package com.example.service

import com.google.cloud.storage.Blob
import com.google.cloud.storage.BlobId
import com.google.cloud.storage.BlobInfo
import com.google.cloud.storage.Storage
import com.google.cloud.storage.StorageException
import com.google.cloud.storage.StorageOptions
import spock.lang.IgnoreIf
import spock.lang.Specification

import java.nio.charset.StandardCharsets

@IgnoreIf(
    value = {!System.getenv('GOOGLE_CLOUD_PROJECT')},
    reason = 'GOOGLE_CLOUD_PROJECT environment variable not set'
)
class MoveBlobTest extends Specification {
    private static final String FLAT_BUCKET_NAME = 'move_blob_test_flat'
    private static final String HIERARCHICAL_BUCKET_NAME = 'move_blob_test_hierarchical'

    // Relying on the GOOGLE_CLOUD_PROJECT environment variable for the project-id value
    private final Storage storage = StorageOptions.newBuilder().build().service

    def "Should fail to atomically move a blob in a flat-namespace bucket"() {
        given: "A source blob"
        Blob sourceBlob = storage.create(
            BlobInfo.newBuilder(FLAT_BUCKET_NAME, 'source-file.txt')
                .setContentType('text/plain')
                .build(),
            'file contents'.getBytes(StandardCharsets.UTF_8)
        )
        and: "A destination blob id"
        BlobId targetBlobId = BlobId.of(FLAT_BUCKET_NAME, 'target-file.txt')

        when: "A move is requested from source to target"
        Blob targetBlob = storage.moveBlob(
            Storage.MoveBlobRequest.newBuilder()
                .setSource(sourceBlob.blobId)
                .setTarget(targetBlobId)
                .build()
        )

        then: "The move operation fails with a StorageException"
        thrown(StorageException)

        and: "The source blob still exists"
        sourceBlob.exists()

        and: "The target blob does not exist"
        !targetBlob?.exists()
    }

    def "Should atomically move a blob in a hierarchical-namespace bucket"() {
        given: "A source blob"
        Blob sourceBlob = storage.create(
            BlobInfo.newBuilder(HIERARCHICAL_BUCKET_NAME, 'source-file.txt')
                .setContentType('text/plain')
                .build(),
            'file contents'.getBytes(StandardCharsets.UTF_8)
        )
        and: "A destination blob id"
        BlobId targetBlobId = BlobId.of(HIERARCHICAL_BUCKET_NAME, 'target-file.txt')

        when: "A move is requested from source to target"
        Blob targetBlob = storage.moveBlob(
            Storage.MoveBlobRequest.newBuilder()
                .setSource(sourceBlob.blobId)
                .setTarget(targetBlobId)
                .build()
        )

        then: "The move operation succeeds and returns a Blob"
        targetBlob

        and: "The source blob no longer exists"
        !sourceBlob.exists()
    }
}