/**
 * @fileoverview Validate closing bracket location in JSX
 * @author Yannick Croissant
 */
'use strict';

// ------------------------------------------------------------------------------
// Rule Definition
// ------------------------------------------------------------------------------
module.exports = function(context) {

  var MESSAGE = 'The closing bracket must be {{location}}{{details}}';
  var MESSAGE_LOCATION = {
    'after-props': 'placed after the last prop',
    'after-tag': 'placed after the opening tag',
    'props-aligned': 'aligned with the last prop',
    'tag-aligned': 'aligned with the opening tag',
    'line-aligned': 'aligned with the line containing the opening tag'
  };
  var DEFAULT_LOCATION = 'tag-aligned';

  var config = context.options[0];
  var options = {
    nonEmpty: DEFAULT_LOCATION,
    selfClosing: DEFAULT_LOCATION
  };

  if (typeof config === 'string') {
    // simple shorthand [1, 'something']
    options.nonEmpty = config;
    options.selfClosing = config;
  } else if (typeof config === 'object') {
    // [1, {location: 'something'}] (back-compat)
    if (config.hasOwnProperty('location')) {
      options.nonEmpty = config.location;
      options.selfClosing = config.location;
    }
    // [1, {nonEmpty: 'something'}]
    if (config.hasOwnProperty('nonEmpty')) {
      options.nonEmpty = config.nonEmpty;
    }
    // [1, {selfClosing: 'something'}]
    if (config.hasOwnProperty('selfClosing')) {
      options.selfClosing = config.selfClosing;
    }
  }

  /**
   * Get expected location for the closing bracket
   * @param {Object} tokens Locations of the opening bracket, closing bracket and last prop
   * @return {String} Expected location for the closing bracket
   */
  function getExpectedLocation(tokens) {
    var location;
    // Is always after the opening tag if there is no props
    if (typeof tokens.lastProp === 'undefined') {
      location = 'after-tag';
    // Is always after the last prop if this one is on the same line as the opening bracket
    } else if (tokens.opening.line === tokens.lastProp.line) {
      location = 'after-props';
    // Else use configuration dependent on selfClosing property
    } else {
      location = tokens.selfClosing ? options.selfClosing : options.nonEmpty;
    }
    return location;
  }

  /**
   * Get the correct 0-indexed column for the closing bracket, given the
   * expected location.
   * @param {Object} tokens Locations of the opening bracket, closing bracket and last prop
   * @param {String} expectedLocation Expected location for the closing bracket
   * @return {?Number} The correct column for the closing bracket, or null
   */
  function getCorrectColumn(tokens, expectedLocation) {
    switch (expectedLocation) {
      case 'props-aligned':
        return tokens.lastProp.column;
      case 'tag-aligned':
        return tokens.opening.column;
      case 'line-aligned':
        return tokens.openingStartOfLine.column;
      default:
        return null;
    }
  }

  /**
   * Check if the closing bracket is correctly located
   * @param {Object} tokens Locations of the opening bracket, closing bracket and last prop
   * @param {String} expectedLocation Expected location for the closing bracket
   * @return {Boolean} True if the closing bracket is correctly located, false if not
   */
  function hasCorrectLocation(tokens, expectedLocation) {
    switch (expectedLocation) {
      case 'after-tag':
        return tokens.tag.line === tokens.closing.line;
      case 'after-props':
        return tokens.lastProp.line === tokens.closing.line;
      case 'props-aligned':
      case 'tag-aligned':
      case 'line-aligned':
        var correctColumn = getCorrectColumn(tokens, expectedLocation);
        return correctColumn === tokens.closing.column;
      default:
        return true;
    }
  }

  /**
   * Get the locations of the opening bracket, closing bracket, last prop, and
   * start of opening line.
   * @param {ASTNode} node The node to check
   * @return {Object} Locations of the opening bracket, closing bracket, last
   * prop and start of opening line.
   */
  function getTokensLocations(node) {
    var opening = context.getFirstToken(node).loc.start;
    var closing = context.getLastTokens(node, node.selfClosing ? 2 : 1)[0].loc.start;
    var tag = context.getFirstToken(node.name).loc.start;
    var lastProp;
    if (node.attributes.length) {
      lastProp = node.attributes[node.attributes.length - 1];
      lastProp = {
        column: context.getFirstToken(lastProp).loc.start.column,
        line: context.getLastToken(lastProp).loc.end.line
      };
    }
    var openingLine = context.getSourceCode().lines[opening.line - 1];
    var openingStartOfLine = {
      column: /^\s*/.exec(openingLine)[0].length,
      line: opening.line
    };
    return {
      tag: tag,
      opening: opening,
      closing: closing,
      lastProp: lastProp,
      selfClosing: node.selfClosing,
      openingStartOfLine: openingStartOfLine
    };
  }

  return {
    JSXOpeningElement: function(node) {
      var tokens = getTokensLocations(node);
      var expectedLocation = getExpectedLocation(tokens);
      if (hasCorrectLocation(tokens, expectedLocation)) {
        return;
      }

      var data = {location: MESSAGE_LOCATION[expectedLocation], details: ''};
      var correctColumn = getCorrectColumn(tokens, expectedLocation);

      if (correctColumn !== null) {
        var expectedNextLine = tokens.lastProp &&
          (tokens.lastProp.line === tokens.closing.line);
        data.details = ' (expected column ' + (correctColumn + 1) +
          (expectedNextLine ? ' on the next line)' : ')');
      }

      context.report({
        node: node,
        loc: tokens.closing,
        message: MESSAGE,
        data: data
      });
    }
  };

};

module.exports.schema = [{
  oneOf: [
    {
      enum: ['after-props', 'props-aligned', 'tag-aligned', 'line-aligned']
    },
    {
      type: 'object',
      properties: {
        location: {
          enum: ['after-props', 'props-aligned', 'tag-aligned', 'line-aligned']
        }
      },
      additionalProperties: false
    }, {
      type: 'object',
      properties: {
        nonEmpty: {
          enum: ['after-props', 'props-aligned', 'tag-aligned', 'line-aligned', false]
        },
        selfClosing: {
          enum: ['after-props', 'props-aligned', 'tag-aligned', 'line-aligned', false]
        }
      },
      additionalProperties: false
    }
  ]
}];
