require('spec.helpers')

describe('recur', function()
  local recur = require('pending.recur')

  describe('parse', function()
    it('parses daily', function()
      local r = recur.parse('daily')
      assert.are.equal('daily', r.freq)
      assert.are.equal(1, r.interval)
      assert.is_false(r.from_completion)
    end)

    it('parses weekdays', function()
      local r = recur.parse('weekdays')
      assert.are.equal('weekly', r.freq)
      assert.are.same({ 'MO', 'TU', 'WE', 'TH', 'FR' }, r.byday)
    end)

    it('parses weekly', function()
      local r = recur.parse('weekly')
      assert.are.equal('weekly', r.freq)
      assert.are.equal(1, r.interval)
    end)

    it('parses biweekly', function()
      local r = recur.parse('biweekly')
      assert.are.equal('weekly', r.freq)
      assert.are.equal(2, r.interval)
    end)

    it('parses monthly', function()
      local r = recur.parse('monthly')
      assert.are.equal('monthly', r.freq)
      assert.are.equal(1, r.interval)
    end)

    it('parses quarterly', function()
      local r = recur.parse('quarterly')
      assert.are.equal('monthly', r.freq)
      assert.are.equal(3, r.interval)
    end)

    it('parses yearly', function()
      local r = recur.parse('yearly')
      assert.are.equal('yearly', r.freq)
      assert.are.equal(1, r.interval)
    end)

    it('parses annual as yearly', function()
      local r = recur.parse('annual')
      assert.are.equal('yearly', r.freq)
    end)

    it('parses 3d as every 3 days', function()
      local r = recur.parse('3d')
      assert.are.equal('daily', r.freq)
      assert.are.equal(3, r.interval)
    end)

    it('parses 2w as biweekly', function()
      local r = recur.parse('2w')
      assert.are.equal('weekly', r.freq)
      assert.are.equal(2, r.interval)
    end)

    it('parses 6m as every 6 months', function()
      local r = recur.parse('6m')
      assert.are.equal('monthly', r.freq)
      assert.are.equal(6, r.interval)
    end)

    it('parses 2y as every 2 years', function()
      local r = recur.parse('2y')
      assert.are.equal('yearly', r.freq)
      assert.are.equal(2, r.interval)
    end)

    it('parses ! prefix as completion-based', function()
      local r = recur.parse('!weekly')
      assert.are.equal('weekly', r.freq)
      assert.is_true(r.from_completion)
    end)

    it('parses raw RRULE fragment', function()
      local r = recur.parse('FREQ=MONTHLY;BYDAY=1MO')
      assert.is_not_nil(r)
    end)

    it('returns nil for invalid input', function()
      assert.is_nil(recur.parse(''))
      assert.is_nil(recur.parse('garbage'))
      assert.is_nil(recur.parse('0d'))
    end)

    it('is case insensitive', function()
      local r = recur.parse('Weekly')
      assert.are.equal('weekly', r.freq)
    end)
  end)

  describe('validate', function()
    it('returns true for valid specs', function()
      assert.is_true(recur.validate('daily'))
      assert.is_true(recur.validate('2w'))
      assert.is_true(recur.validate('!monthly'))
    end)

    it('returns false for invalid specs', function()
      assert.is_false(recur.validate('garbage'))
      assert.is_false(recur.validate(''))
    end)
  end)

  describe('next_due', function()
    it('advances daily by 1 day', function()
      local result = recur.next_due('2099-03-01', 'daily', 'scheduled')
      assert.are.equal('2099-03-02', result)
    end)

    it('advances weekly by 7 days', function()
      local result = recur.next_due('2099-03-01', 'weekly', 'scheduled')
      assert.are.equal('2099-03-08', result)
    end)

    it('advances monthly and clamps day', function()
      local result = recur.next_due('2099-01-31', 'monthly', 'scheduled')
      assert.are.equal('2099-02-28', result)
    end)

    it('advances yearly and handles leap year', function()
      local result = recur.next_due('2096-02-29', 'yearly', 'scheduled')
      assert.are.equal('2097-02-28', result)
    end)

    it('advances biweekly by 14 days', function()
      local result = recur.next_due('2099-03-01', 'biweekly', 'scheduled')
      assert.are.equal('2099-03-15', result)
    end)

    it('advances quarterly by 3 months', function()
      local result = recur.next_due('2099-01-15', 'quarterly', 'scheduled')
      assert.are.equal('2099-04-15', result)
    end)

    it('scheduled mode skips to future if overdue', function()
      local result = recur.next_due('2020-01-01', 'yearly', 'scheduled')
      local today = os.date('%Y-%m-%d') --[[@as string]]
      assert.is_true(result > today)
    end)

    it('completion mode advances from today', function()
      local today = os.date('*t') --[[@as osdate]]
      local expected = os.date(
        '%Y-%m-%d',
        os.time({
          year = today.year,
          month = today.month,
          day = today.day + 7,
        })
      )
      local result = recur.next_due('2020-01-01', 'weekly', 'completion')
      assert.are.equal(expected, result)
    end)

    it('advances 3d by 3 days', function()
      local result = recur.next_due('2099-06-10', '3d', 'scheduled')
      assert.are.equal('2099-06-13', result)
    end)
  end)

  describe('to_rrule', function()
    it('converts daily', function()
      assert.are.equal('RRULE:FREQ=DAILY', recur.to_rrule('daily'))
    end)

    it('converts weekly', function()
      assert.are.equal('RRULE:FREQ=WEEKLY', recur.to_rrule('weekly'))
    end)

    it('converts biweekly with interval', function()
      assert.are.equal('RRULE:FREQ=WEEKLY;INTERVAL=2', recur.to_rrule('biweekly'))
    end)

    it('converts weekdays with BYDAY', function()
      assert.are.equal('RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR', recur.to_rrule('weekdays'))
    end)

    it('converts monthly', function()
      assert.are.equal('RRULE:FREQ=MONTHLY', recur.to_rrule('monthly'))
    end)

    it('converts quarterly with interval', function()
      assert.are.equal('RRULE:FREQ=MONTHLY;INTERVAL=3', recur.to_rrule('quarterly'))
    end)

    it('converts yearly', function()
      assert.are.equal('RRULE:FREQ=YEARLY', recur.to_rrule('yearly'))
    end)

    it('converts 2w with interval', function()
      assert.are.equal('RRULE:FREQ=WEEKLY;INTERVAL=2', recur.to_rrule('2w'))
    end)

    it('prefixes raw RRULE fragment', function()
      assert.are.equal('RRULE:FREQ=MONTHLY;BYDAY=1MO', recur.to_rrule('FREQ=MONTHLY;BYDAY=1MO'))
    end)

    it('returns empty string for invalid spec', function()
      assert.are.equal('', recur.to_rrule('garbage'))
    end)
  end)

  describe('shorthand_list', function()
    it('returns a list of named shorthands', function()
      local list = recur.shorthand_list()
      assert.is_true(#list >= 8)
      assert.is_true(vim.tbl_contains(list, 'daily'))
      assert.is_true(vim.tbl_contains(list, 'weekly'))
      assert.is_true(vim.tbl_contains(list, 'monthly'))
    end)
  end)
end)