#!/usr/bin/env python3
"""Resolve stable Switchyard selectors through the stewarded model catalog."""

from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any


CATALOG_PATH = Path(
    os.environ.get("HERMES_ROUTING_CATALOG_PATH", "/routing-catalog/catalog.json")
)
DEFAULTS = {
    "codex": {
        "low": "gpt-5.6-luna",
        "medium": "gpt-5.6-terra",
        "high": "gpt-5.6-sol",
        "xhigh": "gpt-5.6-sol",
    },
    "claude": {
        "low": "claude-haiku-4-5-20251001",
        "medium": "claude-sonnet-5",
        "high": "claude-opus-5",
        "xhigh": "claude-opus-5",
    },
}
PREFIXES = {"codex": "gpt-", "claude": "claude-"}
CAPABILITY_ROLES = frozenset({"economy", "balanced", "advanced", "frontier"})
TIER_DEFAULTS = {
    "codex": {
        "luna": "gpt-5.6-luna",
        "terra": "gpt-5.6-terra",
        "sol": "gpt-5.6-sol",
    },
    "claude": {
        "haiku": "claude-haiku-4-5-20251001",
        "fable": "claude-fable-5",
        "sonnet": "claude-sonnet-5",
        "opus": "claude-opus-5",
    },
}


def load_catalog(path: Path = CATALOG_PATH) -> dict[str, Any]:
    """Load a valid routing catalog, falling back to an empty mapping."""
    try:
        value = json.loads(path.read_text(encoding="utf-8"))
    except (OSError, ValueError, json.JSONDecodeError):
        return {}
    return value if isinstance(value, dict) else {}


def catalog_contains(provider: str, model: str, catalog: dict[str, Any] | None = None) -> bool:
    """Return whether a provider's stewarded current catalog advertises a model."""
    document = catalog if catalog is not None else load_catalog()
    providers = document.get("providers", {}) if isinstance(document, dict) else {}
    record = providers.get(provider, {}) if isinstance(providers, dict) else {}
    models = record.get("models", []) if isinstance(record, dict) else []
    return isinstance(model, str) and model in models


def resolve_model(
    provider: str,
    selector: str,
    effort: str,
    catalog: dict[str, Any] | None = None,
) -> str:
    """Resolve an automatic or capability-tier selector to an exact model ID."""
    if provider not in DEFAULTS or effort not in DEFAULTS[provider]:
        raise ValueError("unsupported provider or effort")
    prefix = PREFIXES[provider]
    document = catalog if catalog is not None else load_catalog()
    if selector.startswith(prefix) or catalog_contains(provider, selector, document):
        if catalog_contains(provider, selector, document):
            return selector
        providers = document.get("providers", {}) if isinstance(document, dict) else {}
        record = providers.get(provider, {}) if isinstance(providers, dict) else {}
        if isinstance(record, dict) and record.get("live") is True:
            raise ValueError(f"model is not in the current {provider} catalog")
        return selector

    providers = document.get("providers", {}) if isinstance(document, dict) else {}
    record = providers.get(provider, {}) if isinstance(providers, dict) else {}
    if not isinstance(record, dict):
        record = {}
    capability = selector.removeprefix("auto-") if selector.startswith("auto-") else ""
    if capability and capability not in CAPABILITY_ROLES:
        raise ValueError(f"unsupported capability selector {selector!r}")
    if capability:
        mappings = record.get("capability_resolved", {})
        mapping = mappings.get(capability, {}) if isinstance(mappings, dict) else {}
        candidate = mapping.get(effort, "") if isinstance(mapping, dict) else ""
    else:
        mapping_name = "resolved" if selector == "auto" else "tiers"
        mapping = record.get(mapping_name, {})
        candidate = mapping.get(effort if selector == "auto" else selector, "") if isinstance(mapping, dict) else ""
    if (
        selector != "auto"
        and not capability
        and isinstance(candidate, str)
        and candidate
        and selector not in candidate.lower()
    ):
        candidate = ""
    advertised = record.get("models", []) if isinstance(record, dict) else []
    candidate_allowed = isinstance(candidate, str) and candidate and (
        candidate in advertised or (not advertised and candidate.startswith(prefix))
    )
    if not candidate_allowed:
        # A fresh account list is authoritative.  Do not turn a deliberately
        # unresolved/retired selector into a stale baseline model.
        if record.get("live") is True or capability:
            raise ValueError(f"no current {provider} model for selector {selector!r}")
        candidate = (
            DEFAULTS[provider][effort]
            if selector == "auto"
            else TIER_DEFAULTS[provider].get(selector, DEFAULTS[provider][effort])
        )
    return candidate


def resolve_route(route: str, catalog: dict[str, Any] | None = None) -> str:
    """Resolve a route/<provider>/<selector>/<effort> target to a model ID."""
    parts = route.split("/")
    if len(parts) != 4 or parts[0] != "route":
        return route
    return resolve_model(parts[1], parts[2], parts[3], catalog)


def resolve_worker_route(route: str, catalog: dict[str, Any] | None = None) -> str:
    """Resolve a worker selector while preserving the worker route envelope."""
    parts = route.split("/")
    if len(parts) != 4 or parts[0] != "worker":
        raise ValueError("unsupported worker route")
    model = resolve_model(parts[1], parts[2], parts[3], catalog)
    return f"worker/{parts[1]}/{model}/{parts[3]}"