/**
* Tag-closer extension for CodeMirror.
*
* This extension adds a "closeTag" utility function that can be used with key bindings to
* insert a matching end tag after the ">" character of a start tag has been typed. It can
* also complete "</" if a matching start tag is found. It will correctly ignore signal
* characters for empty tags, comments, CDATA, etc.
*
* The function depends on internal parser state to identify tags. It is compatible with the
* following CodeMirror modes and will ignore all others:
* - htmlmixed
* - xml
* - xmlpure
*
* See demos/closetag.html for a usage example.
*
* @author Nathan Williams <[email protected]>
* Contributed under the same license terms as CodeMirror.
*/
(function() {
/** Option that allows tag closing behavior to be toggled. Default is true. */
CodeMirror.defaults['closeTagEnabled'] = true;

/** Array of tag names to add indentation after the start tag for. Default is the list of block-level html tags. */
CodeMirror.defaults['closeTagIndent'] = ['applet', 'blockquote', 'body', 'button', 'div', 'dl', 'fieldset', 'form', 'frameset', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'head', 'html', 'iframe', 'layer', 'legend', 'object', 'ol', 'p', 'select', 'table', 'ul'];

/**
* Call during key processing to close tags. Handles the key event if the tag is closed, otherwise throws CodeMirror.Pass.
* - cm: The editor instance.
* - ch: The character being processed.
* - indent: Optional. Omit or pass true to use the default indentation tag list defined in the 'closeTagIndent' option.
* Pass false to disable indentation. Pass an array to override the default list of tag names.
*/
CodeMirror.defineExtension("closeTag", function(cm, ch, indent) {
if (!cm.getOption('closeTagEnabled')) {
throw CodeMirror.Pass;
}

var mode = cm.getOption('mode');

if (mode == 'text/html') {

/*
* Relevant structure of token:
*
* htmlmixed
* className
* state
* htmlState
* type
* context
* tagName
* mode
*
* xml
* className
* state
* tagName
* type
*/

var pos = cm.getCursor();
var tok = cm.getTokenAt(pos);
var state = tok.state;

if (state.mode && state.mode != 'html') {
throw CodeMirror.Pass; // With htmlmixed, we only care about the html sub-mode.
}

if (ch == '>') {
var type = state.htmlState ? state.htmlState.type : state.type; // htmlmixed : xml

if (tok.className == 'tag' && type == 'closeTag') {
throw CodeMirror.Pass; // Don't process the '>' at the end of an end-tag.
}

cm.replaceSelection('>'); // Mode state won't update until we finish the tag.
pos = {line: pos.line, ch: pos.ch + 1};
cm.setCursor(pos);

tok = cm.getTokenAt(cm.getCursor());
state = tok.state;
type = state.htmlState ? state.htmlState.type : state.type; // htmlmixed : xml

if (tok.className == 'tag' && type != 'selfcloseTag') {
var tagName = state.htmlState ? state.htmlState.context.tagName : state.tagName; // htmlmixed : xml
if (tagName.length > 0) {
insertEndTag(cm, indent, pos, tagName);
}
return;
}

// Undo the '>' insert and allow cm to handle the key instead.
cm.setSelection({line: pos.line, ch: pos.ch - 1}, pos);
cm.replaceSelection("");

} else if (ch == '/') {
if (tok.className == 'tag' && tok.string == '<') {
var tagName = state.htmlState ? (state.htmlState.context ? state.htmlState.context.tagName : '') : state.context.tagName; // htmlmixed : xml # extra htmlmized check is for '</' edge case
if (tagName.length > 0) {
completeEndTag(cm, pos, tagName);
return;
}
}
}

} else if (mode == 'xmlpure') {

var pos = cm.getCursor();
var tok = cm.getTokenAt(pos);
var tagName = tok.state.context.tagName;

if (ch == '>') {
// <foo> tagName=foo, string=foo
// <foo /> tagName=foo, string=/ # ignore
// <foo></foo> tagName=foo, string=/foo # ignore
if (tok.string == tagName) {
cm.replaceSelection('>'); // parity w/html modes
pos = {line: pos.line, ch: pos.ch + 1};
cm.setCursor(pos);

insertEndTag(cm, indent, pos, tagName);
return;
}

} else if (ch == '/') {
// <foo / tagName=foo, string= # ignore
// <foo></ tagName=foo, string=<
if (tok.string == '<') {
completeEndTag(cm, pos, tagName);
return;
}
}
}

throw CodeMirror.Pass; // Bubble if not handled
});

function insertEndTag(cm, indent, pos, tagName) {
if (shouldIndent(cm, indent, tagName)) {
cm.replaceSelection('\n\n</' + tagName + '>', 'end');
cm.indentLine(pos.line + 1);
cm.indentLine(pos.line + 2);
cm.setCursor({line: pos.line + 1, ch: cm.getLine(pos.line + 1).length});
} else {
cm.replaceSelection('</' + tagName + '>');
cm.setCursor(pos);
}
}

function shouldIndent(cm, indent, tagName) {
if (typeof indent == 'undefined' || indent == null || indent == true) {
indent = cm.getOption('closeTagIndent');
}
if (!indent) {
indent = [];
}
return indexOf(indent, tagName.toLowerCase()) != -1;
}

// C&P from codemirror.js...would be nice if this were visible to utilities.
function indexOf(collection, elt) {
if (collection.indexOf) return collection.indexOf(elt);
for (var i = 0, e = collection.length; i < e; ++i)
if (collection[i] == elt) return i;
return -1;
}

function completeEndTag(cm, pos, tagName) {
cm.replaceSelection('/' + tagName + '>');
cm.setCursor({line: pos.line, ch: pos.ch + tagName.length + 2 });
}

})();