import type {
  PresignedUploadPartCapability,
  PresignedUploadPartPort,
} from "../../../application/ports/browser-transfer/presigned-transfer.ts";
import type {
  UploadPartExecutor,
  UploadPartReceipt,
  UploadProviderResult,
} from "../../../application/ports/browser-transfer/resumable-upload.ts";
import {
  browserDataFailure,
  browserDataSuccess,
} from "../../browser-file-storage/result.ts";
import {
  MEDIA_TYPE,
  isSafeUploadReceiptToken,
  SHA256_HEX,
} from "./checkpoint-schema.ts";

export function createPresignedUploadPartExecutor(
  inputPort: PresignedUploadPartPort,
  now: () => number = Date.now,
): UploadPartExecutor<PresignedUploadPartCapability> {
  const put = inputPort?.put;
  if (typeof put !== "function" || typeof now !== "function") {
    throw new TypeError("Presigned upload part dependency is invalid.");
  }
  const executor: UploadPartExecutor<PresignedUploadPartCapability> = {
    async uploadPart(
      input: Parameters<
        UploadPartExecutor<PresignedUploadPartCapability>["uploadPart"]
      >[0],
    ): Promise<
      UploadProviderResult<UploadPartReceipt>
    > {
      const capability = input.capability;
      let nowEpochMs: number;
      try {
        nowEpochMs = now();
      } catch {
        return browserDataFailure("UNAVAILABLE", "UPLOAD_PART", {
          retryable: true,
          recovery: "RESUME",
        });
      }
      if (
        !capability ||
        capability.method !== "PUT" ||
        capability.binding.kind !== "UPLOAD_PART" ||
        capability.binding.protocol !== input.protocol ||
        capability.binding.sessionId !== input.sessionId ||
        capability.binding.requestBindingSha256 !==
          input.requestBindingSha256 ||
        capability.binding.uploadBindingSha256 !==
          input.uploadBindingSha256 ||
        capability.binding.partNumber !== input.part.partNumber ||
        capability.binding.offset !== input.part.offset ||
        capability.binding.idempotencyKey !== input.idempotencyKey ||
        capability.mediaType !== input.mediaType ||
        !MEDIA_TYPE.test(capability.mediaType) ||
        capability.byteLength !== input.part.byteLength ||
        capability.maxBytes < capability.byteLength ||
        capability.maxBytes !== input.part.byteLength ||
        capability.expectedSha256 !== input.part.checksumSha256 ||
        !SHA256_HEX.test(capability.expectedSha256) ||
        capability.expiresAtEpochMs <= nowEpochMs ||
        !(input.bytes instanceof Uint8Array) ||
        input.bytes.byteLength !== input.part.byteLength ||
        typeof capability.capabilityReceipt !== "string"
      ) {
        return browserDataFailure("POLICY_REJECTED", "UPLOAD_PART");
      }
      let uploaded;
      try {
        uploaded = await put.call(inputPort, {
          capability,
          sessionId: input.sessionId,
          requestBindingSha256: input.requestBindingSha256,
          uploadBindingSha256: input.uploadBindingSha256,
          partNumber: input.part.partNumber,
          offset: input.part.offset,
          byteLength: input.part.byteLength,
          checksumSha256: input.part.checksumSha256,
          idempotencyKey: input.idempotencyKey,
          bytes: Uint8Array.from(input.bytes),
          signal: input.signal,
        });
      } catch {
        return browserDataFailure("UNAVAILABLE", "UPLOAD_PART", {
          retryable: true,
          recovery: "RESUME",
        });
      }
      if (!uploaded.ok) return uploaded;
      if (
        uploaded.value.bytesWritten !== input.part.byteLength ||
        uploaded.value.checksumSha256 !== input.part.checksumSha256 ||
        typeof uploaded.value.receiptToken !== "string" ||
        !isSafeUploadReceiptToken(uploaded.value.receiptToken)
      ) {
        return browserDataFailure("INTEGRITY_FAILED", "UPLOAD_PART", {
          recovery: "RECONCILE",
        });
      }
      return browserDataSuccess(
        Object.freeze({
          ...input.part,
          receiptToken: uploaded.value.receiptToken,
        }),
      );
    },
  };
  return Object.freeze(executor);
}