package common

import (
	"bbs-go/internal/models/constants"
	"bbs-go/internal/pkg/html"
	"bbs-go/internal/pkg/markdown"
	"bbs-go/internal/pkg/text"
	"net"
	"net/http"
	"strings"
)

func GetSummary(contentType string, content string) (summary string) {
	if contentType == constants.ContentTypeMarkdown {
		summary = markdown.GetSummary(content, constants.SummaryLen)
	} else if contentType == constants.ContentTypeHtml {
		summary = html.GetSummary(content, constants.SummaryLen)
	} else {
		summary = text.GetSummary(content, constants.SummaryLen)
	}
	return
}

// GetMarkdownSummary 截取markdown摘要
func GetMarkdownSummary(markdownStr string) string {
	return markdown.GetSummary(markdownStr, constants.SummaryLen)
}

// GetRequestIP 尽最大努力实现获取客户端 IP 的算法。
// 解析 X-Real-IP 和 X-Forwarded-For 以便于反向代理（nginx 或 haproxy）可以正常工作。
func GetRequestIP(r *http.Request) string {
	xForwardedFor := r.Header.Get("X-Forwarded-For")
	ip := strings.TrimSpace(strings.Split(xForwardedFor, ",")[0])
	if ip != "" {
		return ip
	}

	ip = strings.TrimSpace(r.Header.Get("X-Real-Ip"))
	if ip != "" {
		return ip
	}

	if ip, _, err := net.SplitHostPort(strings.TrimSpace(r.RemoteAddr)); err == nil {
		return ip
	}
	return ""
}

func GetUserAgent(r *http.Request) string {
	return r.Header.Get("User-Agent")
}

func Distinct[T any](input []T, getKey func(T) any) (output []T) {
	tempMap := map[any]byte{}
	for _, item := range input {
		l := len(tempMap)
		tempMap[getKey(item)] = 0
		if len(tempMap) != l { // 数量发生变化，说明不存在
			output = append(output, item)
		}
	}
	return
}