// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

'use strict';

lib.rtdep('lib.colors');

/**
 * Constructor for TextAttribute objects.
 *
 * These objects manage a set of text attributes such as foreground/
 * background color, bold, faint, italic, blink, underline, and strikethrough.
 *
 * TextAttribute instances can be used to construct a DOM container implementing
 * the current attributes, or to test an existing DOM container for
 * compatibility with the current attributes.
 *
 * @constructor
 * @param {HTMLDocument} document The parent document to use when creating
 *     new DOM containers.
 */
hterm.TextAttributes = function(document) {
  this.document_ = document;
  // These variables contain the source of the color as either:
  // SRC_DEFAULT  (use context default)
  // rgb(...)     (true color form)
  // number       (representing the index from color palette to use)
  this.foregroundSource = this.SRC_DEFAULT;
  this.backgroundSource = this.SRC_DEFAULT;
  this.underlineSource = this.SRC_DEFAULT;

  // These properties cache the value in the color table, but foregroundSource
  // and backgroundSource contain the canonical values.
  this.foreground = this.DEFAULT_COLOR;
  this.background = this.DEFAULT_COLOR;
  this.underlineColor = this.DEFAULT_COLOR;

  this.defaultForeground = 'rgb(255, 255, 255)';
  this.defaultBackground = 'rgb(0, 0, 0)';

  // Any attributes added here that do not default to falsey (e.g. undefined or
  // null) require a bit more care.  createContainer has to always attach the
  // attribute so matchesContainer can work correctly.
  this.bold = false;
  this.faint = false;
  this.italic = false;
  this.blink = false;
  this.underline = false;
  this.strikethrough = false;
  this.inverse = false;
  this.invisible = false;
  this.wcNode = false;
  this.asciiNode = true;
  this.tileData = null;
  this.uri = null;
  this.uriId = null;

  this.colorPalette = null;
  this.resetColorPalette();
};

/**
 * If false, we ignore the bold attribute.
 *
 * This is used for fonts that have a bold version that is a different size
 * than the normal weight version.
 */
hterm.TextAttributes.prototype.enableBold = true;

/**
 * If true, use bright colors (if available) for bold text.
 *
 * This setting is independent of the enableBold setting.
 */
hterm.TextAttributes.prototype.enableBoldAsBright = true;

/**
 * A sentinel constant meaning "whatever the default color is in this context".
 */
hterm.TextAttributes.prototype.DEFAULT_COLOR = lib.f.createEnum('');

/**
 * A constant string used to specify that source color is context default.
 */
hterm.TextAttributes.prototype.SRC_DEFAULT = 'default';

/**
 * The document object which should own the DOM nodes created by this instance.
 *
 * @param {HTMLDocument} document The parent document.
 */
hterm.TextAttributes.prototype.setDocument = function(document) {
  this.document_ = document;
};

/**
 * Create a deep copy of this object.
 *
 * @return {hterm.TextAttributes} A deep copy of this object.
 */
hterm.TextAttributes.prototype.clone = function() {
  var rv = new hterm.TextAttributes(null);

  for (var key in this) {
    rv[key] = this[key];
  }

  rv.colorPalette = this.colorPalette.concat();
  return rv;
};

/**
 * Reset the current set of attributes.
 *
 * This does not affect the palette.  Use resetColorPalette() for that.
 * It also doesn't affect the tile data, it's not meant to.
 */
hterm.TextAttributes.prototype.reset = function() {
  this.foregroundSource = this.SRC_DEFAULT;
  this.backgroundSource = this.SRC_DEFAULT;
  this.underlineSource = this.SRC_DEFAULT;
  this.foreground = this.DEFAULT_COLOR;
  this.background = this.DEFAULT_COLOR;
  this.underlineColor = this.DEFAULT_COLOR;
  this.bold = false;
  this.faint = false;
  this.italic = false;
  this.blink = false;
  this.underline = false;
  this.strikethrough = false;
  this.inverse = false;
  this.invisible = false;
  this.wcNode = false;
  this.asciiNode = true;
  this.uri = null;
  this.uriId = null;
};

