package dbx

import (
	"testing"
	"time"

	"github.com/go-jet/jet/v2/mysql"
	"github.com/stretchr/testify/assert"
	"golang.org/x/exp/constraints"
)

func Test_ApplyPtr(t *testing.T) {
	targetCol := mysql.StringColumn("test")
	var empty string

	cases := []struct {
		name     string
		current  *string
		new      *string
		expected *string
		length   int
	}{
		{"apply updated value", Ptr("hello"), Ptr("world"), Ptr("world"), 1},
		{"apply same value", Ptr("hello"), Ptr("hello"), Ptr("hello"), 0},
		{"apply new value to nil", nil, Ptr("hello"), Ptr("hello"), 1},
		{"apply nil to existing value", Ptr("hello"), nil, Ptr("hello"), 0},
		{"apply empty string to existing value", Ptr("hello"), &empty, nil, 1},
		{"apply empty string to nil", nil, &empty, nil, 0},
	}

	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			modified := make(mysql.ColumnList, 0)
			updated := ApplyPtr(c.current, c.new, &modified, targetCol)
			assert.Len(t, modified, c.length)

			if c.expected == nil {
				assert.Nil(t, updated, "Expected updated value to be nil")
			} else {
				assert.NotNil(t, updated, "Expected updated value to be not nil")
				if updated != nil {
					assert.Equal(t, *c.expected, *updated, "Expected updated value to be equal to new value")
				}
			}
		})
	}
}

func applyComplexPtr_tc[
	Current constraints.Float | constraints.Integer,
	New constraints.Float | constraints.Integer,
](
	t *testing.T,
	name string,
	current *Current,
	new *New,
	expected *Current,
	length int,
) {
	targetCol := mysql.IntegerColumn("test")
	t.Run(name, func(t *testing.T) {
		modified := make(mysql.ColumnList, 0)
		updated := ApplyComplexPtr(current, new, &modified, targetCol)
		assert.Len(t, modified, length)

		if expected == nil {
			assert.Nil(t, updated, "Expected updated value to be nil")
		} else {
			assert.NotNil(t, updated, "Expected updated value to be not nil")
			if updated != nil {
				assert.Equal(t, *expected, *updated, "Expected updated value to be equal to new value")
			}
		}
	})
}

func Test_ApplyComplexPtr(t *testing.T) {
	var empty int
	applyComplexPtr_tc(t, "apply updated value", Ptr(1), Ptr(2), Ptr(2), 1)
	applyComplexPtr_tc(t, "apply same value", Ptr(1), Ptr(1), Ptr(1), 0)
	applyComplexPtr_tc(t, "apply new value to nil", nil, Ptr(2), Ptr(2), 1)
	applyComplexPtr_tc[int, int](t, "apply nil to existing value", Ptr(1), nil, Ptr(1), 0)
	applyComplexPtr_tc(t, "apply zero value to existing value", Ptr(1), &empty, nil, 1)
	applyComplexPtr_tc(t, "apply different type to existing value", Ptr[uint64](1), Ptr[uint16](2), Ptr[uint64](2), 1)
	applyComplexPtr_tc[int](t, "apply zero value to nil", nil, &empty, nil, 0)
}

func applyInterfacePtr_tc[
	T ApplyInterface[T],
](
	t *testing.T,
	name string,
	current *T,
	new *T,
	expected *T,
	length int,
) {
	targetCol := mysql.StringColumn("test")
	t.Run(name, func(t *testing.T) {
		modified := make(mysql.ColumnList, 0)
		updated := ApplyInterfacePtr(current, new, &modified, targetCol)
		assert.Len(t, modified, length)

		if expected == nil {
			assert.Nil(t, updated, "Expected updated value to be nil")
		} else {
			assert.NotNil(t, updated, "Expected updated value to be not nil")
			if updated != nil {
				assert.Equal(t, *expected, *updated, "Expected updated value to be equal to new value")
			}
		}
	})
}

func Test_ApplyInterfacePtr(t *testing.T) {
	var zero time.Time
	applyInterfacePtr_tc(t, "apply updated value",
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		Ptr(time.Date(2023, 10, 2, 0, 0, 0, 0, time.UTC)),
		Ptr(time.Date(2023, 10, 2, 0, 0, 0, 0, time.UTC)),
		1,
	)
	applyInterfacePtr_tc(t, "apply same value",
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		0,
	)
	applyInterfacePtr_tc(t, "apply new value to nil",
		nil,
		Ptr(time.Date(2023, 10, 2, 0, 0, 0, 0, time.UTC)),
		Ptr(time.Date(2023, 10, 2, 0, 0, 0, 0, time.UTC)),
		1,
	)
	applyInterfacePtr_tc(t, "apply nil to existing value",
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		nil,
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		0,
	)
	applyInterfacePtr_tc(t, "apply zero value to existing value",
		Ptr(time.Date(2023, 10, 1, 0, 0, 0, 0, time.UTC)),
		&zero,
		nil,
		1,
	)
	applyInterfacePtr_tc(t, "apply zero value to nil",
		nil,
		&zero,
		nil,
		0,
	)
}

func Test_ApplyVal(t *testing.T) {
	targetCol := mysql.StringColumn("test")
	var empty string

	cases := []struct {
		name     string
		current  string
		new      *string
		expected string
		length   int
	}{
		{"apply updated value", "hello", Ptr("world"), "world", 1},
		{"apply same value", "hello", Ptr("hello"), "hello", 0},
		{"apply new value to empty value", "", Ptr("hello"), "hello", 1},
		{"apply nil to existing value", "hello", nil, "hello", 0},
		{"apply empty string to existing value", "hello", &empty, "", 1},
		{"apply empty string to empty value", "", &empty, "", 0},
	}

	for _, c := range cases {
		t.Run(c.name, func(t *testing.T) {
			modified := make(mysql.ColumnList, 0)
			updated := ApplyVal(c.current, c.new, &modified, targetCol)
			assert.Equal(t, c.expected, updated, "Expected updated value to be equal to new value")
			assert.Len(t, modified, c.length)
		})
	}
}