<?php

namespace App\Http\Controllers\SystemSettings;

use App\Models\Settings\DatabaseConnection;
use App\Utilities\SystemAccess;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;

class Databases extends Controller
{
    public function __construct()
    {
        $this->middleware(function ($request, $next) {
            abort_unless(SystemAccess::canOpenSettings(), 403);

            return $next($request);
        });
    }

    public function index()
    {
        return view('system_settings.databases.index', [
            'connections' => DatabaseConnection::where('company_id', company_id())->orderBy('id')->get(),
        ]);
    }

    public function create()
    {
        return view('system_settings.databases.form', ['connection' => null]);
    }

    public function store(Request $request)
    {
        $data = $this->validateConnection($request);
        $data['company_id'] = company_id();
        $data['enabled'] = (bool) ($data['enabled'] ?? false);

        DatabaseConnection::create($data);

        flash('数据库配置已新增。')->success();

        return redirect()->route('system-settings.databases.index');
    }

    public function edit(int $id)
    {
        return view('system_settings.databases.form', [
            'connection' => $this->findConnection($id),
        ]);
    }

    public function update(int $id, Request $request)
    {
        $connection = $this->findConnection($id);
        $data = $this->validateConnection($request, $connection);
        $data['enabled'] = (bool) ($data['enabled'] ?? false);

        if (empty($data['password'])) {
            unset($data['password']);
        }

        $connection->update($data);

        flash('数据库配置已修改。')->success();

        return redirect()->route('system-settings.databases.index');
    }

    public function destroy(int $id)
    {
        $this->findConnection($id)->delete();

        flash('数据库配置已删除。')->success();

        return redirect()->route('system-settings.databases.index');
    }

    public function export()
    {
        $connections = DatabaseConnection::where('company_id', company_id())->orderBy('id')->get();

        return response()->streamDownload(function () use ($connections) {
            $stream = fopen('php://output', 'w');
            fwrite($stream, "\xEF\xBB\xBF");
            fputcsv($stream, ['name', 'driver', 'host', 'port', 'database_name', 'username', 'password', 'charset', 'enabled']);

            foreach ($connections as $connection) {
                fputcsv($stream, [
                    $connection->name,
                    $connection->driver,
                    $connection->host,
                    $connection->port,
                    $connection->database_name,
                    $connection->username,
                    '',
                    $connection->charset,
                    $connection->enabled ? 1 : 0,
                ]);
            }

            fclose($stream);
        }, 'database-connections.csv', ['Content-Type' => 'text/csv; charset=UTF-8']);
    }

    public function import(Request $request)
    {
        $request->validate(['file' => ['required', 'file', 'mimes:csv,txt', 'max:5120']]);

        $handle = fopen($request->file('file')->getRealPath(), 'r');
        $header = fgetcsv($handle);
        $header = array_map(fn ($value) => trim((string) $value, "\xEF\xBB\xBF \t\n\r\0\x0B"), $header ?: []);
        $required = ['name', 'driver', 'database_name'];

        if (array_diff($required, $header)) {
            fclose($handle);

            return back()->withErrors(['file' => '文件表头不正确，请先导出模板后填写。']);
        }

        $count = 0;

        DB::transaction(function () use ($handle, $header, &$count) {
            while (($row = fgetcsv($handle)) !== false) {
                if (count(array_filter($row, fn ($value) => trim((string) $value) !== '')) === 0) {
                    continue;
                }

                $row = array_pad($row, count($header), '');
                $data = array_combine($header, array_slice($row, 0, count($header)));
                $driver = in_array($data['driver'] ?? '', ['mysql', 'pgsql', 'sqlite', 'sqlsrv'], true)
                    ? $data['driver']
                    : 'mysql';

                $attributes = [
                    'driver' => $driver,
                    'host' => $data['host'] ?: null,
                    'port' => ($data['port'] ?? '') !== '' ? (int) $data['port'] : null,
                    'database_name' => trim((string) ($data['database_name'] ?? '')),
                    'username' => $data['username'] ?: null,
                    'charset' => $data['charset'] ?: 'utf8mb4',
                    'enabled' => filter_var($data['enabled'] ?? true, FILTER_VALIDATE_BOOL),
                ];

                if (($data['password'] ?? '') !== '') {
                    $attributes['password'] = $data['password'];
                }

                if (trim((string) ($data['name'] ?? '')) === '' || $attributes['database_name'] === '') {
                    continue;
                }

                DatabaseConnection::updateOrCreate(
                    ['company_id' => company_id(), 'name' => trim($data['name'])],
                    $attributes
                );
                $count++;
            }
        });

        fclose($handle);
        flash("已导入 {$count} 条数据库配置。")->success();

        return redirect()->route('system-settings.databases.index');
    }

    private function findConnection(int $id): DatabaseConnection
    {
        return DatabaseConnection::where('company_id', company_id())->findOrFail($id);
    }

    private function validateConnection(Request $request, ?DatabaseConnection $connection = null): array
    {
        return $request->validate([
            'name' => [
                'required',
                'string',
                'max:191',
                Rule::unique('system_database_connections', 'name')
                    ->where(fn ($query) => $query->where('company_id', company_id()))
                    ->ignore($connection?->id),
            ],
            'driver' => ['required', Rule::in(['mysql', 'pgsql', 'sqlite', 'sqlsrv'])],
            'host' => ['nullable', 'string', 'max:191'],
            'port' => ['nullable', 'integer', 'between:1,65535'],
            'database_name' => ['required', 'string', 'max:191'],
            'username' => ['nullable', 'string', 'max:191'],
            'password' => ['nullable', 'string', 'max:1000'],
            'charset' => ['required', 'string', 'max:30'],
            'enabled' => ['nullable', 'boolean'],
        ]);
    }
}