package structs

import (
	"fmt"
	"strings"
	"testing"

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

type example struct {
	Attribute1 string
	Attribute2 string
}

func TestCopyOrZeroValue(t *testing.T) {
	var e *example

	zv := CopyOrZeroValue(e)

	if zv == nil {
		t.Error("CopyOrZeroValue returned nil")
	}

	if zv.Attribute1 != "" || zv.Attribute2 != "" {
		t.Error("CopyOrZeroValue didn't return zero value")
	}

	e2 := &example{Attribute1: "One", Attribute2: "Two"}

	cp := CopyOrZeroValue(e2)

	if cp == nil {
		t.Error("CopyOrZeroValue returned nil")
	}

	if cp == e2 {
		t.Error("CopyOrZeroValue returned reference with same address")
	}

	if cp.Attribute1 != e2.Attribute1 || cp.Attribute2 != e2.Attribute2 {
		t.Error("CopyOrZeroValue didn't correctly copy attributes")
	}
}

func TestUniqWithInts(t *testing.T) {
	tests := []struct {
		input    []int
		expected []int
	}{
		{[]int{5, 1, 3, 1, 4}, []int{5, 1, 3, 4}},
		{[]int{1, 1, 1}, []int{1}},
	}
	for i, tt := range tests {
		t.Run(fmt.Sprintf("%d: testing %v", i+1, tt.input), func(t *testing.T) {
			result := Uniq(tt.input)
			assert.EqualValues(t, tt.expected, result)
		})
	}
}

type u struct {
	x int
	y string
}

var (
	u1 = u{x: 1, y: "un"}
	u2 = u{x: 2, y: "deux"}
	u3 = u{x: 3, y: "trois"}
)

func TestUniqWithStructs(t *testing.T) {
	tests := []struct {
		input    []u
		expected []u
	}{
		{[]u{u3, u1, u2, u3, u2, u1}, []u{u3, u1, u2}},
	}
	for i, tt := range tests {
		t.Run(fmt.Sprintf("%d: testing %v", i+1, tt.input), func(t *testing.T) {
			result := Uniq(tt.input)
			assert.EqualValues(t, tt.expected, result)
		})
	}
}

func TestKeys(t *testing.T) {
	tests := []struct {
		input    map[int]string
		expected []int
	}{
		{map[int]string{5: "cinq", 1: "un", 3: "trois", 4: "vier"}, []int{5, 1, 3, 4}},
		{map[int]string{1: "un"}, []int{1}},
	}
	for i, tt := range tests {
		t.Run(fmt.Sprintf("%d: testing %v", i+1, tt.input), func(t *testing.T) {
			result := Keys(tt.input)
			assert.ElementsMatch(t, tt.expected, result)
		})
	}
}

func TestMissing(t *testing.T) {
	tests := []struct {
		source   []string
		input    []string
		expected []string
	}{
		{[]string{"a", "b", "c"}, []string{"c", "b", "a"}, []string{}},
		{[]string{"a", "b", "c"}, []string{"c", "b"}, []string{"a"}},
		{[]string{"a", "b", "c"}, []string{"c", "b", "a", "d"}, []string{}},
		{[]string{}, []string{"c", "b"}, []string{}},
		{[]string{"a", "b", "c"}, []string{}, []string{"a", "b", "c"}},
		{[]string{"a", "b", "b", "c"}, []string{"a", "b"}, []string{"c"}},
	}
	for i, tt := range tests {
		t.Run(fmt.Sprintf("%d: testing [%v] <-> [%v] == [%v]", i+1, strings.Join(tt.source, ", "), strings.Join(tt.input, ", "), strings.Join(tt.expected, ", ")), func(t *testing.T) {
			result := Missing(tt.source, tt.input)
			assert.Equal(t, tt.expected, result)
		})
	}
}

func TestAny(t *testing.T) {
	always := func(s string) bool { return true }
	never := func(s string) bool { return false }
	assert.True(t, Any([]string{"a", "b", "c"}, always))
	assert.False(t, Any([]string{}, always))
	assert.False(t, Any(nil, always))
	assert.False(t, Any([]string{"a", "b", "c"}, never))
	assert.False(t, Any(nil, never))
}

func TestAnyKey(t *testing.T) {
	always := func(s string) bool { return true }
	never := func(s string) bool { return false }

	assert.True(t, AnyKey(map[string]bool{"a": true, "b": false}, always))
	assert.False(t, AnyKey(map[string]bool{}, always))
	assert.False(t, AnyKey[string, bool](nil, always))
	assert.False(t, AnyKey(map[string]bool{"a": true, "b": false}, never))
	assert.False(t, AnyKey[string, bool](nil, never))
}

func TestAnyValue(t *testing.T) {
	always := func(b bool) bool { return true }
	never := func(b bool) bool { return false }

	assert.True(t, AnyValue(map[string]bool{"a": true, "b": false}, always))
	assert.False(t, AnyValue(map[string]bool{}, always))
	assert.False(t, AnyValue[string](nil, always))
	assert.False(t, AnyValue(map[string]bool{"a": true, "b": false}, never))
	assert.False(t, AnyValue[string](nil, never))
}

func TestAnyItem(t *testing.T) {
	always := func(s string, b bool) bool { return true }
	never := func(s string, b bool) bool { return false }

	assert.True(t, AnyItem(map[string]bool{"a": true, "b": false}, always))
	assert.False(t, AnyItem(map[string]bool{}, always))
	assert.False(t, AnyItem(nil, always))
	assert.False(t, AnyItem(map[string]bool{"a": true, "b": false}, never))
	assert.False(t, AnyItem(nil, never))
}

func TestConcat(t *testing.T) {
	assert.Equal(t, []string{"a", "b", "c", "d", "e", "f"}, Concat([]string{"a", "b"}, []string{"c"}, []string{"d", "e", "f"}))
	assert.Equal(t, []string{"a"}, Concat([]string{"a"}))
	assert.Equal(t, []string{"a"}, Concat([]string{}, nil, []string{"a"}))
	assert.Equal(t, []string{}, Concat[string]())
}