"""Author RAG — SuperAdmin Pricing Plan Management.

Routes (all SuperAdmin-only):
  GET    /api/super/pricing-plans              → list all plans
  POST   /api/super/pricing-plans              → create plan
  GET    /api/super/pricing-plans/{id}         → get single plan
  PUT    /api/super/pricing-plans/{id}         → update plan (price, limits, Stripe IDs)
  DELETE /api/super/pricing-plans/{id}         → deactivate (soft delete)
  POST   /api/super/pricing-plans/seed         → seed default plans (first-time setup)
"""

import json
from datetime import datetime, timezone

import structlog
from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.dependencies import get_current_superadmin, get_db
from app.models.pricing_plan import PricingPlan

logger = structlog.get_logger(__name__)
router = APIRouter(prefix="/pricing-plans", tags=["SuperAdmin – Pricing"])


# ── Schemas ───────────────────────────────────────────────────────────────────

class PricingPlanCreate(BaseModel):
    id: str = Field(..., description="Slug ID e.g. 'starter', 'agency', 'enterprise'")
    display_name: str
    monthly_price_usd: float = Field(..., ge=0)
    annual_price_usd: float = Field(..., ge=0)
    stripe_price_id_monthly: str | None = None
    stripe_price_id_annual: str | None = None
    max_books: int = Field(5, ge=-1)
    max_chats_per_month: int = Field(2000, ge=-1)
    max_token_budget: int = Field(500_000, ge=1)
    max_embeds: int = Field(1, ge=-1)
    has_analytics: bool = True
    has_ab_testing: bool = False
    has_white_label: bool = False
    has_api_access: bool = False
    has_webhooks: bool = False
    has_custom_domain: bool = False
    has_priority_support: bool = False
    features: list[str] = []
    is_active: bool = True
    is_popular: bool = False
    sort_order: int = 0
    overage_price_per_1k_tokens: float = Field(0.003, ge=0)


class PricingPlanUpdate(BaseModel):
    display_name: str | None = None
    monthly_price_usd: float | None = Field(None, ge=0)
    annual_price_usd: float | None = Field(None, ge=0)
    stripe_price_id_monthly: str | None = None
    stripe_price_id_annual: str | None = None
    max_books: int | None = Field(None, ge=-1)
    max_chats_per_month: int | None = Field(None, ge=-1)
    max_token_budget: int | None = Field(None, ge=1)
    max_embeds: int | None = Field(None, ge=-1)
    has_analytics: bool | None = None
    has_ab_testing: bool | None = None
    has_white_label: bool | None = None
    has_api_access: bool | None = None
    has_webhooks: bool | None = None
    has_custom_domain: bool | None = None
    has_priority_support: bool | None = None
    features: list[str] | None = None
    is_active: bool | None = None
    is_popular: bool | None = None
    sort_order: int | None = None
    overage_price_per_1k_tokens: float | None = Field(None, ge=0)


def _plan_to_dict(plan: PricingPlan) -> dict:
    return {
        "id": plan.id,
        "display_name": plan.display_name,
        "monthly_price_usd": plan.monthly_price_usd,
        "annual_price_usd": plan.annual_price_usd,
        "stripe_price_id_monthly": plan.stripe_price_id_monthly,
        "stripe_price_id_annual": plan.stripe_price_id_annual,
        "max_books": plan.max_books,
        "max_chats_per_month": plan.max_chats_per_month,
        "max_token_budget": plan.max_token_budget,
        "max_embeds": plan.max_embeds,
        "has_analytics": plan.has_analytics,
        "has_ab_testing": plan.has_ab_testing,
        "has_white_label": plan.has_white_label,
        "has_api_access": plan.has_api_access,
        "has_webhooks": plan.has_webhooks,
        "has_custom_domain": plan.has_custom_domain,
        "has_priority_support": plan.has_priority_support,
        "features": plan.features,
        "is_active": plan.is_active,
        "is_popular": plan.is_popular,
        "sort_order": plan.sort_order,
        "overage_price_per_1k_tokens": plan.overage_price_per_1k_tokens,
        "created_at": plan.created_at.isoformat() if plan.created_at else None,
        "updated_at": plan.updated_at.isoformat() if plan.updated_at else None,
    }


# ── Endpoints ─────────────────────────────────────────────────────────────────

@router.get("/")
async def list_pricing_plans(
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """List all pricing plans (including inactive)."""
    result = await db.execute(
        select(PricingPlan).order_by(PricingPlan.sort_order)
    )
    plans = result.scalars().all()
    return {"plans": [_plan_to_dict(p) for p in plans]}


@router.post("/", status_code=201)
async def create_pricing_plan(
    body: PricingPlanCreate,
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """Create a new pricing plan."""
    existing = await db.get(PricingPlan, body.id)
    if existing:
        raise HTTPException(409, f"Plan '{body.id}' already exists")

    plan = PricingPlan(
        id=body.id,
        display_name=body.display_name,
        monthly_price_usd=body.monthly_price_usd,
        annual_price_usd=body.annual_price_usd,
        stripe_price_id_monthly=body.stripe_price_id_monthly,
        stripe_price_id_annual=body.stripe_price_id_annual,
        max_books=body.max_books,
        max_chats_per_month=body.max_chats_per_month,
        max_token_budget=body.max_token_budget,
        max_embeds=body.max_embeds,
        has_analytics=body.has_analytics,
        has_ab_testing=body.has_ab_testing,
        has_white_label=body.has_white_label,
        has_api_access=body.has_api_access,
        has_webhooks=body.has_webhooks,
        has_custom_domain=body.has_custom_domain,
        has_priority_support=body.has_priority_support,
        features_json=json.dumps(body.features),
        is_active=body.is_active,
        is_popular=body.is_popular,
        sort_order=body.sort_order,
        overage_price_per_1k_tokens=body.overage_price_per_1k_tokens,
    )
    db.add(plan)
    await db.commit()
    logger.info("Pricing plan created", plan_id=body.id, monthly=body.monthly_price_usd)
    return _plan_to_dict(plan)


