// Copyright 2014 The Cayley Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package iterator_test

import (
	"errors"
	"testing"

	"github.com/cayleygraph/cayley/graph"
	"github.com/cayleygraph/cayley/graph/graphmock"
	. "github.com/cayleygraph/cayley/graph/iterator"
)

// Make sure that tags work on the And.
func TestTag(t *testing.T) {
	qs := &graphmock.Oldstore{
		Data: []string{},
		Iter: NewFixed(Identity),
	}
	fix1 := NewFixed(Identity, Int64Node(234))
	fix1.Tagger().Add("foo")
	and := NewAnd(qs, fix1)
	and.Tagger().Add("bar")
	out := fix1.Tagger().Tags()
	if len(out) != 1 {
		t.Errorf("Expected length 1, got %d", len(out))
	}
	if out[0] != "foo" {
		t.Errorf("Cannot get tag back, got %s", out[0])
	}

	if !and.Next() {
		t.Errorf("And did not next")
	}
	val := and.Result()
	if val.(Int64Node) != 234 {
		t.Errorf("Unexpected value")
	}
	tags := make(map[string]graph.Value)
	and.TagResults(tags)
	if tags["bar"].(Int64Node) != 234 {
		t.Errorf("no bar tag")
	}
	if tags["foo"].(Int64Node) != 234 {
		t.Errorf("no foo tag")
	}
}

// Do a simple itersection of fixed values.
func TestAndAndFixedIterators(t *testing.T) {
	qs := &graphmock.Oldstore{
		Data: []string{},
		Iter: NewFixed(Identity),
	}
	fix1 := NewFixed(Identity,
		Int64Node(1),
		Int64Node(2),
		Int64Node(3),
		Int64Node(4),
	)
	fix2 := NewFixed(Identity,
		Int64Node(3),
		Int64Node(4),
		Int64Node(5),
	)
	and := NewAnd(qs, fix1, fix2)
	// Should be as big as smallest subiterator
	size, accurate := and.Size()
	if size != 3 {
		t.Error("Incorrect size")
	}
	if !accurate {
		t.Error("not accurate")
	}

	if !and.Next() || and.Result().(Int64Node) != 3 {
		t.Error("Incorrect first value")
	}

	if !and.Next() || and.Result().(Int64Node) != 4 {
		t.Error("Incorrect second value")
	}

	if and.Next() {
		t.Error("Too many values")
	}

}

// If there's no intersection, the size should still report the same,
// but there should be nothing to Next()
func TestNonOverlappingFixedIterators(t *testing.T) {
	qs := &graphmock.Oldstore{
		Data: []string{},
		Iter: NewFixed(Identity),
	}
	fix1 := NewFixed(Identity,
		Int64Node(1),
		Int64Node(2),
		Int64Node(3),
		Int64Node(4),
	)
	fix2 := NewFixed(Identity,
		Int64Node(5),
		Int64Node(6),
		Int64Node(7),
	)
	and := NewAnd(qs, fix1, fix2)
	// Should be as big as smallest subiterator
	size, accurate := and.Size()
	if size != 3 {
		t.Error("Incorrect size")
	}
	if !accurate {
		t.Error("not accurate")
	}

	if and.Next() {
		t.Error("Too many values")
	}

}

func TestAllIterators(t *testing.T) {
	qs := &graphmock.Oldstore{
		Data: []string{},
		Iter: NewFixed(Identity),
	}
	all1 := NewInt64(1, 5, true)
	all2 := NewInt64(4, 10, true)
	and := NewAnd(qs, all2, all1)

	if !and.Next() || and.Result().(Int64Node) != Int64Node(4) {
		t.Error("Incorrect first value")
	}

	if !and.Next() || and.Result().(Int64Node) != Int64Node(5) {
		t.Error("Incorrect second value")
	}

	if and.Next() {
		t.Error("Too many values")
	}
}

func TestAndIteratorErr(t *testing.T) {
	qs := &graphmock.Oldstore{
		Data: []string{},
		Iter: NewFixed(Identity),
	}
	wantErr := errors.New("unique")
	allErr := newTestIterator(false, wantErr)

	and := NewAnd(qs,
		allErr,
		NewInt64(1, 5, true),
	)

	if and.Next() != false {
		t.Errorf("And iterator did not pass through initial 'false'")
	}
	if and.Err() != wantErr {
		t.Errorf("And iterator did not pass through underlying Err")
	}
}