from __future__ import annotations


def build_session_key(agent_id: str, account_id: str, user_id: str) -> str:
    return f"agent:{agent_id}:synology-chat:{account_id}:direct:{user_id}"


CHANNEL_FORMAT_INSTRUCTIONS = """
### Synology Chat Formatting
Synology Chat supports limited formatting. Use these patterns:

**Links**: Use <URL|display text> to create clickable links.
  Example: <https://example.com|Click here> renders as a clickable link.
  Markdown links [label](url) are automatically converted to <URL|label> format.

**File sharing**: Include a publicly accessible URL to share files or images.
  The NAS will download and attach the file (max 32 MB).

**Interactive buttons**: Bot can send action buttons via attachments.
  Supported button styles: green, grey, red, orange, blue, teal.

**Limitations**:
- No markdown, bold, italic, or code blocks
- No message editing after send
- Keep messages under 2000 characters for best readability

**Best practices**:
- Use short, clear responses (Synology Chat has a minimal UI)
- Use line breaks to separate sections
- Use numbered or bulleted lists for clarity
- Wrap URLs with <URL|label> for user-friendly links
"""