/*
 * Copyright 2026 Oleg Borodin <onborodin@gmail.com>
 *
 * This work is published and licensed under a Creative Commons
 * Attribution-NonCommercial-NoDerivatives 4.0 International License.
 *
 * Distribution of this work is permitted, but commercial use and
 * modifications are strictly prohibited.
 */
package client

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

	"mstore/pkg/auxhttp"
)

func makeHTTPClient() *http.Client {
	transport := &http.Transport{
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify: true,
		},
	}
	client := &http.Client{
		Transport: transport,
	}
	return client
}

func convertFileURI(fileuri string) (string, error) {
	var err error
	var res string
	uri, err := url.Parse(fileuri)
	if err != nil {
		return res, err
	}
	const fileAPI = "/v3/api/file/"
	uri.Path, err = url.JoinPath(fileAPI, uri.Path)
	if err != nil {
		return res, err
	}

	res = uri.String()
	return res, err
}

func convertFilesURI(fileuri string) (string, error) {
	var err error
	var res string
	uri, err := url.Parse(fileuri)
	const filesAPI = "/v3/api/files/"
	uri.Path, err = url.JoinPath(filesAPI, uri.Path)
	if err != nil {
		return res, err
	}
	res = uri.String()
	return res, err
}

func repackServiceURI(fileuri string) (string, string, string, error) {
	var err error
	var res, username, password string
	if !strings.Contains(fileuri, "://") {
		fileuri = "https://" + fileuri
	}
	uri, err := url.Parse(fileuri)
	if err != nil {
		return res, username, password, err
	}
	uri.Path = path.Clean(uri.Path)
	if uri.User != nil {
		username = uri.User.Username()
		password, _ = uri.User.Password()
	}
	uri.User = nil
	uri.Scheme = "https"
	res = uri.String()
	return res, username, password, err
}

func (cli *Client) FileExists(ctx context.Context, fileuri string) (bool, error) {
	var res bool
	var err error
	fileuri, username, password, err := repackServiceURI(fileuri)
	if err != nil {
		return res, err
	}
	fileuri, err = convertFileURI(fileuri)
	if err != nil {
		return res, err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodHead, fileuri, nil)
	if err != nil {
		return res, err
	}
	if username != "" && password != "" {
		basic := auxhttp.EncodeBasicAuth(username, password)
		req.Header.Add("Authorization", basic)
	}
	client := makeHTTPClient()
	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 (cli *Client) PutFile(ctx context.Context, filename, fileuri string) error {
	var err error
	fileuri, username, password, err := repackServiceURI(fileuri)
	if err != nil {
		return err
	}

	fileuri, err = convertFileURI(fileuri)
	if err != nil {
		return err
	}
	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	req, err := http.NewRequestWithContext(ctx, http.MethodPut, fileuri, file)
	if err != nil {
		return err
	}
	fileinfo, err := os.Stat(filename)
	if err != nil {
		return err
	}
	filesize := fileinfo.Size()

	req.ContentLength = filesize
	req.Header.Set("Content-Type", "application/octet-stream")
	if username != "" && password != "" {
		basic := auxhttp.EncodeBasicAuth(username, password)
		req.Header.Add("Authorization", basic)
	}
	client := makeHTTPClient()

	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.Status)
		return err
	}
	return err
}

func (cli *Client) GetFile(ctx context.Context, fileuri, filename string) (int64, error) {
	var err error
	var size int64

	fileuri, username, password, err := repackServiceURI(fileuri)
	if err != nil {
		return size, err
	}

	fileuri, err = convertFileURI(fileuri)
	if err != nil {
		return size, err
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, fileuri, nil)
	if err != nil {
		return size, err
	}

	if username != "" && password != "" {
		basic := auxhttp.EncodeBasicAuth(username, password)
		req.Header.Add("Authorization", basic)
	}

	client := makeHTTPClient()
	resp, err := client.Do(req)
	if err != nil {
		return size, err
	}
	defer resp.Body.Close()

	contentLength := resp.Header.Get("Content-Length")
	if contentLength == "" {
		err = fmt.Errorf("Empty Content-Length received")
		return size, err
	}
	if resp.StatusCode != http.StatusOK {
		err := fmt.Errorf("Received wrong status code: %s", resp.Status)
		return size, err
	}
	declSize, err := strconv.ParseInt(contentLength, 10, 64)
	if err != nil {
		err = fmt.Errorf("Wrong Content-Length value: %v", err)
		return size, err
	}
	dirname := filepath.Dir(filename)
	err = os.MkdirAll(dirname, 0750)
	if err != nil {
		return size, err
	}
	file, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE, 0640)
	if err != nil {
		return size, err
	}
	size, err = io.Copy(file, resp.Body)
	if err != nil {
		return size, err
	}
	if size != declSize {
		err := fmt.Errorf("Mismatch Content-Length and recorded filesize")
		return size, err
	}
	return size, err
}

func (cli *Client) DeleteFile(ctx context.Context, fileuri, filename string) error {
	var err error

	fileuri, username, password, err := repackServiceURI(fileuri)
	if err != nil {
		return err
	}

	fileuri, err = convertFileURI(fileuri)
	if err != nil {
		return err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, fileuri, nil)
	if err != nil {
		return err
	}
	if username != "" && password != "" {
		basic := auxhttp.EncodeBasicAuth(username, password)
		req.Header.Add("Authorization", basic)
	}

	client := makeHTTPClient()
	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.Status)
		return err
	}
	return err
}