package cast

import (
	"bytes"
	"encoding/json"
	"fmt"
	"reflect"
	"slices"
	"strconv"
	"strings"
	"time"

	"gopkg.in/yaml.v3"
)

// If 泛型三元表达式
func If[T any](condition bool, trueVal, falseVal T) T {
	if condition {
		return trueVal
	}
	return falseVal
}

// In 泛型包含判断
func In[T comparable](arr []T, val T) bool {
	return slices.Contains(arr, val)
}

func RealValue(v reflect.Value) reflect.Value {
	for v.Kind() == reflect.Pointer || v.Kind() == reflect.Interface {
		if v.IsNil() {
			return v
		}
		v = v.Elem()
	}
	return v
}

// --- Core Cast Logic ---

func parseInt(s string) int64 {
	i, err := strconv.ParseInt(s, 10, 64)
	if err == nil {
		return i
	}
	if f, err := strconv.ParseFloat(s, 64); err == nil {
		return int64(f)
	}
	return 0
}

func parseUint(s string) uint64 {
	i, err := strconv.ParseUint(s, 10, 64)
	if err == nil {
		return i
	}
	if f, err := strconv.ParseFloat(s, 64); err == nil {
		return uint64(f)
	}
	return 0
}

func Int(value any) int { return int(Int64(value)) }

// Helper for integer coercion to avoid repetition
func toInt64(value any) (int64, bool) {
	switch v := value.(type) {
	case int: return int64(v), true
	case int8: return int64(v), true
	case int16: return int64(v), true
	case int32: return int64(v), true
	case int64: return v, true
	case uint: return int64(v), true
	case uint8: return int64(v), true
	case uint16: return int64(v), true
	case uint32: return int64(v), true
	case uint64: return int64(v), true
	case float32: return int64(v), true
	case float64: return int64(v), true
	case bool: return If(v, int64(1), int64(0)), true
	}
	return 0, false
}

func Int64(value any) int64 {
	if value == nil { return 0 }
	if i, ok := toInt64(value); ok { return i }
	
	switch realValue := value.(type) {
	case []byte: return parseInt(string(realValue))
	case string: return parseInt(realValue)
	}
	
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return Int64(rv.Interface())
		}
	}
	return 0
}

func Uint(value any) uint { return uint(Uint64(value)) }

func Uint64(value any) uint64 {
	if value == nil {
		return 0
	}
	switch realValue := value.(type) {
	case int:
		return uint64(realValue)
	case int8:
		return uint64(realValue)
	case int16:
		return uint64(realValue)
	case int32:
		return uint64(realValue)
	case int64:
		return uint64(realValue)
	case uint:
		return uint64(realValue)
	case uint8:
		return uint64(realValue)
	case uint16:
		return uint64(realValue)
	case uint32:
		return uint64(realValue)
	case uint64:
		return realValue
	case float32:
		return uint64(realValue)
	case float64:
		return uint64(realValue)
	case bool:
		return If(realValue, uint64(1), uint64(0))
	case []byte:
		return parseUint(string(realValue))
	case string:
		return parseUint(realValue)
	}
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return Uint64(rv.Interface())
		}
	}
	return 0
}

func Float(value any) float32 { return float32(Float64(value)) }

func Float64(value any) float64 {
	if value == nil {
		return 0
	}
	switch realValue := value.(type) {
	case int, int8, int16, int32, int64:
		return float64(Int64(realValue))
	case uint, uint8, uint16, uint32, uint64:
		return float64(Uint64(realValue))
	case float32:
		return float64(realValue)
	case float64:
		return realValue
	case bool:
		return If(realValue, 1.0, 0.0)
	case []byte:
		i, err := strconv.ParseFloat(string(realValue), 64)
		if err == nil {
			return i
		}
	case string:
		i, err := strconv.ParseFloat(realValue, 64)
		if err == nil {
			return i
		}
	}
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return Float64(rv.Interface())
		}
	}
	return 0
}

func String(value any) string {
	if value == nil {
		return ""
	}
	switch realValue := value.(type) {
	case int, int8, int16, int32, int64:
		return strconv.FormatInt(Int64(realValue), 10)
	case uint, uint8, uint16, uint32, uint64:
		return strconv.FormatUint(Uint64(realValue), 10)
	case float32:
		return strconv.FormatFloat(float64(realValue), 'f', -1, 32)
	case float64:
		return strconv.FormatFloat(realValue, 'f', -1, 64)
	case bool:
		return If(realValue, "true", "false")
	case string:
		return realValue
	case []byte:
		return string(realValue)
	}
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return String(rv.Interface())
		}
	}
	return fmt.Sprint(value)
}

