1 files changed, 125 insertions, 0 deletions
diff --git a/src/main/kotlin/features/texturepack/NumberMatcher.kt b/src/main/kotlin/features/texturepack/NumberMatcher.kt
new file mode 100644
index 0000000..7e6665f
--- /dev/null
+++ b/src/main/kotlin/features/texturepack/NumberMatcher.kt
@@ -0,0 +1,125 @@
+
+package moe.nea.firmament.features.texturepack
+
+import com.google.gson.JsonElement
+import com.google.gson.JsonPrimitive
+import moe.nea.firmament.util.useMatch
+
+abstract class NumberMatcher {
+    abstract fun test(number: Number): Boolean
+
+
+    companion object {
+        fun parse(jsonElement: JsonElement): NumberMatcher? {
+            if (jsonElement is JsonPrimitive) {
+                if (jsonElement.isString) {
+                    val string = jsonElement.asString
+                    return parseRange(string) ?: parseOperator(string)
+                }
+                if (jsonElement.isNumber) {
+                    val number = jsonElement.asNumber
+                    val hasDecimals = (number.toString().contains("."))
+                    return MatchNumberExact(if (hasDecimals) number.toLong() else number.toDouble())
+                }
+            }
+            return null
+        }
+
+        private val intervalSpec =
+            "(?<beginningOpen>[\\[\\(])(?<beginning>[0-9.]+)?,(?<ending>[0-9.]+)?(?<endingOpen>[\\]\\)])"
+                .toPattern()
+
+        fun parseRange(string: String): RangeMatcher? {
+            intervalSpec.useMatch<Nothing>(string) {
+                // Open in the set-theory sense, meaning does not include its end.
+                val beginningOpen = group("beginningOpen") == "("
+                val endingOpen = group("endingOpen") == ")"
+                val beginning = group("beginning")?.toDouble()
+                val ending = group("ending")?.toDouble()
+                return RangeMatcher(beginning, !beginningOpen, ending, !endingOpen)
+            }
+            return null
+        }
+
+        enum class Operator(val operator: String) {
+            LESS("<") {
+                override fun matches(comparisonResult: Int): Boolean {
+                    return comparisonResult < 0
+                }
+            },
+            LESS_EQUALS("<=") {
+                override fun matches(comparisonResult: Int): Boolean {
+                    return comparisonResult <= 0
+                }
+            },
+            GREATER(">") {
+                override fun matches(comparisonResult: Int): Boolean {
+                    return comparisonResult > 0
+                }
+            },
+            GREATER_EQUALS(">=") {
+                override fun matches(comparisonResult: Int): Boolean {
+                    return comparisonResult >= 0
+                }
+            },
+            ;
+
+            abstract fun matches(comparisonResult: Int): Boolean
+        }
+
+        private val operatorPattern = "(?<operator>${Operator.entries.joinToString("|") {it.operator}})(?<value>[0-9.]+)".toPattern()
+
+        fun parseOperator(string: String): OperatorMatcher? {
+            operatorPattern.useMatch<Nothing>(string) {
+                val operatorName = group("operator")
+                val operator = Operator.entries.find { it.operator == operatorName }!!
+                val value = group("value").toDouble()
+                return OperatorMatcher(operator, value)
+            }
+            return null
+        }
+
+        data class OperatorMatcher(val operator: Operator, val value: Double) : NumberMatcher() {
+            override fun test(number: Number): Boolean {
+                return operator.matches(number.toDouble().compareTo(value))
+            }
+        }
+
+
+        data class MatchNumberExact(val number: Number) : NumberMatcher() {
+            override fun test(number: Number): Boolean {
+                return when (this.number) {
+                    is Double -> number.toDouble() == this.number.toDouble()
+                    else -> number.toLong() == this.number.toLong()
+                }
+            }
+        }
+
+        data class RangeMatcher(
+            val beginning: Double?,
+            val beginningInclusive: Boolean,
+            val ending: Double?,
+            val endingInclusive: Boolean,
+        ) : NumberMatcher() {
+            override fun test(number: Number): Boolean {
+                val value = number.toDouble()
+                if (beginning != null) {
+                    if (beginningInclusive) {
+                        if (value < beginning) return false
+                    } else {
+                        if (value <= beginning) return false
+                    }
+                }
+                if (ending != null) {
+                    if (endingInclusive) {
+                        if (value > ending) return false
+                    } else {
+                        if (value >= ending) return false
+                    }
+                }
+                return true
+            }
+        }
+    }
+
+}