# Proposals API

The Proposals API provides endpoints for managing symbiosis proposals between organizations. Proposals represent requests for resource exchange or collaboration opportunities.

## Base URL
```
https://api.turash.com/api/v1
```

## Endpoints

### Get All Proposals

Retrieve all proposals with optional filtering.

**Endpoint:** `GET /api/v1/proposals`

**Query Parameters:**
- `status` (optional): Filter by proposal status (`pending`, `accepted`, `rejected`)
- `from_org` (optional): Filter by proposing organization ID
- `to_org` (optional): Filter by target organization ID
- `limit` (optional): Maximum number of results (default: 50)
- `offset` (optional): Pagination offset (default: 0)

**Response:**
```json
[
  {
    "id": "proposal-123",
    "from_org_id": "org-456",
    "to_org_id": "org-789",
    "resource_id": "resource-101",
    "resource_type": "input",
    "resource_name": "Organic Waste",
    "message": "We can provide organic waste for your composting needs",
    "status": "pending",
    "created_at": "2024-01-15T10:30:00Z"
  }
]
```

### Get Proposal by ID

Retrieve a specific proposal by its ID.

**Endpoint:** `GET /api/v1/proposals/{id}`

**Path Parameters:**
- `id`: Proposal ID

**Response:**
```json
{
  "id": "proposal-123",
  "from_org_id": "org-456",
  "to_org_id": "org-789",
  "resource_id": "resource-101",
  "resource_type": "input",
  "resource_name": "Organic Waste",
  "message": "We can provide organic waste for your composting needs",
  "status": "pending",
  "created_at": "2024-01-15T10:30:00Z"
}
```

**Error Responses:**
- `404 Not Found` - Proposal not found

### Get Proposals by Organization

Retrieve all proposals where an organization is either the sender or receiver.

**Endpoint:** `GET /api/v1/organizations/{id}/proposals`

**Path Parameters:**
- `id`: Organization ID

**Response:**
```json
{
  "incoming": [
    {
      "id": "proposal-123",
      "from_org_id": "org-456",
      "to_org_id": "org-789",
      "resource_id": "resource-101",
      "resource_type": "input",
      "resource_name": "Organic Waste",
      "message": "We can provide organic waste for your composting needs",
      "status": "pending",
      "created_at": "2024-01-15T10:30:00Z"
    }
  ],
  "outgoing": [
    {
      "id": "proposal-124",
      "from_org_id": "org-789",
      "to_org_id": "org-456",
      "resource_id": "resource-102",
      "resource_type": "output",
      "resource_name": "Heat Energy",
      "message": "Interested in your heat recovery system",
      "status": "accepted",
      "created_at": "2024-01-16T14:20:00Z"
    }
  ]
}
```

### Create Proposal

Create a new symbiosis proposal.

**Endpoint:** `POST /api/v1/proposals`

**Request Body:**
```json
{
  "from_org_id": "org-456",
  "to_org_id": "org-789",
  "resource_id": "resource-101",
  "resource_type": "input",
  "resource_name": "Organic Waste",
  "message": "We can provide organic waste for your composting needs"
}
```

**Required Fields:**
- `from_org_id`: ID of the proposing organization
- `to_org_id`: ID of the target organization
- `resource_id`: ID of the resource flow being proposed
- `resource_type`: Direction of the resource flow (`input` or `output`)
- `resource_name`: Human-readable name of the resource

**Optional Fields:**
- `message`: Additional message or proposal details

**Response:**
```json
{
  "id": "proposal-123",
  "from_org_id": "org-456",
  "to_org_id": "org-789",
  "resource_id": "resource-101",
  "resource_type": "input",
  "resource_name": "Organic Waste",
  "message": "We can provide organic waste for your composting needs",
  "status": "pending",
  "created_at": "2024-01-15T10:30:00Z"
}
```

**Error Responses:**
- `400 Bad Request` - Invalid request data
- `404 Not Found` - Organization or resource not found

### Update Proposal Status

Update the status of an existing proposal.

**Endpoint:** `POST /api/v1/proposals/{id}/status`

**Path Parameters:**
- `id`: Proposal ID

**Request Body:**
```json
{
  "status": "accepted"
}
```

**Valid Status Values:**
- `pending` - Initial status, awaiting response
- `accepted` - Proposal accepted by target organization
- `rejected` - Proposal rejected by target organization

**Response:**
```json
{
  "message": "Proposal status updated successfully"
}
```

**Error Responses:**
- `400 Bad Request` - Invalid status value
- `404 Not Found` - Proposal not found

## Data Types

### Proposal Status
```typescript
type ProposalStatus = 'pending' | 'accepted' | 'rejected';
```

### Proposal Object
```typescript
interface Proposal {
  id: string;
  from_org_id: string;
  to_org_id: string;
  resource_id: string;
  resource_type: 'input' | 'output';
  resource_name: string;
  message?: string;
  status: ProposalStatus;
  created_at: string;
}
```

## Business Rules

### Proposal Lifecycle
1. **Creation**: Proposals are created with `pending` status
2. **Response**: Target organization can accept or reject the proposal
3. **Final State**: Once accepted or rejected, status cannot be changed

### Validation Rules
- Organizations cannot propose to themselves
- Resource must exist and be owned by the proposing organization
- Resource type must match the direction being proposed
- Message length limited to 500 characters

### Permissions
Currently, all proposal operations are publicly accessible. Future implementations will include:
- Authentication requirements
- Authorization based on organization membership
- Proposal creation limits per organization

## Error Codes

| Code | Description |
|------|-------------|
| `VALIDATION_ERROR` | Request data validation failed |
| `PROPOSAL_NOT_FOUND` | Specified proposal does not exist |
| `ORGANIZATION_NOT_FOUND` | Specified organization does not exist |
| `RESOURCE_NOT_FOUND` | Specified resource does not exist |
| `INVALID_STATUS_TRANSITION` | Attempted invalid status change |
| `SELF_PROPOSAL_ERROR` | Organization cannot propose to itself |

## Rate Limits

- Create Proposal: 10 per hour per organization
- Update Status: 50 per hour per organization
- Get Operations: 100 per hour per IP

## WebSocket Events

The API emits WebSocket events for real-time proposal updates:

- `proposal_created`: New proposal submitted
- `proposal_status_changed`: Proposal status updated

**Event Payload:**
```json
{
  "type": "proposal_status_changed",
  "proposal_id": "proposal-123",
  "old_status": "pending",
  "new_status": "accepted",
  "updated_by": "org-789",
  "timestamp": "2024-01-15T10:35:00Z"
}
```