// Copyright 2015 The Hugo 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 hugolib

import (
	"fmt"
	"path/filepath"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
)

func TestDefaultSort(t *testing.T) {
	t.Parallel()
	d1 := time.Now()
	d2 := d1.Add(-1 * time.Hour)
	d3 := d1.Add(-2 * time.Hour)
	d4 := d1.Add(-3 * time.Hour)

	s := newTestSite(t)

	p := createSortTestPages(s, 4)

	// first by weight
	setSortVals([4]time.Time{d1, d2, d3, d4}, [4]string{"b", "a", "c", "d"}, [4]int{4, 3, 2, 1}, p)
	p.Sort()

	assert.Equal(t, 1, p[0].Weight)

	// Consider zero weight, issue #2673
	setSortVals([4]time.Time{d1, d2, d3, d4}, [4]string{"b", "a", "d", "c"}, [4]int{0, 0, 0, 1}, p)
	p.Sort()

	assert.Equal(t, 1, p[0].Weight)

	// next by date
	setSortVals([4]time.Time{d3, d4, d1, d2}, [4]string{"a", "b", "c", "d"}, [4]int{1, 1, 1, 1}, p)
	p.Sort()
	assert.Equal(t, d1, p[0].Date)

	// finally by link title
	setSortVals([4]time.Time{d3, d3, d3, d3}, [4]string{"b", "c", "a", "d"}, [4]int{1, 1, 1, 1}, p)
	p.Sort()
	assert.Equal(t, "al", p[0].LinkTitle())
	assert.Equal(t, "bl", p[1].LinkTitle())
	assert.Equal(t, "cl", p[2].LinkTitle())
}

func TestSortByN(t *testing.T) {
	t.Parallel()
	s := newTestSite(t)
	d1 := time.Now()
	d2 := d1.Add(-2 * time.Hour)
	d3 := d1.Add(-10 * time.Hour)
	d4 := d1.Add(-20 * time.Hour)

	p := createSortTestPages(s, 4)

	for i, this := range []struct {
		sortFunc   func(p Pages) Pages
		assertFunc func(p Pages) bool
	}{
		{(Pages).ByWeight, func(p Pages) bool { return p[0].Weight == 1 }},
		{(Pages).ByTitle, func(p Pages) bool { return p[0].title == "ab" }},
		{(Pages).ByLinkTitle, func(p Pages) bool { return p[0].LinkTitle() == "abl" }},
		{(Pages).ByDate, func(p Pages) bool { return p[0].Date == d4 }},
		{(Pages).ByPublishDate, func(p Pages) bool { return p[0].PublishDate == d4 }},
		{(Pages).ByExpiryDate, func(p Pages) bool { return p[0].ExpiryDate == d4 }},
		{(Pages).ByLastmod, func(p Pages) bool { return p[1].Lastmod == d3 }},
		{(Pages).ByLength, func(p Pages) bool { return p[0].content() == "b_content" }},
	} {
		setSortVals([4]time.Time{d1, d2, d3, d4}, [4]string{"b", "ab", "cde", "fg"}, [4]int{0, 3, 2, 1}, p)

		sorted := this.sortFunc(p)
		if !this.assertFunc(sorted) {
			t.Errorf("[%d] sort error", i)
		}
	}

}

func TestLimit(t *testing.T) {
	t.Parallel()
	s := newTestSite(t)
	p := createSortTestPages(s, 10)
	firstFive := p.Limit(5)
	assert.Equal(t, 5, len(firstFive))
	for i := 0; i < 5; i++ {
		assert.Equal(t, p[i], firstFive[i])
	}
	assert.Equal(t, p, p.Limit(10))
	assert.Equal(t, p, p.Limit(11))
}

func TestPageSortReverse(t *testing.T) {
	t.Parallel()
	s := newTestSite(t)
	p1 := createSortTestPages(s, 10)
	assert.Equal(t, 0, p1[0].fuzzyWordCount)
	assert.Equal(t, 9, p1[9].fuzzyWordCount)
	p2 := p1.Reverse()
	assert.Equal(t, 9, p2[0].fuzzyWordCount)
	assert.Equal(t, 0, p2[9].fuzzyWordCount)
	// cached
	assert.True(t, fastEqualPages(p2, p1.Reverse()))
}

func TestPageSortByParam(t *testing.T) {
	t.Parallel()
	var k interface{} = "arbitrarily.nested"
	s := newTestSite(t)

	unsorted := createSortTestPages(s, 10)
	delete(unsorted[9].params, "arbitrarily")

	firstSetValue, _ := unsorted[0].Param(k)
	secondSetValue, _ := unsorted[1].Param(k)
	lastSetValue, _ := unsorted[8].Param(k)
	unsetValue, _ := unsorted[9].Param(k)

	assert.Equal(t, "xyz100", firstSetValue)
	assert.Equal(t, "xyz99", secondSetValue)
	assert.Equal(t, "xyz92", lastSetValue)
	assert.Equal(t, nil, unsetValue)

	sorted := unsorted.ByParam("arbitrarily.nested")
	firstSetSortedValue, _ := sorted[0].Param(k)
	secondSetSortedValue, _ := sorted[1].Param(k)
	lastSetSortedValue, _ := sorted[8].Param(k)
	unsetSortedValue, _ := sorted[9].Param(k)

	assert.Equal(t, firstSetValue, firstSetSortedValue)
	assert.Equal(t, secondSetValue, lastSetSortedValue)
	assert.Equal(t, lastSetValue, secondSetSortedValue)
	assert.Equal(t, unsetValue, unsetSortedValue)
}

func BenchmarkSortByWeightAndReverse(b *testing.B) {
	s := newTestSite(b)
	p := createSortTestPages(s, 300)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		p = p.ByWeight().Reverse()
	}
}

func setSortVals(dates [4]time.Time, titles [4]string, weights [4]int, pages Pages) {
	for i := range dates {
		pages[i].Date = dates[i]
		pages[i].Lastmod = dates[i]
		pages[i].Weight = weights[i]
		pages[i].title = titles[i]
		// make sure we compare apples and ... apples ...
		pages[len(dates)-1-i].linkTitle = pages[i].title + "l"
		pages[len(dates)-1-i].PublishDate = dates[i]
		pages[len(dates)-1-i].ExpiryDate = dates[i]
		pages[len(dates)-1-i].workContent = []byte(titles[i] + "_content")
	}
	lastLastMod := pages[2].Lastmod
	pages[2].Lastmod = pages[1].Lastmod
	pages[1].Lastmod = lastLastMod

	for _, p := range pages {
		p.resetContent()
	}

}

func createSortTestPages(s *Site, num int) Pages {
	pages := make(Pages, num)

	for i := 0; i < num; i++ {
		p := s.newPage(filepath.FromSlash(fmt.Sprintf("/x/y/p%d.md", i)))
		p.params = map[string]interface{}{
			"arbitrarily": map[string]interface{}{
				"nested": ("xyz" + fmt.Sprintf("%v", 100-i)),
			},
		}

		w := 5

		if i%2 == 0 {
			w = 10
		}
		p.fuzzyWordCount = i
		p.Weight = w
		p.Description = "initial"

		pages[i] = p
	}

	return pages
}