"""
MeshBay Hub — moderation endpoints.

Public reporting flow:
  POST /v1/reports            — report a content hash (no auth required)

  Thresholds:
    1st report  → logged, node admin notified (future: push notification)
    2nd report  → content hash added to blocklist automatically
    3rd+ report → logged as repeat offense (escalation for human review)

Admin endpoints:
  GET  /v1/admin/blocklist    — list blocked hashes
  POST /v1/admin/blocklist    — manually add a hash
  DELETE /v1/admin/blocklist/{hash} — remove a hash

Node integration:
  GET  /v1/blocklist/check?hash=<blake3> — check if a hash is blocked
  GET  /v1/blocklist                     — full blocklist (for node sync)
"""

import logging
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from meshbay_hub.api.deps import get_current_user, require_admin
from meshbay_hub.api.netutil import client_ip
from meshbay_hub.db.engine import get_db
from meshbay_hub.db.models import ContentBlocklist, ContentReport, User

log = logging.getLogger(__name__)

router = APIRouter(tags=["moderation"])

AUTO_BLOCK_THRESHOLD = 2   # reports before automatic block


# ── Models ────────────────────────────────────────────────────────────────────

class ReportRequest(BaseModel):
    content_hash: str   # blake3 hex (64 chars)
    group_id:     str | None = None
    reason:       str = "illegal"
    detail:       str | None = None


class BlocklistAddRequest(BaseModel):
    content_hash: str
    reason:       str


# ── Public endpoints ──────────────────────────────────────────────────────────

@router.post("/v1/reports", status_code=201)
async def report_content(
    body: ReportRequest,
    request: Request,
    db: AsyncSession = Depends(get_db),
):
    """Report a content hash. No authentication required."""
    if len(body.content_hash) != 64 or not all(c in "0123456789abcdef" for c in body.content_hash):
        raise HTTPException(status_code=422, detail="content_hash must be 64 hex chars (blake3)")

    ip = client_ip(request)

    # Count existing reports for this hash
    count_result = await db.execute(
        select(func.count()).where(ContentReport.content_hash == body.content_hash))
    count = count_result.scalar_one()

    report = ContentReport(
        content_hash=body.content_hash,
        group_id=body.group_id,
        reason=body.reason,
        detail=body.detail,
        ip_address=ip,
    )
    db.add(report)

    action = "logged"
    if count + 1 >= AUTO_BLOCK_THRESHOLD:
        # Check if already blocked
        existing = await db.get(ContentBlocklist, body.content_hash)
        if not existing:
            db.add(ContentBlocklist(
                content_hash=body.content_hash,
                reason=f"auto:{body.reason}",
                added_by="auto",
            ))
            action = "auto_blocked"
            log.warning("Content auto-blocked after %d reports: %s", count + 1, body.content_hash[:16])

    await db.commit()
    return {
        "status":       action,
        "content_hash": body.content_hash,
        "report_count": count + 1,
        "threshold":    AUTO_BLOCK_THRESHOLD,
    }


@router.get("/v1/blocklist/check")
async def check_blocklist(
    hash: str,
    db: AsyncSession = Depends(get_db),
):
    """Check if a single hash is blocked. Used by nodes before serving public content."""
    blocked = await db.get(ContentBlocklist, hash)
    return {
        "blocked": blocked is not None,
        "hash":    hash,
        "reason":  blocked.reason if blocked else None,
    }


@router.get("/v1/blocklist")
async def get_blocklist(
    db: AsyncSession = Depends(get_db),
    limit: int = 10000,
):
    """
    Return the full blocklist. Nodes sync this on startup.
    Returns hashes only (not reasons) to minimize data exposure.
    """
    result = await db.execute(
        select(ContentBlocklist.content_hash)
        .order_by(ContentBlocklist.added_at.desc())
        .limit(limit)
    )
    hashes = [row[0] for row in result.fetchall()]
    return {"count": len(hashes), "hashes": hashes}


# ── Admin endpoints ───────────────────────────────────────────────────────────

@router.get("/v1/admin/blocklist")
async def admin_list_blocklist(
    current_user: User = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
    limit: int = 500,
):
    result = await db.execute(
        select(ContentBlocklist)
        .order_by(ContentBlocklist.added_at.desc())
        .limit(limit)
    )
    entries = result.scalars().all()
    return {
        "entries": [
            {
                "hash":     e.content_hash,
                "reason":   e.reason,
                "added_at": e.added_at.isoformat(),
                "added_by": e.added_by,
            }
            for e in entries
        ]
    }


@router.post("/v1/admin/blocklist", status_code=201)
async def admin_add_blocklist(
    body: BlocklistAddRequest,
    current_user: User = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    existing = await db.get(ContentBlocklist, body.content_hash)
    if existing:
        raise HTTPException(status_code=409, detail="Hash already blocked")

    db.add(ContentBlocklist(
        content_hash=body.content_hash,
        reason=body.reason,
        added_by=current_user.username,
    ))
    await db.commit()
    return {"status": "blocked", "hash": body.content_hash}


@router.delete("/v1/admin/blocklist/{content_hash}", status_code=200)
async def admin_remove_blocklist(
    content_hash: str,
    current_user: User = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    entry = await db.get(ContentBlocklist, content_hash)
    if not entry:
        raise HTTPException(status_code=404, detail="Hash not in blocklist")
    await db.delete(entry)
    await db.commit()
    return {"status": "unblocked", "hash": content_hash}