package bind_test

import (
	"code.squareroundforest.org/arpio/bind"
	"reflect"
	"slices"
	"testing"
)

type valuer interface {
	value() int
}

type counter interface {
	count() int
}

type countedSlice []int

type valueInt int

func (s countedSlice) count() int {
	return len(s)
}

func (i *valueInt) value() int {
	return int(*i)
}

func TestScalar(t *testing.T) {
	t.Run("bind scalar", func(t *testing.T) {
		t.Run("no value", func(t *testing.T) {
			var i int
			if bind.BindScalar(&i) {
				t.Fatal()
			}
		})

		t.Run("not scalar", func(t *testing.T) {
			var s struct{ Foo int }
			if bind.BindScalar(&s, "42") {
				t.Fatal()
			}
		})

		t.Run("cannot scan", func(t *testing.T) {
			var i int
			if bind.BindScalar(&i, "foo") {
				t.Fatal()
			}
		})

		t.Run("receiver cannot be set", func(t *testing.T) {
			var i int
			if bind.BindScalar(i, "42") {
				t.Fatal()
			}
		})

		t.Run("one value set", func(t *testing.T) {
			var i int
			if !bind.BindScalar(&i, "42") || i != 42 {
				t.Fatal(i)
			}
		})

		t.Run("multiple values, not slice", func(t *testing.T) {
			var i int
			if bind.BindScalar(&i, "21", "42", "84") {
				t.Fatal()
			}
		})

		t.Run("multiple values, small slice", func(t *testing.T) {
			s := make([]int, 2)
			if bind.BindScalar(&s, "21", "42", "84") {
				t.Fatal()
			}
		})

		t.Run("multiple values set", func(t *testing.T) {
			s := make([]int, 3)
			if !bind.BindScalar(&s, "21", "42", "84") || !slices.Equal(s, []int{21, 42, 84}) {
				t.Fatal()
			}
		})

		t.Run("multiple values set, larger slice", func(t *testing.T) {
			s := make([]int, 4)
			if !bind.BindScalar(&s, "21", "42", "84") || !slices.Equal(s, []int{21, 42, 84, 0}) {
				t.Fatal()
			}
		})

		t.Run("multiple values, cannot scan", func(t *testing.T) {
			s := make([]int, 3)
			if bind.BindScalar(&s, "21", "42", "foo") {
				t.Fatal()
			}
		})

		t.Run("set item of a slice", func(t *testing.T) {
			s := []int{21, 42, 84}
			if !bind.BindScalar(&s, "27") || !slices.Equal(s, []int{27, 42, 84}) {
				t.Fatal(s)
			}
		})

		t.Run("interface receiver", func(t *testing.T) {
			var i any
			if !bind.BindScalar(&i, 42) || i != 42 {
				t.Fatal(i)
			}
		})

		t.Run("interface receiver has value", func(t *testing.T) {
			var (
				i     int
				iface any
			)

			i = 21
			iface = &i
			if ok := bind.BindScalar(&iface, "42"); !ok || iface != "42" || i != 21 {
				t.Fatal(ok, iface)
			}
		})

		t.Run("wrapped with non-empty interface", func(t *testing.T) {
			// this could work in theory, but fails on checking the type of the receiver
			// we leave the test undefiend, and checking only for no panic
			var iface valuer
			i := valueInt(21)
			p := &i
			iface = p
			ok := bind.BindScalar(&iface, "42")
			if ok != (i == 42) {
				t.Fatal()
			}
		})

		t.Run("slice wrapped by empty interface", func(t *testing.T) {
			var iface any
			s := make([]int, 3)
			iface = s
			if ok := bind.BindScalar(&iface, "21", "42", "84"); !ok || !slices.Equal(s, []int{21, 42, 84}) {
				t.Fatal()
			}
		})

		t.Run("value has circular reference", func(t *testing.T) {
			var r any
			var v any
			p := &v
			*p = p
			if bind.BindScalar(&r, p) {
				t.Fatal()
			}
		})

		t.Run("nil value", func(t *testing.T) {
			var v any
			v = 42
			if !bind.BindScalar(&v, nil) || v != nil {
				t.Fatal()
			}
		})

		t.Run("nil value and non-nillable receiver", func(t *testing.T) {
			var v int
			if bind.BindScalar(&v, nil) {
				t.Fatal()
			}
		})

		t.Run("nil receiver", func(t *testing.T) {
			if bind.BindScalar(nil, 42) {
				t.Fatal()
			}
		})
	})

	t.Run("bind scalar with create", func(t *testing.T) {
		t.Run("no value", func(t *testing.T) {
			if _, ok := bind.CreateAndBindScalar[int](); ok {
				t.Fatal()
			}
		})

		t.Run("does not accept scalar", func(t *testing.T) {
			if _, ok := bind.CreateAndBindScalar[struct{ Foo int }]("42"); ok {
				t.Fatal()
			}
		})

		t.Run("empty interface", func(t *testing.T) {
			if v, ok := bind.CreateAndBindScalar[any]("42"); !ok || v != "42" {
				t.Fatal()
			}
		})

		t.Run("scalar", func(t *testing.T) {
			if v, ok := bind.CreateAndBindScalar[int]("42"); !ok || v != 42 {
				t.Fatal()
			}
		})

		t.Run("slice", func(t *testing.T) {
			if v, ok := bind.CreateAndBindScalar[[]int]("21", "42", "84"); !ok || !slices.Equal(v, []int{21, 42, 84}) {
				t.Fatal()
			}
		})

		t.Run("slice with non-scalar type", func(t *testing.T) {
			if _, ok := bind.CreateAndBindScalar[[]func(int)]("21", "42", "84"); ok {
				t.Fatal()
			}
		})

		t.Run("pointer to non-scalar", func(t *testing.T) {
			if _, ok := bind.CreateAndBindScalar[*func()]("42"); ok {
				t.Fatal()
			}
		})

		t.Run("pointer", func(t *testing.T) {
			if v, ok := bind.CreateAndBindScalar[*int]("42"); !ok || *v != 42 {
				t.Fatal()
			}
		})

		t.Run("unscannable", func(t *testing.T) {
			if _, ok := bind.CreateAndBindScalar[int]("foo"); ok {
				t.Fatal()
			}
		})

		t.Run("receiver has circular type", func(t *testing.T) {
			type s []s
			if _, ok := bind.CreateAndBindScalar[s]("foo"); ok {
				t.Fatal()
			}
		})

		t.Run("value has circular reference", func(t *testing.T) {
			var v any
			p := &v
			*p = p
			if _, ok := bind.CreateAndBindScalar[any](p); ok {
				t.Fatal()
			}
		})
	})

	t.Run("bind with reflection type", func(t *testing.T) {
		v, ok := bind.CreateAndBindScalarFor(reflect.TypeFor[int](), 42)
		if !ok || v.Interface() != 42 {
			t.Fatal()
		}
	})
}