/*
* Copyright (C) 2015 Koji Lin <koji.lin@gmail.com>
* Copyright (C) 2011 René Jeschke <rene_jeschke@yahoo.de>
*
* Licensed 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.
*/
package io.kaif.mobile.kmark;
import java.util.LinkedHashMap;
import android.text.SpannableStringBuilder;
/**
* Emitter class responsible for generating HTML output.
*
* @author René Jeschke <rene_jeschke@yahoo.de>
*/
class Emitter {
/**
* Turns every whitespace character into a space character.
*
* @param c
* Character to check
* @return 32 is c was a whitespace, c otherwise
*/
private static char whitespaceToSpace(char c) {
return Character.isWhitespace(c) ? ' ' : c;
}
/**
* Link references.
*/
private final LinkedHashMap<String, LinkRef> linkRefs = new LinkedHashMap<>();
/**
* The configuration.
*/
private final Configuration config;
/**
* Constructor.
*/
public Emitter(final Configuration config) {
this.config = config;
}
/**
* Adds a LinkRef to this set of LinkRefs.
*
* @param key
* The key/id.
*/
public LinkRef addLinkRef(final String key, final String link, final String title) {
final String lowerCase = key.toLowerCase();
final LinkRef linkRef;
if (this.linkRefs.containsKey(lowerCase)) {
linkRef = new LinkRef(this.linkRefs.get(lowerCase).seqNumber, link, title);
} else {
linkRef = new LinkRef(this.linkRefs.size() + 1, link, title);
}
this.linkRefs.put(lowerCase, linkRef);
return linkRef;
}
/**
* Transforms the given block recursively into HTML.
*
* @param out
* The StringBuilder to write to.
* @param root
*/
public void emit(final SpannableStringBuilder out, final Block root) {
root.removeSurroundingEmptyLines();
switch (root.type) {
case NONE:
break;
case PARAGRAPH:
this.config.decorator.openParagraph(out);
break;
case BLOCKQUOTE:
this.config.decorator.openBlockquote(out);
break;
case UNORDERED_LIST:
this.config.decorator.openUnorderedList(out);
break;
case ORDERED_LIST:
this.config.decorator.openOrderedList(out);
break;
case UNORDERED_LIST_ITEM:
this.config.decorator.openUnOrderedListItem(out);
break;
case ORDERED_LIST_ITEM:
this.config.decorator.openOrderedListItem(out);
break;
}
if (root.hasLines()) {
this.emitLines(out, root);
} else {
Block block = root.blocks;
while (block != null) {
this.emit(out, block);
block = block.next;
}
}
switch (root.type) {
case NONE:
break;
case PARAGRAPH:
this.config.decorator.closeParagraph(out);
break;
case BLOCKQUOTE:
this.config.decorator.closeBlockquote(out);
break;
case UNORDERED_LIST:
this.config.decorator.closeUnorderedList(out);
break;
case ORDERED_LIST:
this.config.decorator.closeOrderedList(out);
break;
case UNORDERED_LIST_ITEM:
this.config.decorator.closeUnOrderedListItem(out);
break;
case ORDERED_LIST_ITEM:
this.config.decorator.closeOrderedListItem(out);
break;
}
}
/**
* Transforms lines into HTML.
*
* @param out
* The StringBuilder to write to.
* @param block
* The Block to process.
*/
private void emitLines(final SpannableStringBuilder out, final Block block) {
switch (block.type) {
case FENCED_CODE:
this.emitCodeLines(out, block.lines, block.meta);
break;
default:
this.emitMarkedLines(out, block.lines);
break;
}
}
/**
* Finds the position of the given Token in the given String.
*
* @param in
* The String to search on.
* @param start
* The starting character position.
* @param token
* The token to find.
* @return The position of the token or -1 if none could be found.
*/
private int findToken(final String in, int start, MarkToken token) {
int pos = start;
while (pos < in.length()) {
if (this.getToken(in, pos) == token) {
return pos;
}
pos++;
}
return -1;
}
/**
* Checks if there is a valid markdown link definition.
*
* @param out
* The StringBuilder containing the generated output.
* @param in
* Input String.
* @param start
* Starting position.
* @return The new position or -1 if there is no valid markdown link.
