const fs = require('fs')
const path = require('path')
const {Context} = require('../src/context')

describe('Context', function () {
  let event
  let context

  beforeEach(function () {
    event = {
      event: 'push',
      payload: {
        repository: {
          owner: {login: 'bkeepers'},
          name: 'probot'
        },
        issue: {number: 4}
      }
    }
    context = new Context(event)
  })

  it('inherits the payload', () => {
    expect(context.payload).toBe(event.payload)
  })

  describe('repo', function () {
    it('returns attributes from repository payload', function () {
      expect(context.repo()).toEqual({owner: 'bkeepers', repo: 'probot'})
    })

    it('merges attributes', function () {
      expect(context.repo({foo: 1, bar: 2})).toEqual({
        owner: 'bkeepers', repo: 'probot', foo: 1, bar: 2
      })
    })

    it('overrides repo attributes', function () {
      expect(context.repo({owner: 'muahaha'})).toEqual({
        owner: 'muahaha', repo: 'probot'
      })
    })

    // The `repository` object on the push event has a different format than the other events
    // https://developer.github.com/v3/activity/events/types/#pushevent
    it('properly handles the push event', function () {
      event.payload = require('./fixtures/webhook/push')

      context = new Context(event)
      expect(context.repo()).toEqual({owner: 'bkeepers-inc', repo: 'test'})
    })
  })

  describe('issue', function () {
    it('returns attributes from repository payload', function () {
      expect(context.issue()).toEqual({owner: 'bkeepers', repo: 'probot', number: 4})
    })

    it('merges attributes', function () {
      expect(context.issue({foo: 1, bar: 2})).toEqual({
        owner: 'bkeepers', repo: 'probot', number: 4, foo: 1, bar: 2
      })
    })

    it('overrides repo attributes', function () {
      expect(context.issue({owner: 'muahaha', number: 5})).toEqual({
        owner: 'muahaha', repo: 'probot', number: 5
      })
    })
  })

  describe('config', function () {
    let github

    function readConfig (fileName) {
      const configPath = path.join(__dirname, 'fixtures', 'config', fileName)
      const content = fs.readFileSync(configPath, {encoding: 'utf8'})
      return {data: {content: Buffer.from(content).toString('base64')}}
    }

    beforeEach(function () {
      github = {
        repos: {
          getContent: jest.fn()
        }
      }

      context = new Context(event, github)
    })

    it('gets a valid configuration', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(Promise.resolve(readConfig('basic.yml')))
      const config = await context.config('test-file.yml')

      expect(github.repos.getContent).toHaveBeenCalledWith({
        owner: 'bkeepers',
        repo: 'probot',
        path: '.github/test-file.yml'
      })
      expect(config).toEqual({
        foo: 5,
        bar: 7,
        baz: 11
      })
    })

    it('returns null when the file is missing', async function () {
      const error = new Error('An error occurred')
      error.code = 404
      github.repos.getContent = jest.fn().mockReturnValue(Promise.reject(error))

      expect(await context.config('test-file.yml')).toBe(null)
    })

    it('returns the default config when the file is missing and default config is passed', async function () {
      const error = new Error('An error occurred')
      error.code = 404
      github.repos.getContent = jest.fn().mockReturnValue(Promise.reject(error))
      const defaultConfig = {
        foo: 5,
        bar: 7,
        baz: 11
      }
      const contents = await context.config('test-file.yml', defaultConfig)
      expect(contents).toEqual(defaultConfig)
    })

    it('throws when the configuration file is malformed', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(Promise.resolve(readConfig('malformed.yml')))

      let e
      let contents
      try {
        contents = await context.config('test-file.yml')
      } catch (err) {
        e = err
      }

      expect(contents).toBeUndefined()
      expect(e).toBeDefined()
      expect(e.message).toMatch(/^end of the stream or a document separator/)
    })

    it('throws when loading unsafe yaml', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(readConfig('evil.yml'))

      let e
      let config
      try {
        config = await context.config('evil.yml')
      } catch (err) {
        e = err
      }

      expect(config).toBeUndefined()
      expect(e).toBeDefined()
      expect(e.message).toMatch(/unknown tag/)
    })

    it('returns an empty object when the file is empty', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(readConfig('empty.yml'))

      const contents = await context.config('test-file.yml')

      expect(contents).toEqual({})
    })

    it('overwrites default config settings', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(Promise.resolve(readConfig('basic.yml')))
      const config = await context.config('test-file.yml', {foo: 10})

      expect(github.repos.getContent).toHaveBeenCalledWith({
        owner: 'bkeepers',
        repo: 'probot',
        path: '.github/test-file.yml'
      })
      expect(config).toEqual({
        foo: 5,
        bar: 7,
        baz: 11
      })
    })

    it('uses default settings to fill in missing options', async function () {
      github.repos.getContent = jest.fn().mockReturnValue(Promise.resolve(readConfig('missing.yml')))
      const config = await context.config('test-file.yml', {bar: 7})

      expect(github.repos.getContent).toHaveBeenCalledWith({
        owner: 'bkeepers',
        repo: 'probot',
        path: '.github/test-file.yml'
      })
      expect(config).toEqual({
        foo: 5,
        bar: 7,
        baz: 11
      })
    })
  })
})