Nexus/server/api/servers.py

"""Nexus — Servers API Routes (CRUD + heartbeat + health check + push)
Presentation layer — receives HTTP requests, delegates to ServerService/SyncService.

Live server status comes from Redis (real-time), base info from MySQL.
All write operations require JWT authentication and produce audit logs.
"""

import json
import logging
from typing import Optional, List

from fastapi import APIRouter, Depends, HTTPException, Query

from server.api.dependencies import get_server_service, get_sync_service, get_db
from server.api.auth_jwt import get_current_admin
from server.api.schemas import ServerCreate, ServerUpdate, ServerPush, ServerCheck
from server.application.services.server_service import ServerService
from server.application.services.sync_service import SyncService
from server.domain.models import Server, SyncLog, Admin, AuditLog
from server.infrastructure.redis.client import get_redis
from server.infrastructure.database.audit_log_repo import AuditLogRepositoryImpl

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

logger = logging.getLogger("nexus.servers")

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

REDIS_KEY_PREFIX = "heartbeat:"


# ── CRUD ──

@router.get("/", response_model=dict)
async def list_servers(
    category: Optional[str] = Query(None, description="Filter by category"),
    page: int = Query(1, ge=1, description="Page number"),
    per_page: int = Query(50, ge=1, le=200, description="Items per page"),
    service: ServerService = Depends(get_server_service),
):
    """List servers with live status from Redis (paginated)

    Base info (name/IP/category) from MySQL, real-time status from Redis.
    If Redis heartbeat key exists, override is_online/system_info/last_heartbeat.
    """
    servers = await service.list_servers(category)
    redis = get_redis()

    total = len(servers)
    start = (page - 1) * per_page
    end = start + per_page
    page_servers = servers[start:end]

    result = []
    for server in page_servers:
        server_data = _server_to_dict(server)

        # Overlay Redis heartbeat data (real-time)
        try:
            heartbeat = await redis.hgetall(f"{REDIS_KEY_PREFIX}{server.id}")
            if heartbeat:
                server_data["is_online"] = heartbeat.get("is_online") == "True"
                if heartbeat.get("system_info"):
                    try:
                        server_data["system_info"] = json.loads(heartbeat.get("system_info", "{}"))
                    except (json.JSONDecodeError, TypeError):
                        pass  # Keep MySQL value
                server_data["last_heartbeat"] = heartbeat.get("last_heartbeat", server_data.get("last_heartbeat"))
                server_data["agent_version"] = heartbeat.get("agent_version", server_data.get("agent_version", ""))
                server_data["_source"] = "redis"
        except Exception as e:
            logger.warning(f"Redis read failed for server {server.id}: {e}")

        result.append(server_data)

    return {
        "items": result,
        "total": total,
        "page": page,
        "per_page": per_page,
        "pages": (total + per_page - 1) // per_page,
    }


# ── Dashboard Stats (must be before /{id} to avoid path collision) ──

@router.get("/stats", response_model=dict)
async def server_stats(
    service: ServerService = Depends(get_server_service),
):
    """Aggregated server stats for dashboard — efficient single query"""
    servers = await service.list_servers()
    redis = get_redis()

    total = len(servers)
    online = 0
    offline = 0
    alerts = 0

    for server in servers:
        try:
            heartbeat = await redis.hgetall(f"{REDIS_KEY_PREFIX}{server.id}")
            is_online = heartbeat.get("is_online") == "True" if heartbeat else server.is_online
            if await redis.exists(f"alerts:{server.id}"):
                alerts += 1
        except Exception:
            is_online = server.is_online
        if is_online:
            online += 1
        else:
            offline += 1

    categories = {}
    for server in servers:
        cat = server.category or "uncategorized"
        categories[cat] = categories.get(cat, 0) + 1

    return {
        "total": total,
        "online": online,
        "offline": offline,
        "alerts": alerts,
        "categories": categories,
    }


@router.get("/{id}", response_model=dict)
async def get_server(
    id: int,
    service: ServerService = Depends(get_server_service),
):
    """Get a single server by ID with live status from Redis"""
    server = await service.get_server(id)
    if not server:
        raise HTTPException(status_code=404, detail="Server not found")

    server_data = _server_to_dict(server)

    # Overlay Redis heartbeat data
    redis = get_redis()
    try:
        heartbeat = await redis.hgetall(f"{REDIS_KEY_PREFIX}{id}")
        if heartbeat:
            server_data["is_online"] = heartbeat.get("is_online") == "True"
            if heartbeat.get("system_info"):
                try:
                    server_data["system_info"] = json.loads(heartbeat.get("system_info", "{}"))
                except (json.JSONDecodeError, TypeError):
                    pass
            server_data["last_heartbeat"] = heartbeat.get("last_heartbeat", server_data.get("last_heartbeat"))
            server_data["agent_version"] = heartbeat.get("agent_version", server_data.get("agent_version", ""))
            server_data["_source"] = "redis"
    except Exception as e:
        logger.warning(f"Redis read failed for server {id}: {e}")

    return server_data


@router.post("/", response_model=dict, status_code=201)
async def create_server(
    payload: ServerCreate,
    admin: Admin = Depends(get_current_admin),
    service: ServerService = Depends(get_server_service),
    db: AsyncSession = Depends(get_db),
):
    """Create a new server"""
    server = Server(**payload.model_dump(exclude_none=True))
    created = await service.create_server(server)

    audit_repo = AuditLogRepositoryImpl(db)
    await audit_repo.create(AuditLog(
        admin_username=admin.username,
        action="create_server",
        target_type="server",
        target_id=created.id,
        detail=f"name={created.name} domain={created.domain}",
        ip_address="",
    ))

    return _server_to_dict(created)


