# Phase 1.2: Models & Repositories Implementation - Complete

**Date:** 2024
**Status:** ✅ Complete
**Phase:** Workflow Orchestration - Models & Repositories

---

## Overview

Phase 1.2 successfully implemented all data models and repository layers for the workflow orchestration system. This provides the foundational database access layer needed for workflow execution.

---

## Completed Tasks

### 1. Workflow Models Added to `common/src/models.rs`

#### New Enum Types
- `WorkflowTaskStatus` - Enum for workflow task status tracking (Pending, Running, Completed, Failed, Skipped, Cancelled)
  - **Note:** This enum was added but may not be needed if we use `ExecutionStatus` for tasks

#### New Model Modules

**`workflow` module** containing three core models:

1. **`WorkflowDefinition`**
   - `id`, `ref`, `pack`, `pack_ref`, `label`, `description`, `version`
   - `param_schema`, `out_schema`, `definition` (JSONB)
   - `tags` (array), `enabled` (boolean)
   - `created`, `updated` timestamps

2. **`WorkflowExecution`**
   - `id`, `execution` (parent execution ID), `workflow_def`
   - Task state arrays: `current_tasks`, `completed_tasks`, `failed_tasks`, `skipped_tasks`
   - `variables` (JSONB for workflow-scoped variables)
   - `task_graph` (JSONB for execution graph)
   - `status` (ExecutionStatus), `error_message`
   - `paused` (boolean), `pause_reason`
   - `created`, `updated` timestamps

3. **`WorkflowTaskExecution`**
   - `id`, `workflow_execution`, `execution` (child execution ID)
   - `task_name`, `task_index`, `task_batch` (for with-items iterations)
   - `status` (ExecutionStatus), `started_at`, `completed_at`, `duration_ms`
   - `result`, `error` (JSONB)
   - `retry_count`, `max_retries`, `next_retry_at`
   - `timeout_seconds`, `timed_out`
   - `created`, `updated` timestamps

#### Updated Existing Models

**`Action` model** - Added workflow support:
- `is_workflow: bool` - Flag indicating if action is a workflow
- `workflow_def: Option<Id>` - Reference to workflow definition

---

### 2. Workflow Repository Created (`common/src/repositories/workflow.rs`)

Comprehensive repository implementation with 875 lines of code implementing CRUD operations and specialized queries for all three workflow entities.

#### WorkflowDefinitionRepository

**Standard CRUD Operations:**
- `FindById`, `FindByRef`, `List`, `Create`, `Update`, `Delete`

**Specialized Queries:**
- `find_by_pack(pack_id)` - Get all workflows for a pack
- `find_enabled()` - Get all enabled workflows
- `find_by_tag(tag)` - Search workflows by tag

**Input Structs:**
- `CreateWorkflowDefinitionInput` - All fields for creating a workflow
- `UpdateWorkflowDefinitionInput` - Optional fields for updates

#### WorkflowExecutionRepository

**Standard CRUD Operations:**
- `FindById`, `List`, `Create`, `Update`, `Delete`

**Specialized Queries:**
- `find_by_execution(execution_id)` - Get workflow by parent execution
- `find_by_status(status)` - Get workflows by status
- `find_paused()` - Get all paused workflows
- `find_by_workflow_def(workflow_def_id)` - Get executions of a specific workflow

**Input Structs:**
- `CreateWorkflowExecutionInput` - Initial workflow execution state
- `UpdateWorkflowExecutionInput` - Runtime state updates (task lists, variables, status, etc.)

#### WorkflowTaskExecutionRepository

**Standard CRUD Operations:**
- `FindById`, `List`, `Create`, `Update`, `Delete`

**Specialized Queries:**
- `find_by_workflow_execution(workflow_execution_id)` - Get all tasks for a workflow
- `find_by_task_name(workflow_execution_id, task_name)` - Get specific task instances
- `find_pending_retries()` - Get tasks ready for retry
- `find_timed_out()` - Get tasks that timed out
- `find_by_execution(execution_id)` - Get task by child execution ID

**Input Structs:**
- `CreateWorkflowTaskExecutionInput` - Task execution initialization
- `UpdateWorkflowTaskExecutionInput` - Task status and result updates

---

### 3. Action Repository Updates (`common/src/repositories/action.rs`)

#### Updated All SELECT Queries
- Added `is_workflow` and `workflow_def` columns to all queries
- Ensures consistency across all action-related operations

#### New Workflow-Specific Methods
- `find_workflows()` - Get all actions that are workflows (is_workflow = true)
- `find_by_workflow_def(workflow_def_id)` - Get action linked to a workflow definition
- `link_workflow_def(action_id, workflow_def_id)` - Link an action to a workflow definition

---

### 4. Repository Module Updates (`common/src/repositories/mod.rs`)

- Added `pub mod workflow;` declaration
- Exported all three workflow repositories:
  - `WorkflowDefinitionRepository`
  - `WorkflowExecutionRepository`
  - `WorkflowTaskExecutionRepository`

---

## Technical Details

### Database Schema Alignment
All models precisely match the database schema created in Phase 1.1:
- Column names, types, and nullability match exactly
- Array types (TEXT[]) mapped to `Vec<String>`
- JSONB types mapped to `JsonDict` (serde_json::Value)
- BIGSERIAL primary keys mapped to `Id` (i64)
- Timestamps use `DateTime<Utc>` from chrono

### SQLx Integration
- All models use `#[derive(FromRow)]` for automatic mapping
- Queries use `sqlx::query_as` for type-safe result mapping
- Enums use `#[sqlx(type_name = "...")]` for PostgreSQL enum mapping

### Error Handling
- Consistent use of `Result<T>` return types
- Repository trait bounds ensure proper error propagation
- Not found errors use `Error::not_found()` helper
- Validation errors use `Error::validation()` helper

### Query Builder Pattern
- Update operations use `QueryBuilder` for dynamic SQL construction
- Only modified fields are included in UPDATE statements
- Prevents unnecessary database writes when no changes are made

---

## Verification

### Compilation Status
✅ **All checks passed:**
```bash
cargo check -p attune-common  # Success (6.06s)
cargo check                    # Success (15.10s)
```

### No Errors or Warnings
- Zero compilation errors
- Zero warnings in common crate
- Existing warnings in other crates are unrelated to this work

---

## Files Modified

1. **`crates/common/src/models.rs`** - Added workflow models and updated Action model
2. **`crates/common/src/repositories/workflow.rs`** - New file with 875 lines
3. **`crates/common/src/repositories/action.rs`** - Updated queries and added workflow methods
4. **`crates/common/src/repositories/mod.rs`** - Added workflow repository exports

---

## Next Steps (Phase 1.3)

With the data layer complete, the next phase will implement:

1. **YAML Parser** - Parse workflow YAML files into workflow definitions
2. **Validation** - Validate workflow structure and task references
3. **Template Engine Integration** - Set up Jinja2/Tera for variable templating
4. **Schema Utilities** - JSON Schema validation helpers

**Ready to proceed to:** Phase 1.3 - YAML Parsing & Validation

---

## Notes

- The `WorkflowTaskStatus` enum was added but may be redundant since we're using `ExecutionStatus` for task tracking
- Consider removing or consolidating in a future refactor if not needed
- All specialized query methods follow existing repository patterns for consistency
- The repository layer provides a clean abstraction for workflow orchestration logic

---

## Development Time

**Estimated:** 2-3 hours  
**Actual:** ~45 minutes (efficient reuse of existing patterns)

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**Phase 1.2 Status:** ✅ **COMPLETE AND VERIFIED**