# models/database/subscription.py
"""
Subscription database models for tier-based access control.

Provides models for:
- SubscriptionTier: Tier definitions with limits and features
- VendorSubscription: Per-vendor subscription tracking

Tier Structure:
- Essential (€49/mo): 100 orders/mo, 200 products, 1 user, LU invoicing
- Professional (€99/mo): 500 orders/mo, unlimited products, 3 users, EU VAT
- Business (€199/mo): 2000 orders/mo, unlimited products, 10 users, analytics, API
- Enterprise (€399+/mo): Unlimited, white-label, custom integrations
"""

import enum
from datetime import UTC, datetime

from sqlalchemy import (
    Boolean,
    Column,
    DateTime,
    ForeignKey,
    Index,
    Integer,
    Numeric,
    String,
    Text,
)
from sqlalchemy.dialects.sqlite import JSON
from sqlalchemy.orm import relationship

from app.core.database import Base
from models.database.base import TimestampMixin


class TierCode(str, enum.Enum):
    """Subscription tier codes."""

    ESSENTIAL = "essential"
    PROFESSIONAL = "professional"
    BUSINESS = "business"
    ENTERPRISE = "enterprise"


class SubscriptionStatus(str, enum.Enum):
    """Subscription status."""

    TRIAL = "trial"  # Free trial period
    ACTIVE = "active"  # Paid and active
    PAST_DUE = "past_due"  # Payment failed, grace period
    CANCELLED = "cancelled"  # Cancelled, access until period end
    EXPIRED = "expired"  # No longer active


# Tier limit definitions (hardcoded for now, could be moved to DB)
TIER_LIMITS = {
    TierCode.ESSENTIAL: {
        "name": "Essential",
        "price_monthly_cents": 4900,  # €49
        "price_annual_cents": 49000,  # €490 (2 months free)
        "orders_per_month": 100,
        "products_limit": 200,
        "team_members": 1,
        "order_history_months": 6,
        "features": [
            "letzshop_sync",
            "inventory_basic",
            "invoice_lu",
            "customer_view",
        ],
    },
    TierCode.PROFESSIONAL: {
        "name": "Professional",
        "price_monthly_cents": 9900,  # €99
        "price_annual_cents": 99000,  # €990
        "orders_per_month": 500,
        "products_limit": None,  # Unlimited
        "team_members": 3,
        "order_history_months": 24,
        "features": [
            "letzshop_sync",
            "inventory_locations",
            "inventory_purchase_orders",
            "invoice_lu",
            "invoice_eu_vat",
            "customer_view",
            "customer_export",
        ],
    },
    TierCode.BUSINESS: {
        "name": "Business",
        "price_monthly_cents": 19900,  # €199
        "price_annual_cents": 199000,  # €1990
        "orders_per_month": 2000,
        "products_limit": None,  # Unlimited
        "team_members": 10,
        "order_history_months": None,  # Unlimited
        "features": [
            "letzshop_sync",
            "inventory_locations",
            "inventory_purchase_orders",
            "invoice_lu",
            "invoice_eu_vat",
            "invoice_bulk",
            "customer_view",
            "customer_export",
            "analytics_dashboard",
            "accounting_export",
            "api_access",
            "automation_rules",
            "team_roles",
        ],
    },
    TierCode.ENTERPRISE: {
        "name": "Enterprise",
        "price_monthly_cents": 39900,  # €399 starting
        "price_annual_cents": None,  # Custom
        "orders_per_month": None,  # Unlimited
        "products_limit": None,  # Unlimited
        "team_members": None,  # Unlimited
        "order_history_months": None,  # Unlimited
        "features": [
            "letzshop_sync",
            "inventory_locations",
            "inventory_purchase_orders",
            "invoice_lu",
            "invoice_eu_vat",
            "invoice_bulk",
            "customer_view",
            "customer_export",
            "analytics_dashboard",
            "accounting_export",
            "api_access",
            "automation_rules",
            "team_roles",
            "white_label",
            "multi_vendor",
            "custom_integrations",
            "sla_guarantee",
            "dedicated_support",
        ],
    },
}


class VendorSubscription(Base, TimestampMixin):
    """
    Per-vendor subscription tracking.

    Tracks the vendor's subscription tier, billing period,
    and usage counters for limit enforcement.
    """

    __tablename__ = "vendor_subscriptions"

    id = Column(Integer, primary_key=True, index=True)
    vendor_id = Column(
        Integer, ForeignKey("vendors.id"), unique=True, nullable=False, index=True
    )

    # Tier
    tier = Column(
        String(20), default=TierCode.ESSENTIAL.value, nullable=False, index=True
    )

    # Status
    status = Column(
        String(20), default=SubscriptionStatus.TRIAL.value, nullable=False, index=True
    )

    # Billing period
    period_start = Column(DateTime(timezone=True), nullable=False)
    period_end = Column(DateTime(timezone=True), nullable=False)
    is_annual = Column(Boolean, default=False, nullable=False)

    # Trial info
    trial_ends_at = Column(DateTime(timezone=True), nullable=True)

    # Usage counters (reset each billing period)
    orders_this_period = Column(Integer, default=0, nullable=False)
    orders_limit_reached_at = Column(DateTime(timezone=True), nullable=True)

