Coverage Summary for Class: Almanac (day05p2)

 package day05p2
 
 import com.google.common.collect.ImmutableMap
 import com.google.common.collect.ImmutableSortedMap
 
 
 fun String.toAlmanac(): Almanac {
   val lines = lineSequence().toMutableList()
   val seeds = lines.removeFirst().toSeedRangesSet()
   require(lines.removeFirst().isEmpty())
   val maps = ImmutableMap.builder<Category, AlmanacMap>()
   while (lines.isNotEmpty()) {
     val map = lines.toAlmanacMap()
     maps.put(map.name.source, map)
   }
   return Almanac(seeds, maps.build())
 }
 
 fun String.toAlmanacMap(): AlmanacMap = lineSequence().toMutableList().toAlmanacMap()
 
 
 fun MutableList<String>.toAlmanacMap(): AlmanacMap {
   val name = removeFirst().toMapName()
   val ranges = ImmutableSortedMap.naturalOrder<Long, AlmanacMapRange>()
   while (isNotEmpty()) {
     val line = removeFirst()
     if (line.isBlank()) {
       break
     }
     val range = line.toMapRange(name)
     ranges.put(range.sourceRange.start, range)
   }
   return AlmanacMap(name, ranges.build())
 }
 
 fun String.toMapRange(name: AlmanacMapName): AlmanacMapRange {
   val (destinationRangeStart, sourceRangeStart, rangeLength) = split(" ")
   return AlmanacMapRange(
     name,
     sourceRangeStart.toLong(),
     destinationRangeStart.toLong(),
     rangeLength = rangeLength.toLong()
   )
 }
 
 fun String.toMapName(): AlmanacMapName =
   substringBeforeLast(" map:")
     .split("-to-")
     .let { (source, destination) -> AlmanacMapName(source, destination) }
 
 private val intRegex = """(\d+) (\d+)""".toRegex()
 fun String.toSeedRangesSet(): Set<CategoryNumberRange> = substringAfter("seeds: ").let { seeds ->
   intRegex.findAll(seeds).map { m ->
     m.groupValues.drop(1).let { (start, count) ->
       seedCategory.range(start.toLong(), count.toLong().asCount())
     }
   }.toSet()
 }
 
 data class Almanac(val seeds: Set<CategoryNumberRange>, val maps: Map<Category, AlmanacMap>) {
   init {
     maps.forEach { (source, map) -> require(source == map.name.source) }
   }
 
   fun findLowestLocationNumber(): Long = map(seeds.toMutableList(), locationCategory).minOf { it.start }
 
   fun map(source: MutableList<CategoryNumberRange>, destinationCat: Category): MutableList<CategoryNumberRange> {
     var value = source
     while (true) {
       require(value.isNotEmpty())
       val category = value[0].category
       if (category == destinationCat) return value
       value = maps.getValue(category).map(value)
     }
   }
 }
 
 data class AlmanacMap(val name: AlmanacMapName, val ranges: ImmutableSortedMap<Long, AlmanacMapRange>) {
 
   fun map(sourceRanges: MutableList<CategoryNumberRange>): MutableList<CategoryNumberRange> {
     val result = mutableListOf<CategoryNumberRange>()
     while (sourceRanges.isNotEmpty()) {
       val sourceRange = sourceRanges.removeFirst()
       var mappingResult = ranges.floorEntry(sourceRange.start)?.value?.map(sourceRange)
       if (mappingResult == null ||
         (mappingResult.mappedDestinationRange == null && mappingResult.notMappedSourceRanges.contains(sourceRange))
       ) {
         mappingResult = ranges.floorEntry(sourceRange.end)?.value?.map(sourceRange)
       }
       val mappedDestinationRange = mappingResult?.mappedDestinationRange
       if (mappedDestinationRange != null) {
         result.add(mappedDestinationRange)
         if (mappingResult != null) sourceRanges.addAll(mappingResult.notMappedSourceRanges)
       } else {
         result.add(sourceRange.copy(category = name.destination))
       }
     }
     return result
   }
 }
 
 data class AlmanacMapName(val source: Category, val destination: Category) {
   constructor(source: String, destination: String) : this(Category(source), Category(destination))
 }
 
 data class AlmanacMapRange(
   val sourceRange: CategoryNumberRange,
   val destinationRange: CategoryNumberRange
 ) {
   constructor(name: AlmanacMapName, sourceRangeStart: Long, destinationRangeStart: Long, rangeLength: Long) :
     this(
       name.source.range(sourceRangeStart, rangeLength.asCount()),
       name.destination.range(destinationRangeStart, rangeLength.asCount())
     )
 
   private fun map(source: Long): Long {
     require(sourceRange.contains(source))
     return destinationRange.start + source - sourceRange.start
   }
 
   fun map(source: CategoryNumberRange): MappingResult {
     val overlappingResult = sourceRange.overlapOn(source)
     val mappedDestinationRange = if (overlappingResult.overlapped == null) null else {
       destinationRange.category.range(map(overlappingResult.overlapped.start), map(overlappingResult.overlapped.end))
     }
     return MappingResult(
       mappedDestinationRange,
       overlappingResult.notOverlappedRanges()
     )
   }
 
   data class MappingResult(
     val mappedDestinationRange: CategoryNumberRange?,
     val notMappedSourceRanges: Set<CategoryNumberRange>
   )
 }
 
 data class CategoryNumberRange(val category: Category, val start: Long, val end: Long) {
 
   init {
     require(start <= end)
   }
 
   fun contains(value: Long): Boolean = value in start..end
 
   fun overlapOn(range: CategoryNumberRange): OverlappingResult {
     require(category == range.category)
 
     // no overlap
     if (start > range.end) {
       return OverlappingResult(range, null, null)
     }
     if (end < range.start) {
       return OverlappingResult(null, null, range)
     }
 
     // some overlap
     val left = if (start <= range.start) null else category.range(range.start, start - 1)
     val right = if (end >= range.end) null else category.range(end + 1, range.end)
     val overlapped = category.range(maxOf(start, range.start), minOf(end, range.end))
     return OverlappingResult(left, overlapped, right)
   }
 
   data class OverlappingResult(
     val left: CategoryNumberRange?,
     val overlapped: CategoryNumberRange?,
     val right: CategoryNumberRange?
   ) {
     init {
       require(left != null || overlapped != null || right != null)
       require(sequenceOf(left, overlapped, right).filterNotNull().map { it.category }.distinct().count() == 1)
     }
 
     fun notOverlappedRanges() = sequenceOf(left, right).filterNotNull().toSet()
   }
 }
 
 data class Count(val value: Long)
 
 fun Long.asCount() = Count(this)
 
 val seedCategory = Category("seed")
 val soilCategory = Category("soil")
 val locationCategory = Category("location")
 
 data class Category(val value: String) {
   fun range(start: Long, end: Long) = CategoryNumberRange(this, start, end)
   fun range(start: Long, count: Count) = range(start, start + count.value - 1)
 }