/*jshint globalstrict:false, strict:false, maxlen: 500 */
/*global assertEqual, assertNotEqual, assertTrue, AQL_EXPLAIN, AQL_EXECUTE */

////////////////////////////////////////////////////////////////////////////////
/// @brief tests for optimizer rules
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2012 triagens GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

var jsunity = require("jsunity");
var helper = require("@arangodb/aql-helper");
var isEqual = helper.isEqual;
var getQueryMultiplePlansAndExecutions = helper.getQueryMultiplePlansAndExecutions;

////////////////////////////////////////////////////////////////////////////////
/// @brief test suite
////////////////////////////////////////////////////////////////////////////////

function optimizerRuleTestSuite () {
  var ruleName = "remove-redundant-calculations";

  // various choices to control the optimizer: 
  var paramNone     = { optimizer: { rules: [ "-all" ] } };
  var paramEnabled  = { optimizer: { rules: [ "-all", "+" + ruleName ] } };
  var paramDisabled = { optimizer: { rules: [ "+all", "-" + ruleName ] } };

  return {

////////////////////////////////////////////////////////////////////////////////
/// @brief set up
////////////////////////////////////////////////////////////////////////////////

    setUp : function () {
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief tear down
////////////////////////////////////////////////////////////////////////////////

    tearDown : function () {
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief test that rule has no effect when explicitly disabled
////////////////////////////////////////////////////////////////////////////////

    testRuleDisabled : function () {
      var queries = [
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = i.a LET b = i.a RETURN [ a, b ]",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = LENGTH(i), b = LENGTH(i) RETURN [ a, b ]",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = MAX(i) RETURN MAX(i)",
        "LET a = NOOPT(CONCAT('a', 'b')) FOR i IN [ 1, 2, 3 ] RETURN CONCAT(a, 'b')",
        "FOR i IN [ 1, 2, 3 ] LET a = CONCAT(i, 'b') RETURN CONCAT(a, 'b')"
      ];

      queries.forEach(function(query) {
        var result = AQL_EXPLAIN(query, { }, paramNone);
        assertEqual([ ], result.plan.rules);
      });
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief test that rule has no effect
////////////////////////////////////////////////////////////////////////////////

    testRuleNoEffect : function () {
      var collection = "{ a: [1,2] }, { a: [2,7] }, { a: [3,25] }";
      var queryList = [ 
        ["FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = i.a LET b = i.b RETURN [ a, b ]", true],
        ["FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = LENGTH(i), b = LENGTH(i) + 1 RETURN [ a, b ]", true],
        ["FOR i IN [ " + collection + " ] LET a = MAX(i.a) RETURN MIN(i.a)", true],
        ["FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = RAND(), b = RAND() RETURN [ a, b ]", false],
        ["FOR i IN [ " + collection + " ] LET c = MAX(i.a) COLLECT d = c LET i = RAND() LET b = i.a RETURN d", true],
        ["LET a = NOOPT(CONCAT('a', 'b')) FOR i IN [ 1, 2, 3 ] RETURN CONCAT(a, 'b')", true]
      ];

      queryList.forEach(function(query) {
        var result = AQL_EXPLAIN(query[0], { }, paramEnabled);
        assertEqual([ ], result.plan.rules, query[0]);
        var allresults = getQueryMultiplePlansAndExecutions(query[0], {});
        if (query[1]) {
          for (var j = 1; j < allresults.results.length; j++) {
            assertTrue(isEqual(allresults.results[0],
                               allresults.results[j]),
                       "whether the execution of '" + query +
                       "' this plan gave the wrong results: " + JSON.stringify(allresults.plans[j]) +
                       " Should be: '" + JSON.stringify(allresults.results[0]) +
                       "' but is: " + JSON.stringify(allresults.results[j]) + "'"
                      );
          }
        }
      });
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief test that rule has an effect
////////////////////////////////////////////////////////////////////////////////

    testRuleHasEffect : function () {
      var collection = "{ a: [1,2] }, { a: [2,7] }, { a: [3,25] }";
      var queries = [ 
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = i.a LET b = i.a RETURN [ a, b ]",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = LENGTH(i), b = LENGTH(i) RETURN [ a, b ]",
        "FOR i IN [ " + collection + " ] LET a = MAX(i.a) RETURN MAX(i.a)",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = IS_NUMBER(i), b = IS_NUMBER(i) RETURN [ a, b ]",
        "FOR i IN [ " + collection + " ] LET a = MAX(i.a) COLLECT x = a LET i = x.a, j = x.a RETURN [ i, j ]",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] SORT i.a, i.a RETURN i",
        "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET x = i.a SORT i.a RETURN x"
      ];