*/
private int checkLink(final SpannableStringBuilder out, final String in, int start) {
int pos = start + 1;
final StringBuilder temp = new StringBuilder();
temp.setLength(0);
pos = Utils.readMdLinkId(temp, in, pos);
if (pos < start) {
return -1;
}
String name = temp.toString();
LinkRef lr;
final int oldPos = pos++;
pos = Utils.skipSpaces(in, pos);
if (pos < start) {
lr = this.linkRefs.get(name.toLowerCase());
if (lr != null) {
pos = oldPos;
} else {
return -1;
}
} else if (in.charAt(pos) == '[') {
pos++;
temp.setLength(0);
pos = Utils.readRawUntil(temp, in, pos, ']');
if (pos < start) {
return -1;
}
final String id = temp.length() > 0 ? temp.toString() : name;
lr = this.linkRefs.get(id.toLowerCase());
} else {
lr = this.linkRefs.get(name.toLowerCase());
if (lr != null) {
pos = oldPos;
} else {
return -1;
}
}
if (lr == null) {
return -1;
}
if (lr.hasHttpScheme()) {
this.config.decorator.openLink(out);
this.recursiveEmitLine(out, name, 0, MarkToken.LINK);
this.config.decorator.closeLink(out, lr.link);
} else {
this.recursiveEmitLine(out, name, 0, MarkToken.LINK);
}
return pos;
}
/**
* Recursively scans through the given line, taking care of any markdown
* stuff.
*
* @param out
* The StringBuilder to write to.
* @param in
* Input String.
* @param start
* Start position.
* @param token
* The matching Token (for e.g. '*')
* @return The position of the matching Token or -1 if token was NONE or no
* Token could be found.
*/
private int recursiveEmitLine(final SpannableStringBuilder out,
final String in,
int start,
MarkToken token) {
int pos = start, a, b;
final SpannableStringBuilder temp = new SpannableStringBuilder();
while (pos < in.length()) {
final MarkToken mt = this.getToken(in, pos);
if (token != MarkToken.NONE && (mt == token
|| token == MarkToken.EM_STAR && mt == MarkToken.STRONG_STAR
|| token == MarkToken.EM_UNDERSCORE && mt == MarkToken.STRONG_UNDERSCORE)) {
return pos;
}
switch (mt) {
case LINK:
temp.clear();
b = this.checkLink(temp, in, pos);
if (b > 0) {
out.append(temp);
pos = b;
} else {
out.append(in.charAt(pos));
}
break;
case EM_STAR:
case EM_UNDERSCORE:
temp.clear();
b = this.recursiveEmitLine(temp, in, pos + 1, mt);
if (b > 0) {
this.config.decorator.openEmphasis(out);
out.append(temp);
this.config.decorator.closeEmphasis(out);
pos = b;
} else {
out.append(in.charAt(pos));
}
break;
case STRONG_STAR:
case STRONG_UNDERSCORE:
temp.clear();
b = this.recursiveEmitLine(temp, in, pos + 2, mt);
if (b > 0) {
this.config.decorator.openStrong(out);
out.append(temp);
this.config.decorator.closeStrong(out);
pos = b + 1;
} else {
out.append(in.charAt(pos));
}
break;
case STRIKE:
temp.clear();
b = this.recursiveEmitLine(temp, in, pos + 2, mt);
if (b > 0) {
this.config.decorator.openStrike(out);
out.append(temp);
this.config.decorator.closeStrike(out);
pos = b + 1;
} else {
out.append(in.charAt(pos));
}
break;
case SUPER:
temp.clear();
b = this.recursiveEmitLine(temp, in, pos + 1, mt);
if (b > 0) {
this.config.decorator.openSuper(out);
out.append(temp);
this.config.decorator.closeSuper(out);
pos = b;
} else {
out.append(in.charAt(pos));
}
break;
case CODE_SINGLE:
case CODE_DOUBLE:
a = pos + (mt == MarkToken.CODE_DOUBLE ? 2 : 1);
b = this.findToken(in, a, mt);
if (b > 0) {
pos = b + (mt == MarkToken.CODE_DOUBLE ? 1 : 0);
while (a < b && in.charAt(a) == ' ') {
a++;
}
if (a < b) {
while (in.charAt(b - 1) == ' ') {
b--;
}
this.config.decorator.openCodeSpan(out);
out.append(in.substring(a, b));
this.config.decorator.closeCodeSpan(out);
}
} else {
out.append(in.charAt(pos));
}
break;
case USER:
if (token == MarkToken.LINK) {
out.append(in.charAt(pos));
} else {
temp.clear();
b = this.checkUserLink(temp, in, pos);
if (b > 0) {
out.append(temp);
pos = b;
} else {
out.append(in.charAt(pos));
}
}
break;
case ZONE:
if (token == MarkToken.LINK) {
out.append(in.charAt(pos));
} else {
temp.clear();
b = this.checkZoneLink(temp, in, pos);
if (b > 0) {
out.append(temp);
pos = b;
} else {
out.append(in.charAt(pos));
}
}
break;
case ESCAPE:
pos++;
//$FALL-THROUGH$
default:
out.append(in.charAt(pos));
break;
}
pos++;
}
return -1;
}
/**
* change this should review Account.java
*
* @param out
* @param in
* @param start
* @return
*/
private int checkUserLink(SpannableStringBuilder out, String in, int start) {
