import { Column, CreateDateColumn, Entity, Index, PrimaryGeneratedColumn } from 'typeorm';

/**
 * One backoffice action against a state-changing endpoint.
 *
 * Deliberately does NOT extend `BaseEntity`, which is the repo standard
 * everywhere else. `BaseEntity` carries `updatedAt` and `deletedAt`, and both
 * are wrong here:
 *
 *  - `updatedAt` implies an audit row can be edited. A record that can be
 *    rewritten after the fact is not evidence.
 *  - `deletedAt` (soft delete) would let anyone who can delete erase their own
 *    trail, and TypeORM would then hide those rows from every default query —
 *    the failure would be silent, which is the worst property an audit log can
 *    have.
 *
 * Rows are insert-only: nothing in this module updates or deletes them.
 *
 * `userId` is a bare uuid with NO foreign key into the `iam` schema. Two
 * reasons: cross-schema FKs are forbidden platform-wide, and a FK would let
 * deleting a user cascade away the record of what that user did — exactly
 * backwards. `userName` / `userRole` are point-in-time snapshots for the same
 * reason: resolving them at read time would rewrite history whenever somebody
 * is renamed or changes role.
 */
@Entity({ schema: 'freight', name: 'audit_logs' })
// Every audit query is time-bounded, so created_at leads most indexes.
@Index('IDX_audit_logs_created_at', ['createdAt'])
@Index('IDX_audit_logs_user_id_created_at', ['userId', 'createdAt'])
@Index('IDX_audit_logs_type_created_at', ['type', 'createdAt'])
@Index('IDX_audit_logs_type_resource_id', ['type', 'resourceId'])
@Index('IDX_audit_logs_route_path_created_at', ['routePath', 'createdAt'])
export class AuditLog {
  @PrimaryGeneratedColumn('uuid')
  id!: string;

  /**
   * Human-readable action, e.g. "Approve contract" — taken from the matched
   * entry in `AUDIT_ENDPOINTS`, which sources it from each route's
   * `@ApiOperation` summary.
   */
  @Column({ name: 'title', type: 'varchar', length: 255 })
  title!: string;

  @Column({ name: 'method', type: 'varchar', length: 10 })
  method!: string;

  /**
   * The URL as actually called, real ids and query string included
   * (`/api/contracts/abc-123/cancel?force=true`). Query values run through the
   * same redaction pass as the body, so a `?token=` never lands here.
   */
  @Column({ name: 'url', type: 'text' })
  url!: string;

  /**
   * The route template (`/api/contracts/:id/cancel`).
   *
   * `url` alone cannot be grouped — every contract cancel is a distinct string.
   * This column is the join key back to `AUDIT_ENDPOINTS` and makes
   * "every contract cancellation" one indexed query instead of a regex scan.
   */
  @Column({ name: 'route_path', type: 'varchar', length: 255, nullable: true })
  routePath?: string | null;

  /** Primary entity the action touched: `Contract`, `Booking`, `Locomotive`. */
  @Column({ name: 'type', type: 'varchar', length: 50 })
  type!: string;

  @Column({ name: 'is_success', type: 'boolean' })
  isSuccess!: boolean;

  /** IAM user id. Nullable by design — see the class comment. */
  @Column({ name: 'user_id', type: 'uuid', nullable: true })
  userId?: string | null;

  /**
   * Id of the affected record, recovered from the first path parameter of the
   * matched template.
   *
   * `varchar`, not `uuid`: not every identifier is a uuid
   * (`/api/contract-templates/:code`), and a create has no id at all until it
   * succeeds. A `uuid NOT NULL` column would throw during the write and lose
   * the audit row rather than the id.
   */
  @Column({ name: 'resource_id', type: 'varchar', length: 64, nullable: true })
  resourceId?: string | null;

  /**
   * Sanitized request body. Secrets are replaced with `[REDACTED]` and uploads
   * are reduced to `{ __file, originalName, mimeType, size }` descriptors —
   * never raw bytes. See `audit.sanitizer.ts`.
   */
  @Column({ name: 'request', type: 'jsonb', nullable: true })
  request?: Record<string, unknown> | null;

  /**
   * `isSuccess` alone cannot separate 403 (denied — the security signal worth
   * alerting on) from 500 (broke). Both are simply `false`.
   */
  @Column({ name: 'status_code', type: 'smallint', nullable: true })
  statusCode?: number | null;

  @Column({ name: 'error_message', type: 'text', nullable: true })
  errorMessage?: string | null;

  /** Snapshot of the actor's display name at the time of the action. */
  @Column({ name: 'user_name', type: 'varchar', length: 150, nullable: true })
  userName?: string | null;

  /** Snapshot of the actor's role at the time of the action. */
  @Column({ name: 'user_role', type: 'varchar', length: 100, nullable: true })
  userRole?: string | null;

  /** Non-repudiation: the first thing asked in any incident review. */
  @Column({ name: 'ip_address', type: 'inet', nullable: true })
  ipAddress?: string | null;

  /** Helps separate a real browser session from a script using a stolen token. */
  @Column({ name: 'user_agent', type: 'text', nullable: true })
  userAgent?: string | null;

  /** Correlates this row with application logs/traces for the same request. */
  @Column({ name: 'request_id', type: 'varchar', length: 64, nullable: true })
  requestId?: string | null;

  @Column({ name: 'duration_ms', type: 'integer', nullable: true })
  durationMs?: number | null;

  @CreateDateColumn({ name: 'created_at', type: 'timestamptz' })
  createdAt!: Date;
}