package Torello.HTML;

import Torello.HTML.helper.AttrRegEx;

import Torello.Java.StringParse;

import java.util.Properties;
import java.util.stream.Collectors;
import java.util.function.Predicate;
import java.util.regex.Matcher;

class QuotationMarks
{
    // ********************************************************************************************
    // ********************************************************************************************
    // Attribute-Value Quotation-Marks - REMOVE
    // ********************************************************************************************
    // ********************************************************************************************


    static TagNode removeAVQuotes(
            final TagNode           tn,
            final Predicate<String> attrNameTest
        )
    {
        if (tn.isClosing) throw new OpeningTagNodeExpectedException(
            "Closing TagNode's may not have any attributes, and therefore would not have any " +
            "quotation-marks to remove."
        );


        // Quick "Optimization" (Skip Out if the length is too short for a RegEx-Match)
        // 
        // "+6" ==>  The following six characters:
        // '<', '>', At-Least-1-space, At-Least-1-Attr-Char, '=', At-Least-1-Quote
             
        if (tn.str.length() <= (tn.tok.length() + 6)) return tn;

        // Beging the Quotation-Mark Stripping

        StringBuilder   sb  = new StringBuilder();
        Matcher         m   = AttrRegEx.KEY_VALUE_REGEX.matcher(tn.str);
        int             pos = 0;

        while (m.find())
        {
            // Append the "In-Between" Stuff (The "Split" part, rather than the "Match" part)
            // I have done this enough times to know that this line right here, is the only hard
            // part to remember when "updating" a TagNode (or any string at all) using a RegEx

            sb.append(tn.str.substring(pos, m.start(1)));

            String attrName = m.group(2);

            if (attrNameTest.test(attrName))
            {
                String attrValue = StringParse.ifQuotesStripQuotes(m.group(3));

                if (hasWhiteSpace(attrValue)) throw new QuotesException(
                    "Attempting to remove Quotation-Marks from an Attribute Value that contains " +
                    "Whitespace:\n" +
                    "Attribute-Value: [" + attrValue + "]"
                );

                sb
                    .append(attrName)
                    .append('=')
                    .append(attrValue);
            }

            else sb.append(m.group(1));

            pos = m.end();
        }


        // Oh, and lastly, that thing about the "hard part" when updating a string using a reg-ex
        // is: Don't forget about the very last "non-match" which always is checked immediately
        // after the loop terminates.  Add in that very last "non-match" portion.

        sb.append(tn.str.substring(pos));

        return new TagNode(tn.tok, sb.toString());
    }

    private static final char[] WHITE_SPACE = { '\t', '\n', '\f', '\r', ' ', 0 };

    private static boolean hasWhiteSpace(String attrValue)
    {
        for (int i=0; i < attrValue.length(); i++)
        {
            final char c = attrValue.charAt(i);

            for (char ws : WHITE_SPACE)
                if (c == ws) return true;
        }

        return false;
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // Attribute-Value Quotation-Marks - SET
    // ********************************************************************************************
    // ********************************************************************************************


    static TagNode setAVQuotes(
            final TagNode           tn,
            final Predicate<String> attrNameTest,
            final SD                quote
        )
    {
        if (tn.isClosing) throw new OpeningTagNodeExpectedException(
            "Closing TagNode's may not have any attributes, and therefore would not have any " +
            "location in which to insert quotation-marks."
        );


        // Just keep in mind that the Java-Doc for many of the methods in "setAV" states,
        // explicity that passing 'null' to an 'SD' parameter indicates that the user would like to
        // have No-Quotes applied to an attribute-value.  Here, that option does not exist.

        java.util.Objects.requireNonNull(quote);

        // "+6" ==> Same Calculation as in the Method above
        if (tn.str.length() <= (tn.tok.length() + 6)) return tn;

        // Beging the Quotation-Mark Stripping

        StringBuilder   sb  = new StringBuilder();
        Matcher         m   = AttrRegEx.KEY_VALUE_REGEX.matcher(tn.str);
        int             pos = 0;

        while (m.find())
        {
            sb.append(tn.str.substring(pos, m.start(1)));

            String attrName = m.group(2);

            if (attrNameTest.test(attrName))
            {
                String attrValue = StringParse.ifQuotesStripQuotes(m.group(3));

                if (contains(attrValue, quote.quote)) throw new QuotesException(
                    "Attempting to place quotes around an Attribute-Value which already " +
                    "contains at least one copy of the Quote-Character being applied:\n" +
                    "Value: [" + attrValue + "]\n" +
                    "Quote: " + quote.quote + '\n'
                );

                sb
                    .append(attrName)
                    .append('=')
                    .append(quote.quote + attrValue + quote.quote);
            }

            else sb.append(m.group(1));

            pos = m.end();
        }


        // Oh, and lastly, that thing about the "hard part" when updating a string using a reg-ex
        // is: Don't forget about the very last "non-match" which always is checked immediately
        // after the loop terminates.  Add in that very last "non-match" portion.

        sb.append(tn.str.substring(pos));

        return new TagNode(tn.tok, sb.toString());
    }

    private static boolean contains(String attrValue, char quote)
    {
        for (int i=0; i < attrValue.length(); i++)
            if (attrValue.charAt(i) == quote) return true;

        return false;
    }


    // ********************************************************************************************
    // ********************************************************************************************
    // Attribute-Value Quotation-Marks - GET
    // ********************************************************************************************
    // ********************************************************************************************


    SD getAVQuotes(
            final TagNode   tn,
            final String    attrName
        )
    {
        String attrValue = null; // AV(attrName, true);

        if (attrValue == null) throw new RuntimeException // AttributeNotFoundException
            ("Attribute [" + attrName + "] was not found in TagNode [" + tn.str + "]");

        if (attrValue.length() == 0) throw new RuntimeException( // AttributeNotFoundException (
            "Attribute [" + attrName + "] found in TagNode [" + tn.str + "] has a " +
            "String-Length of 0"
        );

        switch (attrValue.charAt(0))
        {
            case '"':   return SD.SingleQuotes;
            case '\'':  return SD.DoubleQuotes;
            default:    return null;
        }
    }
}