/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id: SingleByteFont.java 1805173 2017-08-16 10:50:04Z ssteiner $ */

package org.apache.fop.fonts;

import java.awt.Rectangle;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.xmlgraphics.fonts.Glyphs;

import org.apache.fop.apps.io.InternalResourceResolver;
import org.apache.fop.fonts.truetype.OpenFont.PostScriptVersion;
import org.apache.fop.util.CharUtilities;

Generic SingleByte font
/**
 * Generic SingleByte font
 */
public class SingleByteFont extends CustomFont {

    
logger /** logger */
    private  static Log log = LogFactory.getLog(SingleByteFont.class);

    protected SingleByteEncoding mapping;
    private boolean useNativeEncoding;

    protected int[] width;

    private Rectangle[] boundingBoxes;

    private Map<Character, Character> alternativeCodes;

    private PostScriptVersion ttPostScriptVersion;

    private int usedGlyphsCount;
    private LinkedHashMap<Integer, String> usedGlyphNames;
    private Map<Integer, Integer> usedGlyphs;
    private Map<Integer, Character> usedCharsIndex;
    private Map<Character, Integer> charGIDMappings;

    public SingleByteFont(InternalResourceResolver resourceResolver) {
        super(resourceResolver);
        setEncoding(CodePointMapping.WIN_ANSI_ENCODING);
    }

    public SingleByteFont(InternalResourceResolver resourceResolver, EmbeddingMode embeddingMode) {
        this(resourceResolver);
        setEmbeddingMode(embeddingMode);
        if (embeddingMode != EmbeddingMode.FULL) {
            usedGlyphNames = new LinkedHashMap<Integer, String>();
            usedGlyphs = new HashMap<Integer, Integer>();
            usedCharsIndex = new HashMap<Integer, Character>();
            charGIDMappings = new HashMap<Character, Integer>();

            // The zeroth value is reserved for .notdef
            usedGlyphs.put(0, 0);
            usedGlyphsCount++;
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public boolean isEmbeddable() {
        return (!(getEmbedFileURI() == null
                && getEmbedResourceName() == null));
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public boolean isSubsetEmbedded() {
        return getEmbeddingMode() != EmbeddingMode.FULL;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public String getEncodingName() {
        return this.mapping.getName();
    }

    
Returns the code point mapping (encoding) of this font.
Returns:
the code point mapping/**
     * Returns the code point mapping (encoding) of this font.
     * @return the code point mapping
     */
    public SingleByteEncoding getEncoding() {
        return this.mapping;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public int getWidth(int i, int size) {
        if (i < 256) {
            int idx = i - getFirstChar();
            if (idx >= 0 && idx < width.length) {
                return size * width[idx];
            }
        } else if (this.additionalEncodings != null) {
            int encodingIndex = (i / 256) - 1;
            SimpleSingleByteEncoding encoding = getAdditionalEncoding(encodingIndex);
            int codePoint = i % 256;
            NamedCharacter nc = encoding.getCharacterForIndex(codePoint);
            UnencodedCharacter uc
                = this.unencodedCharacters.get(nc.getSingleUnicodeValue());
            return size * uc.getWidth();
        }
        return 0;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public int[] getWidths() {
        int[] arr = new int[width.length];
        System.arraycopy(width, 0, arr, 0, width.length);
        return arr;
    }

    public Rectangle getBoundingBox(int glyphIndex, int size) {
        Rectangle bbox = null;
        if (glyphIndex < 256) {
            int idx = glyphIndex - getFirstChar();
            if (idx >= 0 && idx < boundingBoxes.length) {
                bbox =  boundingBoxes[idx];
            }
        } else if (this.additionalEncodings != null) {
            int encodingIndex = (glyphIndex / 256) - 1;
            SimpleSingleByteEncoding encoding = getAdditionalEncoding(encodingIndex);
            int codePoint = glyphIndex % 256;
            NamedCharacter nc = encoding.getCharacterForIndex(codePoint);
            UnencodedCharacter uc = this.unencodedCharacters.get(nc.getSingleUnicodeValue());
            bbox = uc.getBBox();
        }
        return bbox == null ? null : new Rectangle(bbox.x * size, bbox.y * size, bbox.width * size, bbox.height * size);
    }

    
Lookup a character using its alternative names. If found, cache it so we
can speed up lookups.
Params:
c – the character
Returns:
the suggested alternative character present in the font/**
     * Lookup a character using its alternative names. If found, cache it so we
     * can speed up lookups.
     * @param c the character
     * @return the suggested alternative character present in the font
     */
    private char findAlternative(char c) {
        char d;
        if (alternativeCodes == null) {
            alternativeCodes = new java.util.HashMap<Character, Character>();
        } else {
            Character alternative = alternativeCodes.get(c);
            if (alternative != null) {
                return alternative;
            }
        }
        String charName = Glyphs.charToGlyphName(c);
        String[] charNameAlternatives = Glyphs.getCharNameAlternativesFor(charName);
        if (charNameAlternatives != null && charNameAlternatives.length > 0) {
            for (String charNameAlternative : charNameAlternatives) {
                if (log.isDebugEnabled()) {
                    log.debug("Checking alternative for char " + c + " (charname="
                            + charName + "): " + charNameAlternative);
                }
                String s = Glyphs.getUnicodeSequenceForGlyphName(charNameAlternative);
                if (s != null) {
                    d = lookupChar(s.charAt(0));
                    if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
                        alternativeCodes.put(c, d);
                        return d;
                    }
                }
            }
        }

        return SingleByteEncoding.NOT_FOUND_CODE_POINT;
    }

    private char lookupChar(char c) {
        char d = mapping.mapChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return d;
        }

