import { Eltro as t, assert, spy } from 'eltro'
import path from 'path'
import crypto from 'crypto'
import os from 'os'
import fsSyncOriginal from 'fs'
import fsPromisesOriginal from 'fs/promises'
import Cache from '../index.mjs'
import { fakeFs, fakeFsPromises, fakeFsSync } from './helper.mjs'

let fsSync
let fsPromises

t.beforeEach(function() {
  fsSync = fakeFsSync()
  fsPromises = fakeFsPromises()
})

function createCache(opts) {
  return new Cache(opts, fsSync, fsPromises)
}

t.describe('#constructor()', function() {
  t.test('uses default fs', function() {
    let cache = new Cache({})
    assert.strictEqual(cache.fsSync, fsSyncOriginal)
    assert.strictEqual(cache.fsPromises, fsPromisesOriginal)
  })

  t.test('should be able to override the fs', function() {
    let cache = createCache({})
    assert.strictEqual(cache.fsSync, fsSync)
    assert.strictEqual(cache.fsPromises, fsPromises)
  })

  t.test('comes with default options', function() {
    let cache = createCache({})
    assert.ok(cache.id)
    assert.strictEqual(cache.parse_json, true)
    assert.strictEqual(cache.prefix, '')
    assert.strictEqual(cache.hash_alg, 'md5')
    assert.strictEqual(cache.cache_dir, path.join(os.tmpdir(), cache.id))
  })

  t.test('can overwrite options', function() {
    const assertHash = 'sha256'
    const assertDir = '/something/else'
    const assertPrefix = 'blabla'
    const assertParseJson = false

    let cache = createCache({
      prefix: assertPrefix,
      hash_alg: assertHash,
      cache_dir: assertDir,
      parse_json: assertParseJson,
    })

    assert.ok(cache.id)
    assert.strictEqual(cache.parse_json, assertParseJson)
    assert.strictEqual(cache.prefix, assertPrefix + '-')
    assert.strictEqual(cache.hash_alg, assertHash)
    assert.strictEqual(cache.cache_dir, assertDir)
  })

  t.test('should create the directory by default', function() {
    assert.notOk(fsSync.mkdirSync.called)
    let cache = createCache({})
    assert.ok(fsSync.mkdirSync.called)
    assert.strictEqual(fsSync.mkdirSync.firstCall[0], cache.cache_dir)
    assert.strictEqual(fsSync.mkdirSync.firstCall[1]?.recursive, true)
  })

  t.test('should check if hash_alg is valid', function() {
    assert.throws(function() {
      createCache({ hash_alg: 'dafdsagasdgwa4e' })
    })
  })
})

t.describe('FSCache', function() {
  t.describe('#hash()', function() {
    t.test('should use cache hasher to hash string', function() {
      let cache = createCache({ hash_alg: 'sha256' })
      assert.strictEqual(cache.hash('asdf'), crypto.hash('sha256', 'asdf'))

      cache = createCache({ hash_alg: 'md5' })
      assert.strictEqual(cache.hash('asdf'), crypto.hash('md5', 'asdf'))
    })
  })

  t.describe('#_parseCacheData()', function() {
    t.test('should default parse as json', function() {
      let cache = createCache()
      let output = cache._parseCacheData('{"hello":"world"}')
      assert.strictEqual(typeof output, 'object')
      assert.strictEqual(output.hello, 'world')
    })

    t.test('can be overwritten in options', function() {
      let cache = createCache({ parse_json: false })
      let output = cache._parseCacheData('{"hello":"world"}')
      assert.strictEqual(typeof output, 'string')
      assert.strictEqual(output, '{"hello":"world"}')
    })

    t.test('can be overwritten in parameter', function() {
      let cache = createCache()
      let output = cache._parseCacheData('{"hello":"world"}', { parse_json: false })
      assert.strictEqual(typeof output, 'string')
      assert.strictEqual(output, '{"hello":"world"}')
    })
  })

