// Package site 在 /home（及 /）提供产品官网单页（SSR，资源嵌入二进制）。
package site

import (
	"embed"
	"net/http"
	"strings"

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

//go:embed template.html terms.html assets
var files embed.FS

// Handler 官网服务
type Handler struct {
	html  string
	terms string
}

func New() *Handler {
	raw, err := files.ReadFile("template.html")
	if err != nil {
		panic("site: template.html 缺失: " + err.Error())
	}
	terms, err := files.ReadFile("terms.html")
	if err != nil {
		panic("site: terms.html 缺失: " + err.Error())
	}
	return &Handler{html: string(raw), terms: string(terms)}
}

// Register 注册路由：/ 与 /home 均渲染官网
func (h *Handler) Register(r *gin.Engine) {
	r.GET("/", h.Page)
	r.GET("/home", h.Page)
	r.GET("/index.html", h.Page)
	r.GET("/site/assets/*file", h.Asset)
	r.GET("/terms", h.Terms)
}

// Terms 渲染服务条款
func (h *Handler) Terms(c *gin.Context) {
	c.Header("Content-Type", "text/html; charset=utf-8")
	c.Header("Cache-Control", "no-cache")
	_, _ = c.Writer.WriteString(h.terms)
}

// Page 渲染官网
func (h *Handler) Page(c *gin.Context) {
	c.Header("Content-Type", "text/html; charset=utf-8")
	c.Header("Cache-Control", "no-cache")
	_, _ = c.Writer.WriteString(h.html)
}

// Asset 静态资源
func (h *Handler) Asset(c *gin.Context) {
	name := strings.TrimPrefix(c.Param("file"), "/")
	if strings.Contains(name, "..") {
		c.Status(http.StatusBadRequest)
		return
	}
	data, err := files.ReadFile("assets/" + name)
	if err != nil {
		c.Status(http.StatusNotFound)
		return
	}
	switch {
	case strings.HasSuffix(name, ".css"):
		c.Header("Content-Type", "text/css; charset=utf-8")
	case strings.HasSuffix(name, ".js"):
		c.Header("Content-Type", "application/javascript; charset=utf-8")
	case strings.HasSuffix(name, ".svg"):
		c.Header("Content-Type", "image/svg+xml")
	default:
		c.Header("Content-Type", "application/octet-stream")
	}
	c.Header("Cache-Control", "public, max-age=3600")
	c.Data(http.StatusOK, "", data)
}