const chai = require('chai')
const { expect } = chai
const fs = require('fs')
const Settings = require('settings-sharelatex')
const Path = require('path')
const FilestoreApp = require('./FilestoreApp')
const rp = require('request-promise-native').defaults({
  resolveWithFullResponse: true
})
const Stream = require('stream')
const request = require('request')
const { promisify } = require('util')
chai.use(require('chai-as-promised'))

const fsWriteFile = promisify(fs.writeFile)
const fsStat = promisify(fs.stat)
const pipeline = promisify(Stream.pipeline)

async function getMetric(filestoreUrl, metric) {
  const res = await rp.get(`${filestoreUrl}/metrics`)
  expect(res.statusCode).to.equal(200)
  const metricRegex = new RegExp(`^${metric}{[^}]+} ([0-9]+)$`, 'm')
  const found = metricRegex.exec(res.body)
  return parseInt(found ? found[1] : 0) || 0
}

// store settings for multiple backends, so that we can test each one.
// fs will always be available - add others if they are configured
const BackendSettings = {
  FSPersistor: {
    backend: 'fs',
    stores: {
      user_files: Path.resolve(__dirname, '../../../user_files'),
      public_files: Path.resolve(__dirname, '../../../public_files'),
      template_files: Path.resolve(__dirname, '../../../template_files')
    }
  }
}

if (process.env.AWS_ACCESS_KEY_ID) {
  BackendSettings.S3Persistor = {
    backend: 's3',
    s3: {
      key: process.env.AWS_ACCESS_KEY_ID,
      secret: process.env.AWS_SECRET_ACCESS_KEY,
      endpoint: process.env.AWS_S3_ENDPOINT
    },
    stores: {
      user_files: process.env.AWS_S3_USER_FILES_BUCKET_NAME,
      template_files: process.env.AWS_S3_TEMPLATE_FILES_BUCKET_NAME,
      public_files: process.env.AWS_S3_PUBLIC_FILES_BUCKET_NAME
    }
  }
}

describe('Filestore', function() {
  this.timeout(1000 * 10)
  const filestoreUrl = `http://localhost:${Settings.internal.filestore.port}`

  // redefine the test suite for every available backend
  Object.keys(BackendSettings).forEach(backend => {
    describe(backend, function() {
      let app, previousEgress, previousIngress

      before(async function() {
        // create the app with the relevant filestore settings
        Settings.filestore = BackendSettings[backend]
        app = new FilestoreApp()
        await app.runServer()
      })

      after(async function() {
        return app.stop()
      })

      beforeEach(async function() {
        // retrieve previous metrics from the app
        if (Settings.filestore.backend === 's3') {
          ;[previousEgress, previousIngress] = await Promise.all([
            getMetric(filestoreUrl, 's3_egress'),
            getMetric(filestoreUrl, 's3_ingress')
          ])
        }
      })

      it('should send a 200 for the status endpoint', async function() {
        const response = await rp(`${filestoreUrl}/status`)
        expect(response.statusCode).to.equal(200)
        expect(response.body).to.contain('filestore')
        expect(response.body).to.contain('up')
      })

      it('should send a 200 for the health-check endpoint', async function() {
        const response = await rp(`${filestoreUrl}/health_check`)
        expect(response.statusCode).to.equal(200)
        expect(response.body).to.equal('OK')
      })

      describe('with a file on the server', function() {
        let fileId, fileUrl

        const localFileReadPath =
          '/tmp/filestore_acceptance_tests_file_read.txt'
        const constantFileContent = [
          'hello world',
          `line 2 goes here ${Math.random()}`,
          'there are 3 lines in all'
        ].join('\n')

        before(async function() {
          await fsWriteFile(localFileReadPath, constantFileContent)
        })

        beforeEach(async function() {
          fileId = Math.random()
          fileUrl = `${filestoreUrl}/project/acceptance_tests/file/${fileId}`

          const writeStream = request.post(fileUrl)
          const readStream = fs.createReadStream(localFileReadPath)
          // consume the result to ensure the http request has been fully processed
          const resultStream = fs.createWriteStream('/dev/null')
          await pipeline(readStream, writeStream, resultStream)
        })

        it('should return 404 for a non-existant id', async function() {
          const options = { uri: fileUrl + '___this_is_clearly_wrong___' }
          await expect(
            rp.get(options)
          ).to.eventually.be.rejected.and.have.property('statusCode', 404)
        })

        it('should return the file size on a HEAD request', async function() {
          const expectedLength = Buffer.byteLength(constantFileContent)
          const res = await rp.head(fileUrl)
          expect(res.statusCode).to.equal(200)
          expect(res.headers['content-length']).to.equal(
            expectedLength.toString()
          )
        })

