const sinon = require('sinon')
const chai = require('chai')
const { expect } = chai
const SandboxedModule = require('sandboxed-module')
const Errors = require('../../src/Errors')
const StreamModule = require('stream')

const modulePath = '../../src/FSPersistor.js'

describe('FSPersistorTests', function () {
  const stat = { size: 4, isFile: sinon.stub().returns(true) }
  const fd = 1234
  const writeStream = 'writeStream'
  const remoteStream = 'remoteStream'
  const location = '/foo'
  const error = new Error('guru meditation error')
  const md5 = 'ffffffff'

  const files = ['animals/wombat.tex', 'vegetables/potato.tex']
  const globs = [`${location}/${files[0]}`, `${location}/${files[1]}`]
  const filteredFilenames = ['animals_wombat.tex', 'vegetables_potato.tex']
  let fs, stream, FSPersistor, glob, readStream, crypto, Hash, uuid, tempFile

  beforeEach(function () {
    const randomNumber = Math.random().toString()
    readStream = {
      name: 'readStream',
      on: sinon.stub().yields(),
      pipe: sinon.stub(),
    }
    uuid = {
      v1: () => randomNumber,
    }
    tempFile = `/tmp/${randomNumber}`
    fs = {
      createReadStream: sinon.stub().returns(readStream),
      createWriteStream: sinon.stub().returns(writeStream),
      unlink: sinon.stub().yields(),
      open: sinon.stub().yields(null, fd),
      stat: sinon.stub().yields(null, stat),
    }
    glob = sinon.stub().yields(null, globs)
    stream = {
      pipeline: sinon.stub().yields(),
      Transform: StreamModule.Transform,
    }
    Hash = {
      end: sinon.stub(),
      read: sinon.stub().returns(md5),
      digest: sinon.stub().returns(md5),
      setEncoding: sinon.stub(),
    }
    crypto = {
      createHash: sinon.stub().returns(Hash),
    }
    FSPersistor = new (SandboxedModule.require(modulePath, {
      requires: {
        './Errors': Errors,
        fs,
        glob,
        stream,
        crypto,
        'node-uuid': uuid,
        // imported by PersistorHelper but otherwise unused here
        '@overleaf/logger': {},
      },
      globals: { console },
    }))({ paths: { uploadFolder: '/tmp' } })
  })

  describe('sendFile', function () {
    const localFilesystemPath = '/path/to/local/file'
    it('should copy the file', async function () {
      await FSPersistor.sendFile(location, files[0], localFilesystemPath)
      expect(fs.createReadStream).to.have.been.calledWith(localFilesystemPath)
      expect(fs.createWriteStream).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}`
      )
      expect(stream.pipeline).to.have.been.calledWith(readStream, writeStream)
    })

    it('should return an error if the file cannot be stored', async function () {
      stream.pipeline.yields(error)
      await expect(
        FSPersistor.sendFile(location, files[0], localFilesystemPath)
      ).to.eventually.be.rejected.and.have.property('cause', error)
    })
  })

  describe('sendStream', function () {
    it('should write the stream to disk', async function () {
      await FSPersistor.sendStream(location, files[0], remoteStream)
      expect(stream.pipeline).to.have.been.calledWith(remoteStream, writeStream)
    })

    it('should delete the temporary file', async function () {
      await FSPersistor.sendStream(location, files[0], remoteStream)
      expect(fs.unlink).to.have.been.calledWith(tempFile)
    })

    it('should wrap the error from the filesystem', async function () {
      stream.pipeline.yields(error)
      await expect(FSPersistor.sendStream(location, files[0], remoteStream))
        .to.eventually.be.rejected.and.be.instanceOf(Errors.WriteError)
        .and.have.property('cause', error)
    })

    it('should send the temporary file to the filestore', async function () {
      await FSPersistor.sendStream(location, files[0], remoteStream)
      expect(fs.createReadStream).to.have.been.calledWith(tempFile)
    })

    describe('when the md5 hash does not match', function () {
      it('should return a write error', async function () {
        await expect(
          FSPersistor.sendStream(location, files[0], remoteStream, {
            sourceMd5: '00000000',
          })
        )
          .to.eventually.be.rejected.and.be.an.instanceOf(Errors.WriteError)
          .and.have.property('message', 'md5 hash mismatch')
      })

      it('deletes the copied file', async function () {
        try {
          await FSPersistor.sendStream(location, files[0], remoteStream, {
            sourceMd5: '00000000',
          })
        } catch (_) {}
        expect(fs.unlink).to.have.been.calledWith(
          `${location}/${filteredFilenames[0]}`
        )
      })
    })
  })

  describe('getObjectStream', function () {
    it('should use correct file location', async function () {
      await FSPersistor.getObjectStream(location, files[0], {})
      expect(fs.open).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}`
      )
    })

    it('should pass the options to createReadStream', async function () {
      await FSPersistor.getObjectStream(location, files[0], {
        start: 0,
        end: 8,
      })
      expect(fs.createReadStream).to.have.been.calledWith(null, {
        start: 0,
        end: 8,
        fd,
      })
    })

    it('should give a NotFoundError if the file does not exist', async function () {
      const err = new Error()
      err.code = 'ENOENT'
      fs.open.yields(err)

