/* globals Promise, SimplePhoneMatcher, utils, ContactPhotoHelper */

'use strict';

var contacts = window.contacts || {};

contacts.Merger = (function() {
  var DEFAULT_ADR_TYPE = 'home';
  var DEFAULT_TEL_TYPE = 'other';
  var DEFAULT_EMAIL_TYPE = 'other';

  // Performs the merge passing the master contact and matching contacts
  // The master contact is the one that contains the info with more priority
  // The matchingContacts are the contacts which information will merged with
  // the master. It is an Array in which the elements should be ordered
  // by priority i.e. the data from the first elements might take precedence
  // over the data of the last elements according to the merging rules.
  //
  // Each element in the array is an object with the following keys:
  //   * matchingContact: the Contact object matching one or more targets.
  //   * matchings: optional, an object which entries are arrays of
  //     field-matching objects indexed by the field name.
  //
  // Each field-matching object has two fields:
  //   * target: the value that field matched with.
  //   * matchedValue: the value from the matchingContact field matching the
  //     target.
  //
  // Here is an example:
  // {
  //   matchingContact: { ... },
  //   matchings: {
  //     'tel': [{
  //       target: '600000000',
  //       matchedValue: '+34600000000'
  //     }]
  //   }
  // }
  //
  // The `matchings` field can be not present if the matching contact comes
  // from an external source not related with the matching algorithm.
  function doMerge(pmasterContact, pmatchingContacts, callbacks) {
    window.setTimeout(function contactsMerge() {
      mergeAll(pmasterContact, pmatchingContacts, filled, callbacks);
    }, 0);
  }
  
  function doInMemoryMerge(pmasterContact, pmatchingContacts) {
    return new Promise(function (resolve, reject) {
      mergeAll(pmasterContact, pmatchingContacts, inMemoryMergeDone, {
        success: function(masterContact) {
          resolve(masterContact);
        },
        error: function(err) {
          reject(err);
        }
      });
    });
  }
  
  function inMemoryMergeDone(callbacks, matchingContacts, masterContact) {
    callbacks.success(masterContact);
  }

  function isSimContact(contact) {
    return Array.isArray(contact.category) &&
                                        contact.category.indexOf('sim') !== -1;
  }

  function mergeAll(masterContact, matchingContacts, onFilled, callbacks) {
    var emailsHash;
    var categoriesHash;
    var telsHash;
    var mergedContact = {};
    var mergedPhoto;

    mergedContact.givenName = [];
    copyStringArray(masterContact.givenName, mergedContact.givenName);

    mergedContact.familyName = [];
    copyStringArray(masterContact.familyName, mergedContact.familyName);

    mergedContact.photo = masterContact.photo || [];
    mergedPhoto = mergedContact.photo;

    mergedContact.bday = masterContact.bday;
    mergedContact.anniversary = masterContact.anniversary;

    mergedContact.adr = masterContact.adr || [];

    telsHash = {};
    mergedContact.tel = [];
    if (Array.isArray(masterContact.tel)) {
      masterContact.tel.forEach(function(aTel) {
        if (!telsHash[aTel.value]) {
          aTel.type = (Array.isArray(aTel.type) ? aTel.type : [aTel.type]);
          aTel.type[0] = aTel.type[0] || DEFAULT_TEL_TYPE;
          mergedContact.tel.push(aTel);
        }
        var variants = SimplePhoneMatcher.generateVariants(aTel.value);
        variants.forEach(function(aVariant) {
           telsHash[aVariant] = true;
        });
      });
    }

    mergedContact.email = [];
    emailsHash = {};
    populateEmails(masterContact.email, emailsHash, mergedContact.email);

    mergedContact.org = masterContact.org || [];

    mergedContact.category = [];
    categoriesHash = {};
    populateNoDuplicates(masterContact.category, categoriesHash,
                         mergedContact.category);

    mergedContact.url = masterContact.url || [];
    mergedContact.note = masterContact.note || [];

    matchingContacts.forEach(function(aResult) {
      var theMatchingContact = aResult.matchingContact;

