package archiver

import (
	"archive/tar"
	"archive/zip"
	"errors"
	"io"
	"io/fs"
	"os"
	"path/filepath"
	"regexp"
	"strings"
)

type extractOptions struct {
	Perms                    os.FileMode
	Overwrite                bool
	Folder                   string
	NotPreserveFileStructure bool
	Filter                   *regexp.Regexp
	File                     *File
}

func extract(filesystem Filesystem, opts ExtractOptions, archive *Archive) error {
	archive.mu.Lock()
	defer archive.mu.Unlock()

	if filesystem.billyFS == nil {
		filesystem.file = true
	}

	if filesystem.billyFS != nil {
		billyFS := filesystem.billyFS
		if err := billyFS.MkdirAll(opts.Folder, 0740); err != nil {
			return err
		}
	} else if filesystem.file {
		if err := os.MkdirAll(opts.Folder, 0740); err != nil {
			return err
		}
	}

	extOptions := extractOptions{
		Folder:                   opts.Folder,
		NotPreserveFileStructure: opts.NotPreserveFileStructure,
		Overwrite:                opts.Overwrite,
		Filter:                   opts.Filter,
	}

	switch archive.Type {
	case Tar, TarGzip, TarBzip, TarXz:
		return tarExtract(filesystem, extOptions, archive)
	case Zip:
		return zipExtract(filesystem, extOptions, archive)
	default:
		return ErrArchiveTypeNotSupported
	}
}

func extractFile(filesystem Filesystem, opts ExtractFileOptions, file *File) error {
	file.archive.mu.Lock()
	defer file.archive.mu.Unlock()

	if filesystem.billyFS == nil {
		filesystem.file = true
	}

	if filesystem.billyFS != nil {
		billyFS := filesystem.billyFS
		if err := billyFS.MkdirAll(opts.Folder, 0740); err != nil {
			return err
		}
	} else if filesystem.file {
		if err := os.MkdirAll(opts.Folder, 0740); err != nil {
			return err
		}
	}

	extOptions := extractOptions{
		Folder:                   opts.Folder,
		NotPreserveFileStructure: opts.NotPreserveFileStructure,
		Overwrite:                opts.Overwrite,
		File:                     file,
	}

	switch file.archive.Type {
	case Tar, TarGzip, TarBzip, TarXz:
		return tarExtract(filesystem, extOptions, file.archive)
	case Zip:
		return zipExtract(filesystem, extOptions, file.archive)
	default:
		return ErrArchiveTypeNotSupported
	}
}

func zipExtract(filesystem Filesystem, opts extractOptions, archive *Archive) error {
	if filesystem.billyFS == nil {
		filesystem.file = true
	}
	for _, zipF := range archive.reader.(*zip.Reader).File {

		var splitPath []string
		if opts.File != nil {
			splitPath = strings.Split(opts.File.Path, "/")
		} else {
			splitPath = strings.Split(zipF.Name, "/")
		}
		splitPath = splitPath[:len(splitPath)-1]

		if !opts.NotPreserveFileStructure && zipF.FileInfo().IsDir() {
			if opts.File != nil {
				isFound := false
				for _, folder := range splitPath {
					if folder == filepath.Base(zipF.Name) {
						isFound = true
						break
					}
				}
				if isFound {
					if filesystem.billyFS != nil {
						billyFS := filesystem.billyFS
						if err := billyFS.MkdirAll(filepath.Join(opts.Folder, zipF.Name), 0740); err != nil {
							return err
						}
					} else {
						if err := os.MkdirAll(filepath.Join(opts.Folder, zipF.Name), 0740); err != nil {
							return err
						}
					}

					continue
				}
			} else {
				if filesystem.billyFS != nil {
					billyFS := filesystem.billyFS
					if err := billyFS.MkdirAll(filepath.Join(opts.Folder, zipF.Name), 0740); err != nil {
						return err
					}
				} else {
					if err := os.MkdirAll(filepath.Join(opts.Folder, zipF.Name), 0740); err != nil {
						return err
					}
				}
				continue
			}
		}

		if opts.File != nil && zipF.Name != opts.File.Path {
			continue
		}

		if opts.File == nil && opts.Filter != nil {
			if !opts.Filter.MatchString(zipF.Name) {
				continue
			}
		}

		var filePath string
		if !opts.NotPreserveFileStructure {
			filePath = filepath.Join(opts.Folder, zipF.Name)
		} else {
			filePath = filepath.Join(opts.Folder, filepath.Base(zipF.Name))
		}

