Display day change messages

app/src/main/java/com/ubergeek42/WeechatAndroid/relay/Buffer.kt

@@ -25,6 +25,7 @@ class Buffer @WorkerThread constructor(
     @JvmField var shortName: String = ""
     @JvmField var hidden: Boolean = false
     @JvmField var type = BufferSpec.Type.Other
+    @JvmField var displayDayChange: Boolean = false
 
     private var notify: Notify = Notify.default
 
@@ -34,6 +35,7 @@ class Buffer @WorkerThread constructor(
         internal var updateHidden = false
         internal var updateType = false
         internal var updateNotifyLevel = false
+        internal var updateDayChange = false
 
         var number: Int by updatable(::updateName, this@Buffer::number)
         var fullName: String by updatable(::updateName, this@Buffer::fullName)
@@ -42,6 +44,7 @@ class Buffer @WorkerThread constructor(
         var hidden: Boolean by updatable(::updateHidden)
         var type: BufferSpec.Type by updatable(::updateType)
         var notify: Notify? by updatable(::updateNotifyLevel)
+        var displayDayChange: Boolean by updatable(::updateDayChange)
     }
 
     fun update(block: Updater.() -> Unit) {
@@ -65,6 +68,7 @@ class Buffer @WorkerThread constructor(
         if (updater.updateNotifyLevel) notify = updater.notify ?: Notify.default
         if (updater.updateHidden) hidden = updater.hidden
         if (updater.updateType) type = updater.type
+        if (updater.updateDayChange) displayDayChange = updater.displayDayChange
     }
 
     ////////////////////////////////////////////////////////////////////////////////////////////////
@@ -215,7 +219,7 @@ class Buffer @WorkerThread constructor(
         }
 
         synchronized(this) {
-            lines.replaceLines(newLines)
+            lines.replaceLines(newLines, displayDayChange)
         }
    }
 
@@ -227,7 +231,7 @@ class Buffer @WorkerThread constructor(
         val notifyPmOrMessage = line.notifyLevel == LineSpec.NotifyLevel.Message || notifyPm
 
         synchronized(this) {
-            lines.addLast(line)
+            lines.addLast(line, displayDayChange)
 
             // notify levels: 0 none 1 highlight 2 message 3 all
             // treat hidden lines and lines that are not supposed to generate a “notification” as read

app/src/main/java/com/ubergeek42/WeechatAndroid/relay/Lines.kt

@@ -8,6 +8,11 @@ import com.ubergeek42.WeechatAndroid.utils.Linkify
 import com.ubergeek42.WeechatAndroid.utils.Utils
 import com.ubergeek42.WeechatAndroid.utils.invalidatableLazy
 import com.ubergeek42.weechat.Color
+import java.time.Instant
+import java.time.LocalDate
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+import java.time.format.FormatStyle
 import java.util.*
 import kotlin.properties.Delegates.observable
 
@@ -46,6 +51,13 @@ class Lines {
     var maxUnfilteredSize = P.lineIncrement
         private set
 
+    private var dateOfLastUnfilteredLine: LocalDate? = null
+    private var dateOfLastFilteredLine: LocalDate? = null
+
+    private var lastOldDate: LocalDate? = null
+    private lateinit var lastNewDate: LocalDate
+    private lateinit var lastDateLine: Line
+
     // after reconnecting, in *full sync mode*, we are receiving and adding new lines to buffers.
     // there can be inconsistencies; if some lines were added while we were offline,
     // we can't display them, but can display what's on top and what's on bottom.
@@ -87,20 +99,70 @@ class Lines {
     // in very rare cases status might not be FETCHING here, particularly when closing buffers
     // while the app is connecting and has already requested lines
 
-    fun replaceLines(lines: Collection<Line>) {
+    fun replaceLines(lines: Collection<Line>, displayDayChange: Boolean) {
         if (status != Status.Fetching) return
         unfiltered.clear()
         filtered.clear()
-        unfiltered.addAll(lines)
+        dateOfLastUnfilteredLine = null
+        dateOfLastFilteredLine = null
+
         for (line in lines) {
-            if (line.isVisible) filtered.add(line)
+            addLast(line, displayDayChange)
         }
     }
 