func Bool(value any) bool {
	switch realValue := value.(type) {
	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64:
		return Uint64(realValue) != 0
	case bool:
		return realValue
	case []byte:
		s := strings.ToLower(string(realValue))
		return s == "1" || s == "t" || s == "true"
	case string:
		s := strings.ToLower(realValue)
		return s == "1" || s == "t" || s == "true"
	}
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return Bool(rv.Interface())
		}
	}
	return false
}

func Duration(value any) time.Duration {
	if value == nil {
		return 0
	}
	switch realValue := value.(type) {
	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64:
		return time.Duration(Int64(realValue))
	case float32, float64:
		return time.Duration(Float64(realValue) * float64(time.Second))
	case []byte, string:
		if result, err := time.ParseDuration(String(realValue)); err == nil {
			return result
		}
	}
	rv := reflect.ValueOf(value)
	if rv.Kind() == reflect.Pointer || rv.Kind() == reflect.Interface {
		if rv = RealValue(rv); rv.IsValid() && rv.CanInterface() && rv.Kind() != reflect.Pointer {
			return Duration(rv.Interface())
		}
	}
	return 0
}

func ToJSONBytes(value any) ([]byte, error) {
	return fastToJSONBytes(value)
}

func ToJSONDesensitize(value any, keys []string) (string, error) {
	b, err := fastToJSONBytes(value, keys...)
	if err != nil {
		return "", err
	}
	return string(b), nil
}

func ToJSONDesensitizeBytes(value any, keys []string) ([]byte, error) {
	return fastToJSONBytes(value, keys...)
}

func MustJSONBytes(value any) []byte {
	j, err := ToJSONBytes(value)
	if err != nil {
		return []byte{}
	}
	return j
}

func ToJSON(value any) (string, error) {
	j, err := ToJSONBytes(value)
	if err != nil {
		return "", err
	}
	return string(j), nil
}
func MustToJSON(value any) string { return string(MustJSONBytes(value)) }

func PrettyToJSONBytes(value any) []byte {
	j := MustJSONBytes(value)
	r := &bytes.Buffer{}
	if err := json.Indent(r, j, "", "  "); err == nil {
		return r.Bytes()
	}
	return j
}

func PrettyToJSON(value any) string { return string(PrettyToJSONBytes(value)) }

func UnmarshalJSON(data any, value any) error {
	var b []byte
	switch v := data.(type) {
	case string:
		b = []byte(v)
	case []byte:
		b = v
	default:
		return fmt.Errorf("unsupported data type: %T", data)
	}
	return fastUnmarshalJSONBytes(b, value)
}

func FromJSON[T any](data any) (T, error) {
	var v T
	err := UnmarshalJSON(data, &v)
	return v, err
}

func MustFromJSON[T any](data any) T {
	v, err := FromJSON[T](data)
	if err != nil {
		panic(err)
	}
	return v
}

func ToYAML(value any) (string, error) {
	j, err := YAMLBytes(value)
	if err != nil {
		return "", err
	}
	return string(j), nil
}

func MustToYAML(value any) string { return string(MustYAMLBytes(value)) }

func UnmarshalYAML(data any, value any) error {
	var b []byte
	switch v := data.(type) {
	case string:
		b = []byte(v)
	case []byte:
		b = v
	default:
		return fmt.Errorf("unsupported data type: %T", data)
	}
	return yaml.Unmarshal(b, value)
}

func FromYAML[T any](data any) (T, error) {
	var v T
	err := UnmarshalYAML(data, &v)
	return v, err
}

func MustFromYAML[T any](data any) T {
	v, err := FromYAML[T](data)
	if err != nil {
		panic(err)
	}
	return v
}

func YAMLBytes(value any) ([]byte, error) {
	j, err := yaml.Marshal(value)
	if err == nil {
		return j, nil
	}
	return []byte(fmt.Sprint(value)), err
}

func MustYAMLBytes(value any) []byte {
	j, err := YAMLBytes(value)
	if err != nil {
		return []byte{}
	}
	return j
}