		if filesystem.billyFS != nil {
			billyFS := filesystem.billyFS
			if _, err := billyFS.Stat(filepath.Join(opts.Folder, filepath.Dir(zipF.Name))); err != nil {
				if errors.Is(err, fs.ErrNotExist) {
					if err := billyFS.MkdirAll(filepath.Join(opts.Folder, filepath.Dir(zipF.Name)), 0740); err != nil {
						return err
					}
				} else {
					return err
				}
			}
		} else {
			if _, err := os.Stat(filepath.Join(opts.Folder, filepath.Dir(zipF.Name))); err != nil {
				if errors.Is(err, fs.ErrNotExist) {
					if err := os.MkdirAll(filepath.Join(opts.Folder, filepath.Dir(zipF.Name)), 0740); err != nil {
						return err
					}
				} else {
					return err
				}
			}
		}

		if opts.Perms == 0 {
			opts.Perms = zipF.FileInfo().Mode()
		}

		var file io.WriteCloser

		if filesystem.billyFS != nil {
			billyFS := filesystem.billyFS
			var err error
			file, err = billyFS.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, opts.Perms)
			if err != nil {
				return nil
			}
		} else {
			var err error
			file, err = os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, opts.Perms)
			if err != nil {
				return err
			}
		}

		archiveFile, err := zipF.Open()
		if err != nil {
			return err
		}

		if _, err := io.Copy(file, archiveFile); err != nil {
			return err
		}

		if err := archiveFile.Close(); err != nil {
			return err
		}

		if err := file.Close(); err != nil {
			return err
		}

		if opts.File != nil && zipF.Name == opts.File.Path {
			break
		}
	}
	return nil
}

func tarExtract(filesystem Filesystem, opts extractOptions, archive *Archive) error {
	defer tarCleanup(archive)
	if filesystem.billyFS == nil {
		filesystem.file = true
	}
	for {
		header, err := archive.tarReader.Next()
		if err != nil && err != io.EOF {
			return err
		} else if err == io.EOF {
			break
		}

		var splitPath []string
		if opts.File != nil {
			splitPath = strings.Split(opts.File.Path, "/")
		} else {
			splitPath = strings.Split(header.Name, "/")
		}
		splitPath = splitPath[:len(splitPath)-1]

		if !opts.NotPreserveFileStructure && header.Typeflag == tar.TypeDir {
			if opts.File != nil {
				isFound := false
				for _, folder := range splitPath {
					if folder == filepath.Base(header.Name) {
						isFound = true
						break
					}
				}
				if isFound {
					if filesystem.billyFS != nil {
						billyFS := filesystem.billyFS
						if err := billyFS.MkdirAll(filepath.Join(opts.Folder, header.Name), 0740); err != nil {
							return err
						}
					} else {
						if err := os.MkdirAll(filepath.Join(opts.Folder, header.Name), 0740); err != nil {
							return err
						}
					}
					continue
				}
			} else {
				if filesystem.billyFS != nil {
					billyFS := filesystem.billyFS
					if err := billyFS.MkdirAll(filepath.Join(opts.Folder, header.Name), 0740); err != nil {
						return err
					}
				} else {
					if err := os.MkdirAll(filepath.Join(opts.Folder, header.Name), 0740); err != nil {
						return err
					}
				}
				continue
			}

		}

		if opts.File != nil && header.Name != opts.File.Path {
			continue
		}

		if opts.File == nil && opts.Filter != nil {
			if !opts.Filter.MatchString(header.Name) {
				continue
			}
		}

		var filePath string
		if !opts.NotPreserveFileStructure {
			filePath = filepath.Join(opts.Folder, header.Name)
		} else {
			filePath = filepath.Join(opts.Folder, filepath.Base(header.Name))
		}

		if filesystem.billyFS != nil {
			billyFS := filesystem.billyFS
			if _, err := billyFS.Stat(filepath.Join(opts.Folder, filepath.Dir(header.Name))); err != nil {
				if errors.Is(err, fs.ErrNotExist) {
					if err := billyFS.MkdirAll(filepath.Join(opts.Folder, filepath.Dir(header.Name)), 0740); err != nil {
						return err
					}
				} else {
					return err
				}
			}
		} else {
			if _, err := os.Stat(filepath.Join(opts.Folder, filepath.Dir(header.Name))); err != nil {
				if errors.Is(err, fs.ErrNotExist) {
					if err := os.MkdirAll(filepath.Join(opts.Folder, filepath.Dir(header.Name)), 0740); err != nil {
						return err
					}
				} else {
					return err
				}
			}
		}

		if opts.Perms == 0 {
			opts.Perms = header.FileInfo().Mode()
		}
		var file io.WriteCloser

		if filesystem.billyFS != nil {
			billyFS := filesystem.billyFS
			var err error
			file, err = billyFS.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, opts.Perms)
			if err != nil {
				return nil
			}
		} else {
			var err error
			file, err = os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, opts.Perms)
			if err != nil {
				return err
			}
		}

		if _, err = io.Copy(file, archive.tarReader); err != nil {
			return err
		}

		if err := file.Close(); err != nil {
			return err
		}

		if opts.File != nil && header.Name == opts.File.Path {
			break
		}
	}
	return nil
}