import { S3Client, PutObjectCommand, GetObjectCommand } from "npm:@aws-sdk/client-s3@3";
import { mkdir, readFile, writeFile } from "node:fs/promises";
import { dirname, join } from "node:path";
import { config, DATA_DIR } from "./config.ts";

/**
 * Almacenamiento de archivos (Fase 4c): expedientes cifrados, PDFs de
 * gafetes, logos. Antes vivían en el volumen local (panel-data) -- un
 * volumen local no se comparte entre réplicas ni microservicios, así que
 * es el mismo cuello de botella que motivó salir de SQLite, solo que en
 * otra capa. El contenido YA viene cifrado con AES-GCM (docs_crypto.ts)
 * antes de llegar aquí -- el bucket nunca ve texto plano.
 *
 * Backend real: Contabo Object Storage (S3-compatible). Si no hay
 * credenciales S3 configuradas (dev local sin Contabo), cae a disco local
 * bajo DATA_DIR -- útil para desarrollar/probar sin depender de Contabo,
 * pero NO es la ruta recomendada para staging/producción (ver Fase 4c del
 * plan: un volumen local no escala horizontalmente).
 */

let client: S3Client | null = null;

function s3Configured(): boolean {
  return !!(config.s3Endpoint && config.s3Bucket && config.s3AccessKeyId && config.s3SecretAccessKey);
}

function getClient(): S3Client {
  if (!client) {
    client = new S3Client({
      endpoint: config.s3Endpoint,
      region: config.s3Region,
      forcePathStyle: true,
      credentials: {
        accessKeyId: config.s3AccessKeyId,
        secretAccessKey: config.s3SecretAccessKey,
      },
    });
  }
  return client;
}

async function streamToUint8Array(body: unknown): Promise<Uint8Array> {
  const chunks: Uint8Array[] = [];
  // deno-lint-ignore no-explicit-any
  for await (const chunk of body as any) {
    chunks.push(chunk instanceof Uint8Array ? chunk : new Uint8Array(chunk));
  }
  const total = chunks.reduce((n, c) => n + c.length, 0);
  const out = new Uint8Array(total);
  let offset = 0;
  for (const c of chunks) {
    out.set(c, offset);
    offset += c.length;
  }
  return out;
}

export async function putObject(key: string, bytes: Uint8Array): Promise<void> {
  if (s3Configured()) {
    await getClient().send(
      new PutObjectCommand({ Bucket: config.s3Bucket, Key: key, Body: bytes }),
    );
    return;
  }
  const path = join(DATA_DIR, "local-objects", key);
  await mkdir(dirname(path), { recursive: true });
  await writeFile(path, bytes);
}

export async function getObject(key: string): Promise<Uint8Array> {
  if (s3Configured()) {
    const res = await getClient().send(
      new GetObjectCommand({ Bucket: config.s3Bucket, Key: key }),
    );
    return await streamToUint8Array(res.Body);
  }
  const path = join(DATA_DIR, "local-objects", key);
  return await readFile(path);
}

// --- Convenciones de key por dominio (equivalentes a los antiguos
// workerDir/projectDir/companyDir + Deno.readFile/writeFile) ---
export function workerDocKey(workerId: number, storageName: string): string {
  return `expedientes/${workerId}/${storageName}`;
}
export function projectDocKey(projectId: number, storageName: string): string {
  return `proyectos/${projectId}/${storageName}`;
}
export function companyDocKey(companyId: number, storageName: string): string {
  return `empresas/${companyId}/${storageName}`;
}
export function badgeJobPdfKey(jobId: number): string {
  return `pdfs/gafetes-${jobId}.pdf`;
}
export function loanReceiptPdfKey(loanId: number, weekId: number): string {
  return `pdfs/prestamo-${loanId}-semana-${weekId}.pdf`;
}
export function projectLogoKey(projectId: number, side: "left" | "right", ext: string): string {
  return `logos/${projectId}-${side}.${ext}`;
}