var test = require('tap').test
  , LRU = require('../')

test('basic', function (t) {
  var cache = new LRU(10)
  cache.set("key", "value")
  t.equal(cache.get("key"), "value")
  t.equal(cache.get("nada"), undefined)
  t.equal(cache.length, 1)
  t.equal(cache.maxLength, 10)
  t.end()
})

test('least recently set', function (t) {
  var cache = new LRU(2)
  cache.set("a", "A")
  cache.set("b", "B")
  cache.set("c", "C")
  t.equal(cache.get("c"), "C")
  t.equal(cache.get("b"), "B")
  t.equal(cache.get("a"), undefined)
  t.end()
})

test('lru recently gotten', function (t) {
  var cache = new LRU(2)
  cache.set("a", "A")
  cache.set("b", "B")
  cache.get("a")
  cache.set("c", "C")
  t.equal(cache.get("c"), "C")
  t.equal(cache.get("b"), undefined)
  t.equal(cache.get("a"), "A")
  t.end()
})

test('del', function (t) {
  var cache = new LRU(2)
  cache.set("a", "A")
  cache.del("a")
  t.equal(cache.get("a"), undefined)
  t.end()
})

test('maxLength', function (t) {
  var cache = new LRU(3)

  // test changing the maxLength, verify that the LRU items get dropped.
  cache.maxLength = 100
  for (var i = 0; i < 100; i ++) cache.set(i, i)
  t.equal(cache.length, 100)
  for (var i = 0; i < 100; i ++) {
    t.equal(cache.get(i), i)
  }
  cache.maxLength = 3
  t.equal(cache.length, 3)
  for (var i = 0; i < 97; i ++) {
    t.equal(cache.get(i), undefined)
  }
  for (var i = 98; i < 100; i ++) {
    t.equal(cache.get(i), i)
  }

  // now remove the maxLength restriction, and try again.
  cache.maxLength = "hello"
  for (var i = 0; i < 100; i ++) cache.set(i, i)
  t.equal(cache.length, 100)
  for (var i = 0; i < 100; i ++) {
    t.equal(cache.get(i), i)
  }
  // should trigger an immediate resize
  cache.maxLength = 3
  t.equal(cache.length, 3)
  for (var i = 0; i < 97; i ++) {
    t.equal(cache.get(i), undefined)
  }
  for (var i = 98; i < 100; i ++) {
    t.equal(cache.get(i), i)
  }
  t.end()
})

test('reset', function (t) {
  var cache = new LRU(10)
  cache.set("a", "A")
  cache.set("b", "B")
  cache.reset()
  t.equal(cache.length, 0)
  t.equal(cache.maxLength, 10)
  t.equal(cache.get("a"), undefined)
  t.equal(cache.get("b"), undefined)
  t.end()
})

// Note: `<cache>.dump()` is a debugging tool only. No guarantees are made
// about the format/layout of the response.
test('dump', function (t) {
  var cache = new LRU(10)
  var d = cache.dump();
  t.equal(Object.keys(d).length, 0, "nothing in dump for empty cache")
  cache.set("a", "A")
  var d = cache.dump()  // { a: { key: 'a', value: 'A', lu: 0 } }
  t.ok(d.a)
  t.equal(d.a.key, 'a')
  t.equal(d.a.value, 'A')
  t.equal(d.a.lu, 0)

  cache.set("b", "B")
  cache.get("b")
  d = cache.dump()
  t.ok(d.b)
  t.equal(d.b.key, 'b')
  t.equal(d.b.value, 'B')
  t.equal(d.b.lu, 2)

  t.end()
})