// --- Others (Keep logic but clean style) ---

func Split(s, sep string) []string {
	ss := strings.Split(s, sep)
	out := make([]string, 0, len(ss))
	for _, s1 := range ss {
		if s2 := strings.TrimSpace(s1); s2 != "" {
			out = append(out, s2)
		}
	}
	return out
}

func SplitArgs(s string) []string {
	var res []string
	var builder strings.Builder
	inQuote := false
	escaped := false

	chars := []rune(s)
	for i := 0; i < len(chars); i++ {
		c := chars[i]

		if escaped {
			builder.WriteRune(c)
			escaped = false
			continue
		}

		if c == '\\' {
			escaped = true
			continue
		}

		if c == '"' {
			inQuote = !inQuote
			continue
		}

		if c == ' ' && !inQuote {
			if builder.Len() > 0 {
				res = append(res, builder.String())
				builder.Reset()
			}
			continue
		}

		builder.WriteRune(c)
	}

	if builder.Len() > 0 {
		res = append(res, builder.String())
	}
	return res
}

func JoinArgs(arr []string, sep string) string {
	var builder strings.Builder
	for i, s := range arr {
		if i > 0 {
			builder.WriteString(sep)
		}
		// 如果包含空格或引号，则需要包裹引号并转义内部引号
		if strings.ContainsRune(s, ' ') || strings.ContainsRune(s, '"') {
			builder.WriteByte('"')
			builder.WriteString(strings.ReplaceAll(s, "\"", "\\\""))
			builder.WriteByte('"')
		} else {
			builder.WriteString(s)
		}
	}
	return builder.String()
}

func UniqueAppend(to []string, from ...any) []string {
	exists := make(map[string]struct{}, len(to))
	for _, s := range to {
		exists[s] = struct{}{}
	}
	for _, a := range from {
		s := String(a)
		if _, ok := exists[s]; !ok {
			to = append(to, s)
			exists[s] = struct{}{}
		}
	}
	return to
}

func ArrayToBoolMap[T comparable](arr []T) map[T]bool {
	r := map[T]bool{}
	for _, s := range arr {
		r[s] = true
	}
	return r
}

// ToMap 将 source 填充到目标 map 中，自动转换类型。
// 如果 source 是 struct，则提取导出字段（含嵌入字段，字段名首字母转小写）；
// 如果 source 是 slice/array，则视为 [K1, V1, K2, V2, ...] 序列；
// 如果 source 是 map，则进行合并（Merge）。
func ToMap(target any, source any) {
	rv := reflect.ValueOf(target)
	for rv.Kind() == reflect.Pointer {
		if rv.IsNil() {
			if !rv.CanSet() {
				return
			}
			elemType := rv.Type().Elem()
			if elemType.Kind() == reflect.Map || elemType.Kind() == reflect.Pointer || elemType.Kind() == reflect.Struct {
				rv.Set(reflect.New(elemType))
			} else {
				return
			}
		}
		rv = rv.Elem()
	}

	if rv.Kind() != reflect.Map {
		return
	}

	if rv.IsNil() {
		if rv.CanSet() {
			rv.Set(reflect.MakeMap(rv.Type()))
		} else {
			return
		}
	}

	kt := rv.Type().Key()
	vt := rv.Type().Elem()

	sv := RealValue(reflect.ValueOf(source))
	switch sv.Kind() {
	case reflect.Struct:
		fillMapFromStruct(rv, sv, kt, vt)
	case reflect.Slice, reflect.Array:
		for i := 0; i < sv.Len(); i += 2 {
			k := sv.Index(i).Interface()
			var v any
			if i+1 < sv.Len() {
				v = sv.Index(i+1).Interface()
			}
			rv.SetMapIndex(reflectCast(k, kt), reflectCast(v, vt))
		}
	case reflect.Map:
		iter := sv.MapRange()
		for iter.Next() {
			rv.SetMapIndex(reflectCast(iter.Key().Interface(), kt), reflectCast(iter.Value().Interface(), vt))
		}
	}
}

func fillMapFromStruct(targetMap, sv reflect.Value, kt, vt reflect.Type) {
	st := sv.Type()
	for i := 0; i < sv.NumField(); i++ {
		field := st.Field(i)
		if !field.IsExported() {
			continue
		}
		if field.Anonymous {
			fillMapFromStruct(targetMap, sv.Field(i), kt, vt)
			continue
		}
		targetMap.SetMapIndex(reflectCast(GetLowerName(field.Name), kt), reflectCast(sv.Field(i).Interface(), vt))
	}
}