-    fun addLast(line: Line) {
+    private fun makeDateChangeLine(oldDate: LocalDate?, newDate: LocalDate) : Line {
+        val tstamp = newDate.atStartOfDay(ZoneId.systemDefault()).toEpochSecond() * 1000
+        var msg = newDate.format(DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM))
+        if (oldDate != null && oldDate.plusDays(1) != newDate) {
+            msg += " (" +
+                   oldDate.format(DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM)) +
+                   ")"
+        }
+        msg += " --"
+
+        var datePointer = MAX_C_POINTER_VALUE shl 2 + newDate.getYear() shl 32
+                          + newDate.getDayOfYear() shl 20
+        if (oldDate != null) {
+            datePointer += oldDate.getYear() shl 16 + oldDate.getDayOfYear()
+        }
+        return Line(datePointer, LineSpec.Type.Other, tstamp, "--", msg,
+                    nick = null, isVisible = true, isHighlighted = false,
+                    LineSpec.DisplayAs.Unspecified, LineSpec.NotifyLevel.Low)
+    }
+
+    private fun obtainDateChangeLine(oldDate: LocalDate?, newDate: LocalDate) : Line {
+        if (oldDate == null || lastOldDate != oldDate || lastNewDate != newDate) {
+            lastDateLine = makeDateChangeLine(oldDate, newDate)
+            lastOldDate = oldDate
+            lastNewDate = newDate
+        }
+        return lastDateLine
+    }
+
+    fun addLast(line: Line, displayDayChange: Boolean) {
+        if(displayDayChange) {
+                val newDate = Instant.ofEpochSecond(line.timestamp / 1000)
+                              .atZone(ZoneId.systemDefault())
+                              .toLocalDate()
+
+                if (dateOfLastUnfilteredLine != newDate) {
+                    unfiltered.addLast(obtainDateChangeLine(dateOfLastUnfilteredLine, newDate))
+                    dateOfLastUnfilteredLine = newDate
+                    skipUnfiltered++
+                }
+
+                if (line.isVisible && dateOfLastFilteredLine != newDate) {
+                    filtered.addLast(obtainDateChangeLine(dateOfLastFilteredLine, newDate))
+                    dateOfLastFilteredLine = newDate
+                    skipFiltered++
+                }
+        }
+
         if (shouldAddSquiggleOnNewLine) {
             shouldAddSquiggleOnNewLine = false
-            if (status == Status.Init && unfiltered.size > 0) addLast(SquiggleLine())   // invisible
+            if (status == Status.Init && unfiltered.size > 0)
+                addLast(SquiggleLine(), false)   // invisible
         }
 
         if (shouldAddSquiggleOnNewVisibleLine && line.isVisible) {

app/src/main/java/com/ubergeek42/WeechatAndroid/relay/Spec.kt

@@ -39,6 +39,7 @@ enum class Notify(val value: Int) {
     inline val notify: Notify? get() = Notify::value.find(entry.getIntOrNull("notify"))
     inline val type get() = Type.fromLocalVariables(entry.getHashtable("local_variables"))
     inline val hidden get() = entry.getIntOrNull("hidden") == 1
+    inline val displayDayChange get() = entry.getIntOrNull("day_change") == 1
 
     // todo get rid of openWhileRunning
     fun toBuffer(openWhileRunning: Boolean) = Buffer(pointer).apply {
@@ -50,6 +51,7 @@ enum class Notify(val value: Int) {
             notify = this@BufferSpec.notify
             hidden = this@BufferSpec.hidden
             type = this@BufferSpec.type
+            displayDayChange = this@BufferSpec.displayDayChange
         }
 
         if (P.isBufferOpen(pointer)) setOpen(open = true, syncHotlistOnOpen = false)
@@ -67,7 +69,7 @@ enum class Notify(val value: Int) {
 
     companion object {
         const val listBuffersRequest = "(listbuffers) hdata buffer:gui_buffers(*) " +
-                "number,full_name,short_name,type,title,nicklist,local_variables,notify,hidden"
+                "number,full_name,short_name,type,title,nicklist,local_variables,notify,hidden,day_change"
 
         const val renumberRequest = "(renumber) hdata buffer:gui_buffers(*) number"
     }