import 'server-only';
import type PocketBase from 'pocketbase';
import { type ClockEmployee, type ClockEvent, type ClockStore } from './clock';
import { acquireEmployeeLock } from './clock-lock';
import { serverAuth } from './pb';

async function optional<T>(read:()=>Promise<T>):Promise<T|null> {
  try{return await read();}catch(e){if((e as {status?:number}).status===404)return null;throw e;}
}
export async function clockPB() {
  const pb=await serverAuth();
  if(!pb.authStore.isSuperuser)throw new Error('Clock database authentication unavailable.');
  pb.beforeSend=(url,options)=>({url,options:{...options,signal:AbortSignal.timeout(15000)}});
  return pb;
}
export async function clockEmployees(pb:PocketBase):Promise<ClockEmployee[]> {
  const [operators,mechanics]=await Promise.all([
    pb.collection('operators').getFullList({sort:'name',fields:'id,name,employee_code,asset,expand.asset.code',expand:'asset'}),
    pb.collection('mechanics').getFullList({sort:'name',fields:'id,name,employee_code,role'}),
  ]);
  return [...operators.map(e=>({id:`operators:${e.id}`,name:String(e.name||''),employeeNo:String(e.employee_code||''),role:'Operator',asset:String(e.expand?.asset?.code||'')})),
    ...mechanics.map(e=>({id:`mechanics:${e.id}`,name:String(e.name||''),employeeNo:String(e.employee_code||''),role:String(e.role||'Mechanic'),asset:''}))]
    .sort((a,b)=>a.name.localeCompare(b.name));
}
export function clockStore(pb:PocketBase):ClockStore {
  return {
    employees:()=>clockEmployees(pb),
    latest:employee=>optional(()=>pb.collection('clock_events').getFirstListItem<ClockEvent>(pb.filter('employee = {:employee}',{employee}),{sort:'-scanned_at,-id',requestKey:null})),
    event:id=>optional(()=>pb.collection('clock_events').getOne<ClockEvent>(id,{requestKey:null})),
    lock:employee=>acquireEmployeeLock({
      create:employee=>pb.collection('clock_scan_locks').create({employee}),
      find:employee=>optional(()=>pb.collection('clock_scan_locks').getFirstListItem<{id:string;created:string}>(pb.filter('employee = {:employee}',{employee}),{requestKey:null})),
      remove:id=>pb.collection('clock_scan_locks').delete(id),
    },employee),
    unlock:async id=>{
      try{await pb.collection('clock_scan_locks').delete(id);}
      catch(e){if((e as {status:number}).status!==404)console.error('Clock lock release failed; lease will expire.',id);}
    },
    create:event=>pb.collection('clock_events').create<ClockEvent>(event),
  };
}
export async function clockRoster() {
  const pb=await clockPB();
  const [employees,events]=await Promise.all([clockEmployees(pb),pb.collection('clock_events').getFullList<ClockEvent>({sort:'-scanned_at,-id'})]);
  // Actor IDs, GPS and request signatures are server audit details, not roster data.
  return {employees,events:events.map(({id,employee,employee_name,employee_no,site,direction,scanned_at,session_minutes,has_location})=>
    ({id,employee,employee_name,employee_no,site,direction,scanned_at,session_minutes,has_location})),asOf:new Date().toISOString()};
}
export type ClockRoster = Awaited<ReturnType<typeof clockRoster>>;