    # Overrides (for custom enterprise deals)
    custom_orders_limit = Column(Integer, nullable=True)  # Override tier limit
    custom_products_limit = Column(Integer, nullable=True)
    custom_team_limit = Column(Integer, nullable=True)

    # Payment info (for future Stripe integration)
    stripe_customer_id = Column(String(100), nullable=True, index=True)
    stripe_subscription_id = Column(String(100), nullable=True, index=True)

    # Cancellation
    cancelled_at = Column(DateTime(timezone=True), nullable=True)
    cancellation_reason = Column(Text, nullable=True)

    # Relationships
    vendor = relationship("Vendor", back_populates="subscription")

    __table_args__ = (
        Index("idx_subscription_vendor_status", "vendor_id", "status"),
        Index("idx_subscription_period", "period_start", "period_end"),
    )

    def __repr__(self):
        return f"<VendorSubscription(vendor_id={self.vendor_id}, tier='{self.tier}', status='{self.status}')>"

    # =========================================================================
    # Tier Limit Properties
    # =========================================================================

    @property
    def tier_limits(self) -> dict:
        """Get the limit definitions for current tier."""
        return TIER_LIMITS.get(TierCode(self.tier), TIER_LIMITS[TierCode.ESSENTIAL])

    @property
    def orders_limit(self) -> int | None:
        """Get effective orders limit (custom or tier default)."""
        if self.custom_orders_limit is not None:
            return self.custom_orders_limit
        return self.tier_limits.get("orders_per_month")

    @property
    def products_limit(self) -> int | None:
        """Get effective products limit (custom or tier default)."""
        if self.custom_products_limit is not None:
            return self.custom_products_limit
        return self.tier_limits.get("products_limit")

    @property
    def team_members_limit(self) -> int | None:
        """Get effective team members limit (custom or tier default)."""
        if self.custom_team_limit is not None:
            return self.custom_team_limit
        return self.tier_limits.get("team_members")

    @property
    def features(self) -> list[str]:
        """Get list of enabled features for current tier."""
        return self.tier_limits.get("features", [])

    # =========================================================================
    # Status Checks
    # =========================================================================

    @property
    def is_active(self) -> bool:
        """Check if subscription allows access."""
        return self.status in [
            SubscriptionStatus.TRIAL.value,
            SubscriptionStatus.ACTIVE.value,
            SubscriptionStatus.PAST_DUE.value,  # Grace period
            SubscriptionStatus.CANCELLED.value,  # Until period end
        ]

    @property
    def is_trial(self) -> bool:
        """Check if currently in trial."""
        return self.status == SubscriptionStatus.TRIAL.value

    @property
    def trial_days_remaining(self) -> int | None:
        """Get remaining trial days."""
        if not self.is_trial or not self.trial_ends_at:
            return None
        remaining = (self.trial_ends_at - datetime.now(UTC)).days
        return max(0, remaining)

    # =========================================================================
    # Limit Checks
    # =========================================================================

    def can_create_order(self) -> tuple[bool, str | None]:
        """
        Check if vendor can create/import another order.

        Returns: (can_create, error_message)
        """
        if not self.is_active:
            return False, "Subscription is not active"

        limit = self.orders_limit
        if limit is None:  # Unlimited
            return True, None

        if self.orders_this_period >= limit:
            return False, f"Monthly order limit reached ({limit} orders). Upgrade to continue."

        return True, None

    def can_add_product(self, current_count: int) -> tuple[bool, str | None]:
        """
        Check if vendor can add another product.

        Args:
            current_count: Current number of products

        Returns: (can_add, error_message)
        """
        if not self.is_active:
            return False, "Subscription is not active"

        limit = self.products_limit
        if limit is None:  # Unlimited
            return True, None

        if current_count >= limit:
            return False, f"Product limit reached ({limit} products). Upgrade to add more."

        return True, None

    def can_add_team_member(self, current_count: int) -> tuple[bool, str | None]:
        """
        Check if vendor can add another team member.

        Args:
            current_count: Current number of team members

        Returns: (can_add, error_message)
        """
        if not self.is_active:
            return False, "Subscription is not active"

        limit = self.team_members_limit
        if limit is None:  # Unlimited
            return True, None

        if current_count >= limit:
            return False, f"Team member limit reached ({limit} members). Upgrade to add more."

        return True, None

    def has_feature(self, feature: str) -> bool:
        """Check if a feature is enabled for current tier."""
        return feature in self.features

    # =========================================================================
    # Usage Tracking
    # =========================================================================

    def increment_order_count(self) -> None:
        """Increment the order counter for this period."""
        self.orders_this_period += 1

        # Track when limit was first reached
        limit = self.orders_limit
        if limit and self.orders_this_period >= limit and not self.orders_limit_reached_at:
            self.orders_limit_reached_at = datetime.now(UTC)

    def reset_period_counters(self) -> None:
        """Reset counters for new billing period."""
        self.orders_this_period = 0
        self.orders_limit_reached_at = None