/*
    ***** BEGIN LICENSE BLOCK *****
    
    Copyright © 2009 Center for History and New Media
                     George Mason University, Fairfax, Virginia, USA
                     http://zotero.org
    
    This file is part of Zotero.
    
    Zotero is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    
    Zotero is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.
    
    You should have received a copy of the GNU Affero General Public License
    along with Zotero.  If not, see <http://www.gnu.org/licenses/>.
    
    ***** END LICENSE BLOCK *****
*/

const ZOTERO_AC_CONTRACTID = '@mozilla.org/autocomplete/search;1?name=zotero';
const ZOTERO_AC_CLASSNAME = 'Zotero AutoComplete';
const ZOTERO_AC_CID = Components.ID('{06a2ed11-d0a4-4ff0-a56f-a44545eee6ea}');

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;

Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

var Zotero = Components.classes["@zotero.org/Zotero;1"].
getService(Components.interfaces.nsISupports).
wrappedJSObject;

/*
                  * Implements nsIAutoCompleteSearch
                  */
function ZoteroAutoComplete() {}

ZoteroAutoComplete.prototype.startSearch = Zotero.Promise.coroutine(function* (searchString, searchParams, previousResult, listener) {
  // FIXME
  //this.stopSearch();

  var result = Cc["@mozilla.org/autocomplete/simple-result;1"].
  createInstance(Ci.nsIAutoCompleteSimpleResult);
  result.setSearchString(searchString);

  this._result = result;
  this._results = [];
  this._listener = listener;
  this._cancelled = false;

  Zotero.debug("Starting autocomplete search with data '" +
  searchParams + "'" + " and string '" + searchString + "'");

  searchParams = JSON.parse(searchParams);
  if (!searchParams) {
    throw new Error("Invalid JSON passed to autocomplete");
  }
  var [fieldName,, subField] = searchParams.fieldName.split("-");

  var resultsCallback;

  switch (fieldName) {
    case '':
      break;

    case 'tag':
      var sql = "SELECT DISTINCT name AS val, NULL AS id FROM tags WHERE name LIKE ? ESCAPE '\\'";
      var sqlParams = [Zotero.DB.escapeSQLExpression(searchString) + '%'];
      if (searchParams.libraryID !== undefined) {
        sql += " AND tagID IN (SELECT tagID FROM itemTags JOIN items USING (itemID) " +
        "WHERE libraryID=?)";
        sqlParams.push(searchParams.libraryID);
      }
      if (searchParams.itemID) {
        sql += " AND name NOT IN (SELECT name FROM tags WHERE tagID IN (" +
        "SELECT tagID FROM itemTags WHERE itemID = ?))";
        sqlParams.push(searchParams.itemID);
      }
      sql += " ORDER BY val COLLATE locale";
      break;

    case 'creator':
      // Valid fieldMode values:
      // 		0 == search two-field creators
      // 		1 == search single-field creators
      // 		2 == search both
      if (searchParams.fieldMode == 2) {
        var sql = "SELECT DISTINCT CASE fieldMode WHEN 1 THEN lastName " +
        "WHEN 0 THEN firstName || ' ' || lastName END AS val, NULL AS id " +
        "FROM creators ";
        if (searchParams.libraryID !== undefined) {
          sql += "JOIN itemCreators USING (creatorID) JOIN items USING (itemID) ";
        }
        sql += "WHERE CASE fieldMode " +
        "WHEN 1 THEN lastName LIKE ? " +
        "WHEN 0 THEN (firstName || ' ' || lastName LIKE ?) OR (lastName LIKE ?) END ";
        var sqlParams = [searchString + '%', searchString + '%', searchString + '%'];
        if (searchParams.libraryID !== undefined) {
          sql += " AND libraryID=?";
          sqlParams.push(searchParams.libraryID);
        }
        sql += "ORDER BY val";
      } else

