# Workflow Manager

## Overview

**User Code:** `com.finmars.standard-workflow:workflow-manager`  
**Payload:** Optional

The Workflow Manager is designed to execute workers in a specific order with a defined payload. Its primary use case is when no payload is provided.


## Global State Manager Processing Logic

1. Attempt to read the `global_state_manager.json` file. If it doesn't exist, create it.
2. Read the list of files from `/states/managers/`.
3. Categorize by status and save in `global_state_manager.json`:
   - If the file doesn't exist, add it to "to-do"
   - If it's in "to-do", change the status to "in-progress"
   - If the file exists, update its status
4. Read the contents of the file in "in-progress" status

```json
{
    "to-do": [],
    "in-progress": [
        "com.finmars.standard-workflow:workflow-manager-20240821095322.json"
    ],
    "done": [
        "com.finmars.standard-workflow:workflow-manager-20240724101635.json",
        "com.finmars.standard-workflow:workflow-manager-20240724104102.json"
    ],
    "paused": []
}
```

## Interaction with global_state_manager.json

The `global_state_manager.json` file serves as a central registry for all workflow states in the system:

1. **Initialization**: If `global_state_manager.json` doesn't exist, it's created by scanning the `/states/managers/` directory and categorizing all existing state manager files.

2. **Retrieval**: The existing `global_state_manager.json` is loaded and its data is updated.

3. **Updating**: The global state manager is updated by:
   - Identifying and adding new state manager files to the "in-progress" category
   - Checking and updating the status of each tracked state manager file
   - Moving state managers between categories based on their current status

4. **Saving**: After updates, the modified `global_state_manager.json` is saved back to storage.

5. **Workflow Processing**: The main `workflow_manager` function uses data from `global_state_manager.json` to determine which state managers to process when no specific payload is provided.

## State Managers and Workers/Items Interaction

Each state manager file represents an individual workflow instance, containing information about its workers and their respective items (tasks):

1. **Loading**: Individual state manager files are loaded based on paths stored in `global_state_manager.json` or provided in the payload.

2. **Status Propagation**: Each worker's status is updated based on the statuses of its items.

3. **Worker Processing**: For each worker in a state manager:
   - Skipped if status is 'success', 'skip', or 'ignore'
   - If 'in-progress', each item's status is checked:
     - 'in-progress' items: latest state is fetched and updated
     - 'to-do' items: a new workflow is initiated
   - If 'to-do', processing starts with the first 'to-do' item

4. **Item State Management**: Each item within a worker has its own state, including a `state_path` used to fetch and update item-specific states.

5. **Workflow Initiation**: New items are processed by calling the `start_workflow` function with the appropriate user code and payload.

6. **State Updating**: After any changes, the modified state manager is saved back to its file.