from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path


@dataclass(frozen=True, slots=True)
class ChannelConfig:
    name: str
    outbox_path: Path
    upstream_url: str | None  # None => /api/<channel>/* returns 501
    upstream_path: str = "/api/"  # path prefix when proxying (channel injected via {channel})


def build_channels(
    storage_root: Path,
    sre_upstream: str,
    tss_upstream: str | None,
) -> dict[str, ChannelConfig]:
    return {
        "sre": ChannelConfig(
            name="sre",
            outbox_path=storage_root / "external_bridge_outbox.jsonl",
            upstream_url=sre_upstream.rstrip("/"),
            upstream_path="/api/",
        ),
        "tss": ChannelConfig(
            name="tss",
            outbox_path=storage_root / "tss_bridge_outbox.jsonl",
            upstream_url=(tss_upstream.rstrip("/") if tss_upstream else None),
            upstream_path="/api/tss/",
        ),
    }