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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/

// See page 348.

// Search is a demo of the params.Unpack function.
package main

import (
    "fmt"
    "log"
    "net/http"
)

//!+

import "gopl.io/ch12/params"

// search implements the /search URL endpoint.
func search(resp http.ResponseWriter, req *http.Request) {
    var data struct {
        Labels     []string `http:"l"`
        MaxResults int      `http:"max"`
        Exact      bool     `http:"x"`
    }
    data.MaxResults = 10 // set default
    if err := params.Unpack(req, &data); err != nil {
        http.Error(resp, err.Error(), http.StatusBadRequest) // 400
        return
    }

    // ...rest of handler...
    fmt.Fprintf(resp, "Search: %+v\n", data)
}

//!-

func main() {
    http.HandleFunc("/search", search)
    log.Fatal(http.ListenAndServe(":12345", nil))
}

/*
//!+output
$ go build gopl.io/ch12/search
$ ./search &
$ ./fetch 'http://localhost:12345/search'
Search: {Labels:[] MaxResults:10 Exact:false}
$ ./fetch 'http://localhost:12345/search?l=golang&l=programming'
Search: {Labels:[golang programming] MaxResults:10 Exact:false}
$ ./fetch 'http://localhost:12345/search?l=golang&l=programming&max=100'
Search: {Labels:[golang programming] MaxResults:100 Exact:false}
$ ./fetch 'http://localhost:12345/search?x=true&l=golang&l=programming'
Search: {Labels:[golang programming] MaxResults:10 Exact:true}
$ ./fetch 'http://localhost:12345/search?q=hello&x=123'
x: strconv.ParseBool: parsing "123": invalid syntax
$ ./fetch 'http://localhost:12345/search?q=hello&max=lots'
max: strconv.ParseInt: parsing "lots": invalid syntax
//!-output
*/