//  Copyright (c) 2014 Couchbase, Inc.
//  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 numeric_util

import (
	"reflect"
	"testing"
)

// these array encoding values have been verified manually
// against the lucene implementation
func TestPrefixCoded(t *testing.T) {
	tests := []struct {
		input  int64
		shift  uint
		output PrefixCoded
	}{
		{
			input:  1,
			shift:  0,
			output: PrefixCoded{0x20, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1},
		},
		{
			input:  -1,
			shift:  0,
			output: PrefixCoded{0x20, 0x0, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
		},
		{
			input:  -94582,
			shift:  0,
			output: PrefixCoded{0x20, 0x0, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7a, 0x1d, 0xa},
		},
		{
			input:  314729851,
			shift:  0,
			output: PrefixCoded{0x20, 0x1, 0x0, 0x0, 0x0, 0x0, 0x1, 0x16, 0x9, 0x4a, 0x7b},
		},
		{
			input:  314729851,
			shift:  4,
			output: PrefixCoded{0x24, 0x8, 0x0, 0x0, 0x0, 0x0, 0x9, 0x30, 0x4c, 0x57},
		},
		{
			input:  314729851,
			shift:  8,
			output: PrefixCoded{0x28, 0x40, 0x0, 0x0, 0x0, 0x0, 0x4b, 0x4, 0x65},
		},
		{
			input:  314729851,
			shift:  16,
			output: PrefixCoded{0x30, 0x20, 0x0, 0x0, 0x0, 0x0, 0x25, 0x42},
		},
		{
			input:  314729851,
			shift:  32,
			output: PrefixCoded{0x40, 0x8, 0x0, 0x0, 0x0, 0x0},
		},
		{
			input:  1234729851,
			shift:  32,
			output: PrefixCoded{0x40, 0x8, 0x0, 0x0, 0x0, 0x0},
		},
	}

	for _, test := range tests {
		actual, err := NewPrefixCodedInt64(test.input, test.shift)
		if err != nil {
			t.Error(err)
		}
		if !reflect.DeepEqual(actual, test.output) {
			t.Errorf("expected %#v, got %#v", test.output, actual)
		}
		checkedShift, err := actual.Shift()
		if err != nil {
			t.Error(err)
		}
		if checkedShift != test.shift {
			t.Errorf("expected %d, got %d", test.shift, checkedShift)
		}
		// if the shift was 0, make sure we can go back to the original
		if test.shift == 0 {
			backToLong, err := actual.Int64()
			if err != nil {
				t.Error(err)
			}
			if backToLong != test.input {
				t.Errorf("expected %v, got %v", test.input, backToLong)
			}
		}
	}
}