  t.describe('#_parseSetData()', function() {
    t.test('should default stringify to json', function() {
      let cache = createCache()
      let output = cache._parseSetData({ hello: 'world' })
      assert.strictEqual(typeof output, 'string')
      assert.strictEqual(output, '{"hello":"world"}')
    })

    t.test('can be overwritten in options', function() {
      let cache = createCache({ parse_json: false })
      let output = cache._parseSetData('Hello world')
      assert.strictEqual(typeof output, 'string')
      assert.strictEqual(output, 'Hello world')
    })

    t.test('can be overwritten in parameter', function() {
      let cache = createCache()
      let output = cache._parseSetData('Hello world', { parse_json: false })
      assert.strictEqual(typeof output, 'string')
      assert.strictEqual(output, 'Hello world')
    })
  })

  t.describe('#get()', function() {
    t.test('should call promise readFile and parse result', async function() {
      const assertKey = 'asdf1234'
      const assertContent = '{"hello":"world"}'
      const assertResult = { hello: 'world' }
      let cache = createCache()
      fsPromises.readFile.resolves(assertContent)
      cache._parseCacheData = spy().returns(assertResult)

      let output = await cache.get(assertKey)
      assert.strictEqual(output, assertResult)
      assert.ok(fsPromises.readFile.called)
      assert.strictEqual(fsPromises.readFile.firstCall[0], path.join(cache.cache_dir, cache.hash(assertKey)))
      assert.strictEqual(fsPromises.readFile.firstCall[1]?.encoding, 'utf8')
      assert.ok(cache._parseCacheData.called)
      assert.ok(cache._parseCacheData.firstCall[0], assertContent)
    })

    t.test('should pass extra options to the parser', async function() {
      const assertOptions = { a: 1 }
      let cache = createCache()
      cache._parseCacheData = spy()

      await cache.get('asdf', null, assertOptions)

      assert.ok(cache._parseCacheData.called)
      assert.ok(cache._parseCacheData.firstCall[1], assertOptions)
    })

    t.test('should support fallback value if file does not exist', async function() {
      const assertFallback = { a: 1 }
      let cache = createCache()
      fsPromises.readFile.rejects(new Error('asdf'))
      cache._parseCacheData = spy()

      let output = await cache.get('bla', assertFallback)
      assert.strictEqual(output, assertFallback)
      assert.notOk(cache._parseCacheData.called)
    })

    t.test('parser error should propogate', async function() {
      const assertError = new Error('Hello')
      let cache = createCache()
      cache._parseCacheData = spy().throws(assertError)

      let err = await assert.isRejected(cache.get('asdf'))

      assert.strictEqual(err, assertError)
    })
  })

  t.describe('#getSync()', function() {
    t.test('should call sync readFile and parse result', function() {
      const assertKey = 'asdf1234'
      const assertContent = '{"hello":"world"}'
      const assertResult = { hello: 'world' }
      let cache = createCache()
      fsSync.readFileSync.returns(assertContent)
      cache._parseCacheData = spy().returns(assertResult)

      let output = cache.getSync(assertKey)
      assert.strictEqual(output, assertResult)
      assert.ok(fsSync.readFileSync.called)
      assert.strictEqual(fsSync.readFileSync.firstCall[0], path.join(cache.cache_dir, cache.hash(assertKey)))
      assert.strictEqual(fsSync.readFileSync.firstCall[1]?.encoding, 'utf8')
      assert.ok(cache._parseCacheData.called)
      assert.ok(cache._parseCacheData.firstCall[0], assertContent)
    })

    t.test('should pass extra options to the parser', function() {
      const assertOptions = { a: 1 }
      let cache = createCache()
      cache._parseCacheData = spy()

      cache.getSync('asdf', null, assertOptions)

      assert.ok(cache._parseCacheData.called)
      assert.ok(cache._parseCacheData.firstCall[1], assertOptions)
    })

    t.test('should support fallback value if file does not exist', function() {
      const assertFallback = { a: 1 }
      let cache = createCache()
      fsSync.readFileSync.throws(new Error('asdf'))
      cache._parseCacheData = spy()