/**
 * Reset the color palette to the default state.
 */
hterm.TextAttributes.prototype.resetColorPalette = function() {
  this.colorPalette = lib.colors.colorPalette.concat();
  this.syncColors();
};

/**
 * Test if the current attributes describe unstyled text.
 *
 * @return {boolean} True if the current attributes describe unstyled text.
 */
hterm.TextAttributes.prototype.isDefault = function() {
  return (this.foregroundSource == this.SRC_DEFAULT &&
          this.backgroundSource == this.SRC_DEFAULT &&
          !this.bold &&
          !this.faint &&
          !this.italic &&
          !this.blink &&
          !this.underline &&
          !this.strikethrough &&
          !this.inverse &&
          !this.invisible &&
          !this.wcNode &&
          this.asciiNode &&
          this.tileData == null &&
          this.uri == null);
};

/**
 * Create a DOM container (a span or a text node) with a style to match the
 * current set of attributes.
 *
 * This method will create a plain text node if the text is unstyled, or
 * an HTML span if the text is styled.  Due to lack of monospace wide character
 * fonts on certain systems (e.g. Chrome OS), we need to put each wide character
 * in a span of CSS class '.wc-node' which has double column width.
 * Each vt_tiledata tile is also represented by a span with a single
 * character, with CSS classes '.tile' and '.tile_<glyph number>'.
 *
 * @param {string} opt_textContent Optional text content for the new container.
 * @return {HTMLNode} An HTML span or text nodes styled to match the current
 *     attributes.
 */
hterm.TextAttributes.prototype.createContainer = function(opt_textContent) {
  if (this.isDefault()) {
    // Only attach attributes where we need an explicit default for the
    // matchContainer logic below.
    const node = this.document_.createTextNode(opt_textContent);
    node.asciiNode = true;
    return node;
  }

  var span = this.document_.createElement('span');
  var style = span.style;
  var classes = [];

  if (this.foreground != this.DEFAULT_COLOR)
    style.color = this.foreground;

  if (this.background != this.DEFAULT_COLOR)
    style.backgroundColor = this.background;

  if (this.enableBold && this.bold)
    style.fontWeight = 'bold';

  if (this.faint)
    span.faint = true;

  if (this.italic)
    style.fontStyle = 'italic';

  if (this.blink) {
    classes.push('blink-node');
    span.blinkNode = true;
  }

  let textDecorationLine = '';
  span.underline = this.underline;
  if (this.underline) {
    textDecorationLine += ' underline';
    style.textDecorationStyle = this.underline;
  }
  if (this.underlineSource != this.SRC_DEFAULT)
    style.textDecorationColor = this.underlineColor;
  if (this.strikethrough) {
    textDecorationLine += ' line-through';
    span.strikethrough = true;
  }
  if (textDecorationLine)
    style.textDecorationLine = textDecorationLine;

  if (this.wcNode) {
    classes.push('wc-node');
    span.wcNode = true;
  }
  span.asciiNode = this.asciiNode;

  if (this.tileData != null) {
    classes.push('tile');
    classes.push('tile_' + this.tileData);
    span.tileNode = true;
  }

  if (opt_textContent)
    span.textContent = opt_textContent;

  if (this.uri) {
    classes.push('uri-node');
    span.uriId = this.uriId;
    span.title = this.uri;
    span.addEventListener('click', hterm.openUrl.bind(this, this.uri));
  }

  if (classes.length)
    span.className = classes.join(' ');

  return span;
};

/**
 * Tests if the provided object (string, span or text node) has the same
 * style as this TextAttributes instance.
 *
 * This indicates that text with these attributes could be inserted directly
 * into the target DOM node.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj The object to test.
 * @return {boolean} True if the provided container has the same style as
 *     this attributes instance.
 */
hterm.TextAttributes.prototype.matchesContainer = function(obj) {
  if (typeof obj == 'string' || obj.nodeType == Node.TEXT_NODE)
    return this.isDefault();

  var style = obj.style;

