package message

import (
	"encoding/json"
	"fmt"
	"net/url"
	"regexp"
	"strings"
)

type ImageMessage struct {
	Type string           `json:"type"`
	Data ImageMessageData `json:"data"`
}

type ImageMessageData struct {
	URL        string `json:"url,omitzero"`
	Summary    string `json:"summary,omitzero"`
	File       string `json:"file,omitzero"`
	Key        string `json:"key,omitzero"`
	EmojiID    string `json:"emoji_id,omitzero"`
	PackageID  string `json:"emoji_package_id,omitzero"`
	SubType    string `json:"sub_type,omitzero"`
	FileID     string `json:"file_id,omitzero"`
	FileSize   string `json:"file_size,omitzero"`
	FileUnique string `json:"file_unique,omitzero"`
}

func init() {
	RegisterMessageType(TypeImage, func() CQMessage {
		return NewImageMessage()
	})
}

func NewImageMessage() *ImageMessage {
	return &ImageMessage{
		Type: TypeImage,
		Data: ImageMessageData{},
	}
}

func (msg *ImageMessage) SetData(data json.RawMessage) error {
	return json.Unmarshal(data, &msg.Data)
}

func (msg *ImageMessage) ToCQString() string {
	if msg.Data.URL == "" && msg.Data.File == "" {
		return ""
	}
	// URL 转义
	escapedURL, _ := url.QueryUnescape(msg.Data.URL)

	escapedURL = strings.ReplaceAll(escapedURL, ",", ",")
	escapedURL = strings.ReplaceAll(escapedURL, "[", "[")
	escapedURL = strings.ReplaceAll(escapedURL, "]", "]")
	escapedURL = strings.ReplaceAll(escapedURL, "&", "&")

	// 构造 CQ:image 字符串
	cqString := fmt.Sprintf("[CQ:image,file=%s,sub_type=%s,file_id=%s,url=%s,file_size=%s,file_unique=%s]",
		msg.Data.File, msg.Data.SubType, msg.Data.FileID, escapedURL, msg.Data.FileSize, msg.Data.FileUnique)

	return cqString
}

func (msg *ImageMessage) ParseMessage(data string) error {
	// 使用正则表达式提取各个字段
	re := regexp.MustCompile(`\[CQ:image,(.*?)\]`)
	matches := re.FindStringSubmatch(data)
	if len(matches) != 2 {
		return fmt.Errorf("invalid image message format")
	}

	attrs := make(map[string]string)
	pairs := strings.Split(matches[1], ",")
	for _, pair := range pairs {
		if kv := strings.SplitN(pair, "=", 2); len(kv) == 2 {
			attrs[kv[0]] = kv[1]
		}
	}

	msg.Data.URL = attrs["url"]
	msg.Data.URL, _ = url.QueryUnescape(msg.Data.URL)
	msg.Data.URL = strings.ReplaceAll(msg.Data.URL, ",", ",")
	msg.Data.URL = strings.ReplaceAll(msg.Data.URL, "[", "[")
	msg.Data.URL = strings.ReplaceAll(msg.Data.URL, "]", "]")
	msg.Data.URL = strings.ReplaceAll(msg.Data.URL, "&", "&")
	msg.Data.Summary = attrs["summary"]
	msg.Data.File = attrs["file"]
	msg.Data.Key = attrs["key"]
	msg.Data.EmojiID = attrs["emoji_id"]
	msg.Data.PackageID = attrs["emoji_package_id"]
	msg.Data.SubType = attrs["sub_type"]
	msg.Data.FileID = attrs["file_id"]
	msg.Data.FileSize = attrs["file_size"]
	msg.Data.FileUnique = attrs["file_unique"]

	// URL是必需的字段（接收图片时）
	if msg.Data.URL == "" {
		return fmt.Errorf("missing required url field")
	}

	return nil
}