package handler

import (
	"encoding/json"
	"strings"

	"github.com/gin-gonic/gin"
)

// PublicOriginFromRequest 根据当前请求还原对外访问根 URL（https://souldev.xxx），
// 用于开发/预览域名与 API_BASE_URL（常为正式 soulapi）不一致时，头像与 mp_config.apiDomain 与浏览器 Host 对齐。
func PublicOriginFromRequest(c *gin.Context) string {
	if c == nil || c.Request == nil {
		return ""
	}
	proto := strings.TrimSpace(strings.ToLower(c.GetHeader("X-Forwarded-Proto")))
	switch proto {
	case "":
		if c.Request.TLS != nil {
			proto = "https"
		} else {
			proto = "http"
		}
	case "http", "https":
	default:
		proto = "https"
	}
	host := strings.TrimSpace(c.Request.Host)
	if xfh := c.GetHeader("X-Forwarded-Host"); xfh != "" {
		host = strings.TrimSpace(strings.Split(xfh, ",")[0])
	}
	if host == "" {
		return ""
	}
	return proto + "://" + host
}

// patchMiniprogramConfigJSONOrigin 深拷贝 JSON 响应体并将 mpConfig.apiDomain 改为当前请求的公网 origin（若有）。
// 避免 souldev 请求却下发 soulapi 域名导致小程序拼接静态资源/头像域名错误。
func patchMiniprogramConfigJSONOrigin(c *gin.Context, body interface{}) interface{} {
	origin := PublicOriginFromRequest(c)
	if origin == "" || body == nil {
		return body
	}
	b, err := json.Marshal(body)
	if err != nil {
		return body
	}
	var m map[string]interface{}
	if err := json.Unmarshal(b, &m); err != nil {
		return body
	}
	mp, ok := m["mpConfig"].(map[string]interface{})
	if !ok || mp == nil {
		return m
	}
	mp["apiDomain"] = origin
	return m
}