      {
        var sql = "SELECT DISTINCT ";
        if (searchParams.fieldMode == 1) {
          sql += "lastName AS val, creatorID || '-1' AS id";
        }
        // Retrieve the matches in the specified field
        // as well as any full names using the name
        //
        // e.g. "Shakespeare" and "Shakespeare, William"
        //
        // creatorID is in the format "12345-1" or "12345-2",
        // 		- 1 means the row uses only the specified field
        // 		- 2 means it uses both
        else {
            sql += "CASE WHEN firstName='' OR firstName IS NULL THEN lastName " +
            "ELSE lastName || ', ' || firstName END AS val, " +
            "creatorID || '-' || CASE " +
            "WHEN (firstName = '' OR firstName IS NULL) THEN 1 " +
            "ELSE 2 END AS id";
          }

        var fromSQL = " FROM creators ";
        if (searchParams.libraryID !== undefined) {
          fromSQL += "JOIN itemCreators USING (creatorID) JOIN items USING (itemID) ";
        }
        fromSQL += "WHERE " + subField + " LIKE ? " + "AND fieldMode=?";
        var sqlParams = [
        searchString + '%',
        searchParams.fieldMode ? searchParams.fieldMode : 0];

        if (searchParams.itemID) {
          fromSQL += " AND creatorID NOT IN (SELECT creatorID FROM " +
          "itemCreators WHERE itemID=?";
          sqlParams.push(searchParams.itemID);
          if (searchParams.creatorTypeID) {
            fromSQL += " AND creatorTypeID=?";
            sqlParams.push(searchParams.creatorTypeID);
          }
          fromSQL += ")";
        }
        if (searchParams.libraryID !== undefined) {
          fromSQL += " AND libraryID=?";
          sqlParams.push(searchParams.libraryID);
        }

        sql += fromSQL;

        // If double-field mode, include matches for just this field
        // as well (i.e. "Shakespeare"), and group to collapse repeats
        if (searchParams.fieldMode != 1) {
          sql = "SELECT * FROM (" + sql + " UNION SELECT DISTINCT " +
          subField + " AS val, creatorID || '-1' AS id" +
          fromSQL + ") GROUP BY val";
          sqlParams = sqlParams.concat(sqlParams);
        }

        sql += " ORDER BY val";
      }
      break;

    case 'dateModified':
    case 'dateAdded':
      var sql = "SELECT DISTINCT DATE(" + fieldName + ", 'localtime') AS val, NULL AS id FROM items " +
      "WHERE " + fieldName + " LIKE ? ORDER BY " + fieldName;
      var sqlParams = [searchString + '%'];
      break;

    case 'accessDate':
      var fieldID = Zotero.ItemFields.getID('accessDate');

      var sql = "SELECT DISTINCT DATE(value, 'localtime') AS val, NULL AS id FROM itemData " +
      "WHERE fieldID=? AND value LIKE ? ORDER BY value";
      var sqlParams = [fieldID, searchString + '%'];
      break;

    default:
      var fieldID = Zotero.ItemFields.getID(fieldName);
      if (!fieldID) {
        Zotero.debug("'" + fieldName + "' is not a valid autocomplete scope", 1);
        this.updateResults([], false, Ci.nsIAutoCompleteResult.RESULT_IGNORED);
        return;
      }

      // We don't use date autocomplete anywhere, but if we're not
      // disallowing it altogether, we should at least do it right and
      // use the user part of the multipart field
      var valueField = fieldName == 'date' ? 'SUBSTR(value, 12, 100)' : 'value';

      var sql = "SELECT DISTINCT " + valueField + " AS val, NULL AS id " +
      "FROM itemData NATURAL JOIN itemDataValues " +
      "WHERE fieldID=?1 AND " + valueField +
      " LIKE ?2 ";

      var sqlParams = [fieldID, searchString + '%'];
      if (searchParams.itemID) {
        sql += "AND value NOT IN (SELECT value FROM itemData " +
        "NATURAL JOIN itemDataValues WHERE fieldID=?1 AND itemID=?3) ";
        sqlParams.push(searchParams.itemID);
      }
      sql += "ORDER BY value";}