        // Check unencoded characters which are available in the font by
        // character name
        d = mapUnencodedChar(c);
        return d;
    }

    private boolean isSubset() {
        return getEmbeddingMode() == EmbeddingMode.SUBSET;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public char mapChar(char c) {
        notifyMapOperation();
        char d = lookupChar(c);
        if (d == SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            // Check for alternative
            d = findAlternative(c);
            if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
                return d;
            } else {
                this.warnMissingGlyph(c);
                return Typeface.NOT_FOUND;
            }
        }
        if (isEmbeddable() && isSubset()) {
            mapChar(d, c);
        }
        return d;
    }

    private int mapChar(int glyphIndex, char unicode) {
        // Reencode to a new subset font or get the reencoded value
        // IOW, accumulate the accessed characters and build a character map for them
        Integer subsetCharSelector = usedGlyphs.get(glyphIndex);
        if (subsetCharSelector == null) {
            int selector = usedGlyphsCount;
            usedGlyphs.put(glyphIndex, selector);
            usedCharsIndex.put(selector, unicode);
            charGIDMappings.put(unicode, glyphIndex);
            usedGlyphsCount++;
            return selector;
        } else {
            return subsetCharSelector;
        }
    }

    private char getUnicode(int index) {
        Character mapValue = usedCharsIndex.get(index);
        if (mapValue != null) {
            return mapValue;
        } else {
            return CharUtilities.NOT_A_CHARACTER;
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public boolean hasChar(char c) {
        char d = mapping.mapChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return true;
        }
        //Check unencoded characters which are available in the font by character name
        d = mapUnencodedChar(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return true;
        }
        // Check if an alternative exists
        d = findAlternative(c);
        if (d != SingleByteEncoding.NOT_FOUND_CODE_POINT) {
            return true;
        }
        return false;
    }

    /* ---- single byte font specific setters --- */

    
Updates the mapping variable based on the encoding.
Params:
encoding – the name of the encoding/**
     * Updates the mapping variable based on the encoding.
     * @param encoding the name of the encoding
     */
    protected void updateMapping(String encoding) {
        try {
            this.mapping = CodePointMapping.getMapping(encoding);
        } catch (UnsupportedOperationException e) {
            log.error("Font '" + super.getFontName() + "': " + e.getMessage());
        }
    }

    
Sets the encoding of the font.
Params:
encoding – the encoding (ex. "WinAnsiEncoding" or "SymbolEncoding")/**
     * Sets the encoding of the font.
     * @param encoding the encoding (ex. "WinAnsiEncoding" or "SymbolEncoding")
     */
    public void setEncoding(String encoding) {
        updateMapping(encoding);
    }

    
Sets the encoding of the font.
Params:
encoding – the encoding information/**
     * Sets the encoding of the font.
     * @param encoding the encoding information
     */
    public void setEncoding(CodePointMapping encoding) {
        this.mapping = encoding;
    }

    
Controls whether the font is configured to use its native encoding or if it
may need to be re-encoded for the target format.
Params:
value – true indicates that the configured encoding is the font's native encoding/**
     * Controls whether the font is configured to use its native encoding or if it
     * may need to be re-encoded for the target format.
     * @param value true indicates that the configured encoding is the font's native encoding
     */
    public void setUseNativeEncoding(boolean value) {
        this.useNativeEncoding = value;
    }

    
Indicates whether this font is configured to use its native encoding. This
method is used to determine whether the font needs to be re-encoded.
Returns:
true if the font uses its native encoding./**
     * Indicates whether this font is configured to use its native encoding. This
     * method is used to determine whether the font needs to be re-encoded.
     * @return true if the font uses its native encoding.
     */
    public boolean isUsingNativeEncoding() {
        return this.useNativeEncoding;
    }

    
Sets a width for a character.
Params:
index – index of the character
w – the width of the character/**
     * Sets a width for a character.
     * @param index index of the character
     * @param w the width of the character
     */
    public void setWidth(int index, int w) {
        if (this.width == null) {
            this.width = new int[getLastChar() - getFirstChar() + 1];
        }
        this.width[index - getFirstChar()] = w;
    }

    public void setBoundingBox(int index, Rectangle bbox) {
        if (this.boundingBoxes == null) {
            this.boundingBoxes = new Rectangle[getLastChar() - getFirstChar() + 1];
        }
        this.boundingBoxes[index - getFirstChar()] = bbox;
    }

