// Copyright (c) 2022 Nadeen Udantha <me@nadeen.lk>. All rights reserved.

package boihttp

import (
	"bufio"
	"context"
	"io"
	"net"
	url2 "net/url"
)

func DoConn(c *bufio.ReadWriter, method string, url string, hdrs Headers, reqbody io.Reader) (res *Message, resbody io.Reader, err error) {
	resbody = EmptyBody
	if reqbody == nil {
		panic("wtf?")
	}
	u, err := url2.Parse(url)
	if err != nil {
		return
	}
	if hdrs == nil {
		hdrs = make(Headers)
	}
	req := &Message{
		Method:  method,
		Path:    u.RequestURI(),
		Version: VersionHTTP1_1,
		Headers: hdrs,
	}
	req.Set("Host", u.Host)
	req.Set("User-Agent", "boihttp-go/1.0")
	err = req.WriteRequest(c.Writer)
	if err != nil {
		return
	}
	err = c.Writer.Flush()
	if err != nil {
		return
	}
	_, err = c.Writer.ReadFrom(reqbody)
	if err != nil {
		return
	}
	res = new(Message)
	err = res.ReadResponse(c.Reader)
	if err != nil {
		return
	}
	resbody = res.body(c.Reader)
	return
}

func Do(method string, url string, hdrs Headers, reqbody io.Reader, dial DialFunc, ctx context.Context) (res *Message, resbody io.Reader, err error) {
	u, err := url2.Parse(url)
	if err != nil {
		return
	}
	if u.Scheme != "http" {
		panic("wtf?")
	}
	host, port := u.Hostname(), u.Port()
	if port == "" {
		port = "80"
	}
	if dial == nil {
		var d net.Dialer
		dial = d.DialContext
	}
	c, err := dial(ctx, "tcp", net.JoinHostPort(host, port))
	if err != nil {
		return
	}
	rw := bufio.NewReadWriter(bufio.NewReader(c), bufio.NewWriter(c))
	res, resbody, err = DoConn(rw, method, url, hdrs, reqbody)
	if resbody == EmptyBody || resbody.(*io.LimitedReader).N == 0 {
		c.Close()
	}
	resbody = &closeOnEOF{r: reqbody, c: c}
	return
}

type closeOnEOF struct {
	r io.Reader
	c net.Conn
}

func (x *closeOnEOF) Read(p []byte) (n int, err error) {
	n, err = x.r.Read(p)
	if err == io.EOF {
		x.c.Close()
	}
	return
}

type DialFunc func(ctx context.Context, network, addr string) (net.Conn, error)

func Get(url string, hdrs Headers, ctx context.Context) (res *Message, resbody io.Reader, err error) {
	return Do("GET", url, hdrs, EmptyBody, nil, ctx)
}