"""
PodcastItLater Billing Integration.

Stripe subscription management and usage enforcement.
"""

# : out podcastitlater-billing
# : dep stripe
# : dep pytest
# : dep pytest-mock
import Biz.PodcastItLater.Core as Core
import Omni.Log as Log
import os
import stripe
from datetime import datetime
from datetime import timezone

logger = Log.setup()

# Stripe configuration
stripe.api_key = os.getenv("STRIPE_SECRET_KEY", "")
STRIPE_WEBHOOK_SECRET = os.getenv("STRIPE_WEBHOOK_SECRET", "")

# Price IDs from Stripe dashboard
STRIPE_PRICE_ID_PERSONAL = os.getenv("STRIPE_PRICE_ID_PERSONAL", "")
STRIPE_PRICE_ID_PRO = os.getenv("STRIPE_PRICE_ID_PRO", "")

# Map Stripe price IDs to tier names
PRICE_TO_TIER = {
    STRIPE_PRICE_ID_PERSONAL: "personal",
    STRIPE_PRICE_ID_PRO: "pro",
}

# Tier limits (None = unlimited)
TIER_LIMITS = {
    "free": {
        "articles_per_period": 10,
        "minutes_per_period": None,
    },
    "personal": {
        "articles_per_period": 50,
        "minutes_per_period": None,
    },
    "pro": {
        "articles_per_period": None,
        "minutes_per_period": None,
    },
}

# Price map for checkout
PRICE_MAP = {
    "personal": STRIPE_PRICE_ID_PERSONAL,
    "pro": STRIPE_PRICE_ID_PRO,
}


def get_period_boundaries(user: dict) -> tuple[datetime, datetime]:
    """Get billing period boundaries for user.

    For paid users: use Stripe subscription period.
    For free users: use current calendar month (UTC).

    Returns:
        tuple: (period_start, period_end) as datetime objects
    """
    if user.get("plan_tier") != "free" and user.get("current_period_start"):
        # Paid user - use Stripe billing period
        period_start = datetime.fromisoformat(user["current_period_start"])
        period_end = datetime.fromisoformat(user["current_period_end"])
    else:
        # Free user - use calendar month
        now = datetime.now(timezone.utc)
        period_start = now.replace(
            day=1,
            hour=0,
            minute=0,
            second=0,
            microsecond=0,
        )
        # Get first day of next month
        if now.month == 12:  # noqa: PLR2004
            period_end = period_start.replace(year=now.year + 1, month=1)
        else:
            period_end = period_start.replace(month=now.month + 1)

    return period_start, period_end


def get_usage(
    user_id: int,
    period_start: datetime,
    period_end: datetime,
) -> dict:
    """Get usage stats for user in billing period.

    Returns:
        dict with keys: articles (int), minutes (int)
    """
    return Core.Database.get_usage(user_id, period_start, period_end)


def can_submit(user_id: int) -> tuple[bool, str, dict]:
    """Check if user can submit article based on tier limits.

    Returns:
        tuple: (allowed: bool, message: str, usage: dict)
    """
    user = Core.Database.get_user_by_id(user_id)
    if not user:
        return False, "User not found", {}

    tier = user.get("plan_tier", "free")
    limits = TIER_LIMITS.get(tier, TIER_LIMITS["free"])

    # Get billing period boundaries
    period_start, period_end = get_period_boundaries(user)

    # Get current usage
    usage = get_usage(user_id, period_start, period_end)

    # Check article limit
    article_limit = limits["articles_per_period"]
    if article_limit is not None and usage["articles"] >= article_limit:
        msg = (
            f"You've reached your limit of {article_limit} articles "
            "per period. Upgrade to continue."
        )
        return (False, msg, usage)

    # Check minutes limit (if implemented)
    minute_limit = limits.get("minutes_per_period")
    if minute_limit is not None and usage.get("minutes", 0) >= minute_limit:
        return (
            False,
            f"You've reached your limit of {minute_limit} minutes per period. "
            "Please upgrade to continue.",
            usage,
        )

    return True, "", usage


def create_checkout_session(user_id: int, tier: str, base_url: str) -> str:
    """Create Stripe Checkout session for subscription.

