# frozen_string_literal: true

# Copyright (c) 2024 Yegor Bugayenko
#
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# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
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#
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# SOFTWARE.

require 'minitest/autorun'
require_relative '../../lib/factbase/term'
require_relative '../../lib/factbase/syntax'

# Term test.
# Author:: Yegor Bugayenko (yegor256@gmail.com)
# Copyright:: Copyright (c) 2024 Yegor Bugayenko
# License:: MIT
class TestTerm < Minitest::Test
  def test_simple_matching
    t = Factbase::Term.new(:eq, [:foo, 42])
    assert(t.evaluate(fact('foo' => [42]), []))
    assert(!t.evaluate(fact('foo' => 'Hello!'), []))
    assert(!t.evaluate(fact('bar' => ['Hello!']), []))
  end

  def test_eq_matching
    t = Factbase::Term.new(:eq, [:foo, 42])
    assert(t.evaluate(fact('foo' => 42), []))
    assert(t.evaluate(fact('foo' => [10, 5, 6, -8, 'hey', 42, 9, 'fdsf']), []))
    assert(!t.evaluate(fact('foo' => [100]), []))
    assert(!t.evaluate(fact('foo' => []), []))
    assert(!t.evaluate(fact('bar' => []), []))
  end

  def test_eq_matching_time
    now = Time.now
    t = Factbase::Term.new(:eq, [:foo, Time.parse(now.iso8601)])
    assert(t.evaluate(fact('foo' => now), []))
    assert(t.evaluate(fact('foo' => [now, Time.now]), []))
  end

  def test_lt_matching
    t = Factbase::Term.new(:lt, [:foo, 42])
    assert(t.evaluate(fact('foo' => [10]), []))
    assert(!t.evaluate(fact('foo' => [100]), []))
    assert(!t.evaluate(fact('foo' => 100), []))
    assert(!t.evaluate(fact('bar' => 100), []))
  end

  def test_gt_matching
    t = Factbase::Term.new(:gt, [:foo, 42])
    assert(t.evaluate(fact('foo' => [100]), []))
    assert(t.evaluate(fact('foo' => 100), []))
    assert(!t.evaluate(fact('foo' => [10]), []))
    assert(!t.evaluate(fact('foo' => 10), []))
    assert(!t.evaluate(fact('bar' => 10), []))
  end

  def test_lt_matching_time
    t = Factbase::Term.new(:lt, [:foo, Time.now])
    assert(t.evaluate(fact('foo' => [Time.now - 100]), []))
    assert(!t.evaluate(fact('foo' => [Time.now + 100]), []))
    assert(!t.evaluate(fact('bar' => [100]), []))
  end

  def test_gt_matching_time
    t = Factbase::Term.new(:gt, [:foo, Time.now])
    assert(t.evaluate(fact('foo' => [Time.now + 100]), []))
    assert(!t.evaluate(fact('foo' => [Time.now - 100]), []))
    assert(!t.evaluate(fact('bar' => [100]), []))
  end

  def test_false_matching
    t = Factbase::Term.new(:never, [])
    assert(!t.evaluate(fact('foo' => [100]), []))
  end

  def test_not_matching
    t = Factbase::Term.new(:not, [Factbase::Term.new(:always, [])])
    assert(!t.evaluate(fact('foo' => [100]), []))
  end

  def test_not_eq_matching
    t = Factbase::Term.new(:not, [Factbase::Term.new(:eq, [:foo, 100])])
    assert(t.evaluate(fact('foo' => [42, 12, -90]), []))
    assert(!t.evaluate(fact('foo' => 100), []))
  end

  def test_size_matching
    t = Factbase::Term.new(:size, [:foo])
    assert_equal(3, t.evaluate(fact('foo' => [42, 12, -90]), []))
    assert_equal(0, t.evaluate(fact('bar' => 100), []))
  end

  def test_exists_matching
    t = Factbase::Term.new(:exists, [:foo])
    assert(t.evaluate(fact('foo' => [42, 12, -90]), []))
    assert(!t.evaluate(fact('bar' => 100), []))
  end

  def test_absent_matching
    t = Factbase::Term.new(:absent, [:foo])
    assert(t.evaluate(fact('z' => [42, 12, -90]), []))
    assert(!t.evaluate(fact('foo' => 100), []))
  end

  def test_type_matching
    t = Factbase::Term.new(:type, [:foo])
    assert_equal('Integer', t.evaluate(fact('foo' => 42), []))
    assert_equal('Integer', t.evaluate(fact('foo' => [42]), []))
    assert_equal('Array', t.evaluate(fact('foo' => [1, 2, 3]), []))
    assert_equal('String', t.evaluate(fact('foo' => 'Hello, world!'), []))
    assert_equal('Float', t.evaluate(fact('foo' => 3.14), []))
    assert_equal('Time', t.evaluate(fact('foo' => Time.now), []))
    assert_equal('nil', t.evaluate(fact, []))
  end