      var givenName = theMatchingContact.givenName;
      if (Array.isArray(givenName) && givenName[0]) {
        if (mergedContact.givenName.indexOf(givenName[0]) === -1) {
          if (mergedContact.givenName[0] &&
              mergedContact.givenName[0].trim()) {
            mergedContact.givenName.push(givenName[0]);
          }
          else {
            mergedContact.givenName[0] = givenName[0];
          }
        }
      }

      var familyName = theMatchingContact.familyName;
      if (Array.isArray(familyName) && familyName[0]) {
        if (mergedContact.familyName.indexOf(familyName[0]) === -1) {
          if (mergedContact.familyName[0] &&
              mergedContact.familyName[0].trim()) {
            mergedContact.familyName.push(familyName[0]);
          }
          else {
            mergedContact.familyName[0] = familyName[0];
          }
        }
      }

      // Avoiding duplicating givenName - familyName for SIM Contacts
      if ((!isDefined(masterContact.givenName) ||
           !isDefined(masterContact.familyName)) &&
            isSimContact(theMatchingContact)) {

        if (isDefined(mergedContact.givenName) &&
            isDefined(mergedContact.familyName) &&
          mergedContact.familyName[0] === mergedContact.givenName[0]) {

          if (!isDefined(masterContact.givenName)) {
            mergedContact.givenName = [];
            mergedContact.name = mergedContact.familyName;
          }
          if (!isDefined(masterContact.familyName)) {
            mergedContact.familyName = [];
            mergedContact.name = mergedContact.givenName;
          }
        }
      }

      if (!mergedContact.bday && theMatchingContact.bday) {
        mergedContact.bday = theMatchingContact.bday;
      }
      if (!mergedContact.anniversary && theMatchingContact.anniversary) {
        mergedContact.anniversary = theMatchingContact.anniversary;
      }

      if (isDefined(theMatchingContact.org) && mergedContact.org.length === 0) {
        mergedContact.org = theMatchingContact.org;
      }
      if (isDefined(theMatchingContact.category)) {
        populateNoDuplicates(theMatchingContact.category, categoriesHash,
                              mergedContact.category);
      }

      populateEmails(theMatchingContact.email, emailsHash, mergedContact.email);

      if (Array.isArray(theMatchingContact.tel)) {
        var theMatchings = aResult.matchings || {};
        var telMatchings = theMatchings.tel;
        theMatchingContact.tel.forEach(function(aTel) {
          var theValue = aTel.value;
          var target = theValue, matchedValue = '';
          if (telMatchings) {
            var matchedFrom = telMatchings.filter(function(x) {
              return (x.target === theValue || x.matchedValue === theValue);
            });
            if (matchedFrom[0]) {
              target = matchedFrom[0].target;
              matchedValue = matchedFrom[0].matchedValue;
            }
          }
          var variants = SimplePhoneMatcher.generateVariants(theValue);
          var alreadyPresent = false;
          for (var j = 0; j < variants.length; j++) {
            if (telsHash[variants[j]]) {
              alreadyPresent = true;
            }
          }
          if (!alreadyPresent) {
            theValue = target.length > matchedValue.length ?
                              target : matchedValue;
            mergedContact.tel.push({
              type: aTel.type || [DEFAULT_TEL_TYPE],
              value: theValue,
              carrier: aTel.carrier,
              pref: aTel.pref
            });
            variants.forEach(function(aVariant) {
              telsHash[aVariant] = true;
            });
          }
        });
      }

      if (!Array.isArray(mergedPhoto) || mergedPhoto.length === 0 &&
          isDefined(theMatchingContact.photo)) {
        var photo = ContactPhotoHelper.getFullResolution(theMatchingContact);
        mergedPhoto = [photo];
      }

      populateField(
        theMatchingContact.adr,
        mergedContact.adr,
        DEFAULT_ADR_TYPE
      );

      populateField(theMatchingContact.url, mergedContact.url);
      populateField(theMatchingContact.note, mergedContact.note);