// ToSlice 将 source 填充到目标 slice 中，自动转换类型。
// 如果 source 是 map，则展开为 [K1, V1, K2, V2, ...] 序列；
// 如果 source 是 slice/array，则进行元素拷贝/追加；
// 如果 source 是普通值，则直接作为元素追加。
func ToSlice(target any, source any) {
	rv := reflect.ValueOf(target)
	if rv.Kind() != reflect.Pointer || rv.Elem().Kind() != reflect.Slice {
		return
	}
	sliceRv := rv.Elem()
	et := sliceRv.Type().Elem()

	sv := RealValue(reflect.ValueOf(source))
	switch sv.Kind() {
	case reflect.Map:
		iter := sv.MapRange()
		for iter.Next() {
			sliceRv.Set(reflect.Append(sliceRv, reflectCast(iter.Key().Interface(), et)))
			sliceRv.Set(reflect.Append(sliceRv, reflectCast(iter.Value().Interface(), et)))
		}
	case reflect.Slice, reflect.Array:
		for i := 0; i < sv.Len(); i++ {
			sliceRv.Set(reflect.Append(sliceRv, reflectCast(sv.Index(i).Interface(), et)))
		}
	case reflect.Invalid:
		// Nil source, do nothing
	default:
		sliceRv.Set(reflect.Append(sliceRv, reflectCast(source, et)))
	}
}

// MakeMap 泛型构建新 Map
func MakeMap[K comparable, V any](source any) map[K]V {
	m := make(map[K]V)
	ToMap(m, source)
	return m
}

// MakeSlice 泛型构建新 Slice
func MakeSlice[T any](source any) []T {
	var s []T
	ToSlice(&s, source)
	return s
}

func reflectCast(value any, t reflect.Type) reflect.Value {
	switch t.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return reflect.ValueOf(Int64(value)).Convert(t)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return reflect.ValueOf(Uint64(value)).Convert(t)
	case reflect.Float32, reflect.Float64:
		return reflect.ValueOf(Float64(value)).Convert(t)
	case reflect.String:
		return reflect.ValueOf(String(value)).Convert(t)
	case reflect.Bool:
		return reflect.ValueOf(Bool(value)).Convert(t)
	case reflect.Interface:
		if value == nil {
			return reflect.Zero(t)
		}
		return reflect.ValueOf(value)
	}

	if t == reflect.TypeOf(time.Duration(0)) {
		return reflect.ValueOf(Duration(value))
	}

	return reflect.Zero(t)
}

// 补充缺失的 Key 转换工具
func GetLowerName(s string) string {
	if len(s) > 0 && s[0] >= 'A' && s[0] <= 'Z' {
		hasLower := false
		for i := 0; i < len(s); i++ {
			if s[i] >= 'a' && s[i] <= 'z' {
				hasLower = true
				break
			}
		}
		if hasLower {
			return strings.ToLower(s[:1]) + s[1:]
		}
	}
	return s
}

func GetUpperName(s string) string {
	if s == "" {
		return ""
	}
	return strings.ToUpper(s[:1]) + s[1:]
}

// 指针工具
func Ptr[T any](v T) *T { return &v }

// FixUpperCase (保留以支持历史复杂的 Key 转换需求)
func FixUpperCase(data []byte, excludesKeys []string) {
	// 原有逻辑保持
	n := len(data)
	types, keys, tpos := make([]bool, 0), make([]string, 0), -1
	for i := 0; i < n-1; i++ {
		if tpos+1 >= len(types) {
			types = append(types, false)
			keys = append(keys, "")
		}
		switch data[i] {
		case '{':
			tpos++
			types[tpos] = true
			keys[tpos] = ""
		case '}':
			tpos--
		case '[':
			tpos++
			types[tpos] = false
			keys[tpos] = ""
		case ']':
			tpos--
		case '"':
			keyPos := -1
			if i > 0 && (data[i-1] == '{' || (data[i-1] == ',' && tpos >= 0 && types[tpos])) {
				keyPos = i + 1
			}
			i++
			for ; i < n-1; i++ {
				if data[i] == '\\' {
					i++
					continue
				}
				if data[i] == '"' {
					if keyPos >= 0 && len(excludesKeys) > 0 {
						keys[tpos] = string(data[keyPos:i])
					}
					break
				}
			}
			if keyPos >= 0 && (data[keyPos] >= 'A' && data[keyPos] <= 'Z') {
				excluded := false
				if len(excludesKeys) > 0 {
					checkStr := strings.Join(keys[0:tpos+1], ".")
					for _, ek := range excludesKeys {
						if strings.HasSuffix(ek, ".") {
							excluded = strings.HasPrefix(checkStr, ek)
						} else {
							excluded = checkStr == ek
						}
						if excluded {
							break
						}
					}
				}
				if !excluded {
					hasLower := false
					for _, b := range data[keyPos:i] {
						if b >= 'a' && b <= 'z' {
							hasLower = true
							break
						}
					}
					if hasLower {
						data[keyPos] |= 0x20
					}
				}
			}
		}
	}
}