<?php

namespace Modules\M3\Services;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Schema;

/**
 * PostgreSQL replacement for the old IBM i Toolkit program-call transport.
 *
 * The legacy M3 code invokes IBM i programs after writing PostgreSQL-backed
 * staging data. Core no longer connects to DB2. These requests are persisted
 * so a PostgreSQL-native worker/integration can process them without making
 * the web request depend on IBM i drivers.
 */
class PostgresProgramBridge
{
    private string $errorCode = '';

    private string $errorMessage = '';

    private array $options = [];

    public function setOptions(array $options): self
    {
        $this->options = $options;

        return $this;
    }

    public function addParameterChar(string $io, int $size, string $comment = '', string $name = '', mixed $value = null): array
    {
        return compact('io', 'size', 'comment', 'name', 'value');
    }

    public function addParameterPackDec(string $io, int $length, int $scale, string $comment = '', string $name = '', mixed $value = null): array
    {
        return ['type' => 'packed_decimal'] + compact('io', 'length', 'scale', 'comment', 'name', 'value');
    }

    public function addParameterZoned(string $io, int $length, int $scale, string $comment = '', string $name = '', mixed $value = null): array
    {
        return ['type' => 'zoned_decimal'] + compact('io', 'length', 'scale', 'comment', 'name', 'value');
    }

    public function pgmCall(string $program, ?string $library = null, array $parameters = [], array $returnParameters = [], array $options = []): array|false
    {
        return $this->queue('program', $program, $library, [
            'parameters' => $parameters,
            'return_parameters' => $returnParameters,
            'options' => $options,
        ]);
    }

    public function clCommand(string $command): array|false
    {
        return $this->queue('command', $command, null, []);
    }

    public function getErrorCode(): string
    {
        return $this->errorCode;
    }

    public function getErrorMsg(): string
    {
        return $this->errorMessage;
    }

    private function queue(string $type, string $operation, ?string $library, array $payload): array|false
    {
        try {
            $record = [
                'type' => $type,
                'operation' => $operation,
                'library' => $library,
                'payload' => json_encode($payload, JSON_THROW_ON_ERROR),
                'requested_by' => function_exists('m3_user') ? m3_user() : null,
                'status' => 'pending',
                'created_at' => now(),
                'updated_at' => now(),
            ];

            if (Schema::connection(config('m3.connection', 'pgsql'))->hasTable('m3_program_requests')) {
                $id = DB::connection(config('m3.connection', 'pgsql'))
                    ->table('m3_program_requests')
                    ->insertGetId($record);
            } else {
                Log::warning('M3 PostgreSQL program bridge table is not migrated; request logged only.', $record);
                $id = null;
            }

            return ['success' => true, 'queued' => true, 'request_id' => $id, 'io_param' => []];
        } catch (\Throwable $e) {
            $this->errorCode = (string) $e->getCode();
            $this->errorMessage = $e->getMessage();
            Log::error('Unable to queue M3 program request.', ['exception' => $e]);

            return false;
        }
    }
}