package main

import (
    "fmt"
    "net/url"
)

func main() {
    rawURL := "https://user:pass@example.com:8080/path/to/page?param1=value1&param2=value2#section"
    parsed, err := url.Parse(rawURL)
    if err != nil {
        panic(err)
    }

    fmt.Println("Scheme:", parsed.Scheme)     // https
    fmt.Println("User:", parsed.User)         // user:pass
    fmt.Println("Host:", parsed.Host)         // example.com:8080
    fmt.Println("Path:", parsed.Path)         // /path/to/page
    fmt.Println("RawQuery:", parsed.RawQuery) // param1=value1&param2=value2
    fmt.Println("Fragment:", parsed.Fragment) // section
}

values, _ := url.ParseQuery(parsed.RawQuery)
fmt.Println("param1:", values.Get("param1")) // value1
fmt.Println("All param2:", values["param2"]) // [value2]

// 添加新参数
values.Add("param3", "value3")
values.Set("param1", "new_value") // 覆盖原有值

// 重新编码为查询字符串
newQuery := values.Encode() // param1=new_value&param2=value2&param3=value3
parsed.RawQuery = newQuery
fmt.Println("New URL:", parsed.String())

base, _ := url.Parse("https://example.com/base/")
rel, _ := url.Parse("../other/page?from=link")
resolved := base.ResolveReference(rel)
fmt.Println(resolved) // https://example.com/other/page?from=link