import { map, reduce, times } from 'rambda';

 import type { JobId } from '../../types';

 import { groupBy, max } from 'ramda';

 
 type JobTime = {
   jobId: JobId,

   t: number,
   name: string

 };
 
 type JobTimeAssigned = JobTime | {
   processor: number,
 };
 
 type JobTimeAssignedWithC = JobTimeAssigned | {
   c: number,
 };
 
 export const updateCTime = (jobTimes: JobTimeAssigned[]) => {
   let prev = 0;
   let prevProcessor = 0;
 
   const cj = map((jobTime: JobTimeAssigned) => {
     if (jobTime.processor !== prevProcessor) {
       prev = 0;
     }
 
     prev += jobTime.t;
     prevProcessor = jobTime.processor;
 
     return { ...jobTime, c: prev };
   }, jobTimes);
 
   return cj;
 };
 
 export const createSchedule = (jobs: JobTime[], processorCount: number): JobTimeAssignedWithC[] => {
   let G = jobs;
   const sumT = reduce((acc, job) => acc + job.t, 0, G);
   const maxT = reduce((acc, job) => max(acc, job.t), -Infinity, G);
   const K = max(Math.ceil(sumT / processorCount), maxT);
   const R = [];
 
   let processorC = times(() => 0, processorCount + 1);
   let activeProcessor = 1;
 
   while (G.length) {
     if (processorC[activeProcessor] + G[0].t <= K) {
       processorC[activeProcessor] += G[0].t;
       R.push({ ...G[0], processor: activeProcessor });
       [, ...G] = G;
 
       if (processorC[activeProcessor] === K) {
         activeProcessor++;
       }
     } else {
       const tDiff = processorC[activeProcessor] + G[0].t - K;
 
       R.push({ ...G[0], t: G[0].t - tDiff, processor: activeProcessor });
       G[0].t = tDiff;
 
       activeProcessor++;
     }
   }
 
   const withC = updateCTime(R);
   return withC;
 };
 
 export default (jobs: JobTime[], processorCount: number) => {
   const schedule = createSchedule(jobs, processorCount);
 
   const grouped = Object.values(groupBy(jobTime => jobTime.processor, schedule));
 
   return map(map((job: JobTimeAssignedWithC) => ({
     processor: job.processor,
     startTime: job.c - job.t,

     endTime: job.c,
     name: job.name

   })), grouped);
 };