#!/usr/bin/env python3
"""Shared setup-apply contract for staging-to-prod release candidates."""

from __future__ import annotations

from typing import Any


RELEASE_SETUP_CONTRACT_VERSION = "release-setup-apply/v2"
PROD_RELEASE_SETUP_SKIP_POLYMORPHIC_BACKFILL = "false"
PROD_RELEASE_ENSURE_INDEXES_WORKERS = "1"


def describe_release_setup_contract(
    raw_skip_polymorphic_backfill: str | None,
    raw_ensure_indexes_workers: str | None,
) -> dict[str, Any]:
    skip_value = str(raw_skip_polymorphic_backfill or "").strip().lower()
    skip_polymorphic_backfill = (
        skip_value == "true" if skip_value in {"true", "false"} else None
    )
    worker_value = str(raw_ensure_indexes_workers or "").strip()
    try:
        ensure_indexes_workers = int(worker_value)
    except ValueError:
        ensure_indexes_workers = None
    if ensure_indexes_workers is not None and ensure_indexes_workers <= 0:
        ensure_indexes_workers = None

    block_reasons: list[str] = []
    if skip_polymorphic_backfill is not False:
        block_reasons.append("polymorphic_backfill_not_complete")
    if ensure_indexes_workers != int(PROD_RELEASE_ENSURE_INDEXES_WORKERS):
        block_reasons.append("ensure_indexes_workers_not_prod_parity")

    profile = "invalid"
    if skip_polymorphic_backfill is True:
        profile = "deferred-polymorphic-backfill"
    elif skip_polymorphic_backfill is False:
        profile = "full"

    return {
        "schema_version": RELEASE_SETUP_CONTRACT_VERSION,
        "profile": profile,
        "skip_polymorphic_backfill": skip_polymorphic_backfill,
        "ensure_indexes_workers": ensure_indexes_workers,
        "prod_parity": not block_reasons,
        "block_reasons": block_reasons,
    }


def require_prod_release_setup_contract(
    raw_skip_polymorphic_backfill: str | None,
    raw_ensure_indexes_workers: str | None,
) -> dict[str, Any]:
    contract = describe_release_setup_contract(
        raw_skip_polymorphic_backfill,
        raw_ensure_indexes_workers,
    )
    if contract["prod_parity"] is not True:
        reasons = ",".join(str(item) for item in contract["block_reasons"])
        raise ValueError(f"release setup apply does not match prod: {reasons}")
    return contract


def require_prod_release_setup_evidence(raw_evidence: object) -> dict[str, Any]:
    if not isinstance(raw_evidence, dict):
        raise ValueError("release setup apply evidence must be an object")
    if str(raw_evidence.get("schema_version", "")).strip() != RELEASE_SETUP_CONTRACT_VERSION:
        raise ValueError("release setup apply evidence has an unsupported schema")

    contract = require_prod_release_setup_contract(
        str(raw_evidence.get("skip_polymorphic_backfill", "")),
        str(raw_evidence.get("ensure_indexes_workers", "")),
    )
    for field in (
        "profile",
        "skip_polymorphic_backfill",
        "ensure_indexes_workers",
        "prod_parity",
        "block_reasons",
    ):
        if raw_evidence.get(field) != contract[field]:
            raise ValueError(f"release setup apply evidence is inconsistent: {field}")
    return contract