package main // import "contnet.org/util/cnp-req"

import (
	"bytes"
	"flag"
	"fmt"
	"io"
	"os"
	"path"
	"strings"

	"contnet.org/lib/cnp-go"
)

var prog = path.Base(os.Args[0])

func checkerr(err error) {
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s: error: %s\n", prog, err)
		os.Exit(1)
	}
}

type requestPrinter struct {
	out      io.Writer
	body     io.Reader
	n        int64
	notFirst bool
}

func (p *requestPrinter) Read(b []byte) (int, error) {
	n, err := p.body.Read(b)
	p.n += int64(n)
	if n > 0 && !p.notFirst {
		p.out.Write([]byte("> "))
		p.notFirst = true
	}
	p.out.Write(bytes.Replace(b[:n], []byte("\n"), []byte("\n> "), -1))
	if err == io.EOF && p.n > 0 {
		p.out.Write([]byte("\n"))
	}
	return n, err
}

func send(r *cnp.Request, printReq, printHdr, printBody bool) {
	if printReq {
		if r.Body != nil {
			if _, ok := r.Header.Parameters["length"]; !ok {
				r.ComputeLength()
			}

			fmt.Fprint(os.Stderr, "> ")
			r.Header.Write(os.Stderr)
			r.Body = &requestPrinter{out: os.Stderr, body: io.LimitReader(r.Body, r.Length())}
		} else {
			fmt.Fprint(os.Stderr, "> ")
			r.Header.Write(os.Stderr)
		}
	}

	resp, err := cnp.Send(r)
	checkerr(err)
	defer resp.Close()

	if printHdr {
		checkerr(resp.Header.Write(os.Stdout))
	}

	if printBody {
		l := resp.Length()
		if l > 0 {
			resp.Body = io.LimitReader(resp.Body, l)
		}
		_, err = io.Copy(os.Stdout, resp.Body)
		checkerr(err)
	}
}

func usage(f io.Writer) {
	fmt.Fprintf(f, "%s: usage: %s {URL|HOST/PATH} [PARAM=VALUE ...]\n", prog, prog)
}

func main() {
	printReq := flag.Bool("v", false, "print the request header and body")
	printHdr := flag.Bool("i", false, "print the response header")
	noBody := flag.Bool("I", false, "only print the response header without the body")
	rawParams := flag.Bool("r", false, "treat parameters as raw CNP-encoded parameters")
	readBody := flag.Bool("b", false, "read body data from stdin")
	body := flag.String("B", "", "body data")

	flag.Parse()

	if flag.NArg() < 1 {
		usage(os.Stderr)
		os.Exit(2)
	}

	var req *cnp.Request
	var err error
	if strings.HasPrefix(flag.Arg(0), "cnp:") || strings.HasPrefix(flag.Arg(0), "/") {
		req, err = cnp.NewRequestURL(flag.Arg(0), nil)
	} else {
		ss := strings.SplitN(flag.Arg(0), "/", 2)
		if len(ss) != 2 {
			usage(os.Stderr)
			os.Exit(2)
		}
		req, err = cnp.NewRequest(ss[0], "/"+ss[1], nil)
	}
	checkerr(err)

	req.Body = strings.NewReader(*body)
	if *readBody {
		req.Body = os.Stdin
	}

	for _, arg := range flag.Args()[1:] {
		ss := strings.SplitN(arg, "=", 2)
		if len(ss) != 2 {
			checkerr(fmt.Errorf("invalid parameter: %q", arg))
		}
		if *rawParams {
			ss[0], err = cnp.Unescape([]byte(ss[0]))
			checkerr(err)
			ss[1], err = cnp.Unescape([]byte(ss[1]))
			checkerr(err)
		}
		req.SetParam(ss[0], ss[1])
	}

	send(req, *printReq, *printHdr || *noBody, !*noBody)
}