// Copyright 2010 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package utf16

import (
	"fmt"
	"reflect"
	"testing"
	"unicode"
)

type encodeTest struct {
	in  []int
	out []uint16
}

var encodeTests = []encodeTest{
	encodeTest{[]int{1, 2, 3, 4}, []uint16{1, 2, 3, 4}},
	encodeTest{[]int{0xffff, 0x10000, 0x10001, 0x12345, 0x10ffff},
		[]uint16{0xffff, 0xd800, 0xdc00, 0xd800, 0xdc01, 0xd808, 0xdf45, 0xdbff, 0xdfff}},
	encodeTest{[]int{'a', 'b', 0xd7ff, 0xd800, 0xdfff, 0xe000, 0x110000, -1},
		[]uint16{'a', 'b', 0xd7ff, 0xfffd, 0xfffd, 0xe000, 0xfffd, 0xfffd}},
}

func TestEncode(t *testing.T) {
	for _, tt := range encodeTests {
		out := Encode(tt.in)
		if !reflect.DeepEqual(out, tt.out) {
			t.Errorf("Encode(%v) = %v; want %v", hex(tt.in), hex16(out), hex16(tt.out))
		}
	}
}

func TestEncodeRune(t *testing.T) {
	for i, tt := range encodeTests {
		j := 0
		for _, r := range tt.in {
			r1, r2 := EncodeRune(r)
			if r < 0x10000 || r > unicode.MaxRune {
				if j >= len(tt.out) {
					t.Errorf("#%d: ran out of tt.out", i)
					break
				}
				if r1 != unicode.ReplacementChar || r2 != unicode.ReplacementChar {
					t.Errorf("EncodeRune(%#x) = %#x, %#x; want 0xfffd, 0xfffd", r, r1, r2)
				}
				j++
			} else {
				if j+1 >= len(tt.out) {
					t.Errorf("#%d: ran out of tt.out", i)
					break
				}
				if r1 != int(tt.out[j]) || r2 != int(tt.out[j+1]) {
					t.Errorf("EncodeRune(%#x) = %#x, %#x; want %#x, %#x", r, r1, r2, tt.out[j], tt.out[j+1])
				}
				j += 2
				dec := DecodeRune(r1, r2)
				if dec != r {
					t.Errorf("DecodeRune(%#x, %#x) = %#x; want %#x", r1, r2, dec, r)
				}
			}
		}
		if j != len(tt.out) {
			t.Errorf("#%d: EncodeRune didn't generate enough output", i)
		}
	}
}

type decodeTest struct {
	in  []uint16
	out []int
}

var decodeTests = []decodeTest{
	decodeTest{[]uint16{1, 2, 3, 4}, []int{1, 2, 3, 4}},
	decodeTest{[]uint16{0xffff, 0xd800, 0xdc00, 0xd800, 0xdc01, 0xd808, 0xdf45, 0xdbff, 0xdfff},
		[]int{0xffff, 0x10000, 0x10001, 0x12345, 0x10ffff}},
	decodeTest{[]uint16{0xd800, 'a'}, []int{0xfffd, 'a'}},
	decodeTest{[]uint16{0xdfff}, []int{0xfffd}},
}

func TestDecode(t *testing.T) {
	for _, tt := range decodeTests {
		out := Decode(tt.in)
		if !reflect.DeepEqual(out, tt.out) {
			t.Errorf("Decode(%v) = %v; want %v", hex16(tt.in), hex(out), hex(tt.out))
		}
	}
}

type hex []int

func (h hex) Format(f fmt.State, c int) {
	fmt.Fprint(f, "[")
	for i, v := range h {
		if i > 0 {
			fmt.Fprint(f, " ")
		}
		fmt.Fprintf(f, "%x", v)
	}
	fmt.Fprint(f, "]")
}

type hex16 []uint16

func (h hex16) Format(f fmt.State, c int) {
	fmt.Fprint(f, "[")
	for i, v := range h {
		if i > 0 {
			fmt.Fprint(f, " ")
		}
		fmt.Fprintf(f, "%x", v)
	}
	fmt.Fprint(f, "]")
}