int pos = start + 3; // skip /u/
StringBuilder temp = new StringBuilder();
String targetString = in.substring(pos, Math.min(in.length(), pos + 20));
for (int i = 0; i < targetString.length(); i++) {
char c = targetString.charAt(i);
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_') {
temp.append(c);
} else {
break;
}
}
String username = temp.toString();
if (username.length() < 3 || username.equalsIgnoreCase("null")) {
return -1;
}
//TODO support username click
out.append(username);
return pos + username.length() - 1;
}
/**
* change this should review Zone.java
*
* @param out
* @param in
* @param start
* @return
*/
private int checkZoneLink(SpannableStringBuilder out, String in, int start) {
int pos = start + 3; // skip /z/
StringBuilder temp = new StringBuilder();
String targetString = in.substring(pos, Math.min(in.length(), pos + 20));
boolean prevIsDash = false;
for (int i = 0; i < targetString.length(); i++) {
char c = targetString.charAt(i);
if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9')) {
temp.append(c);
prevIsDash = false;
} else if (c == '-') {
if (i == 0) {
return -1; //start with -
}
if (prevIsDash) {
temp.deleteCharAt(temp.length() - 1); //remove last dash
break;
}
temp.append(c);
prevIsDash = true;
} else {
if (prevIsDash) {
temp.deleteCharAt(temp.length() - 1); //remove last dash
}
break;
}
}
String zone = temp.toString();
if (zone.length() < 3 || zone.equalsIgnoreCase("null")) {
return -1;
}
//TODO support zone click
out.append(zone);
return pos + zone.length() - 1;
}
/**
* Check if there is any markdown Token.
*
* @param in
* Input String.
* @param pos
* Starting position.
* @return The Token.
*/
private MarkToken getToken(final String in, final int pos) {
final char c0 = pos > 0 ? whitespaceToSpace(in.charAt(pos - 1)) : ' ';
final char c = whitespaceToSpace(in.charAt(pos));
final char c1 = pos + 1 < in.length() ? whitespaceToSpace(in.charAt(pos + 1)) : ' ';
final char c2 = pos + 2 < in.length() ? whitespaceToSpace(in.charAt(pos + 2)) : ' ';
switch (c) {
case '*':
if (c1 == '*') {
return c0 != ' ' || c2 != ' ' ? MarkToken.STRONG_STAR : MarkToken.EM_STAR;
}
return c0 != ' ' || c1 != ' ' ? MarkToken.EM_STAR : MarkToken.NONE;
case '_':
if (c1 == '_') {
return c0 != ' ' || c2 != ' ' ? MarkToken.STRONG_UNDERSCORE : MarkToken.EM_UNDERSCORE;
}
return c0 != ' ' || c1 != ' ' ? MarkToken.EM_UNDERSCORE : MarkToken.NONE;
case '~':
if (c1 == '~') {
return MarkToken.STRIKE;
}
return MarkToken.NONE;
case '/':
if (c1 == 'u' && c2 == '/') {
return MarkToken.USER;
}
if (c1 == 'z' && c2 == '/') {
return MarkToken.ZONE;
}
return MarkToken.NONE;
case '[':
return MarkToken.LINK;
case ']':
return MarkToken.NONE;
case '`':
return c1 == '`' ? MarkToken.CODE_DOUBLE : MarkToken.CODE_SINGLE;
case '\\':
switch (c1) {
case '\\':
case '[':
case ']':
case '(':
case ')':
case '{':
case '}':
case '#':
case '"':
case '\'':
case '.':
case '>':
case '<':
case '*':
case '+':
case '-':
case '_':
case '!':
case '`':
case '^':
return MarkToken.ESCAPE;
default:
return MarkToken.NONE;
}
case '^':
return c0 == '^' || c1 == '^' ? MarkToken.NONE : MarkToken.SUPER;
default:
return MarkToken.NONE;
}
}
/**
* Writes a set of markdown lines into the StringBuilder.
*
* @param out
* The StringBuilder to write to.
* @param lines
* The lines to write.
*/
private void emitMarkedLines(final SpannableStringBuilder out, final Line lines) {
final SpannableStringBuilder in = new SpannableStringBuilder();
Line line = lines;
while (line != null) {
if (!line.isEmpty) {
in.append(line.value.substring(line.leading, line.value.length() - line.trailing));
if (line.trailing >= 2) {
in.append("\n");
}
}
line = line.next;
}
this.recursiveEmitLine(out, in.toString(), 0, MarkToken.NONE);
}
private void emitCodeLines(final SpannableStringBuilder out,
final Line lines,
final String meta) {
if (out.length() != 0) {
out.append("\n\n");
}
this.config.decorator.openCodeBlock(out);
StringBuilder builder = new StringBuilder();
Line line = lines;
while (line != null) {
if (line.isEmpty) {
builder.append("\n");
} else {
builder.append(line.value).append("\n");
}
line = line.next;
}
out.append(builder.deleteCharAt(builder.length() - 1).toString());
this.config.decorator.closeCodeBlock(out);
}
}