// Package echo 提供本地 HTTP 回显，供自动化回归套件使用（不依赖外网 httpbin）。
package echo

import (
	"encoding/base64"
	"io"
	"net/http"
	"strings"

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

// Mount registers /v1/echo/* routes.
func Mount(r *gin.Engine) {
	e := r.Group("/v1/echo")
	e.GET("/get", getEcho)
	e.POST("/json", jsonEcho)
	e.POST("/form", formEcho)
	e.POST("/multipart", multipartEcho)
	e.GET("/headers", headersEcho)
	e.GET("/cookies", cookiesEcho)
	e.GET("/bearer", bearerEcho)
	e.GET("/basic", basicEcho)
}

func baseMeta(c *gin.Context) gin.H {
	hdrs := gin.H{}
	for k, v := range c.Request.Header {
		if len(v) == 1 {
			hdrs[k] = v[0]
		} else {
			hdrs[k] = v
		}
	}
	q := gin.H{}
	for k, v := range c.Request.URL.Query() {
		if len(v) == 1 {
			q[k] = v[0]
		} else {
			q[k] = v
		}
	}
	return gin.H{
		"ok":      true,
		"service": "opsxapi-echo",
		"method":  c.Request.Method,
		"path":    c.Request.URL.Path,
		"query":   q,
		"headers": hdrs,
	}
}

func getEcho(c *gin.Context) {
	c.JSON(http.StatusOK, baseMeta(c))
}

func jsonEcho(c *gin.Context) {
	body, _ := io.ReadAll(c.Request.Body)
	out := baseMeta(c)
	out["bodyRaw"] = string(body)
	c.JSON(http.StatusOK, out)
}

func formEcho(c *gin.Context) {
	_ = c.Request.ParseForm()
	form := gin.H{}
	for k, v := range c.Request.PostForm {
		if len(v) == 1 {
			form[k] = v[0]
		} else {
			form[k] = v
		}
	}
	out := baseMeta(c)
	out["form"] = form
	c.JSON(http.StatusOK, out)
}

func multipartEcho(c *gin.Context) {
	_ = c.Request.ParseMultipartForm(8 << 20)
	form := gin.H{}
	if c.Request.MultipartForm != nil {
		for k, v := range c.Request.MultipartForm.Value {
			if len(v) == 1 {
				form[k] = v[0]
			} else {
				form[k] = v
			}
		}
	}
	out := baseMeta(c)
	out["form"] = form
	c.JSON(http.StatusOK, out)
}

func headersEcho(c *gin.Context) {
	out := baseMeta(c)
	out["xOpsxProbe"] = c.GetHeader("X-Opsx-Probe")
	c.JSON(http.StatusOK, out)
}

func cookiesEcho(c *gin.Context) {
	out := baseMeta(c)
	cookies := gin.H{}
	for _, ck := range c.Request.Cookies() {
		cookies[ck.Name] = ck.Value
	}
	// 浏览器禁止脚本设置 Cookie 头；回归用例改走 X-Opsx-Cookie
	if raw := c.GetHeader("X-Opsx-Cookie"); raw != "" {
		for _, part := range strings.Split(raw, ";") {
			part = strings.TrimSpace(part)
			if part == "" {
				continue
			}
			kv := strings.SplitN(part, "=", 2)
			if len(kv) == 2 {
				cookies[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1])
			}
		}
	}
	out["cookies"] = cookies
	c.JSON(http.StatusOK, out)
}

func bearerEcho(c *gin.Context) {
	auth := c.GetHeader("Authorization")
	if !strings.HasPrefix(auth, "Bearer ") || strings.TrimSpace(strings.TrimPrefix(auth, "Bearer ")) == "" {
		c.JSON(http.StatusUnauthorized, gin.H{"ok": false, "error": "missing bearer"})
		return
	}
	out := baseMeta(c)
	out["authenticated"] = true
	out["token"] = strings.TrimSpace(strings.TrimPrefix(auth, "Bearer "))
	c.JSON(http.StatusOK, out)
}

func basicEcho(c *gin.Context) {
	auth := c.GetHeader("Authorization")
	if !strings.HasPrefix(auth, "Basic ") {
		c.Header("WWW-Authenticate", `Basic realm="opsxapi"`)
		c.JSON(http.StatusUnauthorized, gin.H{"ok": false, "error": "missing basic"})
		return
	}
	raw, err := base64.StdEncoding.DecodeString(strings.TrimSpace(strings.TrimPrefix(auth, "Basic ")))
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"ok": false, "error": "bad basic"})
		return
	}
	parts := strings.SplitN(string(raw), ":", 2)
	out := baseMeta(c)
	out["authenticated"] = true
	out["user"] = parts[0]
	c.JSON(http.StatusOK, out)
}