package client

import (
	"context"
	"crypto/tls"
	"encoding/base64"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"path"
	"path/filepath"
	"strings"
)

const fileAPI = "/v3/api/file/"

type Client struct{}

func NewClient() *Client {
	return &Client{}
}

func (cli *Client) FileExists(ctx context.Context, ref string) (bool, error) {
	var res bool
	var err error

	ref, err = convertFileLink(ref)
	if err != nil {
		return res, err
	}
	req, err := http.NewRequestWithContext(ctx, "HEAD", ref, nil)
	if err != nil {
		return res, err
	}
	authValue := createBasicAuthPair

	transport := &http.Transport{
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify: true,
		},
	}
	client := &http.Client{
		Transport: transport,
	}
	resp, err := client.Do(req)
	if err != nil {
		return res, err
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusOK {
		res = true
	}
	return res, err
}

func createBasicAuthPair(username, password string) string {
	auth := username + ":" + password
	return "Basic " + base64.StdEncoding.EncodeToString([]byte(auth))
}

func convertFileLink(ref string) (string, error) {
	var err error
	var res string
	if !strings.Contains(ref, "://") {
		ref = "https://" + ref
	}
	url, err := url.Parse(ref)
	if err != nil {
		return res, err
	}
	url.Path = path.Join(fileAPI, url.Path)
	url.User = nil
	res = url.String()
	return res, err
}

func (cli *Client) GetFile(ctx context.Context, ref, filename string) error {
	var err error
	ref, err = convertFileLink(ref)
	if err != nil {
		return err
	}

	req, err := http.NewRequestWithContext(ctx, "GET", ref, nil)
	if err != nil {
		return err
	}
	transport := &http.Transport{
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify: true,
		},
	}
	client := &http.Client{
		Transport: transport,
	}
	resp, err := client.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		err := fmt.Errorf("Received wrong status code: %s", resp.StatusCode)
		return err
	}

	dirname := filepath.Dir(filename)
	err = os.MkdirAll(dirname, 0750)
	if err != nil {
		return err
	}
	file, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE, 0640)
	if err != nil {
		return err
	}
	_, err = io.Copy(file, resp.Body)
	if err != nil {
		return err
	}
	return err
}