import {
  GetObjectCommand,
  HeadObjectCommand,
  PutObjectCommand,
  S3Client,
} from "@aws-sdk/client-s3";
import { getSignedUrl } from "@aws-sdk/s3-request-presigner";
import type { ApiEnv } from "./env.js";

export type PresignPutResult = {
  url: string;
  headers: Record<string, string>;
};

export type DocumentsStore = {
  presignPut(input: { objectKey: string; contentType: string }): Promise<PresignPutResult>;
  objectExists(objectKey: string): Promise<boolean>;
  presignGet(objectKey: string): Promise<string>;
};

const SIGN_EXPIRES_SECONDS = 900;

export function createDocumentsStore(env: ApiEnv): DocumentsStore {
  const client = new S3Client({
    region: env.awsRegion,
    endpoint: env.documentsEndpoint || undefined,
    forcePathStyle: Boolean(env.documentsEndpoint),
    credentials:
      env.documentsAccessKey && env.documentsSecretKey
        ? { accessKeyId: env.documentsAccessKey, secretAccessKey: env.documentsSecretKey }
        : undefined,
  });
  const bucket = env.documentsBucket;

  return {
    async presignPut({ objectKey, contentType }) {
      const url = await getSignedUrl(
        client,
        new PutObjectCommand({ Bucket: bucket, Key: objectKey, ContentType: contentType }),
        { expiresIn: SIGN_EXPIRES_SECONDS },
      );
      return { url, headers: { "Content-Type": contentType } };
    },
    async objectExists(objectKey) {
      try {
        await client.send(new HeadObjectCommand({ Bucket: bucket, Key: objectKey }));
        return true;
      } catch {
        return false;
      }
    },
    async presignGet(objectKey) {
      return getSignedUrl(client, new GetObjectCommand({ Bucket: bucket, Key: objectKey }), {
        expiresIn: SIGN_EXPIRES_SECONDS,
      });
    },
  };
}

export function createMemoryDocumentsStore(): DocumentsStore & { uploaded: Set<string> } {
  const uploaded = new Set<string>();
  return {
    uploaded,
    async presignPut({ objectKey, contentType }) {
      return {
        url: `http://127.0.0.1:9000/seahaven-ap-documents/${objectKey}?presign=put`,
        headers: { "Content-Type": contentType },
      };
    },
    async objectExists(objectKey) {
      return uploaded.has(objectKey);
    },
    async presignGet(objectKey) {
      return `http://127.0.0.1:9000/seahaven-ap-documents/${objectKey}?presign=get`;
    },
  };
}