local timestamp = require "kong.tools.timestamp"
local luatz = require "luatz"

describe("Timestamp", function()
  local table_size = function(t)
    local s = 0
    for _ in pairs(t) do s = s + 1 end
    return s
  end

  it("should get UTC time", function()
    assert.truthy(timestamp.get_utc())
    assert.are.same(13, #tostring(timestamp.get_utc()))
  end)

  it("should get timestamps table when no timestamp is provided", function()
    local timestamps = timestamp.get_timestamps()
    assert.truthy(timestamps)
    assert.are.same(6, table_size(timestamps))

    assert.truthy(timestamps.second)
    assert.truthy(timestamps.minute)
    assert.truthy(timestamps.hour)
    assert.truthy(timestamps.day)
    assert.truthy(timestamps.month)
    assert.truthy(timestamps.year)
  end)

  it("should get timestamps table when the timestamp is provided", function()
    local timestamps = timestamp.get_timestamps(timestamp.get_utc())
    assert.truthy(timestamps)
    assert.are.same(6, table_size(timestamps))

    assert.truthy(timestamps.second)
    assert.truthy(timestamps.minute)
    assert.truthy(timestamps.hour)
    assert.truthy(timestamps.day)
    assert.truthy(timestamps.month)
    assert.truthy(timestamps.year)
  end)

  it("should give the same timestamps table for the same time", function()
    -- Wait til the beginning of a new second before starting the test
    -- to avoid ending up in an edge case when the second is about to end
    local now = os.time()
    while os.time() < now + 1 do
      -- Nothing
    end

    local timestamps_one = timestamp.get_timestamps()
    local timestamps_two = timestamp.get_timestamps(timestamp.get_utc())
    assert.truthy(timestamps_one)
    assert.truthy(timestamps_two)
    assert.are.same(6, table_size(timestamps_one))
    assert.are.same(6, table_size(timestamps_two))
    assert.are.same(timestamps_one, timestamps_two)
  end)

  it("should provide correct timestamp values", function()
    for i = 1, 2 do
      local factor
      if i == 1 then
        factor = 1  -- use base time in seconds
      else
        factor = 1000 -- use base time in milliseconds
      end
      local base = luatz.timetable.new(2016, 10, 10, 10, 10, 10):timestamp()
      local ts = timestamp.get_timestamps(base * factor)
      -- timestamps are always in milliseconds
      assert.equal(base * 1000, ts.second)
      base = base - 10
      assert.equal(base * 1000, ts.minute)
      base = base - 10 * 60
      assert.equal(base * 1000, ts.hour)
      base = base - 10 * 60 * 60
      assert.equal(base * 1000, ts.day)
      base = base - 9 * 60 * 60 * 24
      assert.equal(base * 1000, ts.month)
      base = base - (31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30) * 60 * 60 * 24
      assert.equal(base * 1000, ts.year)
    end
  end)

end)