// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.

// utils.go
package expr

import (
	"fmt"
	"reflect"
)

func isString(v any) (ok bool) {
	_, ok = v.(string)
	return ok
}

func isInteger(v any) (ok bool) {
	_, ok = v.(int64)
	return ok
}

func isFloat(v any) (ok bool) {
	_, ok = v.(float64)
	return ok
}

func isList(v any) (ok bool) {
	_, ok = v.([]any)
	return ok
}

func isDict(v any) (ok bool) {
	_, ok = v.(map[any]any)
	return ok
}

func isNumber(v any) (ok bool) {
	return isFloat(v) || isInteger(v)
}

func isNumberString(v any) (ok bool) {
	return isString(v) || isNumber(v)
}

func isFunctor(v any) (ok bool) {
	_, ok = v.(Functor)
	return
}

func isIterator(v any) (ok bool) {
	_, ok = v.(Iterator)
	return
}

func numAsFloat(v any) (f float64) {
	var ok bool
	if f, ok = v.(float64); !ok {
		i, _ := v.(int64)
		f = float64(i)
	}
	return
}

func toBool(v any) (b bool, ok bool) {
	ok = true
	switch x := v.(type) {
	case string:
		b = len(x) > 0
	case float64:
		b = x != 0.0
	case int64:
		b = x != 0
	case bool:
		b = x
	default:
		ok = false
	}
	return
}

func isFunc(v any) bool {
	return reflect.TypeOf(v).Kind() == reflect.Func
}

func anyInteger(v any) (i int64, ok bool) {
	ok = true
	switch intval := v.(type) {
	case int:
		i = int64(intval)
	case uint8:
		i = int64(intval)
	case uint16:
		i = int64(intval)
	case uint64:
		i = int64(intval)
	case uint32:
		i = int64(intval)
	case int8:
		i = int64(intval)
	case int16:
		i = int64(intval)
	case int32:
		i = int64(intval)
	case int64:
		i = intval
	default:
		ok = false
	}
	return
}

func fromGenericAny(v any) (exprAny any, ok bool) {
	if exprAny, ok = v.(bool); ok {
		return
	}
	if exprAny, ok = v.(string); ok {
		return
	}
	if exprAny, ok = anyInteger(v); ok {
		return
	}
	if exprAny, ok = anyFloat(v); ok {
		return
	}
	return
}

func anyFloat(v any) (float float64, ok bool) {
	ok = true
	switch floatval := v.(type) {
	case float32:
		float = float64(floatval)
	case float64:
		float = floatval
	default:
		ok = false
	}
	return
}

func CopyMap[K comparable, V any](dest, source map[K]V) map[K]V {
	for k, v := range source {
		dest[k] = v
	}
	return dest
}

func CloneMap[K comparable, V any](source map[K]V) map[K]V {
	dest := make(map[K]V, len(source))
	return CopyMap(dest, source)
}

func CopyFilteredMap[K comparable, V any](dest, source map[K]V, filter func(key K) (accept bool)) map[K]V {
	// fmt.Printf("--- Clone with filter %p\n", filter)
	if filter == nil {
		return CopyMap(dest, source)
	} else {
		for k, v := range source {
			if filter(k) {
				// fmt.Printf("\tClone var %q\n", k)
				dest[k] = v
			}
		}
	}
	return dest
}

func CloneFilteredMap[K comparable, V any](source map[K]V, filter func(key K) (accept bool)) map[K]V {
	dest := make(map[K]V, len(source))
	return CopyFilteredMap(dest, source, filter)
}

func toInt(value any, description string) (i int, err error) {
	if valueInt64, ok := value.(int64); ok {
		i = int(valueInt64)
	} else {
		err = fmt.Errorf("%s expected integer, got %T (%v)", description, value, value)
	}
	return
}