refactor(chapter): Make chapter recognition return its value

Also move it to domain module

domain/src/commonMain/kotlin/yokai/domain/chapter/services/ChapterRecognition.kt

@@ -0,0 +1,117 @@
+package yokai.domain.chapter.services
+
+/**
+ * -R> = regex conversion.
+ */
+object ChapterRecognition {
+
+    private const val NUMBER_PATTERN = """([0-9]+)(\.[0-9]+)?(\.?[a-z]+)?"""
+
+    /**
+     * All cases with Ch.xx
+     * Mokushiroku Alice Vol.1 Ch. 4: Misrepresentation -R> 4
+     */
+    private val basic = Regex("""(?<=ch\.) *$NUMBER_PATTERN""")
+
+    /**
+     * Example: Bleach 567: Down With Snowwhite -R> 567
+     */
+    private val number = Regex(NUMBER_PATTERN)
+
+    /**
+     * Regex used to remove unwanted tags
+     * Example Prison School 12 v.1 vol004 version1243 volume64 -R> Prison School 12
+     */
+    private val unwanted = Regex("""\b(?:v|ver|vol|version|volume|season|s)[^a-z]?[0-9]+""")
+
+    /**
+     * Regex used to remove unwanted whitespace
+     * Example One Piece 12 special -R> One Piece 12special
+     */
+    private val unwantedWhiteSpace = Regex("""\s(?=extra|special|omake)""")
+
+    fun parseChapterNumber(chapterName: String, mangaTitle: String, chapterNumber: Float? = null): Float {
+        // If chapter number is known return.
+        if (chapterNumber != null && (chapterNumber == -2f || chapterNumber > -1f)) {
+            return chapterNumber
+        }
+
+        // Get chapter title with lower case
+        var name = chapterName.lowercase()
+
+        // Remove manga title from chapter title.
+        name = name.replace(mangaTitle.lowercase(), "").trim()
+
+        // Remove comma's or hyphens.
+        name = name.replace(',', '.').replace('-', '.')
+
+        // Remove unwanted white spaces.
+        name = unwantedWhiteSpace.replace(name, "")
+
+        // Remove unwanted tags.
+        name = unwanted.replace(name, "")
+
+        basic.find(name)?.let { return getChapterNumberFromMatch(it) }
+
+        number.find(name)?.let { return getChapterNumberFromMatch(it) }
+
+        return chapterNumber ?: -1f
+    }
+
+    /**
+     * Check if volume is found and return it
+     * @param match result of regex
+     * @return chapter number if found else null
+     */
+    private fun getChapterNumberFromMatch(match: MatchResult): Float {
+        return match.let {
+            val initial = it.groups[1]?.value?.toFloat()!!
+            val subChapterDecimal = it.groups[2]?.value
+            val subChapterAlpha = it.groups[3]?.value
+            val addition = checkForDecimal(subChapterDecimal, subChapterAlpha)
+            initial.plus(addition)
+        }
+    }
+
+    /**
+     * Check for decimal in received strings
+     * @param decimal decimal value of regex
+     * @param alpha alpha value of regex
+     * @return decimal/alpha float value
+     */
+    private fun checkForDecimal(decimal: String?, alpha: String?): Float {
+        if (!decimal.isNullOrEmpty()) {
+            return decimal.toFloat()
+        }
+
+        if (!alpha.isNullOrEmpty()) {
+            if (alpha.contains("extra")) {
+                return .99f
+            }
+
+            if (alpha.contains("omake")) {
+                return .98f
+            }
+
+            if (alpha.contains("special")) {
+                return .97f
+            }
+
+            val trimmedAlpha = alpha.trimStart('.')
+            if (trimmedAlpha.length == 1) {
+                return parseAlphaPostFix(trimmedAlpha[0])
+            }
+        }
+
+        return .0f
+    }
+
+    /**
+     * x.a -> x.1, x.b -> x.2, etc
+     */
+    private fun parseAlphaPostFix(alpha: Char): Float {
+        val number = alpha.code - ('a'.code - 1)
+        if (number >= 10) return 0f
+        return number / 10f
+    }
+}