package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	"github.com/mattermost/mattermost-server/v5/model"
)

func main() {
	url := strings.TrimPrefix(os.Args[1], "-") // -?https://MACHINE/api/v4/files/FILE
	s := strings.Split(url, "/")
	machine, fileId := s[2], s[6]

	netrcPath, ok := os.LookupEnv("NETRC")
	if !ok {
		netrcPath = filepath.Join(os.Getenv("HOME"), ".netrc")
	}
	data, err := ioutil.ReadFile(netrcPath)
	if err != nil {
		panic(err)
	}
	var login string
	var password string
	for _, line := range strings.Split(string(data), "\n") {
		if i := strings.Index(line, "#"); i >= 0 {
			line = line[:i]
		}
		f := strings.Fields(line)
		if len(f) >= 6 &&
			f[0] == "machine" && f[1] == machine &&
			f[2] == "login" && f[4] == "password" {
			login, password = f[3], f[5]
			break
		}
	}
	if login == "" || password == "" {
		fmt.Fprintln(os.Stderr, "No credentials found for:", machine)
		os.Exit(1)
	}

	Client := model.NewAPIv4Client("https://" + machine)
	Client.Login(login, password)
	info, _ := Client.GetFileInfo(fileId)
	if info == nil {
		os.Exit(1)
	}
	filename := info.Name
	if len(os.Args) > 2 {
		filename = os.Args[2]
	} else {
		fmt.Fprintln(os.Stderr, "Name:", info.Name)
		fmt.Fprintln(os.Stderr, "Type:", info.MimeType)
		fmt.Fprintln(os.Stderr, "Size:", info.Size)
		fmt.Fprintln(os.Stderr, "Download? Ctrl-D/C")
		os.Stdin.Read(make([]byte, 1))
	}
	data, _ = Client.GetFile(fileId)
	if err = ioutil.WriteFile(filename, data, os.FileMode(0666)); err != nil {
		panic(err)
	}
}