function GroupList() {

  lastChange=0;
  
  this.loadFromLocalStorage=function() {
    if (localStorage.groups!==undefined) {
      var data=JSON.parse(localStorage.groups);
      this.lastChange=data.lastChange;
      for (el in data.groups) {
        this[el]=new Group(el,data.groups[el]);
      }
    }
  }

  this.export=function() {
    ret={};
    for (el in this) {
      if (this.isGroup(this[el])) {
        ret[el]=this[el].export();
      }
    }
    return ret;
  }

  this.save=function() {
    localStorage.groups=JSON.stringify({
      'lastChange': new Date().getTime(),
      'groups': this.export()
    });
  }

  this.each=function(fct) {
    var idx=0;
    for (el in this) {
      if(this.isGroup(this[el])) {
        fct(idx++,this[el]);
      }
    }
  }

  this.count=function() {
    len=0;
    for (el in this) {
      if (this.isGroup(this[el])) len=len+1;
    }
    return len;
  }

  this.isGroup=function(el) {
    return (el.isGroup!==undefined);
  }

  this.removeGroup=function(name) {
    if (this.isGroup(this[name])) {
      delete this[name];
      return true;
    }
    return false;
  }
}

function Group(name,data) {
  this.name=name;
  this.contributors=[];
  this.contributions=[];


  this.isGroup=function() {
    return true;
  }

  this.export=function() {
    var contributors=[];
    for (idx in this.contributors) {
      contributors.push(this.contributors[idx].export());
    }
    var contributions=[];
    for (idx in this.contributions) {
      contributions.push(this.contributions[idx].export());
    }
    return {
      'name': this.name,
      'contributors': contributors,
      'contributions': contributions
    };
  }

  /*
   * Contributors
   */
  this.removeContributor=function(c) {
    this.contributors=this.contributors.filter(function(v){
      return (v.name!=c);
    });
  }

  this.contributorByName=function(name) {
    for (c in this.contributors) {
      if (this.contributors[c].name == name) return this.contributors[c];
    }
    return undefined;
  }

  this.contributorByEmail=function(email) {
    for (c in this.contributors) {
      if (this.contributors[c].email == email) return this.contributors[c];
    }
    return undefined;
  }

  this.addContributor=function(c) {
    c.id=this.contributors.length;
    this.contributors.push(c);
  }

  this.replaceContributor=function(idx,c) {
    c.id=idx;
    this.contributors[idx]=c;
  }

  /*
   * Contributions
   */
  this.contributionsByContributorName=function(name) {
    var ret=[];
    for (idx in this.contributions) {
      if (this.contributions[idx].contributor.name==name) {
        ret.push(this.contributions[idx]);
      }
    }
    return ret;
  }

  this.addContribution=function(c) {
    c.id=this.contributions.length;
    this.contributions.push(c);
  }

  this.replaceContribution=function(idx,c) {
    c.id=idx;
    this.contributions[idx]=c;
  }

  /*
   * Balance
   */
  this.balance=function() {
    ret={}
    for (idx in this.contributors) {
      sum=0;
      c=this.contributors[idx].name;
      cl=this.contributionsByContributorName(c);
      for (idc in cl) {
        sum+=cl[idc].cost;
      }
      ret[c]=sum;
    }
    return ret;
  }

  /*
   * Contructor
   */
  if (jQuery.type(data)=='object') {
    try {
      this.name=data.name;
      if (jQuery.type(data.contributors) == 'array') {
        for (idx in data.contributors) {
          this.contributors.push(new Contributor(
            data.contributors[idx].name,
            data.contributors[idx].email,
            idx
          ));
        }
      }
      if (jQuery.type(data.contributions) == 'array') {
        for (idx in data.contributions) {
          this.contributions.push(new Contribution(
            this.contributorByName(data.contributions[idx].contributor),
            data.contributions[idx].cost,
            data.contributions[idx].title,
            data.contributions[idx].date,
            idx,
            data.contributions[idx].lastChange
          ));
        }
      }
    }
    catch (e) {
      alert('Une erreur est survenue en chargeant le groupe '+this.name+' depuis le cache');
    }
  }
}

function Contributor(name,email,id) {
  this.name=name;
  this.email=email;
  this.id=id;
  this.export=function() {
    return {
      'name': this.name,
      'email': this.email
    };
  }
}

function Contribution(contributor,cost,title,date,id,lastChange) {
  this.contributor=contributor;
  this.cost=cost;
  this.title=title;
  this.date=date;
  this.id=id;
  this.lastChange=lastChange || new Date().getTime();
  this.export=function() {
    return {
      'contributor': this.contributor.name,
      'cost': this.cost,
      'title': this.title,
      'date': this.date,
      'lastChange': this.lastChange,
    };
  }

  this.getTitle=function() {
    if (jQuery.type(this.title)=='string') {
      return this.title;
    }
    return '';
  }
}