package database

import (
	"context"
	"encoding/hex"
	"log/slog"

	"github.com/jackc/pgx/v5"
	"golang.org/x/crypto/blake2b"

	"git.jmbit.de/jmb/scanfile/server/internal/sqlc"
	"git.jmbit.de/jmb/scanfile/server/internal/store"
)

// CreateFile() creates the filesystem object and the DB entry for a file
func CreateFile(ctx context.Context, name string, fileBytes []byte) (sqlc.File, error) {
	queries := sqlc.New(pool)
	file := sqlc.File{
		Name: name,
	}
	var err error

	bl2hash := blake2b.Sum256(fileBytes)
	slog.Debug("calculated Blake2b hash", "file-name", name, "file-bl2", hex.EncodeToString(bl2hash[:]), "file-size", len(fileBytes))
	mime, _ := store.GetBytesFileType(fileBytes[:262])

	file, err = queries.CreateFile(ctx, sqlc.CreateFileParams{
		Name:     name,
		Mimetype: mime,
		Size:     int64(len(fileBytes)),
		Blake2:   bl2hash[:],
	})
	if err == pgx.ErrNoRows {
		file, err := queries.GetFileByBlake2(ctx, bl2hash[:])
		if err != nil {
			slog.Error("Error saving file to database", "error", err, "file-name", name)
			return file, err
		}
		slog.Debug("File already exists", "file-uuid", file.ID.String(), "file-name", file.Name, "file-bl2", hex.EncodeToString(file.Blake2), "file-size", file.Size, "file-mime", file.Mimetype, "file-description", file.Description.String)
		return file, nil
	}
	if err != nil {
		slog.Error("Error saving file to database", "error", err, "file-name", name)
		err = nil
	} else {
		slog.Debug("New file created", "file-uuid", file.ID.String(), "file-name", file.Name, "file-bl2", hex.EncodeToString(file.Blake2), "file-size", file.Size, "file-mime", file.Mimetype, "file-description", file.Description.String)
	}

	//Using UUIDs instead of the file hash to make switching storage backends easier
	_, err = store.SaveFile(file.ID.String(), fileBytes)
	if err != nil {
		slog.Error("Error saving file to disk", "error", err, "file-uuid", file.ID.String())
		errdel := queries.DeleteFile(ctx, file.ID)
		if errdel != nil {
			slog.Error("Error deleting file from database", "error", errdel, "file-uuid", file.ID.String())
		}
		return file, err
	}

	return file, nil
}