/**
 * Create Subtasks from TODO
 * Just add a TODO line in the issue description like this TODO @someone Android Bug: Summary of the new issue
 * Syntax: TODO <Assignee> <Type> <Subsystem> <Priority>: <summary>
 *
 */

var entities = require('@jetbrains/youtrack-scripting-api/entities');

exports.rule = entities.Issue.onChange({
  title: 'Create Subtasks from TODO',
  guard: function(ctx) {
    return ctx.issue.isChanged('description'); // optimize blob (description) read
  },
  action: function(ctx) {
    var issue = ctx.issue;

    var description = issue.description;
    if (!description) {
      return;
    }
    console.log(description)
    var si = 0;
    var td = 0;
    var li = si-1;
    if( description.indexOf("TODO") == 0){
      description = "List:\n" + description;
      issue.description = description;
    }
    while (td !== -1) {
      td = description.indexOf("TODO", si);
      li = issue.description.indexOf("TODO", li+1);
	  if(li<=0) li = issue.description.length;
      si = td+1;
      var co = description.indexOf(":", td);
      var nl = description.indexOf("\n", td);
      if (nl>0 && nl<co) continue;
      var pml = co - td-4;
      if (pml < 0){
        break;
      }
      var pms = description.substr(td+4, pml);
      var nl = description.indexOf("\n", co);
      if(nl==-1) nl = description.length;
      var ml = nl-co-1;
      if(ml<=0) break;
      var ms = description.substr(co+1, ml);
      flds = ["Subsystem", "Type", "Priority", "Assignee"];
      vs = {}
      for(fll = 0; fll < flds.length; fll++){
        fld = flds[fll];
        var ss = findFieldValuesInString(issue.project.fields.find(e => e.name == fld), pms);
        var vv = issue.fields[fld];
        if(ss !== null && ss.length > 0){
        if(ss.length==1)
            vv =ss[0];
        }
        vs[fld] = vv;
      }
      var newIssue = new entities.Issue(ctx.currentUser, issue.project,
                                        ms);
      for(fll = 0; fll < flds.length; fll++){
        fld = flds[fll];
        newIssue.fields[fld] = vs[fld];
      }
      issue.description = issue.description.substr(0, li) + description.substr(td).replace("TODO", newIssue.id);
      newIssue.links['subtask of'].add(issue);
      console.log(newIssue);
    }
  },
  requirements: {
    // TODO: add requirements
  }
});

function findFieldValuesInString(fld, msg) {
  var values = [];
  values = fld.values;
  fv = [];
  e = values.entries();
  for (i = 0; i < values.size; i++) {
    var vale = e.next().value;
    var vname = vale.name;
    if(vname === undefined) vname = vale.login;
    if(vname === undefined) continue;
    if (msg.toLowerCase().includes(vname.toLowerCase())){
	  	fv.push(vale);
    }
  }
  return fv;
}