      queries.forEach(function(query) {
        var result = AQL_EXPLAIN(query, { }, paramEnabled);
        assertEqual([ ruleName ], result.plan.rules, query);
        var allresults = getQueryMultiplePlansAndExecutions(query, {});
        for (var j = 1; j < allresults.results.length; j++) {
            assertTrue(isEqual(allresults.results[0],
                               allresults.results[j]),
                       "whether the execution of '" + query +
                       "' this plan gave the wrong results: " + JSON.stringify(allresults.plans[j]) +
                       " Should be: '" + JSON.stringify(allresults.results[0]) +
                       "' but is: " + JSON.stringify(allresults.results[j]) + "'"
                      );
        }
      });
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief test generated plans
////////////////////////////////////////////////////////////////////////////////

    testPlans : function () {
      var query = "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET x = i.a RETURN i.a";
      var actual = AQL_EXPLAIN(query, null, paramEnabled);
      var nodes = helper.getLinearizedPlan(actual).reverse(), node;

      node = nodes[0];
      assertEqual("ReturnNode", node.type);
      var variable = node.inVariable.id;
      
      // this node becomes superfluous
      node = nodes[1];
      assertEqual("CalculationNode", node.type);
      assertNotEqual(variable, node.outVariable.id);

      node = nodes[2];
      assertEqual("CalculationNode", node.type);
      assertEqual(variable, node.outVariable.id);
      
      node = nodes[3];
      assertEqual("EnumerateListNode", node.type);
      var allresults = getQueryMultiplePlansAndExecutions(query, {});
      for (var j = 1; j < allresults.results.length; j++) {
        assertTrue(isEqual(allresults.results[0],
                           allresults.results[j]),
                   "whether the execution of '" + query +
                   "' this plan gave the wrong results: " + JSON.stringify(allresults.plans[j]) +
                   " Should be: '" + JSON.stringify(allresults.results[0]) +
                   "' but is: " + JSON.stringify(allresults.results[j]) + "'"
                  );
      }
    },

////////////////////////////////////////////////////////////////////////////////
/// @brief test results
////////////////////////////////////////////////////////////////////////////////

    testResults : function () {
      var queries = [ 
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] SORT i.a + 2 RETURN  /* */ i.a + 2", [ 3, 4, 5 ] ],
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] SORT       i.a RETURN  /* */ i.a", [ 1, 2, 3 ] ],
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] SORT i.a SORT i.a RETURN i.a", [ 1, 2, 3 ] ],
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET x = [ i.a ] RETURN [ i.a ]", [ [ 1 ], [ 2 ], [ 3 ] ] ],
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET a = IS_NUMBER(i.a) RETURN IS_NUMBER(i.a)", [ true, true, true ] ],
        [ "FOR i IN [ { a: 1 }, { a: 2 }, { a: 3 } ] LET r = MAX([ i.a ]) == 3 RETURN MAX([ i.a ]) == 3", [ false, false, true ] ],
        [ "LET v = [ { a: 1 }, { a: 2 }, { a: 3 } ] FOR i IN v LET r = MAX(v[*].a) == 3 RETURN MAX(v[*].a) == 3", [ true, true, true ] ],
        [ "FOR i IN [ { a: 'foo' }, { a: 'food' }, { a: 'foobar' } ] LET a = LENGTH(i.a), b = LENGTH(i.a) RETURN [ a, b ]", [ [ 3, 3 ], [ 4, 4 ], [ 6, 6 ] ] ],
        [ "FOR i IN [ { a: 'foo' }, { a: 'food' }, { a: 'foobar' } ] LET a = LENGTH(i.a) SORT a LET b = LENGTH(i.a) SORT b RETURN [ a, b ]", [ [ 3, 3 ], [ 4, 4 ], [ 6, 6 ] ] ]
      ];

      queries.forEach(function(query) {
        var planDisabled   = AQL_EXPLAIN(query[0], { }, paramDisabled);
        var planEnabled    = AQL_EXPLAIN(query[0], { }, paramEnabled);
        var resultDisabled = AQL_EXECUTE(query[0], { }, paramDisabled).json;
        var resultEnabled  = AQL_EXECUTE(query[0], { }, paramEnabled).json;

        assertTrue(isEqual(resultDisabled, resultEnabled), query[0]);

        assertTrue(planDisabled.plan.rules.indexOf(ruleName) === -1, query[0]);
        assertTrue(planEnabled.plan.rules.indexOf(ruleName) !== -1, query[0]);

        assertEqual(resultDisabled, query[1], query[0]);
        assertEqual(resultEnabled, query[1], query[0]);
        var allresults = getQueryMultiplePlansAndExecutions(query[0], {});
        for (var j = 1; j < allresults.results.length; j++) {
            assertTrue(isEqual(allresults.results[0],
                               allresults.results[j]),
                       "whether the execution of '" + query[0] +
                       "' this plan gave the wrong results: " + JSON.stringify(allresults.plans[j]) +
                       " Should be: '" + JSON.stringify(allresults.results[0]) +
                       "' but is: " + JSON.stringify(allresults.results[j]) + "'"
                      );
        }
      });
    }

  };
}

////////////////////////////////////////////////////////////////////////////////
/// @brief executes the test suite
////////////////////////////////////////////////////////////////////////////////

jsunity.run(optimizerRuleTestSuite);

return jsunity.done();