package files

import (
	"fmt"
	"reflect"
	"sort"
	"testing"

	"github.com/calmh/syncthing/cid"
	"github.com/calmh/syncthing/lamport"
	"github.com/calmh/syncthing/protocol"
	"github.com/calmh/syncthing/scanner"
)

type fileList []scanner.File

func (l fileList) Len() int {
	return len(l)
}

func (l fileList) Less(a, b int) bool {
	return l[a].Name < l[b].Name
}

func (l fileList) Swap(a, b int) {
	l[a], l[b] = l[b], l[a]
}

func TestGlobalSet(t *testing.T) {
	m := NewSet()

	local := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1000},
		scanner.File{Name: "c", Version: 1000},
		scanner.File{Name: "d", Version: 1000},
	}

	remote := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1001},
		scanner.File{Name: "c", Version: 1002},
		scanner.File{Name: "e", Version: 1000},
	}

	expectedGlobal := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1001},
		scanner.File{Name: "c", Version: 1002},
		scanner.File{Name: "d", Version: 1000},
		scanner.File{Name: "e", Version: 1000},
	}

	m.ReplaceWithDelete(cid.LocalID, local)
	m.Replace(1, remote)

	g := m.Global()

	sort.Sort(fileList(g))
	sort.Sort(fileList(expectedGlobal))

	if !reflect.DeepEqual(g, expectedGlobal) {
		t.Errorf("Global incorrect;\n A: %v !=\n E: %v", g, expectedGlobal)
	}

	if lb := len(m.files); lb != 7 {
		t.Errorf("Num files incorrect %d != 7\n%v", lb, m.files)
	}
}

func TestLocalDeleted(t *testing.T) {
	m := NewSet()
	lamport.Default = lamport.Clock{}

	local1 := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1000},
		scanner.File{Name: "c", Version: 1000},
		scanner.File{Name: "d", Version: 1000},
	}

	m.ReplaceWithDelete(cid.LocalID, local1)

	local2 := []scanner.File{
		local1[0],
		local1[2],
	}

	expectedGlobal1 := []scanner.File{
		local1[0],
		scanner.File{Name: "b", Version: 1001, Flags: protocol.FlagDeleted},
		local1[2],
		scanner.File{Name: "d", Version: 1002, Flags: protocol.FlagDeleted},
	}

	m.ReplaceWithDelete(cid.LocalID, local2)
	g := m.Global()
	sort.Sort(fileList(g))
	sort.Sort(fileList(expectedGlobal1))

	if !reflect.DeepEqual(g, expectedGlobal1) {
		t.Errorf("Global incorrect;\n A: %v !=\n E: %v", g, expectedGlobal1)
	}

	local3 := []scanner.File{
		local1[0],
	}

	expectedGlobal2 := []scanner.File{
		local1[0],
		scanner.File{Name: "b", Version: 1001, Flags: protocol.FlagDeleted},
		scanner.File{Name: "c", Version: 1003, Flags: protocol.FlagDeleted},
		scanner.File{Name: "d", Version: 1002, Flags: protocol.FlagDeleted},
	}

	m.ReplaceWithDelete(cid.LocalID, local3)
	g = m.Global()
	sort.Sort(fileList(g))
	sort.Sort(fileList(expectedGlobal2))

	if !reflect.DeepEqual(g, expectedGlobal2) {
		t.Errorf("Global incorrect;\n A: %v !=\n E: %v", g, expectedGlobal2)
	}
}

func BenchmarkSetLocal10k(b *testing.B) {
	m := NewSet()

	var local []scanner.File
	for i := 0; i < 10000; i++ {
		local = append(local, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	var remote []scanner.File
	for i := 0; i < 10000; i++ {
		remote = append(remote, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	m.Replace(1, remote)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		m.ReplaceWithDelete(cid.LocalID, local)
	}
}

func BenchmarkSetLocal10(b *testing.B) {
	m := NewSet()

	var local []scanner.File
	for i := 0; i < 10; i++ {
		local = append(local, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	var remote []scanner.File
	for i := 0; i < 10000; i++ {
		remote = append(remote, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	m.Replace(1, remote)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		m.ReplaceWithDelete(cid.LocalID, local)
	}
}