    Args:
        user_id: User ID
        tier: Subscription tier (personal or pro)
        base_url: Base URL for success/cancel redirects

    Returns:
        Checkout session URL to redirect user to

    Raises:
        ValueError: If tier is invalid or price ID not configured
    """
    if tier not in PRICE_MAP:
        msg = f"Invalid tier: {tier}"
        raise ValueError(msg)

    price_id = PRICE_MAP[tier]
    if not price_id:
        msg = f"Stripe price ID not configured for tier: {tier}"
        raise ValueError(msg)

    user = Core.Database.get_user_by_id(user_id)
    if not user:
        msg = f"User not found: {user_id}"
        raise ValueError(msg)

    # Create checkout session
    session_params = {
        "mode": "subscription",
        "line_items": [{"price": price_id, "quantity": 1}],
        "success_url": f"{base_url}/billing?status=success",
        "cancel_url": f"{base_url}/billing?status=cancel",
        "client_reference_id": str(user_id),
        "metadata": {"user_id": str(user_id), "tier": tier},
        "allow_promotion_codes": True,
    }

    # Use existing customer if available
    if user.get("stripe_customer_id"):
        session_params["customer"] = user["stripe_customer_id"]
    else:
        session_params["customer_email"] = user["email"]

    session = stripe.checkout.Session.create(**session_params)

    logger.info(
        "Created checkout session for user %s, tier %s: %s",
        user_id,
        tier,
        session.id,
    )

    return session.url


def create_portal_session(user_id: int, base_url: str) -> str:
    """Create Stripe Billing Portal session.

    Args:
        user_id: User ID
        base_url: Base URL for return redirect

    Returns:
        Portal session URL to redirect user to

    Raises:
        ValueError: If user has no Stripe customer ID
    """
    user = Core.Database.get_user_by_id(user_id)
    if not user:
        msg = f"User not found: {user_id}"
        raise ValueError(msg)

    if not user.get("stripe_customer_id"):
        msg = "User has no Stripe customer ID"
        raise ValueError(msg)

    session = stripe.billing_portal.Session.create(
        customer=user["stripe_customer_id"],
        return_url=f"{base_url}/billing",
    )

    logger.info("Created portal session for user %s: %s", user_id, session.id)

    return session.url


def handle_webhook_event(payload: bytes, sig_header: str) -> dict:
    """Verify and process Stripe webhook event.

    Args:
        payload: Raw webhook body
        sig_header: Stripe-Signature header value

    Returns:
        dict with processing status

    Note:
        May raise stripe.error.SignatureVerificationError if invalid signature
    """
    # Verify webhook signature
    event = stripe.Webhook.construct_event(
        payload,
        sig_header,
        STRIPE_WEBHOOK_SECRET,
    )

    event_id = event["id"]
    event_type = event["type"]

    # Check if already processed (idempotency)
    if Core.Database.has_processed_stripe_event(event_id):
        logger.info("Skipping already processed event: %s", event_id)
        return {"status": "skipped", "reason": "already_processed"}

    # Process event based on type
    logger.info("Processing webhook event: %s (%s)", event_id, event_type)

    try:
        if event_type == "checkout.session.completed":
            _handle_checkout_completed(event["data"]["object"])
        elif event_type == "customer.subscription.created":
            _handle_subscription_created(event["data"]["object"])
        elif event_type == "customer.subscription.updated":
            _handle_subscription_updated(event["data"]["object"])
        elif event_type == "customer.subscription.deleted":
            _handle_subscription_deleted(event["data"]["object"])
        elif event_type == "invoice.payment_failed":
            _handle_payment_failed(event["data"]["object"])
        else:
            logger.info("Unhandled event type: %s", event_type)
            return {"status": "ignored", "type": event_type}

