package luajit

/*
#include <lua.h>
*/
import "C"
import (
	"fmt"
	"strconv"
)

// LuaType represents Lua value types
type LuaType int

const (
	TypeNone          LuaType = -1
	TypeNil           LuaType = 0
	TypeBoolean       LuaType = 1
	TypeLightUserData LuaType = 2
	TypeNumber        LuaType = 3
	TypeString        LuaType = 4
	TypeTable         LuaType = 5
	TypeFunction      LuaType = 6
	TypeUserData      LuaType = 7
	TypeThread        LuaType = 8
)

func (t LuaType) String() string {
	switch t {
	case TypeNone:
		return "none"
	case TypeNil:
		return "nil"
	case TypeBoolean:
		return "boolean"
	case TypeLightUserData:
		return "lightuserdata"
	case TypeNumber:
		return "number"
	case TypeString:
		return "string"
	case TypeTable:
		return "table"
	case TypeFunction:
		return "function"
	case TypeUserData:
		return "userdata"
	case TypeThread:
		return "thread"
	default:
		return "unknown"
	}
}

// ConvertValue converts a value to the requested type with comprehensive type conversion
func ConvertValue[T any](value any) (T, bool) {
	var zero T

	if value == nil {
		return zero, false
	}

	if result, ok := value.(T); ok {
		return result, true
	}

	switch any(zero).(type) {
	case string:
		return convertToString[T](value)
	case int:
		return convertToInt[T](value)
	case float64:
		return convertToFloat[T](value)
	case bool:
		return convertToBool[T](value)
	case []int:
		return convertToIntSlice[T](value)
	case []string:
		return convertToStringSlice[T](value)
	case []bool:
		return convertToBoolSlice[T](value)
	case []float64:
		return convertToFloatSlice[T](value)
	case []any:
		return convertToAnySlice[T](value)
	case map[string]string:
		return convertToStringMap[T](value)
	case map[string]int:
		return convertToIntMap[T](value)
	case map[int]any:
		return convertToIntKeyMap[T](value)
	case map[string]any:
		return convertToAnyMap[T](value)
	}

	return zero, false
}

func convertToString[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case float64:
		if v == float64(int(v)) {
			return any(strconv.Itoa(int(v))).(T), true
		}
		return any(fmt.Sprintf("%g", v)).(T), true
	case int:
		return any(strconv.Itoa(v)).(T), true
	case bool:
		return any(strconv.FormatBool(v)).(T), true
	}
	return zero, false
}

func convertToInt[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case float64:
		return any(int(v)).(T), true
	case string:
		if i, err := strconv.Atoi(v); err == nil {
			return any(i).(T), true
		}
	case bool:
		if v {
			return any(1).(T), true
		}
		return any(0).(T), true
	}
	return zero, false
}

func convertToFloat[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case int:
		return any(float64(v)).(T), true
	case string:
		if f, err := strconv.ParseFloat(v, 64); err == nil {
			return any(f).(T), true
		}
	case bool:
		if v {
			return any(1.0).(T), true
		}
		return any(0.0).(T), true
	}
	return zero, false
}

func convertToBool[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case string:
		switch v {
		case "true", "yes", "1":
			return any(true).(T), true
		case "false", "no", "0":
			return any(false).(T), true
		}
	case int:
		return any(v != 0).(T), true
	case float64:
		return any(v != 0).(T), true
	}
	return zero, false
}

func convertToIntSlice[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case []float64:
		result := make([]int, len(v))
		for i, f := range v {
			result[i] = int(f)
		}
		return any(result).(T), true
	case []any:
		result := make([]int, 0, len(v))
		for _, item := range v {
			if i, ok := ConvertValue[int](item); ok {
				result = append(result, i)
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToStringSlice[T any](value any) (T, bool) {
	var zero T
	if v, ok := value.([]any); ok {
		result := make([]string, 0, len(v))
		for _, item := range v {
			if s, ok := ConvertValue[string](item); ok {
				result = append(result, s)
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToBoolSlice[T any](value any) (T, bool) {
	var zero T
	if v, ok := value.([]any); ok {
		result := make([]bool, 0, len(v))
		for _, item := range v {
			if b, ok := ConvertValue[bool](item); ok {
				result = append(result, b)
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToFloatSlice[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case []int:
		result := make([]float64, len(v))
		for i, n := range v {
			result[i] = float64(n)
		}
		return any(result).(T), true
	case []any:
		result := make([]float64, 0, len(v))
		for _, item := range v {
			if f, ok := ConvertValue[float64](item); ok {
				result = append(result, f)
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToAnySlice[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case []int:
		result := make([]any, len(v))
		for i, n := range v {
			result[i] = n
		}
		return any(result).(T), true
	case []string:
		result := make([]any, len(v))
		for i, s := range v {
			result[i] = s
		}
		return any(result).(T), true
	case []bool:
		result := make([]any, len(v))
		for i, b := range v {
			result[i] = b
		}
		return any(result).(T), true
	case []float64:
		result := make([]any, len(v))
		for i, f := range v {
			result[i] = f
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToStringMap[T any](value any) (T, bool) {
	var zero T
	if v, ok := value.(map[string]any); ok {
		result := make(map[string]string, len(v))
		for k, val := range v {
			if s, ok := ConvertValue[string](val); ok {
				result[k] = s
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToIntMap[T any](value any) (T, bool) {
	var zero T
	if v, ok := value.(map[string]any); ok {
		result := make(map[string]int, len(v))
		for k, val := range v {
			if i, ok := ConvertValue[int](val); ok {
				result[k] = i
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToIntKeyMap[T any](value any) (T, bool) {
	var zero T
	if v, ok := value.(map[string]any); ok {
		result := make(map[int]any, len(v))
		for k, val := range v {
			if i, err := strconv.Atoi(k); err == nil {
				result[i] = val
			} else {
				return zero, false
			}
		}
		return any(result).(T), true
	}
	return zero, false
}

func convertToAnyMap[T any](value any) (T, bool) {
	var zero T
	switch v := value.(type) {
	case map[string]string:
		result := make(map[string]any, len(v))
		for k, s := range v {
			result[k] = s
		}
		return any(result).(T), true
	case map[string]int:
		result := make(map[string]any, len(v))
		for k, i := range v {
			result[k] = i
		}
		return any(result).(T), true
	case map[int]any:
		result := make(map[string]any, len(v))
		for k, val := range v {
			result[strconv.Itoa(k)] = val
		}
		return any(result).(T), true
	}
	return zero, false
}

// GetTypedValue gets a value from the state with type conversion
func GetTypedValue[T any](s *State, index int) (T, bool) {
	value, err := s.ToValue(index)
	if err != nil {
		var zero T
		return zero, false
	}
	return ConvertValue[T](value)
}

// GetGlobalTyped gets a global variable with type conversion
func GetGlobalTyped[T any](s *State, name string) (T, bool) {
	s.GetGlobal(name)
	defer s.Pop(1)
	return GetTypedValue[T](s, -1)
}