<?php

namespace App\Http\Controllers\Api\Admin\IpPool;

use App\Http\Controllers\Controller;
use App\Models\IpPool;
use App\Models\ModuleIpAddress;
use App\Models\ModuleNetwork;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class IpPoolController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $perPage       = min((int) $request->get('per_page', 15), 500);
        $filter        = $request->get('filter');
        $networkId     = $request->get('network_id');

        $query = IpPool::with('network:id,name,type,network');

        if ($filter) {
            $query->where('ip_address', 'like', "%{$filter}%");
        }

        if ($networkId) {
            $query->where('module_network_id', $networkId);
        }

        $paginator = $query->paginate($perPage);

        // Enrich each item with usage info
        $usedIps = ModuleIpAddress::whereIn('ip', $paginator->pluck('ip_address')->toArray())
            ->where('status', 1)
            ->with('host:id,name')
            ->select(['id', 'ip', 'vm_name', 'module_host_id', 'module_network_id', 'status'])
            ->get()
            ->keyBy('ip');

        // Get vmware info for used IPs
        $vmwareMap = [];
        if ($usedIps->isNotEmpty()) {
            $vmwares = DB::table('module_vmware as mv')
                ->join('module_ip_address as mia', 'mv.module_ip_address', '=', 'mia.id')
                ->whereIn('mia.ip', $usedIps->keys()->toArray())
                ->leftJoin('services as s', 's.id', '=', 'mv.service_id')
                ->leftJoin('customers as c', 'c.id', '=', 'mv.customer_id')
                ->select([
                    'mia.ip',
                    'mv.name as vm_name',
                    'mv.id as vm_id',
                    's.id as service_id',
                    's.status as service_status',
                    'c.fullname',
                    'c.email',
                ])
                ->get();

            foreach ($vmwares as $vm) {
                $vmwareMap[$vm->ip] = $vm;
            }
        }

        $items = $paginator->map(function (IpPool $pool) use ($usedIps, $vmwareMap) {
            $data = $pool->toArray();
            $ip   = $pool->ip_address;

            if (isset($usedIps[$ip])) {
                $mia             = $usedIps[$ip];
                $vm              = $vmwareMap[$ip] ?? null;
                $data['usage']   = [
                    'assigned'       => true,
                    'vm_name'        => $vm?->vm_name ?? $mia->vm_name,
                    'vm_id'          => $vm?->vm_id ?? null,
                    'service_id'     => $vm?->service_id ?? null,
                    'service_status' => $vm?->service_status ?? null,
                    'customer_name'  => $vm?->fullname ?? null,
                    'customer_email' => $vm?->email ?? null,
                ];
            } else {
                $data['usage'] = ['assigned' => false];
            }

            return $data;
        });

        return response()->json([
            'error' => false,
            'data'  => [
                'items'        => $items->values(),
                'total'        => $paginator->total(),
                'per_page'     => $paginator->perPage(),
                'current_page' => $paginator->currentPage(),
                'last_page'    => $paginator->lastPage(),
            ],
        ]);
    }

    public function show(int $id): JsonResponse
    {
        $pool = IpPool::with('network:id,name,type,network')->find($id);

        if (!$pool) {
            return response()->json(['error' => true, 'message' => "Không tìm thấy IP Pool #{$id}"], 404);
        }

        return response()->json(['error' => false, 'data' => $pool]);
    }

    /**
     * Bulk create: ip_address may be comma-separated (e.g. "10.0.0.1,10.0.0.2").
     */
    public function store(Request $request): JsonResponse
    {
        $request->validate([
            'ip_address'        => 'required|string',
            'module_network_id' => 'required|integer|exists:module_network,id',
        ]);

        $networkId   = (int) $request->module_network_id;
        $rawIps      = $request->ip_address;
        $ips         = array_filter(array_map('trim', explode(',', $rawIps)));

        if (empty($ips)) {
            return response()->json(['error' => true, 'message' => 'Không có địa chỉ IP hợp lệ'], 422);
        }

        // Validate each IP
        $invalid = [];
        foreach ($ips as $ip) {
            if (!filter_var($ip, FILTER_VALIDATE_IP)) {
                $invalid[] = $ip;
            }
        }

        if (!empty($invalid)) {
            return response()->json([
                'error'   => true,
                'message' => 'Địa chỉ IP không hợp lệ: ' . implode(', ', $invalid),
            ], 422);
        }

        // Check duplicates already in pool
        $existing = IpPool::where('module_network_id', $networkId)
            ->whereIn('ip_address', $ips)
            ->pluck('ip_address')
            ->toArray();

        if (!empty($existing)) {
            return response()->json([
                'error'   => true,
                'message' => 'Địa chỉ IP đã tồn tại trong pool: ' . implode(', ', $existing),
            ], 422);
        }

        DB::beginTransaction();
        try {
            $created = [];
            foreach ($ips as $ip) {
                $created[] = IpPool::create([
                    'ip_address'        => $ip,
                    'module_network_id' => $networkId,
                ]);
            }
            DB::commit();

            return response()->json(['error' => false, 'data' => $created, 'count' => count($created)], 201);
        } catch (\Exception $e) {
            DB::rollBack();
            return response()->json(['error' => true, 'message' => $e->getMessage()], 500);
        }
    }

    public function update(int $id, Request $request): JsonResponse
    {
        $pool = IpPool::find($id);

        if (!$pool) {
            return response()->json(['error' => true, 'message' => "Không tìm thấy IP Pool #{$id}"], 404);
        }

        $request->validate([
            'ip_address'        => 'required|string|max:45',
            'module_network_id' => 'required|integer|exists:module_network,id',
        ]);

        if (!filter_var($request->ip_address, FILTER_VALIDATE_IP)) {
            return response()->json(['error' => true, 'message' => 'Địa chỉ IP không hợp lệ'], 422);
        }

        // Check duplicate (excluding self)
        $duplicate = IpPool::where('module_network_id', $request->module_network_id)
            ->where('ip_address', $request->ip_address)
            ->where('id', '!=', $id)
            ->exists();

        if ($duplicate) {
            return response()->json([
                'error'   => true,
                'message' => 'Địa chỉ IP đã tồn tại trong pool này',
            ], 422);
        }

        DB::beginTransaction();
        try {
            $pool->update($request->only(['ip_address', 'module_network_id']));
            DB::commit();

            return response()->json(['error' => false, 'data' => $pool->fresh('network')]);
        } catch (\Exception $e) {
            DB::rollBack();
            return response()->json(['error' => true, 'message' => $e->getMessage()], 500);
        }
    }

    public function destroy(int $id): JsonResponse
    {
        $pool = IpPool::find($id);

        if (!$pool) {
            return response()->json(['error' => true, 'message' => "Không tìm thấy IP Pool #{$id}"], 404);
        }

        // Check if IP is currently assigned
        $inUse = ModuleIpAddress::where('ip', $pool->ip_address)
            ->where('module_network_id', $pool->module_network_id)
            ->where('status', 1)
            ->exists();

        if ($inUse) {
            return response()->json([
                'error'   => true,
                'message' => 'Không thể xoá — IP này đang được gán cho một máy chủ',
            ], 422);
        }

        $pool->delete();

        return response()->json(['error' => false, 'message' => 'Đã xoá IP Pool thành công']);
    }

    public function networks(): JsonResponse
    {
        $networks = ModuleNetwork::select(['id', 'name', 'type', 'network'])
            ->orderBy('name')
            ->get();

        return response()->json(['error' => false, 'data' => $networks]);
    }
}