        it('should be able get the file back', async function() {
          const res = await rp.get(fileUrl)
          expect(res.body).to.equal(constantFileContent)
        })

        it('should be able to get back the first 9 bytes of the file', async function() {
          const options = {
            uri: fileUrl,
            headers: {
              Range: 'bytes=0-8'
            }
          }
          const res = await rp.get(options)
          expect(res.body).to.equal('hello wor')
        })

        it('should be able to get back bytes 4 through 10 of the file', async function() {
          const options = {
            uri: fileUrl,
            headers: {
              Range: 'bytes=4-10'
            }
          }
          const res = await rp.get(options)
          expect(res.body).to.equal('o world')
        })

        it('should be able to delete the file', async function() {
          const response = await rp.del(fileUrl)
          expect(response.statusCode).to.equal(204)
          await expect(
            rp.get(fileUrl)
          ).to.eventually.be.rejected.and.have.property('statusCode', 404)
        })

        it('should be able to copy files', async function() {
          const newProjectID = 'acceptance_tests_copyied_project'
          const newFileId = Math.random()
          const newFileUrl = `${filestoreUrl}/project/${newProjectID}/file/${newFileId}`
          const opts = {
            method: 'put',
            uri: newFileUrl,
            json: {
              source: {
                project_id: 'acceptance_tests',
                file_id: fileId
              }
            }
          }
          let response = await rp(opts)
          expect(response.statusCode).to.equal(200)
          response = await rp.del(fileUrl)
          expect(response.statusCode).to.equal(204)
          response = await rp.get(newFileUrl)
          expect(response.body).to.equal(constantFileContent)
        })

        if (backend === 'S3Persistor') {
          it('should record an egress metric for the upload', async function() {
            const metric = await getMetric(filestoreUrl, 's3_egress')
            expect(metric - previousEgress).to.equal(constantFileContent.length)
          })

          it('should record an ingress metric when downloading the file', async function() {
            await rp.get(fileUrl)
            const metric = await getMetric(filestoreUrl, 's3_ingress')
            expect(metric - previousIngress).to.equal(
              constantFileContent.length
            )
          })

          it('should record an ingress metric for a partial download', async function() {
            const options = {
              uri: fileUrl,
              headers: {
                Range: 'bytes=0-8'
              }
            }
            await rp.get(options)
            const metric = await getMetric(filestoreUrl, 's3_ingress')
            expect(metric - previousIngress).to.equal(9)
          })
        }
      })

      describe('with a pdf file', function() {
        let fileId, fileUrl, localFileSize
        const localFileReadPath = Path.resolve(
          __dirname,
          '../../fixtures/test.pdf'
        )

        beforeEach(async function() {
          fileId = Math.random()
          fileUrl = `${filestoreUrl}/project/acceptance_tests/file/${fileId}`
          const stat = await fsStat(localFileReadPath)
          localFileSize = stat.size
          const writeStream = request.post(fileUrl)
          const endStream = fs.createWriteStream('/dev/null')
          const readStream = fs.createReadStream(localFileReadPath)
          await pipeline(readStream, writeStream, endStream)
        })

        it('should be able get the file back', async function() {
          const response = await rp.get(fileUrl)
          expect(response.body.substring(0, 8)).to.equal('%PDF-1.5')
        })

        if (backend === 'S3Persistor') {
          it('should record an egress metric for the upload', async function() {
            const metric = await getMetric(filestoreUrl, 's3_egress')
            expect(metric - previousEgress).to.equal(localFileSize)
          })
        }

        describe('getting the preview image', function() {
          this.timeout(1000 * 20)
          let previewFileUrl

          beforeEach(function() {
            previewFileUrl = `${fileUrl}?style=preview`
          })

          it('should not time out', async function() {
            const response = await rp.get(previewFileUrl)
            expect(response.statusCode).to.equal(200)
          })

          it('should respond with image data', async function() {
            // note: this test relies of the imagemagick conversion working
            const response = await rp.get(previewFileUrl)
            expect(response.body.length).to.be.greaterThan(400)
            expect(response.body.substr(1, 3)).to.equal('PNG')
          })
        })

        describe('warming the cache', function() {
          this.timeout(1000 * 20)
          let previewFileUrl

          beforeEach(function() {
            previewFileUrl = `${fileUrl}?style=preview&cacheWarm=true`
          })

          it('should not time out', async function() {
            const response = await rp.get(previewFileUrl)
            expect(response.statusCode).to.equal(200)
          })

          it("should respond with only an 'OK'", async function() {
            // note: this test relies of the imagemagick conversion working
            const response = await rp.get(previewFileUrl)
            expect(response.body).to.equal('OK')
          })
        })
      })
    })
  })
})