"""License management endpoints."""
from datetime import date, datetime, timezone
from typing import Optional
from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, update

from app.auth.dependencies import require_super_admin
from app.database import get_db
from app.models.user import HubUser
from app.models.license import License, LicenseStatus
from app.models.school import School, SchoolStatus

router = APIRouter(prefix="/api/licenses", tags=["licenses"])

class LicenseUpdate(BaseModel):
    status: Optional[LicenseStatus] = None
    expires_at: Optional[date] = None
    max_students: Optional[int] = None
    notes: Optional[str] = None

@router.get("")
async def list_licenses(
    _admin: HubUser = Depends(require_super_admin),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(select(License))
    return [
        {
            "id": l.id, "school_id": l.school_id, "key": l.key,
            "status": l.status.value, "tier": l.tier,
            "issued_at": l.issued_at.isoformat(),
            "expires_at": l.expires_at.isoformat() if l.expires_at else None,
            "last_validated_at": l.last_validated_at.isoformat() if l.last_validated_at else None,
            "last_seen_ip": l.last_seen_ip,
            "max_students": l.max_students,
        }
        for l in result.scalars().all()
    ]

@router.put("/{license_id}")
async def update_license(
    license_id: str,
    body: LicenseUpdate,
    _admin: HubUser = Depends(require_super_admin),
    db: AsyncSession = Depends(get_db),
):
    lic = (await db.execute(select(License).where(License.id == license_id))).scalar_one_or_none()
    if not lic:
        raise HTTPException(404, "License not found")
    for field, value in body.model_dump(exclude_none=True).items():
        setattr(lic, field, value)
    await db.commit()
    return {"id": lic.id, "status": lic.status.value, "expires_at": lic.expires_at.isoformat() if lic.expires_at else None}

@router.post("/{license_id}/revoke")
async def revoke_license(
    license_id: str,
    _admin: HubUser = Depends(require_super_admin),
    db: AsyncSession = Depends(get_db),
):
    lic = (await db.execute(select(License).where(License.id == license_id))).scalar_one_or_none()
    if not lic:
        raise HTTPException(404, "License not found")
    lic.status = LicenseStatus.revoked
    # Also suspend the school
    school = (await db.execute(select(School).where(School.id == lic.school_id))).scalar_one_or_none()
    if school:
        school.status = SchoolStatus.suspended
    await db.commit()
    return {"message": "License revoked"}

@router.post("/validate")
async def validate_license(
    request: Request,
    db: AsyncSession = Depends(get_db),
):
    """Called by on-prem TapTrack to validate their license key. No auth required — uses key."""
    body = await request.json()
    key: str = body.get("key", "")
    if not key:
        raise HTTPException(400, "License key required")
    lic = (await db.execute(select(License).where(License.key == key))).scalar_one_or_none()
    if not lic:
        return {"valid": False, "reason": "Key not found"}
    if lic.status == LicenseStatus.revoked:
        return {"valid": False, "reason": "License revoked"}
    if lic.expires_at and lic.expires_at < date.today():
        lic.status = LicenseStatus.expired
        await db.commit()
        return {"valid": False, "reason": "License expired", "expired_at": lic.expires_at.isoformat()}
    # Update validation metadata
    lic.last_validated_at = datetime.now(timezone.utc)
    lic.last_seen_ip = request.client.host if request.client else None
    school = (await db.execute(select(School).where(School.id == lic.school_id))).scalar_one_or_none()
    await db.commit()
    return {
        "valid": True,
        "school_id": lic.school_id,
        "school_name": school.name if school else None,
        "tier": lic.tier,
        "max_students": lic.max_students,
        "expires_at": lic.expires_at.isoformat() if lic.expires_at else None,
        "sms_sender_name": school.sms_sender_name if school else "SCHOOL",
        "sms_credits": float(school.sms_credits) if school else 0.0,
        "features": _tier_features(lic.tier),
    }

@router.get("/school/{school_id}")
async def get_school_license(
    school_id: str,
    _admin: HubUser = Depends(require_super_admin),
    db: AsyncSession = Depends(get_db),
):
    """Get the license for a specific school."""
    lic = (await db.execute(select(License).where(License.school_id == school_id))).scalar_one_or_none()
    if not lic:
        raise HTTPException(404, "No license found for this school")
    return {
        "id": lic.id, "school_id": lic.school_id, "key": lic.key,
        "status": lic.status.value, "tier": lic.tier,
        "issued_at": lic.issued_at.isoformat(),
        "expires_at": lic.expires_at.isoformat() if lic.expires_at else None,
        "last_validated_at": lic.last_validated_at.isoformat() if lic.last_validated_at else None,
        "last_seen_ip": lic.last_seen_ip, "max_students": lic.max_students,
    }


def _tier_features(tier: str) -> dict:
    base = {"sms": True, "reports": True, "websocket": True, "multi_terminal": True}
    if tier == "premium":
        base.update({"api_keys": True, "webhooks": True, "bulk_enrollment": True})
    elif tier == "basic":
        base.update({"multi_terminal": False, "api_keys": False, "webhooks": False})
    return base