    
Adds an unencoded character (one that is not supported by the primary encoding).
Params:
ch – the named character
width – the width of the character/**
     * Adds an unencoded character (one that is not supported by the primary encoding).
     * @param ch the named character
     * @param width the width of the character
     */
    public void addUnencodedCharacter(NamedCharacter ch, int width, Rectangle bbox) {
        if (this.unencodedCharacters == null) {
            this.unencodedCharacters = new HashMap<Character, UnencodedCharacter>();
        }
        if (ch.hasSingleUnicodeValue()) {
            UnencodedCharacter uc = new UnencodedCharacter(ch, width, bbox);
            this.unencodedCharacters.put(ch.getSingleUnicodeValue(), uc);
        } else {
            //Cannot deal with unicode sequences, so ignore this character
        }
    }

    
Makes all unencoded characters available through additional encodings. This method
is used in cases where the fonts need to be encoded in the target format before
all text of the document is processed (for example in PostScript when resource optimization
is disabled).
/**
     * Makes all unencoded characters available through additional encodings. This method
     * is used in cases where the fonts need to be encoded in the target format before
     * all text of the document is processed (for example in PostScript when resource optimization
     * is disabled).
     */
    public void encodeAllUnencodedCharacters() {
        if (this.unencodedCharacters != null) {
            Set<Character> sortedKeys = new TreeSet<Character>(this.unencodedCharacters.keySet());
            for (Character ch : sortedKeys) {
                char mapped = mapChar(ch);
                assert mapped != Typeface.NOT_FOUND;
            }
        }
    }

    
Returns an array with the widths for an additional encoding.
Params:
index – the index of the additional encoding
Returns:
the width array/**
     * Returns an array with the widths for an additional encoding.
     * @param index the index of the additional encoding
     * @return the width array
     */
    public int[] getAdditionalWidths(int index) {
        SimpleSingleByteEncoding enc = getAdditionalEncoding(index);
        int[] arr = new int[enc.getLastChar() - enc.getFirstChar() + 1];
        for (int i = 0, c = arr.length; i < c; i++) {
            NamedCharacter nc = enc.getCharacterForIndex(enc.getFirstChar() + i);
            UnencodedCharacter uc = this.unencodedCharacters.get(
                    nc.getSingleUnicodeValue());
            arr[i] = uc.getWidth();
        }
        return arr;
    }

    protected static final class UnencodedCharacter {

        private final NamedCharacter character;
        private final int width;
        private final Rectangle bbox;

        public UnencodedCharacter(NamedCharacter character, int width, Rectangle bbox) {
            this.character = character;
            this.width = width;
            this.bbox = bbox;
        }

        public NamedCharacter getCharacter() {
            return this.character;
        }

        public int getWidth() {
            return this.width;
        }

        public Rectangle getBBox() {
            return bbox;
        }

        
{@inheritDoc} /** {@inheritDoc} */
        @Override
        public String toString() {
            return getCharacter().toString();
        }
    }

    
Sets the version of the PostScript table stored in the TrueType font represented by
this instance.
Params:
version – version of the post table/**
     * Sets the version of the PostScript table stored in the TrueType font represented by
     * this instance.
     *
     * @param version version of the post table
     */
    public void setTrueTypePostScriptVersion(PostScriptVersion version) {
        ttPostScriptVersion = version;
    }

    
Returns the version of the PostScript table stored in the TrueType font represented by
this instance.
Returns:
the version of the post table/**
     * Returns the version of the PostScript table stored in the TrueType font represented by
     * this instance.
     *
     * @return the version of the post table
     */
    public PostScriptVersion getTrueTypePostScriptVersion() {
        assert getFontType() == FontType.TRUETYPE;
        return ttPostScriptVersion;
    }

    
Returns a Map of used Glyphs.
Returns:
Map Map of used Glyphs/**
     * Returns a Map of used Glyphs.
     * @return Map Map of used Glyphs
     */
    public Map<Integer, Integer> getUsedGlyphs() {
        return Collections.unmodifiableMap(usedGlyphs);
    }

    public char getUnicodeFromSelector(int selector) {
        return getUnicode(selector);
    }

    public int getGIDFromChar(char ch) {
        return charGIDMappings.get(ch);
    }

    public char getUnicodeFromGID(int glyphIndex) {
        int selector = usedGlyphs.get(glyphIndex);
        return usedCharsIndex.get(selector);
    }

    public void mapUsedGlyphName(int gid, String value) {
        usedGlyphNames.put(gid, value);
    }

    public Map<Integer, String> getUsedGlyphNames() {
        return usedGlyphNames;
    }

    public String getGlyphName(int idx) {
        if (idx < mapping.getCharNameMap().length) {
            return mapping.getCharNameMap()[idx];
        } else {
            int selector = usedGlyphs.get(idx);
            char theChar = usedCharsIndex.get(selector);
            return unencodedCharacters.get(theChar).getCharacter().getName();
        }
    }
}