/*
 * Jake JavaScript build tool
 * Copyright 2112 Matthew Eernisse (mde@fleegix.org)
 *
 * 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.
 *
*/
var fs = require('fs')
, path = require('path')
, minimatch = require('minimatch')
, utils = require('utilities')
, globSync;

globSync = function (pat) {
  var dirname = utils.file.basedir(pat)
    , files
    , matches;

  try {
    files = utils.file.readdirR(dirname).map(function(file){
      return file.replace(/\\/g, '/');
    });
  }
  // Bail if path doesn't exist -- assume no files
  catch(e) {
    console.error(e.message);
  }

  if (files) {
    pat = path.normalize(pat);
    // Hack, Minimatch doesn't support backslashes in the pattern
    // https://github.com/isaacs/minimatch/issues/7
    pat = pat.replace(/\\/g, '/');
    matches = minimatch.match(files, pat, {});
  }
  return matches || [];
};

// Constants
// ---------------
// List of all the builtin Array methods we want to override
var ARRAY_METHODS = Object.getOwnPropertyNames(Array.prototype)
// Array methods that return a copy instead of affecting the original
  , SPECIAL_RETURN = {
      'concat': true
    , 'slice': true
    , 'filter': true
    , 'map': true
    }
// Default file-patterns we want to ignore
  , DEFAULT_IGNORE_PATTERNS = [
      /(^|[\/\\])CVS([\/\\]|$)/
    , /(^|[\/\\])\.svn([\/\\]|$)/
    , /(^|[\/\\])\.git([\/\\]|$)/
    , /\.bak$/
    , /~$/
    ]
// Ignore core files
  , DEFAULT_IGNORE_FUNCS = [
      function (name) {
        var isDir = false
          , stats;
        try {
          stats = fs.statSync(name);
          isDir = stats.isDirectory();
        }
        catch(e) {}
        return (/(^|[\/\\])core$/).test(name) && !isDir;
      }
    ];

var FileList = function () {
  var self = this
    , wrap;

  // List of glob-patterns or specific filenames
  this.pendingAdd = [];
  // Switched to false after lazy-eval of files
  this.pending = true;
  // Used to calculate exclusions from the list of files
  this.excludes = {
    pats: DEFAULT_IGNORE_PATTERNS.slice()
  , funcs: DEFAULT_IGNORE_FUNCS.slice()
  , regex: null
  };
  this.items = [];

  // Wrap the array methods with the delegates
  wrap = function (prop) {
    var arr;
    self[prop] = function () {
      if (self.pending) {
        self.resolve();
      }
      if (typeof self.items[prop] == 'function') {
        // Special method that return a copy
        if (SPECIAL_RETURN[prop]) {
          arr = self.items[prop].apply(self.items, arguments);
          return FileList.clone(self, arr);
        }
        else {
          return self.items[prop].apply(self.items, arguments);
        }
      }
      else {
        return self.items[prop];
      }
    };
  };
  for (var i = 0, ii = ARRAY_METHODS.length; i < ii; i++) {
    wrap(ARRAY_METHODS[i]);
  }

  // Include whatever files got passed to the constructor
  this.include.apply(this, arguments);

  // Fix constructor linkage
  this.constructor = FileList;
};

FileList.prototype = new (function () {
  var globPattern = /[*?\[\{]/;

  var _addMatching = function (pat) {
        var matches = globSync(pat);
        this.items = this.items.concat(matches);
      }

    , _resolveAdd = function (name) {
        if (globPattern.test(name)) {
          _addMatching.call(this, name);
        }
        else {
          this.push(name);
        }
      }

