# Phase 0 — Research: Remove Legacy BulkOperationRun & Canonicalize Operations (v1.0)

**Branch**: 056-remove-legacy-bulkops  
**Date**: 2026-01-18

## Goals for Research

- Resolve spec clarifications and translate them into concrete implementation constraints.
- Identify existing repo patterns for:
  - run identity / dedupe
  - summary_counts normalization
  - locks / concurrency limiting
  - idempotent selection hashing
- Enumerate known legacy usage locations to inform the discovery report.

## Findings & Decisions

### Decision 1 — Per-target scope concurrency

- **Decision**: Concurrency limits are configuration-driven **with default = 1** per target scope.
- **Rationale**: Default=1 is the safest choice against Graph throttling and reduces blast radius when many tenants/scope targets are active.
- **Alternatives considered**:
  - Default=2: more throughput but higher throttling risk.
  - Default=5: increases throttling/incident risk.
  - Hardcoded values: hard to tune per environment.
- **Implementation constraint**: Limit is enforced per `entra_tenant_id` or `directory_context_id`.

### Decision 2 — Selection Identity (idempotency fingerprint)

- **Decision**: Hybrid selection identity.
  - If the user explicitly selects IDs: fingerprint includes an **IDs-hash**.
  - If the user selects via filter/query (“select all”): fingerprint includes a **query/filter hash**.
- **Rationale**: Supports both UX patterns and avoids duplicate runs while remaining deterministic.
- **Alternatives considered**:
  - IDs-hash only: cannot represent “select all by filter”.
  - Query-hash only: cannot safely represent explicit selections.
  - Always store both: increases complexity without clear value.

### Decision 3 — Legacy history handling

- **Decision**: Do not import legacy bulk-run history into OperationRun.
- **Rationale**: Minimizes migration risk and avoids polluting the canonical run surface with “synthetic” imported data.
- **Alternatives considered**:
  - One-time import: adds complexity, new semantics, and additional testing burden.

### Decision 4 — Canonical summary metrics

- **Decision**: Summary metrics are derived and rendered from `operation_runs.summary_counts` using the canonical key registry.
- **Rationale**: Ensures consistent Monitoring UX and prevents ad-hoc keys.
- **Alternatives considered**:
  - Per-operation bespoke metrics: causes UX drift and breaks shared widgets.

### Decision 5 — Reuse existing repo patterns

- **Decision**: Reuse existing run, lock, and selection hashing patterns already present in the repository.
- **Rationale**: Aligns with constitution and avoids divergent implementations.
- **Evidence in repo**:
  - `OperationRunService` provides tenant-wide active-run dedupe and safe dispatch failure handling.
  - `OperationCatalog` centralizes labels/durations and allowed summary keys.
  - `InventoryConcurrencyLimiter` shows slot-based lock acquisition with config-driven maxima.
  - `InventorySyncService` shows deterministic selection hashing and selection-level locks.

## Legacy Usage Inventory (initial)

This is a starting list derived from a repo search; the Phase 2 Discovery Report must expand/confirm.

- Legacy bulk-run model: `app/Models/BulkOperationRun.php`
- Legacy bulk-run service: `app/Services/BulkOperationService.php`
- Legacy jobs using BulkOperationRun/Service:
  - `app/Jobs/BulkPolicySyncJob.php`
  - `app/Jobs/BulkPolicyDeleteJob.php`
  - `app/Jobs/BulkBackupSetDeleteJob.php`
  - `app/Jobs/BulkPolicyVersionPruneJob.php`
  - `app/Jobs/BulkPolicyVersionForceDeleteJob.php`
  - `app/Jobs/BulkRestoreRunDeleteJob.php`
  - `app/Jobs/BulkTenantSyncJob.php`
  - `app/Jobs/CapturePolicySnapshotJob.php`
  - `app/Jobs/GenerateDriftFindingsJob.php` (mixed usage)
- Legacy DB artifacts:
  - `database/migrations/2025_12_23_215901_create_bulk_operation_runs_table.php`
  - `database/migrations/2026_01_11_120001_add_idempotency_key_to_bulk_operation_runs_table.php`
  - `database/migrations/2025_12_24_005055_increase_bulk_operation_runs_status_length.php`
- Legacy test data:
  - `database/factories/BulkOperationRunFactory.php`
  - `database/seeders/BulkOperationsTestSeeder.php`

## Open Questions

None remaining for Phase 0 (spec clarifications resolved). Any additional unknowns found during discovery are to be added to the Phase 2 discovery report and/or tasks.
