'use strict';

// Disable dot-notation warnings in this file since we handle a lot
//   of random incoming view options, some that can't be dot-referenced.
/* jshint -W069 */

function cbCompare(a, b) {
  if (Array.isArray(a) && Array.isArray(b)) {
    if (a.length < b.length) {
      return -1;
    } else if (a.length > b.length) {
      return +1;
    }
    for (var i = 0; i < a.length; ++i) {
      var subCmp = cbCompare(a[i], b[i]);
      if (subCmp !== 0) {
        return subCmp;
      }
    }
    return true;
  }
  if (a < b ) {
    return -1;
  } else if (a > b) {
    return +1;
  } else {
    return 0;
  }
}

function cbIndexOf(arr, val) {
  for (var i = 0; i < arr.length; ++i) {
    if (cbCompare(arr[i], val) === 0) {
      return i;
    }
  }
  return -1;
}

function cbNormKey(key, groupLevel) {
  if (Array.isArray(key)) {
    if (groupLevel === -1) {
      return key;
    } else if (groupLevel === 0) {
      return null;
    } else {
      return key.slice(0, groupLevel);
    }
  } else {
    return key;
  }
}

function optTryParse(opt) {
  if (opt) {
    return JSON.parse(opt);
  } else {
    return undefined;
  }
}
function optDefault(opt, defaultVal) {
  if (opt) {
    return opt;
  } else {
    return defaultVal;
  }
}

function execute(options, indexedItems, viewReduceFunc) {
  //console.log('indexer opts', options);
  var startKey = optTryParse(options['startkey']);
  var startKeyDocId = optTryParse(options['startkey_docid']);
  var endKey = optTryParse(options['endkey']);
  var endKeyDocId = optTryParse(options['endkey_docid']);

  var inclusiveStart = true;
  var inclusiveEnd = true;

  if (options['inclusive_end'] !== undefined) {
    if (!options['inclusive_end'] || options['inclusive_end'] === 'false') {
      inclusiveEnd = false;
    }
  }

  if (options['descending']) {
    var _startKey = startKey;
    startKey = endKey;
    endKey = _startKey;
    var _startKeyDocId = startKeyDocId;
    startKeyDocId = endKeyDocId;
    endKeyDocId = _startKeyDocId;
    var _inclusiveStart = inclusiveStart;
    inclusiveStart = inclusiveEnd;
    inclusiveEnd = _inclusiveStart;
  }

  var key = optTryParse(options['key']);
  var keys = optTryParse(options['keys']);

  var results = [];

  for (var cur in indexedItems.results) {
    var docId = cur;
    var row = indexedItems.results[docId];
    var docKey = row[0];
    var docVal = row[1];

    if (key !== undefined) {
      if (cbCompare(docKey, key) !== 0) {
        //console.log('[skip] no key match', docKey, key);
        continue;
      }
    }
    if (keys !== undefined) {
      if (keys.indexOf(docKey) === -1) {
        //console.log('[skip] no keys match', docKey);
        continue;
      }
    }

    if (inclusiveStart) {
      if (startKey && cbCompare(docKey, startKey) < 0) {
        //console.log('[skip] before start key incl', docKey, startKey);
        continue;
      }
      if (startKeyDocId && cbCompare(docId, startKeyDocId) < 0 ) {
        //console.log('[skip] before start id incl', docId, startKeyDocId);
        continue;
      }
    } else {
      if (startKey && cbCompare(docKey, startKey) <= 0) {
        //console.log('[skip] before start key', docKey, startKey);
        continue;
      }
      if (startKeyDocId && cbCompare(docId, startKeyDocId) <= 0) {
        //console.log('[skip] before start id', docId, startKeyDocId);
        continue;
      }
    }

    if (inclusiveEnd) {
      if (endKey && cbCompare(docKey, endKey) > 0) {
        //console.log('[skip] after start key incl', docKey, endKey);
        continue;
      }
      if (endKeyDocId && cbCompare(docId, endKeyDocId) > 0) {
        //console.log('[skip] after start id incl', docId, endKeyDocId);
        continue;
      }
    } else {
      if (endKey && cbCompare(docKey, endKey) >= 0) {
        //console.log('[skip] after start key', docKey, endKey);
        continue;
      }
      if (endKeyDocId && cbCompare(docId, endKeyDocId) >= 0) {
        //console.log('[skip] after start id', docId, endKeyDocId);
        continue;
      }
    }

    var itemOut = {
      id: docId,
      key: docKey,
      value: docVal
    };
    results.push(itemOut);
  }

  if (options['descending']) {
    results.sort(function(a,b){ return cbCompare(a, b); });
  } else {
    results.sort(function(a,b){ return cbCompare(b, a); });
  }

  /* REDUCER */
  var doReduce = true;
  if (options['reduce'] !== undefined) {
    if (!options['reduce'] || options['reduce'] === 'false') {
      doReduce = false;
    }
  }

  var groupLevel = optDefault(options['group_level'], 0);
  if (options['group'] === 'true') {
    // `group=true` sets group_level to infinite
    groupLevel = -1;
  }
  //console.log('REDUCER GROUPLEVEL', groupLevel);

  if (doReduce && viewReduceFunc !== undefined) {
    //console.log('VIEW PRE REDUCE', results);

    var keysN = [];
    for (var m = 0; m < results.length; ++m) {
      var keyN = cbNormKey(results[m].key, groupLevel);
      if (cbIndexOf(keysN, keyN) < 0) {
        keysN.push(keyN);
      }
    }

    var reducedResults = [];

    for (var j = 0; j < keysN.length; ++j) {
      var values = [];
      for (var k = 0; k < results.length; ++k) {
        var keyZ = cbNormKey(results[k].key, groupLevel);
        if (cbCompare(keyZ, keysN[j]) === 0) {
          values.push(results[k].value);
        }
      }
      var result = viewReduceFunc(keysN[j], values, false);
      reducedResults.push({
        key: keysN[j],
        value: result
      });
    }
    results = reducedResults;
  }

  /* FINALIZE */
  if (options['skip']) {
    results = results.slice(options['skip']);
  }
  if (options['limit']) {
    results = results.slice(0, options['limit']);
  }

  // Finally, output the results
  var topLevel = {
    rows: results,
    total_rows: indexedItems.length
  };
  return topLevel;
}