package stat

import (
	"fmt"
	"reflect"
)

// Series
//
//	Data structure for 1-dimensional cross-sectional and time series data
//	一维横截面和时间序列数据的数据结构
type Series interface {
	// Name 取得series名称
	Name() string
	// Rename renames the series.
	Rename(name string)
	// Type returns the type of Data the series holds.
	// 返回series的数据类型
	Type() Type
	// Values 获得全部数据集
	Values() any
	// NaN 输出默认的NaN
	NaN() any

	// Floats 强制转成[]float32
	Floats() []float32
	// DTypes 强制转[]stat.DType
	DTypes() []DType
	// Ints 强制转换成整型
	Ints() []Int
	// Strings 强制转换string切片
	Strings() []string
	// Bools 强制转换成bool切片
	Bools() []bool

	// sort.Interface

	// Len 获得行数, 实现sort.Interface接口的获取元素数量方法
	Len() int
	// Less 实现sort.Interface接口的比较元素方法
	Less(i, j int) bool
	// Swap 实现sort.Interface接口的交换元素方法
	Swap(i, j int)

	// Empty returns an empty Series of the same type
	Empty(t ...Type) Series
	// Copy 复制
	Copy() Series
	// Reverse 序列反转
	Reverse() Series
	// Select 选取一段记录
	Select(r ScopeLimit) Series
	// Append 增加一批记录
	Append(values ...any) Series
	// Concat concatenates two series together. It will return a new Series with the
	// combined elements of both Series.
	Concat(x Series) Series

	// Records returns the elements of a Series as a []string
	Records(round ...bool) []string
	// IndexOf 取一条记录, index<0时, 从后往前取值
	IndexOf(index int, opt ...any) any
	// Subset 获取子集
	Subset(start, end int, opt ...any) Series
	// Repeat elements of an array.
	Repeat(x any, repeats int) Series
	// FillNa Fill NA/NaN values using the specified method.
	FillNa(v any, inplace bool) Series

	// Ref 引用其它周期的数据
	Ref(periods any) (s Series)
	// Shift index by desired number of periods with an optional time freq.
	//	使用可选的时间频率按所需的周期数移动索引.
	Shift(periods int) Series
	// Rolling 序列化版本
	Rolling(param any) RollingAndExpandingMixin
	// Apply 接受一个回调函数
	Apply(f func(idx int, v any))
	// Apply2 增加替换功能, 默认不替换
	Apply2(f func(idx int, v any) any, args ...bool) Series
	// Logic 逻辑处理
	Logic(f func(idx int, v any) bool) []bool
	// EWM Provide exponentially weighted (EW) calculations.
	//
	//	Exactly one of ``com``, ``span``, ``halflife``, or ``alpha`` must be
	//	provided if ``times`` is not provided. If ``times`` is provided,
	//	``halflife`` and one of ``com``, ``span`` or ``alpha`` may be provided.
	EWM(alpha EW) ExponentialMovingWindow

	// Mean calculates the average value of a series
	Mean() DType
	// StdDev calculates the standard deviation of a series
	StdDev() DType
	// Max 找出最大值
	Max() any
	// ArgMax Returns the indices of the maximum values along an axis
	ArgMax() int
	// Min 找出最小值
	Min() any
	// ArgMin Returns the indices of the minimum values along an axis
	ArgMin() int
	// Diff 元素的第一个离散差
	Diff(param any) (s Series)
	// Std 计算标准差
	Std() DType
	// Sum 计算累和
	Sum() DType
	Add(x any) Series
	Sub(x any) Series
	Mul(x any) Series
	Div(x any) Series
	Eq(x any) Series
	Gt(x any) Series
	Gte(x any) Series
	Lt(x any) Series
	Lte(x any) Series
	And(x any) Series
}

// DetectTypeBySlice 检测类型
func DetectTypeBySlice(arr ...any) (Type, error) {
	var hasFloat32s, hasFloat64s, hasInts, hasBools, hasStrings bool
	for _, v := range arr {
		switch value := v.(type) {
		case string:
			hasStrings = true
			continue
		case float32:
			hasFloat32s = true
			continue
		case float64:
			hasFloat64s = true
			continue
		case int, int32, int64:
			hasInts = true
			continue
		case bool:
			hasBools = true
			continue
		default:
			vv := reflect.ValueOf(v)
			vk := vv.Kind()
			switch vk {
			case reflect.Slice, reflect.Array: // 切片或数组
				for i := 0; i < vv.Len(); i++ {
					tv := vv.Index(i).Interface()
					t_, err := DetectTypeBySlice(tv)
					if err == nil {
						return t_, nil
					}
				}
			case reflect.Struct: // 忽略结构体
				continue
			default:
			}
			_ = value
		}
	}

	switch {
	case hasStrings:
		return SERIES_TYPE_STRING, nil
	case hasBools:
		return SERIES_TYPE_BOOL, nil
	case hasFloat32s:
		return SERIES_TYPE_FLOAT32, nil
	case hasFloat64s:
		return SERIES_TYPE_FLOAT64, nil
	case hasInts:
		return SERIES_TYPE_INT64, nil
	default:
		return SERIES_TYPE_STRING, fmt.Errorf("couldn't detect type")
	}
}

// NewSeries 构建一个新的Series
func NewSeries[T BaseType](data ...T) Series {
	var S Series
	values := []T{}
	if len(data) > 0 {
		values = append(values, data...)
	}
	S = NDArray[T](values)
	return S
}