@router.get("/{plan_id}")
async def get_pricing_plan(
    plan_id: str,
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """Get a single pricing plan by ID."""
    plan = await db.get(PricingPlan, plan_id)
    if not plan:
        raise HTTPException(404, f"Plan '{plan_id}' not found")
    return _plan_to_dict(plan)


@router.put("/{plan_id}")
async def update_pricing_plan(
    plan_id: str,
    body: PricingPlanUpdate,
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """Update a pricing plan.

    Only provided fields are updated. This is the primary tool for:
    - Changing prices (monthly_price_usd, annual_price_usd)
    - Setting Stripe Price IDs after creating them in Stripe Dashboard
    - Adjusting plan limits (max_books, max_chats_per_month, etc.)
    - Toggling feature flags (has_white_label, has_api_access, etc.)
    """
    plan = await db.get(PricingPlan, plan_id)
    if not plan:
        raise HTTPException(404, f"Plan '{plan_id}' not found")

    update_data = body.model_dump(exclude_none=True)
    for field, value in update_data.items():
        if field == "features":
            plan.features_json = json.dumps(value)
        else:
            setattr(plan, field, value)

    await db.commit()
    logger.info("Pricing plan updated", plan_id=plan_id, fields=list(update_data.keys()))
    return _plan_to_dict(plan)


@router.delete("/{plan_id}", status_code=200)
async def deactivate_pricing_plan(
    plan_id: str,
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """Deactivate a plan (hides from public pricing page — does NOT cancel existing subscriptions)."""
    plan = await db.get(PricingPlan, plan_id)
    if not plan:
        raise HTTPException(404, f"Plan '{plan_id}' not found")
    plan.is_active = False
    await db.commit()
    logger.info("Pricing plan deactivated", plan_id=plan_id)
    return {"message": f"Plan '{plan_id}' deactivated"}


@router.post("/seed", status_code=201)
async def seed_default_plans(
    db: AsyncSession = Depends(get_db),
    _sa=Depends(get_current_superadmin),
):
    """Seed the three default plans (Starter / Agency / Enterprise).

    Only inserts plans that don't already exist. Safe to call multiple times.
    After seeding, paste your Stripe Price IDs via PUT /{plan_id}.
    """
    defaults = [
        {
            "id": "starter",
            "display_name": "Starter",
            "monthly_price_usd": 49.0,
            "annual_price_usd": 39.0,
            "max_books": 5,
            "max_chats_per_month": 2000,
            "max_token_budget": 500_000,
            "max_embeds": 1,
            "has_analytics": True,
            "features_json": json.dumps([
                "5 books", "2,000 chats/month",
                "1 website embed", "Basic analytics", "Email support",
            ]),
            "is_active": True,
            "is_popular": False,
            "sort_order": 1,
        },
        {
            "id": "agency",
            "display_name": "Agency",
            "monthly_price_usd": 499.0,
            "annual_price_usd": 399.0,
            "max_books": 25,
            "max_chats_per_month": 10_000,
            "max_token_budget": 3_000_000,
            "max_embeds": 3,
            "has_analytics": True,
            "has_ab_testing": True,
            "has_webhooks": True,
            "has_priority_support": True,
            "features_json": json.dumps([
                "25 books", "10,000 chats/month", "3 website embeds",
                "Full analytics + A/B testing", "Webhooks",
                "Priority support", "99.9% uptime SLA",
            ]),
            "is_active": True,
            "is_popular": True,
            "sort_order": 2,
        },
        {
            "id": "enterprise",
            "display_name": "Enterprise",
            "monthly_price_usd": 4999.0,
            "annual_price_usd": 3999.0,
            "max_books": -1,
            "max_chats_per_month": -1,
            "max_token_budget": 50_000_000,
            "max_embeds": -1,
            "has_analytics": True,
            "has_ab_testing": True,
            "has_white_label": True,
            "has_api_access": True,
            "has_webhooks": True,
            "has_custom_domain": True,
            "has_priority_support": True,
            "features_json": json.dumps([
                "Unlimited books & chats", "Unlimited embeds + API access",
                "White-label (remove branding)", "Custom domain",
                "Custom integrations & SSO", "Dedicated account manager",
                "99.9% uptime SLA",
            ]),
            "is_active": True,
            "is_popular": False,
            "sort_order": 3,
        },
    ]

    created = []
    skipped = []
    for data in defaults:
        existing = await db.get(PricingPlan, data["id"])
        if existing:
            skipped.append(data["id"])
            continue
        db.add(PricingPlan(**data))
        created.append(data["id"])

    if created:
        await db.commit()

    logger.info("Default pricing plans seeded", created=created, skipped=skipped)
    return {
        "created": created,
        "skipped": skipped,
        "message": "Add your Stripe Price IDs via PUT /api/super/pricing-plans/{id}",
    }