// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict'

const tap = require('tap')
const silentConsole = {
  log() {},
  error() {}
}
const common = require('../common')
const assert = require('assert')

// This test verifies that:
// 1. unshift() does not cause colliding _read() calls.
// 2. unshift() after the 'end' event is an error, but after the EOF
//    signalling null, it is ok, and just creates a new readable chunk.
// 3. push() after the EOF signaling null is an error.
// 4. _read() is not called after pushing the EOF null chunk.

const stream = require('../../lib/ours/index')
const hwm = 10
const r = stream.Readable({
  highWaterMark: hwm,
  autoDestroy: false
})
const chunks = 10
const data = Buffer.allocUnsafe(chunks * hwm + Math.ceil(hwm / 2))
for (let i = 0; i < data.length; i++) {
  const c = 'asdf'.charCodeAt(i % 4)
  data[i] = c
}
let pos = 0
let pushedNull = false
r._read = function (n) {
  assert(!pushedNull, '_read after null push')

  // Every third chunk is fast
  push(!(chunks % 3))
  function push(fast) {
    assert(!pushedNull, 'push() after null push')
    const c = pos >= data.length ? null : data.slice(pos, pos + n)
    pushedNull = c === null
    if (fast) {
      pos += n
      r.push(c)
      if (c === null) pushError()
    } else {
      setTimeout(function () {
        pos += n
        r.push(c)
        if (c === null) pushError()
      }, 1)
    }
  }
}
function pushError() {
  r.unshift(Buffer.allocUnsafe(1))
  w.end()
  assert.throws(
    () => {
      r.push(Buffer.allocUnsafe(1))
    },
    {
      code: 'ERR_STREAM_PUSH_AFTER_EOF',
      name: 'Error',
      message: 'stream.push() after EOF'
    }
  )
}
const w = stream.Writable()
const written = []
w._write = function (chunk, encoding, cb) {
  written.push(chunk.toString())
  cb()
}
r.on('end', common.mustNotCall())
r.on('readable', function () {
  let chunk
  while (null !== (chunk = r.read(10))) {
    w.write(chunk)
    if (chunk.length > 4) r.unshift(Buffer.from('1234'))
  }
})
w.on(
  'finish',
  common.mustCall(function () {
    // Each chunk should start with 1234, and then be asfdasdfasdf...
    // The first got pulled out before the first unshift('1234'), so it's
    // lacking that piece.
    assert.strictEqual(written[0], 'asdfasdfas')
    let asdf = 'd'
    silentConsole.error(`0: ${written[0]}`)
    for (let i = 1; i < written.length; i++) {
      silentConsole.error(`${i.toString(32)}: ${written[i]}`)
      assert.strictEqual(written[i].slice(0, 4), '1234')
      for (let j = 4; j < written[i].length; j++) {
        const c = written[i].charAt(j)
        assert.strictEqual(c, asdf)
        switch (asdf) {
          case 'a':
            asdf = 's'
            break
          case 's':
            asdf = 'd'
            break
          case 'd':
            asdf = 'f'
            break
          case 'f':
            asdf = 'a'
            break
        }
      }
    }
  })
)
process.on('exit', function () {
  assert.strictEqual(written.length, 18)
  silentConsole.log('ok')
})

/* replacement start */
process.on('beforeExit', (code) => {
  if (code === 0) {
    tap.pass('test succeeded')
  } else {
    tap.fail(`test failed - exited code ${code}`)
  }
})
/* replacement end */