  sql += " LIMIT 50";

  var onRow = null;
  // If there's a result callback (e.g., for sorting), don't use a row handler
  if (!resultsCallback) {
    onRow = function (row, cancel) {
      if (this._cancelled) {
        Zotero.debug("Cancelling query");
        cancel();
        return;
      }
      var value = row.getResultByIndex(0);
      var id = row.getResultByIndex(1);
      this.updateResult(value, id);
    }.bind(this);
  }
  var resultCode;
  try {
    let results = yield Zotero.DB.queryAsync(sql, sqlParams, { onRow: onRow });
    // Post-process the results
    if (resultsCallback) {
      resultsCallback(results);
      this.updateResults(
      Object.values(results).map(x => x.val),
      Object.values(results).map(x => x.id),
      false);

    }
    resultCode = null;
    Zotero.debug("Autocomplete query completed");
  }
  catch (e) {
    Zotero.debug(e, 1);
    resultCode = Ci.nsIAutoCompleteResult.RESULT_FAILURE;
    Zotero.debug("Autocomplete query aborted");
  } finally
  {
    this.updateResults(null, null, false, resultCode);
  };
});


ZoteroAutoComplete.prototype.updateResult = function (value, id) {
  Zotero.debug(`Appending autocomplete value '${value}'` + (id ? " (" + id + ")" : ''));
  // Add to nsIAutoCompleteResult
  this._result.appendMatch(value, value, null, null, null, id);
  // Add to our own list
  this._results.push(value);
  // Only update the UI every 10 records
  if (this._result.matchCount % 10 == 0) {
    this._result.setSearchResult(Ci.nsIAutoCompleteResult.RESULT_SUCCESS_ONGOING);
    this._listener.onSearchResult(this, this._result);
  }
};


ZoteroAutoComplete.prototype.updateResults = function (values, ids, ongoing, resultCode) {
  if (!values) {
    values = [];
  }
  if (!ids) {
    ids = [];
  }

  for (let i = 0; i < values.length; i++) {
    let value = values[i];

    if (!this._results.includes(value)) {
      let id = ids[i] || null;
      Zotero.debug("Adding autocomplete value '" + value + "'" + (id ? " (" + id + ")" : ""));
      this._result.appendMatch(value, value, null, null, null, id);
      this._results.push(value);
    } else
    {
      //Zotero.debug("Skipping existing value '" + result + "'");
    }
  }

  if (!resultCode) {
    resultCode = "RESULT_";
    if (!this._result.matchCount) {
      resultCode += "NOMATCH";
    } else
    {
      resultCode += "SUCCESS";
    }
    if (ongoing) {
      resultCode += "_ONGOING";
    }
    resultCode = Ci.nsIAutoCompleteResult[resultCode];
  }

  Zotero.debug("Found " + this._result.matchCount +
  " result" + (this._result.matchCount != 1 ? "s" : ""));

  this._result.setSearchResult(resultCode);
  this._listener.onSearchResult(this, this._result);
};


// FIXME
ZoteroAutoComplete.prototype.stopSearch = function () {
  Zotero.debug('Stopping autocomplete search');
  this._cancelled = true;
};

//
// XPCOM goop
//

ZoteroAutoComplete.prototype.classDescription = ZOTERO_AC_CLASSNAME;
ZoteroAutoComplete.prototype.classID = ZOTERO_AC_CID;
ZoteroAutoComplete.prototype.contractID = ZOTERO_AC_CONTRACTID;
ZoteroAutoComplete.prototype.QueryInterface = XPCOMUtils.generateQI([
Components.interfaces.nsIAutoCompleteSearch,
Components.interfaces.nsIAutoCompleteObserver,
Components.interfaces.nsISupports]);

var NSGetFactory = XPCOMUtils.generateNSGetFactory([ZoteroAutoComplete]);