  def test_regexp_matching
    t = Factbase::Term.new(:matches, [:foo, '[a-z]+'])
    assert(t.evaluate(fact('foo' => 'hello'), []))
    assert(t.evaluate(fact('foo' => 'hello 42'), []))
    assert(!t.evaluate(fact('foo' => 42), []))
  end

  def test_or_matching
    t = Factbase::Term.new(
      :or,
      [
        Factbase::Term.new(:eq, [:foo, 4]),
        Factbase::Term.new(:eq, [:bar, 5])
      ]
    )
    assert(t.evaluate(fact('foo' => [4]), []))
    assert(t.evaluate(fact('bar' => [5]), []))
    assert(!t.evaluate(fact('bar' => [42]), []))
  end

  def test_when_matching
    t = Factbase::Term.new(
      :when,
      [
        Factbase::Term.new(:eq, [:foo, 4]),
        Factbase::Term.new(:eq, [:bar, 5])
      ]
    )
    assert(t.evaluate(fact('foo' => 4, 'bar' => 5), []))
    assert(!t.evaluate(fact('foo' => 4), []))
    assert(t.evaluate(fact('foo' => 5, 'bar' => 5), []))
  end

  def test_defn_simple
    t = Factbase::Term.new(:defn, [:foo, 'self.to_s'])
    assert_equal(true, t.evaluate(fact('foo' => 4), []))
    t1 = Factbase::Term.new(:foo, ['hello, world!'])
    assert_equal('(foo \'hello, world!\')', t1.evaluate(fact, []))
  end

  def test_defn_again_by_mistake
    t = Factbase::Term.new(:defn, [:and, 'self.to_s'])
    assert_raises do
      t.evaluate(fact, [])
    end
  end

  def test_defn_bad_name_by_mistake
    t = Factbase::Term.new(:defn, [:to_s, 'self.to_s'])
    assert_raises do
      t.evaluate(fact, [])
    end
  end

  def test_defn_bad_name_spelling_by_mistake
    t = Factbase::Term.new(:defn, [:'some-key', 'self.to_s'])
    assert_raises do
      t.evaluate(fact, [])
    end
  end

  def test_undef_simple
    t = Factbase::Term.new(:defn, [:hello, 'self.to_s'])
    assert_equal(true, t.evaluate(fact, []))
    t = Factbase::Term.new(:undef, [:hello])
    assert_equal(true, t.evaluate(fact, []))
  end

  def test_past
    t = Factbase::Term.new(:prev, [:foo])
    assert_nil(t.evaluate(fact('foo' => 4), []))
    assert_equal([4], t.evaluate(fact('foo' => 5), []))
  end

  def test_at
    t = Factbase::Term.new(:at, [1, :foo])
    assert_nil(t.evaluate(fact('foo' => 4), []))
    assert_equal(5, t.evaluate(fact('foo' => [4, 5]), []))
  end

  def test_either
    t = Factbase::Term.new(:either, [Factbase::Term.new(:at, [5, :foo]), 42])
    assert_equal([42], t.evaluate(fact('foo' => 4), []))
  end

  def test_report_missing_term
    t = Factbase::Term.new(:something, [])
    msg = assert_raises do
      t.evaluate(fact, [])
    end.message
    assert(msg.include?('not defined at (something)'), msg)
  end

  def test_report_other_error
    t = Factbase::Term.new(:at, [])
    msg = assert_raises do
      t.evaluate(fact, [])
    end.message
    assert(msg.include?('at (at)'), msg)
  end

  def test_aggregation
    maps = [
      { 'x' => 1, 'y' => 0, 'z' => 4 },
      { 'x' => 2, 'y' => 42, 'z' => 3 },
      { 'x' => 3, 'y' => 42, 'z' => 5 },
      { 'x' => 4, 'y' => 42, 'z' => 2 },
      { 'x' => 5, 'y' => 42, 'z' => 1 },
      { 'x' => 8, 'y' => 0, 'z' => 6 }
    ]
    {
      '(eq x (agg (eq y 42) (min x)))' => '(eq x 2)',
      '(eq z (agg (eq y 0) (max z)))' => '(eq x 8)',
      '(eq x (agg (and (eq y 42) (gt z 1)) (max x)))' => '(eq x 4)',
      '(and (eq x (agg (eq y 42) (min x))) (eq z 3))' => '(eq x 2)'
    }.each do |q, r|
      t = Factbase::Syntax.new(q).to_term
      f = maps.find { |m| t.evaluate(fact(m), maps) }
      assert(Factbase::Syntax.new(r).to_term.evaluate(fact(f), []))
    end
  end

  private

  def fact(map = {})
    Factbase::Fact.new(Mutex.new, map)
  end
end