Initial commit

app/src/main/java/io/timelimit/android/logic/RemainingTime.kt

@@ -0,0 +1,100 @@
+/*
+ * TimeLimit Copyright <C> 2019 Jonas Lochmann
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package io.timelimit.android.logic
+
+import android.util.SparseLongArray
+import io.timelimit.android.data.model.TimeLimitRule
+
+data class RemainingTime(val includingExtraTime: Long, val default: Long) {
+    init {
+        if (includingExtraTime < 0 || default < 0) {
+            throw IllegalStateException("time is < 0")
+        }
+
+        if (includingExtraTime < default) {
+            throw IllegalStateException("extra time < default time")
+        }
+    }
+
+    companion object {
+        fun min(a: RemainingTime?, b: RemainingTime?): RemainingTime? = if (a == null) {
+            b
+        } else if (b == null) {
+            a
+        } else {
+            RemainingTime(
+                    includingExtraTime = Math.min(a.includingExtraTime, b.includingExtraTime),
+                    default = Math.min(a.default, b.default)
+            )
+        }
+
+        private fun getRulesRelatedToDay(dayOfWeek: Int, rules: List<TimeLimitRule>): List<TimeLimitRule> {
+            return rules.filter { (it.dayMask.toInt() and (1 shl dayOfWeek)) != 0 }
+        }
+
+        fun getRemainingTime(dayOfWeek: Int, usedTimes: SparseLongArray, rules: List<TimeLimitRule>, extraTime: Long): RemainingTime? {
+            if (extraTime < 0) {
+                throw IllegalStateException("extra time < 0")
+            }
+
+            val relatedRules = getRulesRelatedToDay(dayOfWeek, rules)
+            val withoutExtraTime = getRemainingTime(usedTimes, relatedRules, false)
+            val withExtraTime = getRemainingTime(usedTimes, relatedRules, true)
+
+            if (withoutExtraTime == null && withExtraTime == null) {
+                // no rules
+                return null
+            } else if (withoutExtraTime != null && withExtraTime != null) {
+                // with rules for extra time
+                val additionalTimeWithExtraTime = withExtraTime - withoutExtraTime
+
+                if (additionalTimeWithExtraTime < 0) {
+                    throw IllegalStateException("additional time with extra time < 0")
+                }
+
+                return RemainingTime(
+                        includingExtraTime = withoutExtraTime + Math.min(extraTime, additionalTimeWithExtraTime),
+                        default = withoutExtraTime
+                )
+            } else if (withoutExtraTime != null) {
+                // without rules for extra time
+                return RemainingTime(
+                        includingExtraTime = withoutExtraTime + extraTime,
+                        default = withoutExtraTime
+                )
+            } else {
+                throw IllegalStateException()
+            }
+        }
+
+        private fun getRemainingTime(usedTimes: SparseLongArray, relatedRules: List<TimeLimitRule>, assumeMaximalExtraTime: Boolean): Long? {
+            return relatedRules.filter { (!assumeMaximalExtraTime) || it.applyToExtraTimeUsage }.map {
+                var usedTime = 0L
+
+                for (day in 0..6) {
+                    if ((it.dayMask.toInt() and (1 shl day)) != 0) {
+                        usedTime += usedTimes[day]
+                    }
+                }
+
+                val maxTime = it.maximumTimeInMillis
+                val remaining = Math.max(0, maxTime - usedTime)
+
+                remaining
+            }.min()
+        }
+    }
+}