      await expect(FSPersistor.getObjectStream(location, files[0], {}))
        .to.eventually.be.rejected.and.be.an.instanceOf(Errors.NotFoundError)
        .and.have.property('cause', err)
    })

    it('should wrap any other error', async function () {
      fs.open.yields(error)
      await expect(FSPersistor.getObjectStream(location, files[0], {}))
        .to.eventually.be.rejectedWith('failed to open file for streaming')
        .and.be.an.instanceOf(Errors.ReadError)
        .and.have.property('cause', error)
    })
  })

  describe('getObjectSize', function () {
    const badFilename = 'neenaw.tex'
    const size = 65536
    const noentError = new Error('not found')
    noentError.code = 'ENOENT'

    beforeEach(function () {
      fs.stat
        .yields(error)
        .withArgs(`${location}/${filteredFilenames[0]}`)
        .yields(null, { size })
        .withArgs(`${location}/${badFilename}`)
        .yields(noentError)
    })

    it('should return the file size', async function () {
      expect(await FSPersistor.getObjectSize(location, files[0])).to.equal(size)
    })

    it('should throw a NotFoundError if the file does not exist', async function () {
      await expect(
        FSPersistor.getObjectSize(location, badFilename)
      ).to.eventually.be.rejected.and.be.an.instanceOf(Errors.NotFoundError)
    })

    it('should wrap any other error', async function () {
      await expect(FSPersistor.getObjectSize(location, 'raccoon'))
        .to.eventually.be.rejected.and.be.an.instanceOf(Errors.ReadError)
        .and.have.property('cause', error)
    })
  })

  describe('copyObject', function () {
    it('Should open the source for reading', async function () {
      await FSPersistor.copyObject(location, files[0], files[1])
      expect(fs.createReadStream).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}`
      )
    })

    it('Should open the target for writing', async function () {
      await FSPersistor.copyObject(location, files[0], files[1])
      expect(fs.createWriteStream).to.have.been.calledWith(
        `${location}/${filteredFilenames[1]}`
      )
    })

    it('Should pipe the source to the target', async function () {
      await FSPersistor.copyObject(location, files[0], files[1])
      expect(stream.pipeline).to.have.been.calledWith(readStream, writeStream)
    })
  })

  describe('deleteObject', function () {
    it('Should call unlink with correct options', async function () {
      await FSPersistor.deleteObject(location, files[0])
      expect(fs.unlink).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}`
      )
    })

    it('Should propagate the error', async function () {
      fs.unlink.yields(error)
      await expect(
        FSPersistor.deleteObject(location, files[0])
      ).to.eventually.be.rejected.and.have.property('cause', error)
    })
  })

  describe('deleteDirectory', function () {
    it('Should call glob with correct options', async function () {
      await FSPersistor.deleteDirectory(location, files[0])
      expect(glob).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}_*`
      )
    })

    it('Should call unlink on the returned files', async function () {
      await FSPersistor.deleteDirectory(location, files[0])
      for (const filename of globs) {
        expect(fs.unlink).to.have.been.calledWith(filename)
      }
    })

    it('Should propagate the error', async function () {
      glob.yields(error)
      await expect(
        FSPersistor.deleteDirectory(location, files[0])
      ).to.eventually.be.rejected.and.have.property('cause', error)
    })
  })

  describe('checkIfObjectExists', function () {
    const badFilename = 'pototo'
    const noentError = new Error('not found')
    noentError.code = 'ENOENT'

    beforeEach(function () {
      fs.stat
        .yields(error)
        .withArgs(`${location}/${filteredFilenames[0]}`)
        .yields(null, {})
        .withArgs(`${location}/${badFilename}`)
        .yields(noentError)
    })

    it('Should call stat with correct options', async function () {
      await FSPersistor.checkIfObjectExists(location, files[0])
      expect(fs.stat).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}`
      )
    })

    it('Should return true for existing files', async function () {
      expect(
        await FSPersistor.checkIfObjectExists(location, files[0])
      ).to.equal(true)
    })

    it('Should return false for non-existing files', async function () {
      expect(
        await FSPersistor.checkIfObjectExists(location, badFilename)
      ).to.equal(false)
    })

    it('should wrap the error if there is a problem', async function () {
      await expect(FSPersistor.checkIfObjectExists(location, 'llama'))
        .to.eventually.be.rejected.and.be.an.instanceOf(Errors.ReadError)
        .and.have.property('cause', error)
    })
  })

  describe('directorySize', function () {
    it('should wrap the error', async function () {
      glob.yields(error)
      await expect(FSPersistor.directorySize(location, files[0]))
        .to.eventually.be.rejected.and.be.an.instanceOf(Errors.ReadError)
        .and.include({ cause: error })
        .and.have.property('info')
        .which.includes({ location, name: files[0] })
    })

    it('should filter the directory name', async function () {
      await FSPersistor.directorySize(location, files[0])
      expect(glob).to.have.been.calledWith(
        `${location}/${filteredFilenames[0]}_*`
      )
    })

    it('should sum directory files size', async function () {
      expect(await FSPersistor.directorySize(location, files[0])).to.equal(
        stat.size * files.length
      )
    })
  })
})