import { SoftDeleteAudit } from "@tria-plc/api-common/modules/typeorm/audit.entity";
import {
  Check,
  Column,
  Entity,
  JoinColumn,
  ManyToOne,
  PrimaryGeneratedColumn,
  Unique,
} from "typeorm";

import { JobTitle } from "../../job-titles/entities/job-title.entity";

/**
 * The headcount / vacancy layer over `iam.positions`.
 *
 * Stores NOTHING IAM already holds — not the unit, not the organization. Both
 * come from `iam.positions` and are read by joining. A copy here would be a
 * second answer that goes stale the moment a position is moved.
 *
 * It EXTENDS a position, never replaces it: `positionId` is a soft reference to
 * the IAM slot, unique here so a position cannot acquire two competing headcount
 * records. IAM keeps owning who holds the position; HR adds what it is graded as,
 * how many bodies it is budgeted for, and whether it is open for recruitment
 * (which 3.5 reads when creating a job opening).
 */
@Entity({ schema: "hr", name: "job_positions" })
@Unique("uq_job_positions_position_id", ["positionId"])
@Check("ck_job_positions_budgeted_count", `"budgeted_count" >= 0`)
@Check("ck_job_positions_current_count", `"current_count" >= 0`)
export class JobPosition extends SoftDeleteAudit {
  @PrimaryGeneratedColumn("uuid")
  id!: string;

  /** Soft reference → `iam.positions.id`. */
  @Column({ type: "uuid", name: "position_id" })
  positionId!: string;

  @Column({ type: "uuid", name: "job_title_id", nullable: true })
  jobTitleId?: string | null;

  @ManyToOne(() => JobTitle, { nullable: true, onDelete: "SET NULL" })
  @JoinColumn({ name: "job_title_id" })
  jobTitle?: JobTitle | null;

  @Column({ type: "int", name: "budgeted_count", default: 1 })
  budgetedCount!: number;

  /**
   * Cache of the current holder count in IAM. Refreshed from
   * `IamDirectoryService.countCurrentPositionHolders` whenever the position is
   * read or written through HR — IAM stays the source of truth, this column just
   * makes "which posts are under-filled" answerable in one query.
   */
  @Column({ type: "int", name: "current_count", default: 0 })
  currentCount!: number;

  /** Open for recruitment. Independent of vacancy: a post can be under-filled
   *  and still frozen, which is exactly what a hiring freeze is. */
  @Column({ type: "boolean", name: "is_open", default: false })
  isOpen!: boolean;

  @Column({ type: "uuid", name: "created_by", nullable: true })
  createdBy?: string | null;
}