@router.put("/{id}", response_model=dict)
async def update_server(
    id: int,
    payload: ServerUpdate,
    admin: Admin = Depends(get_current_admin),
    service: ServerService = Depends(get_server_service),
    db: AsyncSession = Depends(get_db),
):
    """Update an existing server"""
    server = await service.get_server(id)
    if not server:
        raise HTTPException(status_code=404, detail="Server not found")
    for key, value in payload.model_dump(exclude_unset=True).items():
        if hasattr(server, key) and key != "id":
            setattr(server, key, value)
    updated = await service.update_server(server)

    audit_repo = AuditLogRepositoryImpl(db)
    await audit_repo.create(AuditLog(
        admin_username=admin.username,
        action="update_server",
        target_type="server",
        target_id=id,
        detail=f"name={updated.name}",
        ip_address="",
    ))

    return _server_to_dict(updated)


@router.delete("/{id}", status_code=204)
async def delete_server(
    id: int,
    admin: Admin = Depends(get_current_admin),
    service: ServerService = Depends(get_server_service),
    db: AsyncSession = Depends(get_db),
):
    """Delete a server"""
    server = await service.get_server(id)
    if not server:
        raise HTTPException(status_code=404, detail="Server not found")
    result = await service.delete_server(id)
    if not result:
        raise HTTPException(status_code=404, detail="Server not found")

    audit_repo = AuditLogRepositoryImpl(db)
    await audit_repo.create(AuditLog(
        admin_username=admin.username,
        action="delete_server",
        target_type="server",
        target_id=id,
        detail=f"name={server.name}",
        ip_address="",
    ))


# ── Health Check ──

@router.post("/check", response_model=dict)
async def check_servers(
    payload: ServerCheck,
    service: ServerService = Depends(get_server_service),
):
    """Check health status of specified servers (Agent-based, no SSH)"""
    return await service.check_all_servers(payload.server_ids)


# ── Push ──

@router.post("/push", response_model=dict)
async def push_to_servers(
    payload: ServerPush,
    admin: Admin = Depends(get_current_admin),
    sync_service: SyncService = Depends(get_sync_service),
):
    """Push files to multiple servers (batch mode with concurrency control)"""
    results = await sync_service.batch_push(
        server_ids=payload.server_ids,
        source_path=payload.source_path,
        sync_mode=payload.sync_mode,
        operator=admin.username,
        batch_size=payload.batch_size,
        concurrency=payload.concurrency,
    )
    return {sid: _sync_log_to_dict(log) for sid, log in results.items()}


# ── Sync Logs ──

@router.get("/logs", response_model=list)
async def get_all_sync_logs(
    limit: int = Query(100, ge=1, le=500),
    db: AsyncSession = Depends(get_db),
):
    """Get recent sync logs across all servers (for dashboard charts)"""
    result = await db.execute(
        select(SyncLog).order_by(SyncLog.started_at.desc()).limit(limit)
    )
    logs = result.scalars().all()
    return [_sync_log_to_dict(log) for log in logs]


@router.get("/{id}/logs", response_model=list)
async def get_server_logs(
    id: int,
    limit: int = Query(50, ge=1, le=200),
    sync_service: SyncService = Depends(get_sync_service),
):
    """Get sync logs for a specific server"""
    logs = await sync_service.get_sync_logs(id, limit)
    return [_sync_log_to_dict(log) for log in logs]


# ── Helper functions ──

def _server_to_dict(server: Server) -> dict:
    """Convert Server model to API response dict (hide sensitive fields)"""
    return {
        "id": server.id,
        "name": server.name,
        "domain": server.domain,
        "port": server.port,
        "username": server.username,
        "auth_method": server.auth_method,
        "agent_port": server.agent_port,
        "description": server.description,
        "target_path": server.target_path,
        "category": server.category,
        "platform_id": server.platform_id,
        "node_id": server.node_id,
        "protocols": server.protocols,
        "extra_attrs": server.extra_attrs,
        "connectivity": server.connectivity,
        "ssh_key_configured": server.ssh_key_configured,
        "is_online": server.is_online,
        "last_heartbeat": str(server.last_heartbeat) if server.last_heartbeat else None,
        "system_info": server.system_info,
        "agent_version": server.agent_version,
        "created_at": str(server.created_at) if server.created_at else None,
        "updated_at": str(server.updated_at) if server.updated_at else None,
    }


def _sync_log_to_dict(log) -> dict:
    """Convert SyncLog model to API response dict"""
    return {
        "id": log.id,
        "server_id": log.server_id,
        "source_path": log.source_path,
        "target_path": log.target_path,
        "trigger_type": log.trigger_type,
        "operator": log.operator,
        "status": log.status,
        "sync_mode": log.sync_mode,
        "files_total": log.files_total,
        "files_transferred": log.files_transferred,
        "duration_seconds": log.duration_seconds,
        "error_message": log.error_message,
        "started_at": str(log.started_at) if log.started_at else None,
        "finished_at": str(log.finished_at) if log.finished_at else None,
    }