package main

import (
	"encoding/json"
	"fmt"
	"io"
	"io/fs"
	"mime/multipart"
	"net/http"
	"net/textproto"
	"os"
	"path/filepath"
	"strings"

	"github.com/sethvargo/go-githubactions"
)

type AddResponse struct {
	Bytes int64
	Hash  string
	Name  string
	Size  string
}

type IpfsMultipartWriter struct {
	multipart.Writer
}

var quoteEscaper = strings.NewReplacer("\\", "\\\\", `"`, "\\\"")

func escapeQuotes(s string) string {
	return quoteEscaper.Replace(s)
}

func NewIpfsMultipartWriter(w io.Writer) *IpfsMultipartWriter {
	return &IpfsMultipartWriter{
		Writer: *multipart.NewWriter(w),
	}
}

func (w *IpfsMultipartWriter) CreateIpfsDirectoryPart(name string) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("Content-Disposition", fmt.Sprintf(`form-data; name="file"; filename="%s"`, name))
	h.Set("Content-Type", "application/x-directory")
	return w.CreatePart(h)
}

func (w *IpfsMultipartWriter) CreateIpfsFilePart(absPath, name string) (io.Writer, error) {
	h := make(textproto.MIMEHeader)
	h.Set("AbsPath", absPath)
	h.Set("Content-Disposition", fmt.Sprintf(`form-data; name="file"; filename="%s"`, escapeQuotes(name)))
	h.Set("Content-Type", "application/octet-stream")
	return w.CreatePart(h)
}

func main() {
	githubactions.Infof("Checking inputs...")

	// Check inputs
	path := githubactions.GetInput("path_to_add")
	if path == "" {
		githubactions.Fatalf("Missing: path_to_add")
	}

	ipfsHost := githubactions.GetInput("ipfs_host")
	if ipfsHost == "" {
		githubactions.Fatalf("Missing: ipfs_host")
	}

	ipfsPort := githubactions.GetInput("ipfs_port")
	if ipfsPort == "" {
		githubactions.Fatalf("Missing: ipfs_port")
	}

	targetPath, err := os.Open(path)
	if err != nil {
		githubactions.Fatalf("Unable to access path_to_add: %v", err.Error())
	}
	defer targetPath.Close()

	targetPathInfo, err := targetPath.Stat()
	if err != nil {
		githubactions.Fatalf("Unable to access to access path_to_add info: %v", fmt.Errorf("%w", err))
	}

	if !targetPathInfo.IsDir() {
		githubactions.Fatalf("%v is not a directory", path)
	}

	githubactions.Infof("Inputs OK")

	body, writer := io.Pipe()

	r := io.TeeReader(body, os.Stdout)

	url := fmt.Sprintf("http://%v:%v/api/v0/add", ipfsHost, ipfsPort)
	req, err := http.NewRequest(http.MethodPost, url, r)
	if err != nil {
		githubactions.Fatalf("Unable to create request: %v", err.Error())
	}

	mwriter := NewIpfsMultipartWriter(writer)
	req.Header.Add("Content-Type", mwriter.FormDataContentType())

	go func() {
		defer mwriter.Close()
		defer writer.Close()

		w, err := mwriter.CreateIpfsDirectoryPart(path)
		if err != nil {
			githubactions.Fatalf("Unable to create root dir path: %v", fmt.Errorf("%w", err))
		}

		err = filepath.Walk(path, func(innerPath string, info fs.FileInfo, err error) error {
			if err != nil {
				return err
			}

			if info.IsDir() {
				return nil
			}

			absPath, err := filepath.Rel(path, innerPath)
			if err != nil {
				return err
			}

			w, err = mwriter.CreateIpfsFilePart(absPath, innerPath)
			if err != nil {
				return err
			}

			fileReader, err := os.Open(innerPath)
			if err != nil {
				return err
			}
			defer fileReader.Close()

			written, err := io.Copy(w, fileReader)
			if err != nil {
				return fmt.Errorf("error copying %s (%d bytes written): %v", innerPath, written, err)
			}

			return nil
		})

		if err != nil {
			githubactions.Fatalf("Unable to create request body: %v", fmt.Errorf("%w", err))
		}
	}()

	githubactions.Infof("Calling node API")
	client := &http.Client{}
	res, err := client.Do(req)
	if err != nil {
		githubactions.Fatalf(err.Error())
	}

	githubactions.Infof("Reading response")
	resBody, err := io.ReadAll(res.Body)
	if err != nil {
		githubactions.Fatalf(err.Error())
	}

	githubactions.Infof("Response: %v", string(resBody))

	var ipfsAddResponse AddResponse
	json.Unmarshal(resBody, &ipfsAddResponse)

	githubactions.Infof("Upload size is %v", ipfsAddResponse.Bytes)
	githubactions.Infof("CID is %v", ipfsAddResponse.Hash)
	githubactions.SetOutput("cid", ipfsAddResponse.Hash)
}