package name.blackcap.passman

import java.util.Formatter

private val UNPRINTABLE = setOf<Character.UnicodeBlock>(
    Character.UnicodeBlock.COMBINING_DIACRITICAL_MARKS,
    Character.UnicodeBlock.COMBINING_DIACRITICAL_MARKS_EXTENDED,
    Character.UnicodeBlock.COMBINING_HALF_MARKS,
    Character.UnicodeBlock.COMBINING_DIACRITICAL_MARKS_SUPPLEMENT,
    Character.UnicodeBlock.COMBINING_MARKS_FOR_SYMBOLS,
    Character.UnicodeBlock.HIGH_PRIVATE_USE_SURROGATES,
    Character.UnicodeBlock.HIGH_SURROGATES,
    Character.UnicodeBlock.LOW_SURROGATES,
    Character.UnicodeBlock.PRIVATE_USE_AREA,
    Character.UnicodeBlock.SPECIALS,

)

private val DELIM = '"'

private val EXEMPT = setOf<Char>(' ')
private val PREFIXED = setOf<Char>(DELIM, '\\')

fun see(input: String): String {
    val accum = StringBuilder()
    val formatter = Formatter(accum)
    accum.append(DELIM)
    for (ch in input) {
        val block = Character.UnicodeBlock.of(ch)
        if (ch in EXEMPT) {
            accum.append(ch)
        } else if (block == null || block in UNPRINTABLE || Character.isSpaceChar(ch) || Character.isWhitespace(ch)) {
            formatter.format("\\u%04x", ch.code)
        } else if (ch in PREFIXED) {
            accum.append('\\')
            accum.append(ch)
        } else {
            accum.append(ch)
        }
    }
    accum.append(DELIM)
    return accum.toString()
}

fun dump(input: String): String {
    val accum = StringBuilder()
    var needSpace = false
    for (ch in input) {
        if (needSpace) {
            accum.append(' ')
        }
        accum.append(ch.code)
        needSpace = true
    }
    return accum.toString()
}