package gitea

import (
	"context"
	"errors"
	"io"
	"mime/multipart"
	"net/http"
	"net/url"
	"strconv"
)

func (c Client) uploadAsset(ctx context.Context, client *http.Client, token, apiRoot string, releaseID int64, filename string, content io.Reader) (int, error) {
	if content == nil {
		return 0, failure(FailureInvalid, "upload release asset", 0, errors.New("asset content reader is required"))
	}
	uploadURL := apiRoot + "/releases/" + strconv.FormatInt(releaseID, 10) + "/assets"
	parsed, err := url.Parse(uploadURL)
	if err != nil {
		return 0, failure(FailureInvalid, "prepare asset upload", 0, err)
	}
	query := parsed.Query()
	query.Set("name", filename)
	parsed.RawQuery = query.Encode()
	reader, writer := io.Pipe()
	multipartWriter := multipart.NewWriter(writer)
	writeDone := make(chan error, 1)
	go func() {
		part, partErr := multipartWriter.CreateFormFile("attachment", filename)
		if partErr == nil {
			_, partErr = io.Copy(part, content)
		}
		closeErr := multipartWriter.Close()
		if partErr == nil {
			partErr = closeErr
		}
		_ = writer.CloseWithError(partErr)
		writeDone <- partErr
	}()

	request, err := http.NewRequestWithContext(ctx, http.MethodPost, parsed.String(), reader)
	if err != nil {
		_ = reader.CloseWithError(err)
		<-writeDone
		return 0, failure(FailureInvalid, "upload release asset", 0, err)
	}
	request.Header.Set("Authorization", "token "+token)
	request.Header.Set("Accept", "application/json")
	request.Header.Set("Content-Type", multipartWriter.FormDataContentType())
	response, requestErr := client.Do(request)
	if requestErr != nil {
		_ = reader.CloseWithError(requestErr)
		<-writeDone
		return 0, failure(FailureTransport, "upload release asset", 0, requestErr)
	}
	defer response.Body.Close()
	writeErr := <-writeDone
	if response.StatusCode < 200 || response.StatusCode >= 300 {
		return response.StatusCode, responseFailure("upload release asset", response.StatusCode)
	}
	var uploaded assetResponse
	if err := decodeJSON(response.Body, &uploaded); err != nil {
		return response.StatusCode, failure(FailureMalformed, "decode uploaded asset", response.StatusCode, err)
	}
	if uploaded.ID <= 0 || uploaded.Name != filename {
		return response.StatusCode, failure(FailureMalformed, "verify uploaded asset", response.StatusCode, errors.New("upload response does not identify the selected asset"))
	}
	if writeErr != nil {
		return response.StatusCode, failure(FailureMalformed, "stream uploaded asset", response.StatusCode, writeErr)
	}
	return response.StatusCode, nil
}