package jsonpack

import (
	"errors"
	"fmt"
	"reflect"
	"strings"

	"github.com/samber/lo"
)

type JsonEncode struct {
	strings  []string
	integers []string
	floats   []string
}

func (oJsonEncode *JsonEncode) astBuilder(item any) (AstToken, error) {
	itemType := reflect.ValueOf(item).Kind()

	if item == nil {
		return AstToken{category: "null", index: TOKEN_NULL}, nil
	}

	if itemType == reflect.Slice {
		tokens := []AstToken{}

		value := reflect.ValueOf(item)

		for i := 0; i < value.Len(); i++ {
			// value.Index(i).Interface() 把 value 转换为 interface{} 类型
			if resp, err := oJsonEncode.astBuilder(value.Index(i).Interface()); err == nil {
				tokens = append(tokens, resp)
			} else {
				return AstToken{}, err
			}
		}

		// return tokens, nil

		// Create a new sub-AST of type Array (@)
		return AstToken{category: "@", child: tokens}, nil
	}

	if itemType == reflect.Map {
		// Create a new sub-AST of type Object ($)
		// tokens := []any{AstToken{category: "$"}}
		tokens := []AstToken{}

		iter := reflect.ValueOf(item).MapRange()

		for iter.Next() {
			if resp, err := oJsonEncode.astBuilder(iter.Key().Interface()); err == nil {
				tokens = append(tokens, resp)
			} else {
				return AstToken{}, err
			}

			if resp, err := oJsonEncode.astBuilder(iter.Value().Interface()); err == nil {
				tokens = append(tokens, resp)
			} else {
				return AstToken{}, err
			}
		}

		// return tokens, nil
		return AstToken{category: "$", child: tokens}, nil
	}

	if item == "" {
		return AstToken{category: "empty", index: TOKEN_EMPTY_STRING}, nil
	}

	if itemType == reflect.String {
		value := item.(string)
		index := lo.IndexOf[string](oJsonEncode.strings, value)

		if index == -1 {
			oJsonEncode.strings = append(oJsonEncode.strings, astEncode(value))
			index = len(oJsonEncode.strings) - 1
		}

		return AstToken{category: "strings", index: index}, nil
	}

	switch itemType {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:

		value := astBase10to36(item.(int))
		index := lo.IndexOf[string](oJsonEncode.integers, value)

		if index == -1 {
			oJsonEncode.integers = append(oJsonEncode.integers, value)
			index = len(oJsonEncode.integers) - 1
		}

		return AstToken{category: "integers", index: index}, nil
	}

	if itemType == reflect.Float32 || itemType == reflect.Float64 {
		value := fmt.Sprintf("%v", item.(float64))
		index := lo.IndexOf[string](oJsonEncode.floats, value)

		if index == -1 {
			// 浮点数不用转36进制
			oJsonEncode.floats = append(oJsonEncode.floats, value)
			index = len(oJsonEncode.floats) - 1
		}

		return AstToken{category: "floats", index: index}, nil
	}

	if itemType == reflect.Bool {
		if item.(bool) {
			return AstToken{category: "boolean", index: TOKEN_TRUE}, nil
		} else {
			return AstToken{category: "boolean", index: TOKEN_FALSE}, nil
		}
	}

	return AstToken{}, errors.New(fmt.Sprintln("未知类型:", itemType, item))
}

func (oJsonEncode *JsonEncode) astParser(token AstToken) (string, error) {

	if token.category == "@" || token.category == "$" {
		var packed strings.Builder

		packed.WriteString(token.category)

		childPacked := []string{}

		for _, tk := range token.child {
			if resp, err := oJsonEncode.astParser(tk); err == nil {
				childPacked = append(childPacked, resp)
			} else {
				return "", err
			}
		}

		packed.WriteString(strings.Join(childPacked, "|"))
		packed.WriteString("]")

		return packed.String(), nil
	}

	switch token.category {
	case "strings":
		return astBase10to36(token.index), nil
	case "integers":
		return astBase10to36(token.index + len(oJsonEncode.strings)), nil
	case "floats":
		return astBase10to36(token.index + len(oJsonEncode.strings) + len(oJsonEncode.integers)), nil
	case "boolean":
		return fmt.Sprintf("%v", token.index), nil
	case "null":
		return fmt.Sprintf("%v", TOKEN_NULL), nil
	case "empty":
		return fmt.Sprintf("%v", TOKEN_EMPTY_STRING), nil
	}

	return "", errors.New(fmt.Sprintln("未知类型:", token.category))
}

func (oJsonEncode *JsonEncode) toString(token AstToken) (string, error) {
	str, err := oJsonEncode.astParser(token)
	
	if err != nil {
		return "", err
	}

	var packed strings.Builder

	packed.WriteString(strings.Join(oJsonEncode.strings, "|"))
	packed.WriteString("^")
	packed.WriteString(strings.Join(oJsonEncode.integers, "|"))
	packed.WriteString("^")
	packed.WriteString(strings.Join(oJsonEncode.floats, "|"))
	packed.WriteString("^")

	packed.WriteString(str)

	return packed.String(), nil
}