package v1

import (
	"crypto/sha256"
	"encoding/hex"
	"io"
	"mime/multipart"
	"net/http"
	"os"

	"github.com/go-chi/chi/v5"

	"code.icb4dc0.de/prskr/searcherside/core/ports"
	"code.icb4dc0.de/prskr/searcherside/internal/logging"
)

type IndexHandler struct {
	MaxMemoryBytes int64
	Indexer        ports.IndexCurator
}

func (h IndexHandler) IngestIndex(writer http.ResponseWriter, req *http.Request) {
	logger := logging.GetLogger(req.Context())

	if err := req.ParseMultipartForm(h.MaxMemoryBytes); err != nil {
		logger.WarnContext(req.Context(), "Failed to parse multipart form", logging.Error(err))
		http.Error(writer, "Failed to parse multipart form", http.StatusInternalServerError)
		return
	}

	if len(req.MultipartForm.File) != 1 {
		http.Error(writer, "Only a single file can be uploaded", http.StatusBadRequest)
		return
	}

	var indexFile *multipart.FileHeader

	for _, files := range req.MultipartForm.File {
		if len(files) != 1 {
			http.Error(writer, "Only a single file can be uploaded", http.StatusBadRequest)
			return
		}

		indexFile = files[0]
		break
	}

	indexTempFile, err := os.CreateTemp(os.TempDir(), "searcherside-index-*")
	if err != nil {
		logger.ErrorContext(req.Context(), "Failed to create temporary index file", logging.Error(err))
		http.Error(writer, "Failed to create temporary index file", http.StatusInternalServerError)
		return
	}

	hash := sha256.New()

	stream, err := indexFile.Open()
	if err != nil {
		logger.ErrorContext(req.Context(), "Failed to open index file", logging.Error(err))
		http.Error(writer, "Failed to open index file", http.StatusBadRequest)
		return
	}

	if _, err := io.Copy(io.MultiWriter(hash, indexTempFile), stream); err != nil {
		logger.ErrorContext(req.Context(), "Failed to copy index file", logging.Error(err))
		http.Error(writer, "Failed to copy index file", http.StatusBadRequest)
		return
	}

	if err := stream.Close(); err != nil {
		logger.ErrorContext(req.Context(), "Failed to close index file", logging.Error(err))
	}

	if err := indexTempFile.Close(); err != nil {
		logger.ErrorContext(req.Context(), "Failed to close temporary index file", logging.Error(err))
		http.Error(writer, "Failed to close temporary index file", http.StatusInternalServerError)
		return
	}

	go func() {
		indexErr := h.Indexer.Ingest(req.Context(), ports.IngestIndexRequest{
			FilePath: indexTempFile.Name(),
			Hash:     hex.EncodeToString(hash.Sum(nil)),
			Module:   chi.URLParam(req, "module"),
			Instance: chi.URLParam(req, "instance"),
		})

		if indexErr != nil {
			logger.ErrorContext(req.Context(), "Failed to ingest index", logging.Error(indexErr))
		}
	}()

	writer.WriteHeader(http.StatusAccepted)
}