      let output = cache.getSync('bla', assertFallback)
      assert.strictEqual(output, assertFallback)
      assert.notOk(cache._parseCacheData.called)
    })

    t.test('parser error should propogate', async function() {
      const assertError = new Error('Hello')
      let cache = createCache()
      cache._parseCacheData = spy().throws(assertError)

      assert.throws(function() {
        cache.getSync('asdf')
      }, assertError)
    })
  })

  t.describe('#set()', function() {
    t.test('should call promise writeFile', async function() {
      const assertKey = 'asdf1234'
      const assertInput = { hello: 'world' }
      const assertContent = JSON.stringify(assertInput)

      let cache = createCache()
      cache._parseSetData = spy().returns(assertContent)
      await cache.set(assertKey, assertInput)

      assert.ok(fsPromises.writeFile.called)
      assert.strictEqual(fsPromises.writeFile.firstCall[0], path.join(cache.cache_dir, cache.hash(assertKey)))
      assert.strictEqual(fsPromises.writeFile.firstCall[1], assertContent)
      assert.strictEqual(fsPromises.writeFile.firstCall[2]?.encoding, 'utf8')
      assert.ok(cache._parseSetData.called)
      assert.ok(cache._parseSetData.firstCall[0], assertInput)
    })

    t.test('should pass extra options to the parser', async function() {
      const assertOptions = { a: 1 }
      let cache = createCache()
      cache._parseSetData = spy()

      await cache.set('asdf', null, assertOptions)

      assert.ok(cache._parseSetData.called)
      assert.ok(cache._parseSetData.firstCall[1], assertOptions)
    })

    t.test('should pass extra options to the parser', async function() {
      const assertEncoding = 'asdf'

      let cache = createCache()
      await cache.set('asdf', null, { encoding: assertEncoding })

      assert.strictEqual(fsPromises.writeFile.firstCall[2]?.encoding, assertEncoding)
    })

    t.test('parse error should reject properly', async function() {
      const assertError = new Error('what is up')

      let cache = createCache()
      cache._parseSetData = spy().throws(assertError)
      
      // make sure it's properly promise wrapped
      let inbetween = cache.set('asdf')
      let err = await assert.isRejected(inbetween)

      assert.strictEqual(err, assertError)
    })
  })

  t.describe('#setSync()', function() {
    t.test('should call sync writeFileSync', function() {
      const assertKey = 'asdf1234'
      const assertInput = { hello: 'world' }
      const assertContent = JSON.stringify(assertInput)

      let cache = createCache()
      cache._parseSetData = spy().returns(assertContent)
      cache.setSync(assertKey, assertInput)

      assert.ok(fsSync.writeFileSync.called)
      assert.strictEqual(fsSync.writeFileSync.firstCall[0], path.join(cache.cache_dir, cache.hash(assertKey)))
      assert.strictEqual(fsSync.writeFileSync.firstCall[1], assertContent)
      assert.strictEqual(fsSync.writeFileSync.firstCall[2]?.encoding, 'utf8')
      assert.ok(cache._parseSetData.called)
      assert.ok(cache._parseSetData.firstCall[0], assertInput)
    })

    t.test('should pass extra options to the parser', function() {
      const assertOptions = { a: 1 }
      let cache = createCache()
      cache._parseSetData = spy()

      cache.setSync('asdf', null, assertOptions)

      assert.ok(cache._parseSetData.called)
      assert.ok(cache._parseSetData.firstCall[1], assertOptions)
    })

    t.test('should pass extra options to the parser', function() {
      const assertEncoding = 'asdf'

      let cache = createCache()
      cache.setSync('asdf', null, { encoding: assertEncoding })

      assert.strictEqual(fsSync.writeFileSync.firstCall[2]?.encoding, assertEncoding)
    })

    t.test('parse error should throw', function() {
      const assertError = new Error('what is up')

      let cache = createCache()
      cache._parseSetData = spy().throws(assertError)

      assert.throws(function() {
        cache.setSync('asdf')
      }, assertError)
    })
  })
})