    , _calculateExcludeRe = function () {
        var pats = this.excludes.pats
          , pat
          , excl = []
          , matches = [];

        for (var i = 0, ii = pats.length; i < ii; i++) {
          pat = pats[i];
          if (typeof pat == 'string') {
            // Glob, look up files
            if (/[*?]/.test(pat)) {
              matches = globSync(pat);
              matches = matches.map(function (m) {
                return utils.string.escapeRegExpChars(m);
              });
              excl = excl.concat(matches);
            }
            // String for regex
            else {
              excl.push(utils.string.escapeRegExpChars(pat));
            }
          }
          // Regex, grab the string-representation
          else if (pat instanceof RegExp) {
            excl.push(pat.toString().replace(/^\/|\/$/g, ''));
          }
        }
        if (excl.length) {
          this.excludes.regex = new RegExp('(' + excl.join(')|(') + ')');
        }
        else {
          this.excludes.regex = /^$/;
        }
      }

    , _resolveExclude = function () {
        var self = this;
        _calculateExcludeRe.call(this);
        // No `reject` method, so use reverse-filter
        this.items = this.items.filter(function (name) {
          return !self.shouldExclude(name);
        });
      };

  /**
   * Includes file-patterns in the FileList. Should be called with one or more
   * pattern for finding file to include in the list. Arguments should be strings
   * for either a glob-pattern or a specific file-name, or an array of them
   */
  this.include = function (items) {
    if (items) {
      this.pendingAdd = this.pendingAdd.concat(items).filter(function (item) {
        return !!item;
      });
    }
    return this;
  };

  /**
   * Indicates whether a particular file would be filtered out by the current
   * exclusion rules for this FileList.
   * @param {String} name The filename to check
   * @return {Boolean} Whether or not the file should be excluded
   */
  this.shouldExclude = function (name) {
    if (!this.excludes.regex) {
      _calculateExcludeRe.call(this);
    }
    var excl = this.excludes;
    return excl.regex.test(name) || excl.funcs.some(function (f) {
      return !!f(name);
    });
  };

  /**
   * Excludes file-patterns from the FileList. Should be called with one or more
   * pattern for finding file to include in the list. Arguments can be:
   * 1. Strings for either a glob-pattern or a specific file-name
   * 2. Regular expression literals
   * 3. Functions to be run on the filename that return a true/false
   */
  this.exclude = function () {
    var args = Array.isArray(arguments[0]) ? arguments[0] : arguments
      , arg;
    for (var i = 0, ii = args.length; i < ii; i++) {
      arg = args[i];
      if (typeof arg == 'function' && !(arg instanceof RegExp)) {
        this.excludes.funcs.push(arg);
      }
      else {
        this.excludes.pats.push(arg);
      }
    }
    if (!this.pending) {
      _resolveExclude.call(this);
    }
    return this;
  };

  /**
   * Populates the FileList from the include/exclude rules with a list of
   * actual files
   */
  this.resolve = function () {
    var name
      , uniqueFunc = function (p, c) {
          if (p.indexOf(c) < 0) {
            p.push(c);
          }
          return p;
        };
    if (this.pending) {
      this.pending = false;
      while ((name = this.pendingAdd.shift())) {
        _resolveAdd.call(this, name);
      }
      // Reduce to a unique list
      this.items = this.items.reduce(uniqueFunc, []);
      // Remove exclusions
      _resolveExclude.call(this);
    }
    return this;
  };

  /**
   * Convert to a plain-jane array
   */
  this.toArray = function () {
    // Call slice to ensure lazy-resolution before slicing items
    var ret = this.slice().items.slice();
    return ret;
  };

  /**
   * Clear any pending items -- only useful before
   * calling `resolve`
   */
  this.clearInclusions = function () {
    this.pendingAdd = [];
    return this;
  };

  /**
   * Clear any current exclusion rules
   */
  this.clearExclusions = function () {
    this.excludes = {
      pats: []
    , funcs: []
    , regex: null
    };
    return this;
  };

})();

// Static method, used to create copy returned by special
// array methods
FileList.clone = function (list, items) {
  var clone = new FileList();
  if (items) {
    clone.items = items;
  }
  clone.pendingAdd = list.pendingAdd;
  clone.pending = list.pending;
  for (var p in list.excludes) {
    clone.excludes[p] = list.excludes[p];
  }
  return clone;
};

exports.FileList = FileList;