package reflux

import (
	"fmt"
	"testing"
)

// 标量直读快路径必须与参照实现 refx 逐格等价 —— 包括溢出截断、负数转无符号 panic
// 这些边角行为。这里对"字段类型 × 访问器方法"做全矩阵对拍。

type myStr string
type myInt int
type myBool bool
type myFloat float64

type convBox struct {
	Str    string
	NamedS myStr
	I      int
	NamedI myInt
	I8     int8
	I16    int16
	I32    int32
	I64    int64
	U      uint
	U8     uint8
	U16    uint16
	U32    uint32
	U64    uint64
	F32    float32
	F64    float64
	B      bool
	NamedB myBool
	NamedF myFloat
	Neg    int     // 负数: 转无符号应该 panic
	Over   int     // 300: 读成 Int8 应该截断成 44
	FracF  float64 // 3.9: 读成整数应该截断成 3
	NumStr string  // "123": 字符串转数字
	BadStr string  // "abc": 转数字应该 panic
	PtrStr *string
	AnyVal any
}

func newConvBox() *convBox {
	s := "viaptr"
	return &convBox{
		Str: "hello", NamedS: "named",
		I: 42, NamedI: 7,
		I8: -8, I16: -16, I32: -32, I64: -64,
		U: 1, U8: 2, U16: 3, U32: 4, U64: 5,
		F32: 1.5, F64: 2.5,
		B: true, NamedB: true, NamedF: 3.5,
		Neg: -1, Over: 300, FracF: 3.9,
		NumStr: "123", BadStr: "abc",
		PtrStr: &s, AnyVal: 99,
	}
}

// accessors 是所有会做类型转换的访问器方法
var accessors = []struct {
	name string
	call func(R) any
}{
	{"String", func(r R) any { return r.String() }},
	{"Bool", func(r R) any { return r.Bool() }},
	{"Int", func(r R) any { return r.Int() }},
	{"Int8", func(r R) any { return r.Int8() }},
	{"Int16", func(r R) any { return r.Int16() }},
	{"Int32", func(r R) any { return r.Int32() }},
	{"Int64", func(r R) any { return r.Int64() }},
	{"Uint", func(r R) any { return r.Uint() }},
	{"Uint8", func(r R) any { return r.Uint8() }},
	{"Uint16", func(r R) any { return r.Uint16() }},
	{"Uint32", func(r R) any { return r.Uint32() }},
	{"Uint64", func(r R) any { return r.Uint64() }},
	{"Float32", func(r R) any { return r.Float32() }},
	{"Float64", func(r R) any { return r.Float64() }},
	{"Any", func(r R) any { return r.Any() }},
}

var convFields = []string{
	"Str", "NamedS", "I", "NamedI", "I8", "I16", "I32", "I64",
	"U", "U8", "U16", "U32", "U64", "F32", "F64",
	"B", "NamedB", "NamedF", "Neg", "Over", "FracF",
	"NumStr", "BadStr", "PtrStr", "AnyVal",
}

// callSafe 调用访问器, 把 panic 也当成一种"结果"记录下来。
func callSafe(r R, f func(R) any) (result any, panicked bool) {
	defer func() {
		if rec := recover(); rec != nil {
			panicked = true
		}
	}()
	return f(r), false
}

func TestScalarFastPathMatchesReflux(t *testing.T) {
	box := newConvBox()
	rx := newLegacy(box)
	fx := New(box)

	for _, field := range convFields {
		for _, acc := range accessors {
			t.Run(field+"/"+acc.name, func(t *testing.T) {
				wantVal, wantPanic := callSafe(rx.Get(field), acc.call)
				gotVal, gotPanic := callSafe(fx.Get(field), acc.call)

				if wantPanic != gotPanic {
					t.Fatalf("panic 行为不一致: reflux panic=%v, fastx panic=%v (值 reflux=%#v fastx=%#v)",
						wantPanic, gotPanic, wantVal, gotVal)
				}
				if wantPanic {
					return // 两边都 panic, 一致
				}
				if fmt.Sprintf("%v", wantVal) != fmt.Sprintf("%v", gotVal) {
					t.Fatalf("结果不一致: reflux=%#v, fastx=%#v", wantVal, gotVal)
				}
			})
		}
	}
}

// 单独把几个最容易出错的边角行为钉死
func TestScalarEdgeCases(t *testing.T) {
	box := newConvBox()
	fx := New(box)
	rx := newLegacy(box)

	// 整数溢出静默截断: 300 -> int8 = 44
	if got, want := fx.Get("Over").Int8(), rx.Get("Over").Int8(); got != want || got != 44 {
		t.Fatalf("溢出截断: fastx=%d reflux=%d, 期望 44", got, want)
	}
	// 负数转无符号: 两边都必须 panic
	if _, p1 := callSafe(fx.Get("Neg"), func(r R) any { return r.Uint8() }); !p1 {
		t.Fatal("负数转 Uint8 应该 panic")
	}
	// 浮点截断: 3.9 -> int = 3
	if got, want := fx.Get("FracF").Int(), rx.Get("FracF").Int(); got != want || got != 3 {
		t.Fatalf("浮点截断: fastx=%d reflux=%d, 期望 3", got, want)
	}
	// 字符串转数字仍然可用(走 cast 回退)
	if got := fx.Get("NumStr").Int(); got != 123 {
		t.Fatalf("字符串转数字: %d", got)
	}
	// 非数字字符串转数字: 两边都 panic
	if _, p := callSafe(fx.Get("BadStr"), func(r R) any { return r.Int() }); !p {
		t.Fatal("\"abc\" 转 Int 应该 panic")
	}
	// 具名类型走快路径, 结果与 reflux 一致
	if got, want := fx.Get("NamedS").String(), rx.Get("NamedS").String(); got != want {
		t.Fatalf("具名 string: fastx=%q reflux=%q", got, want)
	}
	// 指针字段自动解引用后仍能直读
	if got := fx.Get("PtrStr").String(); got != "viaptr" {
		t.Fatalf("指针字段: %q", got)
	}
}