    }); // matchingResults

    mergedContact.name = [((mergedContact.givenName[0] ?
                           mergedContact.givenName[0] : '') + ' ' +
                          (mergedContact.familyName[0] ?
                            mergedContact.familyName[0] : '')).trim()];

    fillMasterContact(masterContact, mergedContact, mergedPhoto,
                      onFilled.bind(null, callbacks, matchingContacts));
  }
  
  function filled(callbacks, matchingContacts, masterContact) {
    // Updating the master contact
    var req = navigator.mozContacts.save(
      utils.misc.toMozContact(masterContact));

    req.onsuccess = function() {
      // Now for all the matchingContacts they have to be removed
      matchingContacts.forEach(function(aMatchingContact) {
        // Only remove those contacts which are already in the DB
        if (aMatchingContact.matchingContact.id) {
          var contact = aMatchingContact.matchingContact;
          navigator.mozContacts.remove(utils.misc.toMozContact(contact));
        }
      });

      if (typeof callbacks.success === 'function') {
        callbacks.success(masterContact);
      }
    };

    req.onerror = function() {
      window.console.error('Error while saving merged Contact: ',
                           req.error.name);
      typeof callbacks.error === 'function' && callbacks.error(req.error);
    };
  }

  function isDefined(field) {
    return (Array.isArray(field) && field[0] &&
            ((typeof field[0] === 'string' && field[0].trim().length > 0) ||
             typeof field[0] === 'object'));
  }

  function copyStringArray(source, dest) {
    if (Array.isArray(source)) {
      source.forEach(function(aVal) {
        if (aVal && aVal.trim()) {
          dest.push(aVal);
        }
      });
    }
  }

  function populateEmails(sourceEmails, hash, out) {
    if (Array.isArray(sourceEmails)) {
      sourceEmails.forEach(function(aEmail) {
        aEmail.type = Array.isArray(aEmail.type) ? aEmail.type : [aEmail.type];
        aEmail.type[0] = aEmail.type[0] || DEFAULT_EMAIL_TYPE;
        var value = aEmail.value;
        if (value && value.trim()) {
          value = value.toLowerCase();
          if (!hash[value]) {
            aEmail.value = value;
            out.push(aEmail);
            hash[value] = true;
          }
        }
      });
    }
  }

  function populateNoDuplicates(source, hash, out) {
    if (Array.isArray(source)) {
      source.forEach(function(aCat) {
        if (!hash[aCat]) {
          out.push(aCat);
          hash[aCat] = true;
        }
      });
    }
  }

  function populateField(source, destination, defaultType) {
    if (Array.isArray(source)) {
      // The easiest way to compare two objects is to compare their's
      // stringified JSON representations as strings. So we create
      // temporary Array with JSONs of the objects to compare.
      var stringifiedDestination = destination.map(function(element){
        return JSON.stringify(element);
      });

      source.forEach(function(as, index) {
        // If the source value and destination value is the same we
        // don't want to merge and will leave contact as it is. This
        // prevents duplication of the data like in Bug 935636
        if (stringifiedDestination.indexOf(JSON.stringify(as)) === -1) {
          if (defaultType && (!as.type || !as.type[0])) {
            as.type = [defaultType];
          }
          destination.push(as);
        }
      });
    }
  }

  function fillMasterContact(masterContact, mergedContact, mergedPhotos, done) {
    var fields = ['familyName', 'givenName', 'name', 'org', 'email', 'tel',
                  'bday', 'anniversary', 'adr', 'category',
                  'url', 'note', 'photo'];

    fields.forEach(function(aField) {
      masterContact[aField] = mergedContact[aField];
    });

    if (!Array.isArray(mergedPhotos) || !mergedPhotos[0] ||
        mergedPhotos.length >= 2) {
      done(masterContact);
      return;
    }

    var mergedPhoto = mergedPhotos[0];

    utils.thumbnailImage(mergedPhoto, function gotTumbnail(thumbnail) {
      if (mergedPhoto !== thumbnail) {
        masterContact.photo = [mergedPhoto, thumbnail];
      } else {
        masterContact.photo = [mergedPhoto];
      }
      done(masterContact);
    });
  }

  return {
    merge: doMerge,
    inMemoryMerge: doInMemoryMerge
  };

})();