--
-- Tests for the doclayout module
--
local doclayout = require 'doclayout'
local tasty = require 'tasty'

local group = tasty.test_group
local test = tasty.test_case
local assert = tasty.assert

-- Check existence static fields
return {
  group 'constructors' {
    test('empty', function ()
      assert.are_equal(type(doclayout.empty), 'userdata')
    end),
    test('blankline', function ()
      assert.are_equal(type(doclayout.blankline), 'userdata')
    end),
    test('cr', function ()
      assert.are_equal(type(doclayout.cr), 'userdata')
    end),
    test('space', function ()
      assert.are_equal(type(doclayout.space), 'userdata')
    end),

    group 'concat' {
      test('without sep', function ()
        local list = {
          doclayout.literal 'one',
          doclayout.literal 'two',
          doclayout.literal 'three'
        }
        local sep = doclayout.cr
        assert.are_equal(
          doclayout.concat(list, sep),
          list[1] .. sep .. list[2] .. sep .. list[3])
      end),
      test('without sep', function ()
        local list = {
          doclayout.literal 'one',
          doclayout.literal 'two',
          doclayout.literal 'three'
        }
        assert.are_equal(doclayout.concat(list), list[1] .. list[2] .. list[3])
      end),
    }
  },

  group 'render' {
    test('empty doc', function ()
      assert.are_equal(doclayout.render(doclayout.empty), '')
    end)
  },

  group 'document querying' {
    test('is_empty', function ()
      assert.is_truthy(doclayout.is_empty(doclayout.empty))
      assert.is_truthy(doclayout.is_empty(''))
      assert.is_falsy(doclayout.is_empty('non-empty'))
    end),

    test('height', function ()
      assert.are_equal(doclayout.height(doclayout.empty), 1)
      assert.are_equal(doclayout.height('line'), 1)
      assert.are_equal(doclayout.height(doclayout.literal 'p' / 'q'), 2)
      assert.are_equal(doclayout.height(doclayout.literal 'p' // 'q'), 3)
    end),

    test('min_offset', function ()
      assert.are_equal(doclayout.min_offset 'four', 4)
      assert.are_equal(
        doclayout.min_offset(doclayout.literal 'four' + 'radio'),
        5
      )
    end),

    test('offset', function ()
      assert.are_equal(doclayout.offset 'four', 4)
      assert.are_equal(doclayout.offset(doclayout.literal 'four' / 'radio'), 5)
    end),

    test('real_length', function ()
      assert.are_equal(doclayout.real_length(''), 0)
      assert.are_equal(doclayout.real_length('a'), 1)
      assert.are_equal(doclayout.real_length('❄'), 1)
      assert.are_equal(doclayout.real_length('シ'), 2)
    end),
  },

  group 'Doc type' {
    test('empty strings equal the empty Doc', function ()
      assert.are_equal(doclayout.empty .. '', doclayout.empty)
    end),

    test('strings can be used as Doc values', function ()
      assert.are_equal(doclayout.render('hello world'), 'hello world')
    end),

    test('numbers can be used as Doc values', function ()
      assert.are_equal(doclayout.render(42), '42')
    end),

    test('equality', function ()
      assert.is_truthy(doclayout.literal "true", doclayout.literal "true")
    end),

    test('concatenate docs', function ()
      assert.are_equal(
        tostring(doclayout.literal 'Rock-' .. doclayout.literal 'Ola'),
       'Rock-Ola'
      )
    end),

    test('has tostring method', function ()
      local str = 'just a literal string for now'
      assert.are_equal(tostring(str), str)
    end),

    test('adding concatenates with space', function ()
      local helloworld = doclayout.literal 'Hello,'
        .. doclayout.space
        .. doclayout.literal 'World'
      assert.are_equal(doclayout.literal 'Hello,' + 'World', helloworld)
    end),

    test('dividing sets the first above the second', function ()
           local first = doclayout.literal 'first'
           local second = doclayout.literal 'second'
           assert.are_equal(first / second, first .. doclayout.cr .. second)
    end),

    test('// separates docs with blank line', function ()
      local first = doclayout.literal 'first'
      local second = doclayout.literal 'second'
      assert.are_equal(first // second, first .. doclayout.blankline .. second)
    end),
  }
}