.tachiyomi.ui.manga.track.SetTrackReadingDatesDialog
 import eu.kanade.tachiyomi.ui.manga.track.TrackItem
 import eu.kanade.tachiyomi.ui.security.SecureActivityDelegate
 import eu.kanade.tachiyomi.util.chapter.ChapterFilter
@@ -895,6 +896,15 @@ class MangaDetailsPresenter(
         updateRemote(track, item.service)
     }
 
+    fun getSuggestedDate(readingDate: SetTrackReadingDatesDialog.ReadingDate): Long? {
+        val chapters = db.getHistoryByMangaId(manga.id ?: 0L).executeAsBlocking()
+        val date = when (readingDate) {
+            SetTrackReadingDatesDialog.ReadingDate.Start -> chapters.minByOrNull { it.last_read }?.last_read
+            SetTrackReadingDatesDialog.ReadingDate.Finish -> chapters.maxByOrNull { it.last_read }?.last_read
+        } ?: return null
+        return if (date <= 0L) null else date
+    }
+
     companion object {
         const val MULTIPLE_VOLUMES = 1
         const val TENS_OF_CHAPTERS = 2

app/src/main/java/eu/kanade/tachiyomi/ui/manga/track/SetTrackReadingDatesDialog.kt

@@ -3,15 +3,22 @@ package eu.kanade.tachiyomi.ui.manga.track
 import android.app.Dialog
 import android.os.Bundle
 import androidx.core.os.bundleOf
+import com.afollestad.date.dayOfMonth
+import com.afollestad.date.month
+import com.afollestad.date.year
 import com.afollestad.materialdialogs.MaterialDialog
 import com.afollestad.materialdialogs.datetime.datePicker
 import com.bluelinelabs.conductor.Controller
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.database.models.Track
+import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.data.track.TrackManager
 import eu.kanade.tachiyomi.ui.base.controller.DialogController
+import eu.kanade.tachiyomi.util.view.setDate
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
+import uy.kohesive.injekt.injectLazy
+import java.text.DateFormat
 import java.util.Calendar
 
 class SetTrackReadingDatesDialog<T> : DialogController
@@ -20,16 +27,23 @@ class SetTrackReadingDatesDialog<T> : DialogController
     private val item: TrackItem
 
     private val dateToUpdate: ReadingDate
+    private val suggestedDate: Long?
+
+    private val preferences: PreferencesHelper by injectLazy()
+    private val dateFormat: DateFormat by lazy {
+        preferences.dateFormat()
+    }
 
     private lateinit var listener: Listener
 
-    constructor(target: T, listener: Listener, dateToUpdate: ReadingDate, item: TrackItem) : super(
+    constructor(target: T, listener: Listener, dateToUpdate: ReadingDate, item: TrackItem, suggestedDate: Long?) : super(
         bundleOf(KEY_ITEM_TRACK to item.track)
     ) {
         targetController = target
         this.listener = listener
         this.item = item
         this.dateToUpdate = dateToUpdate
+        this.suggestedDate = suggestedDate
     }
 
     @Suppress("unused")
@@ -38,6 +52,7 @@ class SetTrackReadingDatesDialog<T> : DialogController
         val service = Injekt.get<TrackManager>().getService(track.sync_id)!!
         item = TrackItem(track, service)
         dateToUpdate = ReadingDate.Start
+        suggestedDate = null
     }
 