  // We don't want to put multiple characters in a wcNode or a tile.
  // See the comments in createContainer.
  // For attributes that default to false, we do not require that obj have them
  // declared, so always normalize them using !! (to turn undefined into false)
  // in the compares below.
  return (!(this.wcNode || obj.wcNode) &&
          this.asciiNode == obj.asciiNode &&
          !(this.tileData != null || obj.tileNode) &&
          this.uriId == obj.uriId &&
          this.foreground == style.color &&
          this.background == style.backgroundColor &&
          this.underlineColor == style.textDecorationColor &&
          (this.enableBold && this.bold) == !!style.fontWeight &&
          this.blink == !!obj.blinkNode &&
          this.italic == !!style.fontStyle &&
          this.underline == obj.underline &&
          !!this.strikethrough == !!obj.strikethrough);
};

hterm.TextAttributes.prototype.setDefaults = function(foreground, background) {
  this.defaultForeground = foreground;
  this.defaultBackground = background;

  this.syncColors();
};

/**
 * Updates foreground and background properties based on current indices and
 * other state.
 *
 * @param {string} terminalForeground The terminal foreground color for use as
 *     inverse text background.
 * @param {string} terminalBackground The terminal background color for use as
 *     inverse text foreground.
 *
 */
hterm.TextAttributes.prototype.syncColors = function() {
  function getBrightIndex(i) {
    if (i < 8) {
      // If the color is from the lower half of the ANSI 16, add 8.
      return i + 8;
    }

    // If it's not from the 16 color palette, ignore bold requests.  This
    // matches the behavior of gnome-terminal.
    return i;
  }

  var foregroundSource = this.foregroundSource;
  var backgroundSource = this.backgroundSource;
  var defaultForeground = this.DEFAULT_COLOR;
  var defaultBackground = this.DEFAULT_COLOR;

  if (this.inverse) {
    foregroundSource = this.backgroundSource;
    backgroundSource = this.foregroundSource;
    // We can't inherit the container's color anymore.
    defaultForeground = this.defaultBackground;
    defaultBackground = this.defaultForeground;
  }

  if (this.enableBoldAsBright && this.bold) {
    if (Number.isInteger(foregroundSource)) {
      foregroundSource = getBrightIndex(foregroundSource);
    }
  }

  if (foregroundSource == this.SRC_DEFAULT)
    this.foreground = defaultForeground;
  else if (Number.isInteger(foregroundSource))
    this.foreground = this.colorPalette[foregroundSource];
  else
    this.foreground = foregroundSource;

  if (this.faint) {
    var colorToMakeFaint = ((this.foreground == this.DEFAULT_COLOR) ?
                            this.defaultForeground : this.foreground);
    this.foreground = lib.colors.mix(colorToMakeFaint, 'rgb(0, 0, 0)', 0.3333);
  }

  if (backgroundSource == this.SRC_DEFAULT)
    this.background = defaultBackground;
  else if (Number.isInteger(backgroundSource))
    this.background = this.colorPalette[backgroundSource];
  else
    this.background = backgroundSource;

  // Process invisible settings last to keep it simple.
  if (this.invisible)
    this.foreground = this.background;

  if (this.underlineSource == this.SRC_DEFAULT)
    this.underlineColor = '';
  else if (Number.isInteger(this.underlineSource))
    this.underlineColor = this.colorPalette[this.underlineSource];
  else
    this.underlineColor = this.underlineSource;
};

/**
 * Static method used to test if the provided objects (strings, spans or
 * text nodes) have the same style.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj1 An object to test.
 * @param {string|HTMLNode} obj2 Another object to test.
 * @return {boolean} True if the containers have the same style.
 */
hterm.TextAttributes.containersMatch = function(obj1, obj2) {
  if (typeof obj1 == 'string')
    return hterm.TextAttributes.containerIsDefault(obj2);

  if (obj1.nodeType != obj2.nodeType)
    return false;

  if (obj1.nodeType == Node.TEXT_NODE)
    return true;

  var style1 = obj1.style;
  var style2 = obj2.style;

  return (style1.color == style2.color &&
          style1.backgroundColor == style2.backgroundColor &&
          style1.backgroundColor == style2.backgroundColor &&
          style1.fontWeight == style2.fontWeight &&
          style1.fontStyle == style2.fontStyle &&
          style1.textDecoration == style2.textDecoration &&
          style1.textDecorationColor == style2.textDecorationColor &&
          style1.textDecorationStyle == style2.textDecorationStyle &&
          style1.textDecorationLine == style2.textDecorationLine);
};

