"""API endpoints for master promotion."""
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel

router = APIRouter(prefix="/api/master", tags=["master"])


class PromoteRequest(BaseModel):
    old_master_name: str
    acknowledge_pending: bool = False
    acknowledge_errors: bool = False


@router.get("/promote/{replica_id}/preflight")
async def preflight_endpoint(replica_id: int):
    """Dry-run pre-flight check. No state is modified."""
    from ..sync.promote import preflight

    result = await preflight(replica_id)
    return {
        "can_promote": result.can_promote,
        "error": result.error,
        "detail": result.detail,
        "pending_entries": result.pending_entries,
        "error_entries": result.error_entries,
        "ok_entries": result.ok_entries,
        "missing_doc_count": result.missing_doc_count,
        "replica_doc_count": result.replica_doc_count,
        "master_doc_count": result.master_doc_count,
    }


@router.post("/promote/{replica_id}")
async def promote_endpoint(replica_id: int, body: PromoteRequest):
    """Execute promotion. Pauses scheduler, runs transaction, resumes scheduler."""
    from ..sync.promote import promote

    try:
        result = await promote(
            replica_id=replica_id,
            old_master_name=body.old_master_name,
            acknowledge_pending=body.acknowledge_pending,
            acknowledge_errors=body.acknowledge_errors,
        )
    except ValueError as exc:
        error_code = exc.args[0] if exc.args else "UNKNOWN"
        detail_msg = exc.args[1] if len(exc.args) > 1 else str(exc)
        status = 409 if error_code == "SYNC_RUNNING" else 422
        raise HTTPException(status_code=status, detail={"error": error_code, "detail": detail_msg})

    return {
        "ok": result.ok,
        "new_master": {"url": result.new_master_url, "name": result.new_master_name},
        "old_master_replica_id": result.old_master_replica_id,
        "sync_map_rebuilt": {
            "replicas_affected": result.replicas_affected,
            "entries_mapped": result.entries_mapped,
            "entries_skipped": result.entries_skipped,
        },
    }