func BenchmarkAddLocal10k(b *testing.B) {
	m := NewSet()

	var local []scanner.File
	for i := 0; i < 10000; i++ {
		local = append(local, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	var remote []scanner.File
	for i := 0; i < 10000; i++ {
		remote = append(remote, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	m.Replace(1, remote)
	m.ReplaceWithDelete(cid.LocalID, local)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		b.StopTimer()
		for j := range local {
			local[j].Version++
		}
		b.StartTimer()
		m.Update(cid.LocalID, local)
	}
}

func BenchmarkAddLocal10(b *testing.B) {
	m := NewSet()

	var local []scanner.File
	for i := 0; i < 10; i++ {
		local = append(local, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	var remote []scanner.File
	for i := 0; i < 10000; i++ {
		remote = append(remote, scanner.File{Name: fmt.Sprintf("file%d"), Version: 1000})
	}

	m.Replace(1, remote)
	m.ReplaceWithDelete(cid.LocalID, local)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		for j := range local {
			local[j].Version++
		}
		m.Update(cid.LocalID, local)
	}
}

func TestGlobalReset(t *testing.T) {
	m := NewSet()

	local := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1000},
		scanner.File{Name: "c", Version: 1000},
		scanner.File{Name: "d", Version: 1000},
	}

	remote := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1001},
		scanner.File{Name: "c", Version: 1002},
		scanner.File{Name: "e", Version: 1000},
	}

	expectedGlobalKey := map[string]key{
		"a": keyFor(local[0]),
		"b": keyFor(local[1]),
		"c": keyFor(local[2]),
		"d": keyFor(local[3]),
	}

	m.ReplaceWithDelete(cid.LocalID, local)
	m.Replace(1, remote)
	m.Replace(1, nil)

	if !reflect.DeepEqual(m.globalKey, expectedGlobalKey) {
		t.Errorf("Global incorrect;\n%v !=\n%v", m.globalKey, expectedGlobalKey)
	}

	if lb := len(m.files); lb != 4 {
		t.Errorf("Num files incorrect %d != 4\n%v", lb, m.files)
	}
}

func TestNeed(t *testing.T) {
	m := NewSet()

	local := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1000},
		scanner.File{Name: "c", Version: 1000},
		scanner.File{Name: "d", Version: 1000},
	}

	remote := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1001},
		scanner.File{Name: "c", Version: 1002},
		scanner.File{Name: "e", Version: 1000},
	}

	shouldNeed := []scanner.File{
		scanner.File{Name: "b", Version: 1001},
		scanner.File{Name: "c", Version: 1002},
		scanner.File{Name: "e", Version: 1000},
	}

	m.ReplaceWithDelete(cid.LocalID, local)
	m.Replace(1, remote)

	need := m.Need(0)
	if !reflect.DeepEqual(need, shouldNeed) {
		t.Errorf("Need incorrect;\n%v !=\n%v", need, shouldNeed)
	}
}

func TestChanges(t *testing.T) {
	m := NewSet()

	local1 := []scanner.File{
		scanner.File{Name: "a", Version: 1000},
		scanner.File{Name: "b", Version: 1000},
		scanner.File{Name: "c", Version: 1000},
		scanner.File{Name: "d", Version: 1000},
	}

	local2 := []scanner.File{
		local1[0],
		// [1] deleted
		local1[2],
		scanner.File{Name: "d", Version: 1002},
		scanner.File{Name: "e", Version: 1000},
	}

	m.ReplaceWithDelete(cid.LocalID, local1)
	c0 := m.Changes(cid.LocalID)

	m.ReplaceWithDelete(cid.LocalID, local2)
	c1 := m.Changes(cid.LocalID)
	if !(c1 > c0) {
		t.Fatal("Change number should have incremented")
	}

	m.ReplaceWithDelete(cid.LocalID, local2)
	c2 := m.Changes(cid.LocalID)
	if c2 != c1 {
		t.Fatal("Change number should be unchanged")
	}
}