// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package transport

import (
_	"errors"
	"io"
_	"os"
	"net/url"
	"net/http"
	"strings"
	"fmt"
	"bytes"
	"context"
	"path/filepath"
)

type BufferCloser struct {
	stream io.Closer
	*bytes.Buffer
}

type HTTP struct {
	uri *url.URL
	path string
	exttype string
	fileext string
	buffer BufferCloser
	getRequest *http.Request
	getResponse *http.Response
	postRequest *http.Request
	postResponse *http.Response
	Client *http.Client
}

func (b BufferCloser) Close() error {
	if b.stream != nil {
		return b.stream.Close()
	}
	return nil
}

func NewHTTP(u *url.URL, ctx context.Context) (h *HTTP, err error) {
	h = &HTTP {
		uri: u,
		path: filepath.Join(u.Hostname(), u.RequestURI()),
		Client: http.DefaultClient,
	}
	h.extension()

	h.postRequest, err = http.NewRequestWithContext(ctx, "POST", u.String(), h.buffer)
	if err != nil {
		return
	}
	h.getRequest, err = http.NewRequestWithContext(ctx, "GET", u.String(), nil)
	return
}

func (h *HTTP) extension() {
	elements := strings.Split(h.path, ".")
	numberOfElements := len(elements)
	if numberOfElements > 2 {
		h.exttype = elements[numberOfElements - 2]
		h.fileext = elements[numberOfElements - 1]
	}
	h.exttype = elements[numberOfElements - 1]
}

func (h *HTTP) URI() *url.URL {
	return h.uri
}

func (h *HTTP) Path() string {
	return h.path
}

func (h *HTTP) Signature() (documentSignature string) {
	if h.getResponse != nil {
		documentSignature = h.getResponse.Header.Get("Signature")
		if documentSignature == "" {
			signatureResp, signatureErr := h.Client.Get(fmt.Sprintf("%s.sig", h.uri.String()))
			if signatureErr == nil {
				defer signatureResp.Body.Close()
				readSignatureBody, readSignatureErr := io.ReadAll(signatureResp.Body)
				if readSignatureErr == nil {
					documentSignature = string(readSignatureBody)
				}
			}
		}
	}
	return documentSignature
}

func (h *HTTP) ContentType() (contenttype string) {
	contenttype = h.getResponse.Header.Get("Content-Type")
	switch contenttype {
	case "application/octet-stream":
		return h.exttype
	default:
	}
	return
}

func (h *HTTP) Gzip() bool {
	return h.fileext == "gz"
}

func (h *HTTP) Reader() io.ReadCloser {
	var err error
	if h.getResponse, err = h.Client.Do(h.getRequest); err != nil {
		panic(err)
	}
	return h.getResponse.Body
}

func (h *HTTP) Writer() io.WriteCloser {
	var err error
	if h.postResponse, err = h.Client.Do(h.postRequest); err != nil {
		panic(err)
	}
	return h.buffer
}