from __future__ import annotations

from decimal import Decimal
from typing import Any

from .ltv import build_ltv_simulations
from .models import EconomicsSnapshot, PricingModel


def _fallback_catalog(models: list[PricingModel]) -> dict[str, Any]:
    return {
        "version": 1,
        "currency": "EUR",
        "horizon_months": 24,
        "monthly_discount_rate_pct": "1.0",
        "required_improvement_factor": "1.05",
        "profiles": [
            {
                "id": "observatory-default",
                "name": "Observatory default",
                "segment": "coulomb-social-members",
                "eligible_model_ids": [model.id for model in models if model.status in ("active", "candidate")],
                "members_per_customer": 1,
                "expected_monthly_usage_units": "120000",
                "usage_variance_pct": "25",
                "monthly_churn_pct": "5.0",
                "monthly_default_pct": "1.0",
                "monthly_support_cost": "0.00",
                "monthly_risk_cost": "0.00",
                "acquisition_cost": "0.00",
                "upfront_investment_cost": "0.00",
                "notes": "Fallback scenario when no explicit LTV scenario catalog is provided."
            }
        ],
        "notes": "Fallback scenario catalog generated inside observatory.simulator.",
    }


def _fallback_usage_records(snapshot: EconomicsSnapshot, ai_cost_per_member: Decimal) -> list[dict[str, Any]]:
    return [
        {
            "id": "fallback-usage",
            "period": snapshot.period,
            "member_id": "fallback",
            "tokens": 120000,
            "cost_eur": ai_cost_per_member,
            "source": "fallback",
        }
    ]


def build_pricing_simulations(
    snapshot: EconomicsSnapshot,
    models: list[PricingModel],
    ai_cost_per_member: Decimal,
    usage_records: list[dict[str, Any]] | None = None,
    scenario_catalog: dict[str, Any] | None = None,
) -> dict[str, Any]:
    return build_ltv_simulations(
        snapshot,
        models,
        usage_records or _fallback_usage_records(snapshot, ai_cost_per_member),
        scenario_catalog or _fallback_catalog(models),
    )