|
| 1 | +package kategory.fold |
| 2 | + |
| 3 | +import kategory.common.utils.fullName |
| 4 | +import me.eugeniomarletti.kotlin.metadata.escapedClassName |
| 5 | +import java.io.File |
| 6 | + |
| 7 | +class AutoFoldFileGenerator( |
| 8 | + private val annotatedList: Collection<AnnotatedFold>, |
| 9 | + private val generatedDir: File |
| 10 | +) { |
| 11 | + |
| 12 | + fun generate() = annotatedList.map(this::processElement) |
| 13 | + .map { (element, fold) -> |
| 14 | + "${foldAnnotationClass.simpleName}.${element.type.simpleName.toString().toLowerCase()}.kt" to |
| 15 | + fileHeader(element.classData.`package`.escapedClassName) + fold |
| 16 | + }.map { (name, fileString) -> File(generatedDir, name).writeText(fileString) } |
| 17 | + |
| 18 | + private fun processElement(annotatedFold: AnnotatedFold): Pair<AnnotatedFold, String> = |
| 19 | + annotatedFold to annotatedFold.targets.let { targets -> |
| 20 | + val sourceClassName = annotatedFold.classData.fullName.escapedClassName |
| 21 | + val sumTypeParams = typeParams(annotatedFold.typeParams) |
| 22 | + val returnType = getFoldType(annotatedFold.typeParams) |
| 23 | + val functionTypeParams = functionTypeParams(annotatedFold.typeParams, returnType) |
| 24 | + |
| 25 | + """inline fun $functionTypeParams $sourceClassName$sumTypeParams.fold( |
| 26 | + |${params(targets, returnType)} |
| 27 | + |): $returnType = when (this) { |
| 28 | + |${patternMatching(targets)} |
| 29 | + |} |
| 30 | + """.trimMargin() |
| 31 | + } |
| 32 | + |
| 33 | + fun typeParams(params: List<String>): String = |
| 34 | + if (params.isNotEmpty()) params.joinToString(prefix = "<", postfix = ">") |
| 35 | + else "" |
| 36 | + |
| 37 | + fun params(variants: List<Variant>, returnType: String): String = variants.joinToString(transform = { variant -> |
| 38 | + " crossinline ${variant.simpleName.decapitalize()}: (${variant.fullName.escapedClassName}${typeParams(variant.typeParams)}) -> $returnType" |
| 39 | + }, separator = ",\n") |
| 40 | + |
| 41 | + fun patternMatching(variants: List<Variant>): String = variants.joinToString(transform = { variant -> |
| 42 | + " is ${variant.fullName.escapedClassName} -> ${variant.simpleName.decapitalize().escapedClassName}(this)" |
| 43 | + }, separator = "\n") |
| 44 | + |
| 45 | + fun functionTypeParams(params: List<String>, returnType: String): String = |
| 46 | + if (params.isEmpty()) "" |
| 47 | + else params.joinToString(prefix = "<", postfix = ", $returnType>") |
| 48 | + |
| 49 | + fun getFoldType(params: List<String>): String { |
| 50 | + fun check(param: String, next: List<String>): String = (param[0] + 1).let { |
| 51 | + if (next.contains(it.toString())) check(next.firstOrNull() ?: "", next.drop(1)) |
| 52 | + else it.toString() |
| 53 | + } |
| 54 | + |
| 55 | + return check(params.firstOrNull() ?: "", params.drop(1)) |
| 56 | + } |
| 57 | + |
| 58 | + fun fileHeader(packageName: String): String = |
| 59 | + """package $packageName |
| 60 | + | |
| 61 | + |""".trimMargin() |
| 62 | + |
| 63 | +} |
| 64 | + |
0 commit comments