<?php

namespace App\Imports;

use App\Models\IpPool;
use App\Models\ModuleNetwork;
use Carbon\Carbon;
use Illuminate\Support\Str;
use Maatwebsite\Excel\Concerns\ToModel;
use Maatwebsite\Excel\Concerns\WithHeadingRow;
use Maatwebsite\Excel\Concerns\WithUpsertColumns;
use Maatwebsite\Excel\Concerns\WithUpserts;
use Maatwebsite\Excel\Concerns\WithValidation;

class IpPoolImport implements ToModel, WithHeadingRow, WithValidation, WithUpserts, WithUpsertColumns
{
    /** @var array<string, ModuleNetwork> */
    private array $networkCache = [];

    public function model(array $row)
    {
        $network = $this->resolveNetwork($row['ten_mang'] ?? null, $row['cidr'] ?? null);

        return new IpPool([
            // uuid has no DB default and must be set on insert; excluded from upsertColumns() so it's never overwritten
            'uuid'              => (string) Str::uuid(),
            'ip_address'        => $row['ip_address'],
            'module_network_id' => $network?->id,
            // ip_pools.cidr is NOT NULL; fall back to the network's own prefix (or 24) when the row omits it
            'cidr'              => $this->parsePrefixLength($row['cidr'] ?? null)
                ?? $this->parsePrefixLength($network?->network)
                ?? 24,
            'gateway'           => $row['gateway'] ?? null,
            'netmask'           => $row['subnet_mask'] ?? null,
            'owner_type'        => $row['owner_type'] ?? null,
            'ip_role'           => $row['ip_role'] ?? null,
            'parent_ip'         => $row['parent_ip'] ?? null,
            'customer_name'     => $row['ten_khach_hang'] ?? null,
            'service_name'      => $row['ten_dich_vu'] ?? null,
            'allocated_at'      => $this->parseDate($row['ngay_cap_phat'] ?? null),
            'revoked_at'        => $this->parseDate($row['ngay_thu_hoi'] ?? null),
            'allocation_status' => $row['trang_thai'] ?? null,
            'contact_email'     => $row['contact_email'] ?? null,
            'contact_cc'        => $row['contact_cc'] ?? null,
            'contact_phone'     => $row['contact_phone'] ?? null,
            'monthly_cost'      => $row['monthly_cost'] ?: null,
            'selling_price'     => $row['selling_price'] ?: null,
            'additional_info'   => $row['thong_tin_bo_sung'] ?? null,
            'last_email_type'   => $row['last_email_type'] ?? null,
            'last_email_at'     => $this->parseDate($row['last_email_at'] ?? null),
            'updated_by'        => $row['updated_by'] ?? null,
            'note'              => $row['ghi_chu'] ?? null,
        ]);
    }

    public function rules(): array
    {
        $multiEmail = function (string $attribute, mixed $value, \Closure $fail) {
            foreach (preg_split('/[,;]+/', (string) $value) as $email) {
                $email = trim($email);
                if ($email !== '' && !filter_var($email, FILTER_VALIDATE_EMAIL)) {
                    $fail("Email không hợp lệ: {$email}");
                }
            }
        };

        return [
            'ten_mang'      => 'required|string|max:255',
            'cidr'          => 'nullable|string|max:45',
            'ip_address'    => 'required|ip',
            'contact_email' => ['nullable', 'string', $multiEmail],
            'contact_cc'    => ['nullable', 'string', $multiEmail],
            'monthly_cost'  => 'nullable|numeric',
            'selling_price' => 'nullable|numeric',
        ];
    }

    /**
     * CSV dates come as "dd/mm/yyyy" or "dd/mm/yyyy H:i:s" (Vietnamese sheet export).
     */
    private function parseDate(?string $value): ?string
    {
        $value = trim((string) $value);
        if ($value === '') {
            return null;
        }

        try {
            return Carbon::createFromFormat('d/m/Y H:i:s', $value)->toDateTimeString();
        } catch (\Throwable) {
            // not a datetime, try date-only below
        }

        try {
            return Carbon::createFromFormat('d/m/Y', $value)->startOfDay()->toDateTimeString();
        } catch (\Throwable) {
            return null;
        }
    }

    /**
     * CSV gives CIDR as "/22"; the ip_pools.cidr column only stores the prefix length.
     */
    private function parsePrefixLength(?string $cidr): ?int
    {
        // "/22" or "111.111.111.0/22" -> 22
        return preg_match('/(\d+)$/', (string) $cidr, $m) ? (int) $m[1] : null;
    }

    public function uniqueBy(): array
    {
        return ['ip_address', 'module_network_id'];
    }

    public function upsertColumns(): array
    {
        return [
            'cidr', 'gateway', 'netmask', 'owner_type', 'ip_role', 'parent_ip',
            'customer_name', 'service_name', 'allocated_at', 'revoked_at', 'allocation_status',
            'contact_email', 'contact_cc', 'contact_phone', 'monthly_cost', 'selling_price',
            'additional_info', 'last_email_type', 'last_email_at', 'updated_by', 'note',
        ];
    }

    private function resolveNetwork(?string $name, ?string $cidr): ?ModuleNetwork
    {
        if (!$name) {
            return null;
        }

        $key = $name . '|' . $cidr;

        if (isset($this->networkCache[$key])) {
            return $this->networkCache[$key];
        }

        $network = ModuleNetwork::where('name', $name)->first()
            ?? ($cidr ? ModuleNetwork::where('network', $cidr)->first() : null)
            ?? ModuleNetwork::create(['name' => $name, 'network' => $cidr]);

        return $this->networkCache[$key] = $network;
    }
}