        # Mark event as processed
        Core.Database.mark_stripe_event_processed(event_id, event_type, payload)
    except Exception:
        logger.exception("Error processing webhook event %s", event_id)
        raise
    else:
        return {"status": "processed", "type": event_type}


def _handle_checkout_completed(session: dict) -> None:
    """Handle checkout.session.completed event."""
    user_id = int(session.get("client_reference_id", 0))
    customer_id = session.get("customer")

    if not user_id or not customer_id:
        logger.warning(
            "Missing user_id or customer_id in checkout session: %s",
            session["id"],
        )
        return

    # Link Stripe customer to user
    Core.Database.set_user_stripe_customer(user_id, customer_id)
    logger.info("Linked user %s to Stripe customer %s", user_id, customer_id)


def _handle_subscription_created(subscription: dict) -> None:
    """Handle customer.subscription.created event."""
    _update_subscription_state(subscription)


def _handle_subscription_updated(subscription: dict) -> None:
    """Handle customer.subscription.updated event."""
    _update_subscription_state(subscription)


def _handle_subscription_deleted(subscription: dict) -> None:
    """Handle customer.subscription.deleted event."""
    customer_id = subscription["customer"]

    # Find user by customer ID
    user = Core.Database.get_user_by_stripe_customer_id(customer_id)
    if not user:
        logger.warning("User not found for customer: %s", customer_id)
        return

    # Downgrade to free
    Core.Database.downgrade_to_free(user["id"])
    logger.info("Downgraded user %s to free tier", user["id"])


def _handle_payment_failed(invoice: dict) -> None:
    """Handle invoice.payment_failed event."""
    customer_id = invoice["customer"]
    subscription_id = invoice.get("subscription")

    # Find user by customer ID
    user = Core.Database.get_user_by_stripe_customer_id(customer_id)
    if not user:
        logger.warning("User not found for customer: %s", customer_id)
        return

    # Update subscription status to past_due
    if subscription_id:
        Core.Database.update_subscription_status(user["id"], "past_due")
        logger.warning(
            "Payment failed for user %s, subscription %s",
            user["id"],
            subscription_id,
        )


def _update_subscription_state(subscription: dict) -> None:
    """Update user subscription state from Stripe subscription object."""
    customer_id = subscription["customer"]
    subscription_id = subscription["id"]
    status = subscription["status"]
    cancel_at_period_end = subscription.get("cancel_at_period_end", False)

    # Get billing period
    period_start = datetime.fromtimestamp(
        subscription["current_period_start"],
        tz=timezone.utc,
    )
    period_end = datetime.fromtimestamp(
        subscription["current_period_end"],
        tz=timezone.utc,
    )

    # Determine tier from price ID
    price_id = subscription["items"]["data"][0]["price"]["id"]
    tier = PRICE_TO_TIER.get(price_id, "free")

    # Find user by customer ID
    user = Core.Database.get_user_by_stripe_customer_id(customer_id)
    if not user:
        logger.warning("User not found for customer: %s", customer_id)
        return

    # Update user subscription
    Core.Database.update_user_subscription(
        user["id"],
        subscription_id,
        status,
        period_start,
        period_end,
        tier,
        cancel_at_period_end,
    )

    logger.info(
        "Updated user %s subscription: tier=%s, status=%s",
        user["id"],
        tier,
        status,
    )


def get_tier_info(tier: str) -> dict:
    """Get tier information for display.

    Returns:
        dict with keys: name, articles_limit, price, description
    """
    tier_info = {
        "free": {
            "name": "Free",
            "articles_limit": 10,
            "price": "$0",
            "description": "10 articles per month",
        },
        "personal": {
            "name": "Personal",
            "articles_limit": 50,
            "price": "$9/mo",
            "description": "50 articles per month",
        },
        "pro": {
            "name": "Pro",
            "articles_limit": None,
            "price": "$29/mo",
            "description": "Unlimited articles",
        },
    }
    return tier_info.get(tier, tier_info["free"])