package Torello.JavaDoc;

import java.io.IOException;
import java.util.Vector;

import Torello.HTML.*;

import Torello.HTML.NodeSearch.TagNodeFind;
import Torello.Java.HiLiteMe;
import Torello.JDUInternal.Throwables.HiLiteError;

/**
 * A simple Functional-Interface allowing a user to swap in any customized, alternate or
 * proprietary Syntax HiLiter to replace the default HiLiter used by this Upgrader Tool.
 * 
 * <BR /><BR /><EMBED CLASS='external-html' DATA-FILE-ID=HILITER>
 */
@FunctionalInterface
public interface HiLiter
{
    /**
     * This {@code Functional Interface} expects this method to be implemented.  Any HiLiter that
     * would be "plugged into" this Documentation Tool must be able to <B>Pretty-Print HiLite</B>
     * input Source-Code (passed as a {@code java.lang.String}) <I>and return HTML</I>.
     * 
     * <BR /><BR /><B>NOTE:</B> Any Code HiLiter that can operate with this input may be plugged
     * in here.  In order to "Vectorize" HTML, just use the
     * {@code HTMLPage.getPageTokens(String, false)} method.
     *
     * @param code This is the Source-Code as a {@code java.lang.String}
     * 
     * @param codeType This is a short descriptor of what kind of code is being passed.  The most
     * frequent values for this parameter are: {@code 'java', 'html', 'js'} etc...
     * 
     * @param snippetOrComplete This is a {@code boolean} that when {@code TRUE}, indicates that
     * a <B>code-snippet</B> has been passed, and when {@code FALSE} indicates that a <B>complete
     * source code file</B> has been passed.
     * 
     * @return The intention is to return a Vectorized-HTML page (or sub-page) that contains a
     * <B>HiLited &AMP; Pretty-Printed</B> version of the source-code.
     * 
     * @throws IOException This method is not defined, but it is permitted to throw 
     * {@code IOException} - if there have been I/O problems when attempting to transform the
     * source-code.
     *
     * @throws HiLiteException This exception may be used if other problems occur during the
     * transformation process.
     */
    public Vector<HTMLNode> hiLite
        (String code, String codeType, boolean snippetOrComplete)
        throws IOException, HiLiteException;

    /**
     * The Default <B>Code HiLiter</B> uses the class {@link Torello.Java.HiLiteMe}.  This method
     * is invoked by the {@link Upgrade} class and used to HiLite <I>BOTH</I> code-snippets
     * <I>AND</I> complete source-code files.
     * 
     * @param c This is the Server-Cache that <I>may or may not be used</I>.  If this parameter
     * is passed {@code 'null'}, it will be ignored.
     * 
     * @param snippetStyleCode Some of the source-code passed to this {@code HiLiter} will be
     * short <I>code-snippets</I>, while other passed values of source-code will be <I>complete
     * source-code files.</I>  This {@code String} is the {@code 'Style Parameter'} used for
     * code-snippets.
     * 
     * <BR /><BR />You may view the complete-list of valid Style Parameters in use with this
     * HiLiter with {@link HiLiteMe#getStyleTypes()}.
     * 
     * @param completeStyleCode When the {@code HiLiter} is asked to Hi-Lite and entire source
     * code file, this parameter will be used for a {@code 'Style Parameter'} with the 
     * {@code HiLiter}.
     * 
     * @return An instance of {@code HiLiter} that can be used by the {@code Upgrade} Tool
     * 
     * @throws IllegalArgumentException If invalid Styling-Parameters were passed either to
     * {@code 'snippetStyleCode'} or {@code 'completeStyleCode'}.
     * 
     * @see HiLiteMe#prettyPrintScrapeToVectorAndSimplify(String, String, String, boolean)
     * @see HiLiteMe#prettyPrintScrapeToVectorAndSimplify(String, String, String, boolean, HiLiteMe.Cache)
     */
    public static HiLiter getDefault
        (Torello.Java.HiLiteMe.Cache c, String snippetStyleCode, String completeStyleCode)
    {
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // FAIL-FAST: Make sure that VALID Code-Styling Parameters were passed before building
        //            the HiLiter
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        if (! HiLiteMe.isStyleType(snippetStyleCode)) throw new IllegalArgumentException(
            "You have passed \"" + snippetStyleCode + "\" to parameter 'snippetStyleCode', but " +
            "this is not actually a valid Style Parameter for class HiLite.Me.  Review the list " +
            "Style Types in that class using HiLiteMe.getStyleTypes(), or look at the docs for " +
            "that class"
        );

        if (! HiLiteMe.isStyleType(completeStyleCode)) throw new IllegalArgumentException(
            "You have passed \"" + completeStyleCode + "\" to parameter 'completeStyleCode', but " +
            "this is not actually a valid Style Parameter for class HiLite.Me.  Review the list " +
            "Style Types in that class using HiLiteMe.getStyleTypes(), or look at the docs for " +
            "that class"
        );

        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
        // Return a HiLiter instance that uses Torello.Java.HiLiteMe
        // *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

        return (c == null)
            ? new HiLiter()
            {
                private final String snippetSC  = snippetStyleCode;
                private final String completeSC = completeStyleCode;

                public Vector<HTMLNode> hiLite
                    (String code, String codeType, boolean snippetOrComplete)
                    throws IOException
                { 
                    return snippetOrComplete

                        ? HiLiteMe.prettyPrintScrapeToVectorAndSimplify
                            (code, codeType, snippetSC, false)

                        : addAnchorIDs(
                            HiLiteMe.prettyPrintScrapeToVectorAndSimplify
                                (code, codeType, completeSC, true));
                }
            }
            : new HiLiter()
            {
                // This one has a Cache
                private final Torello.Java.HiLiteMe.Cache cache = c;

                private final String snippetSC  = snippetStyleCode;
                private final String completeSC = completeStyleCode;

                public Vector<HTMLNode> hiLite
                    (String code, String codeType, boolean snippetOrComplete)
                    throws IOException
                {
                    // The Parameters to this Invokation are identical to the call above.  See
                    // comments above...  This method includes 'cache' parameter, which is the last
                    // parameter to this method.

                    return snippetOrComplete

                        ? HiLiteMe.prettyPrintScrapeToVectorAndSimplify
                            (code, codeType, snippetSC, false /* no line nums */,  cache)

                        : addAnchorIDs(
                            HiLiteMe.prettyPrintScrapeToVectorAndSimplify
                                (code, codeType, completeSC, true /* line nums */,  cache));
                }
            };
    }

    static Vector<HTMLNode> addAnchorIDs(Vector<HTMLNode> v)
    {
        int pos = TagNodeFind.first(v, TC.OpeningTags, "pre") + 1;

        if (pos == 0) throw new HiLiteError
            ("A <PRE> Element was not found in the returned HTML from Pygments.org");

        StringBuilder sb = new StringBuilder();

        for (String s : v.elementAt(pos).str.split("\n"))
            sb.append("<A ID=L" + s.trim() + ">" + s.trim() + "</A>\n");

        v.setElementAt(new TextNode(sb.toString()), pos);

        return v;
    }
}