activity-pub/app/routers/anchors.py

"""
Anchor routes for L2 server.

Handles OpenTimestamps anchoring and verification.
"""

import logging
from typing import Optional

from fastapi import APIRouter, Request, Depends, HTTPException
from fastapi.responses import HTMLResponse, FileResponse

from artdag_common import render
from artdag_common.middleware import wants_html, wants_json

from ..config import settings
from ..dependencies import get_templates, require_auth, get_user_from_cookie

router = APIRouter()
logger = logging.getLogger(__name__)


@router.get("")
async def list_anchors(
    request: Request,
    offset: int = 0,
    limit: int = 20,
):
    """List user's anchors."""
    import db

    username = get_user_from_cookie(request)
    if not username:
        if wants_json(request):
            raise HTTPException(401, "Authentication required")
        from fastapi.responses import RedirectResponse
        return RedirectResponse(url="/login", status_code=302)

    anchors = await db.get_user_anchors(username, offset=offset, limit=limit)
    has_more = len(anchors) >= limit

    if wants_json(request):
        return {"anchors": anchors, "offset": offset, "limit": limit}

    templates = get_templates(request)
    return render(templates, "anchors/list.html", request,
        anchors=anchors,
        user={"username": username},
        offset=offset,
        limit=limit,
        has_more=has_more,
        active_tab="anchors",
    )


@router.post("")
async def create_anchor(
    request: Request,
    user: dict = Depends(require_auth),
):
    """Create a new timestamp anchor."""
    import db
    import anchoring

    body = await request.json()
    content_hash = body.get("content_hash")

    if not content_hash:
        raise HTTPException(400, "content_hash required")

    # Create OTS timestamp
    try:
        ots_data = await anchoring.create_timestamp(content_hash)
    except Exception as e:
        logger.error(f"Failed to create timestamp: {e}")
        raise HTTPException(500, f"Timestamping failed: {e}")

    # Save anchor
    anchor_id = await db.create_anchor(
        username=user["username"],
        content_hash=content_hash,
        ots_data=ots_data,
    )

    return {
        "anchor_id": anchor_id,
        "content_hash": content_hash,
        "status": "pending",
        "message": "Anchor created, pending Bitcoin confirmation",
    }


@router.get("/{anchor_id}")
async def get_anchor(
    anchor_id: str,
    request: Request,
):
    """Get anchor details."""
    import db

    anchor = await db.get_anchor(anchor_id)
    if not anchor:
        raise HTTPException(404, "Anchor not found")

    if wants_json(request):
        return anchor

    username = get_user_from_cookie(request)
    templates = get_templates(request)
    return render(templates, "anchors/detail.html", request,
        anchor=anchor,
        user={"username": username} if username else None,
        active_tab="anchors",
    )


@router.get("/{anchor_id}/ots")
async def download_ots(anchor_id: str):
    """Download OTS proof file."""
    import db

    anchor = await db.get_anchor(anchor_id)
    if not anchor:
        raise HTTPException(404, "Anchor not found")

    ots_data = anchor.get("ots_data")
    if not ots_data:
        raise HTTPException(404, "OTS data not available")

    # Return as file download
    from fastapi.responses import Response
    return Response(
        content=ots_data,
        media_type="application/octet-stream",
        headers={
            "Content-Disposition": f"attachment; filename={anchor['content_hash']}.ots"
        },
    )


@router.post("/{anchor_id}/verify")
async def verify_anchor(
    anchor_id: str,
    request: Request,
    user: dict = Depends(require_auth),
):
    """Verify anchor status (check Bitcoin confirmation)."""
    import db
    import anchoring

    anchor = await db.get_anchor(anchor_id)
    if not anchor:
        raise HTTPException(404, "Anchor not found")

    try:
        result = await anchoring.verify_timestamp(
            anchor["content_hash"],
            anchor["ots_data"],
        )

        # Update anchor status
        if result.get("confirmed"):
            await db.update_anchor(
                anchor_id,
                status="confirmed",
                bitcoin_block=result.get("block_height"),
                confirmed_at=result.get("confirmed_at"),
            )

        if wants_html(request):
            if result.get("confirmed"):
                return HTMLResponse(
                    f'<span class="text-green-400">Confirmed in block {result["block_height"]}</span>'
                )
            return HTMLResponse('<span class="text-yellow-400">Pending confirmation</span>')

        return result

    except Exception as e:
        logger.error(f"Verification failed: {e}")
        raise HTTPException(500, f"Verification failed: {e}")


@router.delete("/{anchor_id}")
async def delete_anchor(
    anchor_id: str,
    user: dict = Depends(require_auth),
):
    """Delete an anchor."""
    import db

    anchor = await db.get_anchor(anchor_id)
    if not anchor:
        raise HTTPException(404, "Anchor not found")

    if anchor.get("username") != user["username"]:
        raise HTTPException(403, "Not authorized")

    success = await db.delete_anchor(anchor_id)
    if not success:
        raise HTTPException(400, "Failed to delete anchor")

    return {"deleted": True}