from __future__ import annotations

from decimal import Decimal, ROUND_HALF_UP

from .economics import active_pricing_model
from .models import EconomicsSnapshot, PricingModel, Product

TWOPLACES = Decimal("0.01")


def _quantize(value: Decimal) -> Decimal:
    return value.quantize(TWOPLACES, rounding=ROUND_HALF_UP)


def build_cost_floor(
    snapshot: EconomicsSnapshot,
    models: list[PricingModel],
) -> dict:
    active = next((m for m in models if m.status == "active"), None)
    return {
        "period": snapshot.period,
        "currency": snapshot.currency,
        "monthly_infrastructure_cost": snapshot.monthly_infrastructure_cost,
        "monthly_payment_processing_cost": snapshot.monthly_payment_processing_cost,
        "monthly_total_platform_cost": snapshot.monthly_total_platform_cost,
        "cost_per_member": snapshot.cost_per_member,
        "active_members": snapshot.active_members,
        "monthly_revenue": snapshot.monthly_revenue,
        "gross_margin": snapshot.gross_margin,
        "gross_margin_pct": snapshot.gross_margin_pct,
        "active_price": active.access_fee_amount if active else Decimal("0"),
        "active_model_id": active.id if active else None,
        "active_model_name": active.name if active else None,
    }


def build_value_range_view(
    raw: dict,
    snapshot: EconomicsSnapshot,
    product: Product,
    models: list[PricingModel],
) -> dict:
    model = active_pricing_model(models, product)
    current = model.access_fee_amount
    segments = []
    lows: list[Decimal] = []
    highs: list[Decimal] = []
    for item in raw.get("segments", []):
        low = Decimal(str(item["low_eur"]))
        high = Decimal(str(item["high_eur"]))
        lows.append(low)
        highs.append(high)
        segments.append(
            {
                **item,
                "headroom_to_high_eur": _quantize(high - current),
                "below_floor": current < low,
            }
        )

    aggregate_low = min(lows) if lows else current
    aggregate_high = max(highs) if highs else current

    return {
        "currency": raw.get("currency", snapshot.currency),
        "product_id": raw.get("product_id", product.id),
        "current_price_eur": current,
        "aggregate_low_eur": aggregate_low,
        "aggregate_high_eur": aggregate_high,
        "cost_per_member_eur": snapshot.cost_per_member,
        "segments": segments,
        "value_drivers": raw.get("value_drivers", []),
        "notes": raw.get("notes", ""),
    }


def build_market_price_view(raw: dict) -> dict:
    alternatives = list(raw.get("alternatives", []))
    prices = [
        Decimal(str(item["price_monthly_eur"]))
        for item in alternatives
        if item.get("price_monthly_eur") not in (None, "", "0", "0.00")
    ]
    return {
        "currency": raw.get("currency", "EUR"),
        "last_reviewed": raw.get("last_reviewed"),
        "alternative_count": len(alternatives),
        "priced_alternative_count": len(prices),
        "market_low_eur": min(prices) if prices else None,
        "market_high_eur": max(prices) if prices else None,
        "alternatives": alternatives,
        "notes": raw.get("notes", ""),
    }