"""ops-warden routing contract.

ops-warden routes non-SSH credential needs here. It must NOT vend secret values.
A route result is a pointer: catalog id, readiness, decision status, and the safe
next command. This module computes that pointer for a lane. No value is read.
"""
from __future__ import annotations

from dataclasses import dataclass, asdict
from pathlib import Path
from typing import Any

from secrets_engine.catalog import CatalogEntry
from secrets_engine.decisions import Decision, resolve_decision
from secrets_engine.errors import DecisionError
from secrets_engine.openbao import OpenBaoClient


@dataclass
class RouteResult:
    catalog_id: str
    kind: str
    owner: str
    stage: str
    decision_status: str
    decision_ref: str
    review_url: str
    metadata_applied: bool
    value_present: bool
    missing_fields: list[str]
    ready: bool
    next_command: str
    missing: str

    def to_json(self) -> dict[str, Any]:
        return asdict(self)


def route_lane(
    entry: CatalogEntry,
    *,
    hub_url: str,
    repo_root: Path,
    client: OpenBaoClient | None = None,
) -> RouteResult:
    """Build the front-door routing pointer for a lane. Never reads the value."""
    decision_status = "n/a (bootstrap-only)"
    decision_ref = entry.approval.get("decision_ref", "")
    review_url = ""
    decision: Decision | None = None
    if entry.approval_required():
        try:
            decision = resolve_decision(
                hub_url=hub_url, repo_root=repo_root, decision_ref=decision_ref
            )
            decision_status = decision.status
            review_url = decision.review_url
        except DecisionError:
            decision_status = "missing"

    metadata_applied = False
    value_present = False
    missing_fields: list[str] = list(entry.fields) if entry.stores_kv_value() else []
    if client is not None and client.is_reachable():
        if entry.has_delivery_auth:
            policy_applied = client.read_policy(entry.policy_name) is not None
            role_applied = client.approle_exists(entry.role_name)
            metadata_applied = policy_applied and role_applied
        if entry.stores_kv_value():
            # One read produces booleans only; readiness requires every field.
            presence = client.kv_fields_present(entry.mount, entry.path, entry.fields)
            missing_fields = [field for field in entry.fields if not presence.get(field)]
            value_present = bool(entry.fields) and not missing_fields
        else:
            # Auth-capability lanes have no stored value; a fresh secret_id is minted
            # on demand through the handoff command once metadata exists.
            value_present = metadata_applied

    approved = not entry.approval_required() or (decision is not None and decision.is_approved())
    ready = approved and metadata_applied and value_present

    if not approved:
        missing = f"approved decision for '{decision_ref}'"
        next_command = f"secrets-engine decision inspect {decision_ref or entry.id}"
    elif not metadata_applied:
        if entry.kind == "kv" and entry.delivery_auth_management == "existing":
            missing = "externally managed OpenBao policy/AppRole readiness"
            next_command = (
                f"secrets-engine verify {entry.id} --positive --negative"
            )
        elif entry.kind == "kv" and not entry.has_delivery_auth:
            missing = "native delivery auth declaration"
            next_command = f"secrets-engine plan {decision_ref or entry.id} --stage {entry.stage}"
        else:
            missing = "OpenBao policy/role apply"
            next_command = f"secrets-engine apply {decision_ref or entry.id} --stage {entry.stage}"
    elif entry.kind == "auth-capability":
        missing = ""
        next_command = (
            f"secrets-engine handoff {entry.id} --stage {entry.stage} "
            "--role-id-file <path> --secret-id-file <path>"
        )
    elif not value_present:
        names = ", ".join(missing_fields)
        missing = f"provisioned secret fields: {names}"
        next_field = missing_fields[0] if missing_fields else entry.fields[0]
        next_command = (
            f"secrets-engine provision {entry.id} --stage {entry.stage} "
            f"--field {next_field} --from-file <path>"
        )
    else:
        missing = ""
        if {"exec-env", "npm-config"}.intersection(entry.delivery_modes):
            next_command = f"secrets-engine exec --catalog {entry.id} -- <command...>"
        else:
            next_command = (
                f"secrets-engine verify {entry.id} --positive --negative"
            )

    return RouteResult(
        catalog_id=entry.id,
        kind=entry.kind,
        owner=entry.owner,
        stage=entry.stage,
        decision_status=decision_status,
        decision_ref=decision_ref,
        review_url=review_url,
        metadata_applied=metadata_applied,
        value_present=value_present,
        missing_fields=missing_fields,
        ready=ready,
        next_command=next_command,
        missing=missing,
    )