// Copyright (c) 2023 Open Anolis Community Distro SIG, all rights reserved.
//
// Author: Jacob Wang <jacob.wang@openanolis.org>
//         Xiao Lun <xiaolun@linux.alibaba.com>
//         Zhao Hang <zhaohang_mskdxl@qq.com>

package directives

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

	"github.com/go-git/go-git/v5"
	pkgcrewpb "pkgcrew/pb"
	"pkgcrew/pkg/data"
)

// returns right if not empty, else left
func eitherString(left string, right string) string {
	if right != "" {
		return right
	}

	return left
}

func add(cfg *pkgcrewpb.Cfg, pd *data.ProcessData, md *data.ModeData, patchTree *git.Worktree, pushTree *git.Worktree) error {
	for _, add := range cfg.Add {
		var replacingBytes []byte
		var filePath string

		switch addType := add.Source.(type) {
		case *pkgcrewpb.Add_File:
			filePath = eitherString(filepath.Base(addType.File), add.Name)
			if pd.UpstreamCentos {
				filePath = checkAddPrefix(eitherString(filepath.Base(addType.File), add.Name))
			}

			fPatch, err := patchTree.Filesystem.OpenFile(addType.File, os.O_RDONLY, 0o644)
			if err != nil {
				return errors.New(fmt.Sprintf("COULD_NOT_OPEN_FROM:%s", addType.File))
			}

			replacingBytes, err = ioutil.ReadAll(fPatch)
			if err != nil {
				return errors.New(fmt.Sprintf("COULD_NOT_READ_FROM:%s", addType.File))
			}
			break
		case *pkgcrewpb.Add_Lookaside:
			filePath = eitherString(filepath.Base(addType.Lookaside), add.Name)
			if pd.UpstreamCentos {
				filePath = checkAddPrefix(eitherString(filepath.Base(addType.Lookaside), add.Name))
			}
			var err error
			replacingBytes, err = pd.BlobStorage.Read(addType.Lookaside)
			if err != nil {
				return err
			}

			hashFunction := pd.CompareHash(replacingBytes, addType.Lookaside)
			if hashFunction == nil {
				return errors.New(fmt.Sprintf("LOOKASIDE_HASH_DOES_NOT_MATCH:%s", addType.Lookaside))
			}

			md.SourcesToIgnore = append(md.SourcesToIgnore, &data.IgnoredSource{
				Name:         filePath,
				HashFunction: hashFunction,
			})
			break
		}

		f, err := pushTree.Filesystem.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
		if err != nil {
			return errors.New(fmt.Sprintf("COULD_NOT_OPEN_DESTINATION:%s", filePath))
		}

		_, err = f.Write(replacingBytes)
		if err != nil {
			return errors.New(fmt.Sprintf("COULD_NOT_WRITE_DESTIONATION:%s", filePath))
		}
	}

	return nil
}