package webpath

import (
	"net/url"
	"strings"
)

// LegacyPathRemap 旧版 app 导航路径 → 当前 h5 SSR 实际路由。
var LegacyPathRemap = map[string]string{
	"/avtopic/": "/video/all",
	"/avtopic":  "/video/all",
	"/dh/":      "/nav",
	"/dh":       "/nav",
}

// SkipPublicPaths 当前 web 无对应页面、或不应对外暴露的路径。
var SkipPublicPaths = map[string]struct{}{
	"/topic/":         {},
	"/topic":          {},
	"/history/":       {},
	"/history":        {},
	"/tag/all/":       {},
	"/tag/all":        {},
	"/useragreement/": {},
	"/useragreement":  {},
	"/privacypolicy/": {},
	"/privacypolicy":  {},
	"/dmca/":          {},
	"/dmca":           {},
}

// NormalizePublicURL 将 URL 规范为 web 可访问地址；第二个返回值 false 表示应跳过。
func NormalizePublicURL(raw string) (string, bool) {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return "", false
	}

	parsed, err := url.Parse(raw)
	if err != nil {
		return "", false
	}

	path := parsed.Path
	if path == "" {
		path = "/"
	}
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}

	normalizedPath := normalizePathKey(path)
	if _, skip := SkipPublicPaths[normalizedPath]; skip {
		return "", false
	}
	if mapped, ok := LegacyPathRemap[normalizedPath]; ok {
		path = mapped
		parsed.Path = path
	}

	if parsed.Path != "/" {
		parsed.Path = strings.TrimRight(parsed.Path, "/")
		if parsed.Path == "" {
			parsed.Path = "/"
		}
	}

	return parsed.String(), true
}

// NormalizePublicPath 规范单条站内 path（不含域名）。
func NormalizePublicPath(path string) (string, bool) {
	path = strings.TrimSpace(path)
	if path == "" {
		return "", false
	}
	if strings.Contains(path, "://") {
		return NormalizePublicURL(path)
	}
	base := "https://example.com"
	normalized, ok := NormalizePublicURL(base + path)
	if !ok {
		return "", false
	}
	parsed, err := url.Parse(normalized)
	if err != nil {
		return "", false
	}
	return parsed.Path, true
}

func normalizePathKey(path string) string {
	path = strings.TrimSpace(path)
	if path == "" {
		return "/"
	}
	if !strings.HasPrefix(path, "/") {
		path = "/" + path
	}
	lower := strings.ToLower(path)
	if lower != "/" && !strings.HasSuffix(lower, "/") {
		lower += "/"
	}
	return lower
}