     override fun onCreateDialog(savedViewState: Bundle?): Dialog {
@@ -53,12 +68,59 @@ class SetTrackReadingDatesDialog<T> : DialogController
             }
             .neutralButton(R.string.remove) {
                 listener.setReadingDate(item, dateToUpdate, 0L)
+            }.apply {
+                getSuggestedDate()?.let {
+                    message(text = it,
+                    applySettings = {
+                        messageTextView.setOnClickListener {
+                            this@apply.setDate(suggestedDate ?: 0L)
                         }
+                    })
+                }
+            }
+    }
+
+    private fun getSuggestedDate(): String? {
+        item.track ?: return null
+        val date = when (dateToUpdate) {
+            ReadingDate.Start -> item.track.started_reading_date
+            ReadingDate.Finish -> item.track.finished_reading_date
+        }
+        if (date != 0L) {
+            if (suggestedDate != null) {
+                val calendar = Calendar.getInstance()
+                calendar.timeInMillis = date
+                val suggestedCalendar = Calendar.getInstance()
+                suggestedCalendar.timeInMillis = suggestedDate
+                return if (date > suggestedDate &&
+                    (suggestedCalendar.year != calendar.year ||
+                        suggestedCalendar.month != calendar.month ||
+                        suggestedCalendar.dayOfMonth != calendar.dayOfMonth)
+                ) {
+                    activity?.getString(
+                        R.string.suggested_date_,
+                        dateFormat.format(suggestedDate)
+                    )
+                } else {
+                    null
+                }
+            }
+        }
+        suggestedDate?.let {
+            return activity?.getString(
+                R.string.suggested_date_,
+                dateFormat.format(suggestedDate)
+            )
+        }
+        return null
     }
 
     private fun getCurrentDate(): Calendar {
         // Today if no date is set, otherwise the already set date
         return Calendar.getInstance().apply {
+            suggestedDate?.let {
+                timeInMillis = it
+            }
             item.track?.let {
                 val date = when (dateToUpdate) {
                     ReadingDate.Start -> it.started_reading_date

app/src/main/java/eu/kanade/tachiyomi/ui/manga/track/TrackingBottomSheet.kt

@@ -187,14 +187,26 @@ class TrackingBottomSheet(private val controller: MangaDetailsController) :
         val item = adapter?.getItem(position) ?: return
         if (item.track == null) return
 
-        SetTrackReadingDatesDialog(controller, this, SetTrackReadingDatesDialog.ReadingDate.Start, item).showDialog(controller.router)
+        val suggestedDate = presenter.getSuggestedDate(SetTrackReadingDatesDialog.ReadingDate.Start)
+        SetTrackReadingDatesDialog(controller,
+            this,
+            SetTrackReadingDatesDialog.ReadingDate.Start,
+            item,
+            suggestedDate)
+            .showDialog(controller.router)
     }
 
     override fun onFinishDateClick(position: Int) {
         val item = adapter?.getItem(position) ?: return
         if (item.track == null) return
 
-        SetTrackReadingDatesDialog(controller, this, SetTrackReadingDatesDialog.ReadingDate.Finish, item).showDialog(controller.router)
+        val suggestedDate = presenter.getSuggestedDate(SetTrackReadingDatesDialog.ReadingDate.Finish)
+        SetTrackReadingDatesDialog(controller,
+            this,
+            SetTrackReadingDatesDialog.ReadingDate.Finish,
+            item,
+            suggestedDate)
+            .showDialog(controller.router)
     }
 
     override fun setStatus(item: TrackItem, selection: Int) {

app/src/main/java/eu/kanade/tachiyomi/util/view/MaterialDialogExtensions.kt

@@ -0,0 +1,12 @@
+package eu.kanade.tachiyomi.util.view
+
+import com.afollestad.date.DatePicker
+import com.afollestad.materialdialogs.MaterialDialog
+import java.util.Calendar
+
+fun MaterialDialog.setDate(date: Long) {
+    val datePicker = findViewById<DatePicker>(com.afollestad.materialdialogs.datetime.R.id.datetimeDatePicker) ?: return
+    val calendar = Calendar.getInstance()
+    calendar.timeInMillis = date
+    datePicker.setDate(calendar)
+}

app/src/main/res/values/strings.xml

@@ -436,6 +436,7 @@
     <string name="started_reading_date">Started reading date</string>
     <string name="finished_reading_date">Finished reading date</string>
     <string name="myanimelist_relogin">Please login to MAL again</string>
+    <string name="suggested_date_">Suggested date: %1$s</string>
 
     <!-- Migration -->
     <string name="select_sources">Select sources</string>