/**
 * Static method to test if a given DOM container represents unstyled text.
 *
 * For the purposes of this method, a string is considered a text node.
 *
 * @param {string|HTMLNode} obj1 An object to test.
 * @return {boolean} True if the object is unstyled.
 */
hterm.TextAttributes.containerIsDefault = function(obj) {
  return typeof obj == 'string'  || obj.nodeType == Node.TEXT_NODE;
};

/**
 * Static method to get the column width of a node's textContent.
 *
 * @param {HTMLElement} node The HTML element to get the width of textContent
 *     from.
 * @return {integer} The column width of the node's textContent.
 */
hterm.TextAttributes.nodeWidth = function(node) {
  if (!node.asciiNode) {
    return lib.wc.strWidth(node.textContent);
  } else {
    return node.textContent.length;
  }
}

/**
 * Static method to get the substr of a node's textContent.  The start index
 * and substr width are computed in column width.
 *
 * @param {HTMLElement} node The HTML element to get the substr of textContent
 *     from.
 * @param {integer} start The starting offset in column width.
 * @param {integer} width The width to capture in column width.
 * @return {integer} The extracted substr of the node's textContent.
 */
hterm.TextAttributes.nodeSubstr = function(node, start, width) {
  if (!node.asciiNode) {
    return lib.wc.substr(node.textContent, start, width);
  } else {
    return node.textContent.substr(start, width);
  }
}

/**
 * Static method to get the substring based of a node's textContent.  The
 * start index of end index are computed in column width.
 *
 * @param {HTMLElement} node The HTML element to get the substr of textContent
 *     from.
 * @param {integer} start The starting offset in column width.
 * @param {integer} end The ending offset in column width.
 * @return {integer} The extracted substring of the node's textContent.
 */
hterm.TextAttributes.nodeSubstring = function(node, start, end) {
  if (!node.asciiNode) {
    return lib.wc.substring(node.textContent, start, end);
  } else {
    return node.textContent.substring(start, end);
  }
};

/**
 * Static method to split a string into contiguous runs of single-width
 * characters and runs of double-width characters.
 *
 * @param {string} str The string to split.
 * @return {Array} An array of objects that contain substrings of str, where
 *     each substring is either a contiguous runs of single-width characters
 *     or a double-width character.  For objects that contain a double-width
 *     character, its wcNode property is set to true.  For objects that contain
 *     only ASCII content, its asciiNode property is set to true.
 */
hterm.TextAttributes.splitWidecharString = function(str) {
  var rv = [];
  var base = 0, length = 0, wcStrWidth = 0, wcCharWidth;
  var asciiNode = true;

  for (var i = 0; i < str.length;) {
    var c = str.codePointAt(i);
    var increment;
    if (c < 128) {
      wcStrWidth += 1;
      length += 1;
      increment = 1;
    } else {
      increment = (c <= 0xffff) ? 1 : 2;
      wcCharWidth = lib.wc.charWidth(c);
      if (wcCharWidth <= 1) {
        wcStrWidth += wcCharWidth;
        length += increment;
        asciiNode = false;
      } else {
        if (length) {
          rv.push({
            str: str.substr(base, length),
            asciiNode: asciiNode,
            wcStrWidth: wcStrWidth,
          });
          asciiNode = true;
          wcStrWidth = 0;
        }
        rv.push({
          str: str.substr(i, increment),
          wcNode: true,
          asciiNode: false,
          wcStrWidth: 2,
        });
        base = i + increment;
        length = 0;
      }
    }
    i += increment;
  }

  if (length) {
    rv.push({
      str: str.substr(base, length),
      asciiNode: asciiNode,
      wcStrWidth: wcStrWidth,
    });
  }

  return rv;
};