package Filesystem

import (
	"PackageManager/Client/Database"
	"PackageManager/Color"
	"PackageManager/Variables"
	"fmt"
	"log"
	"os"
	"path/filepath"

	bolt "go.etcd.io/bbolt"
)

type FilesystemStatus struct {
	NewFiles      []string
	PickedFiles   []string
	ModifiedFiles []string
	MissingFiles  []string
}

func ShowFilesystemDiff(root string) error {
	var (
		fsStatus FilesystemStatus
		//f        string
		e error
	)

	fsStatus, e = GetFilesystemDiff(root)
	if e != nil {
		return e
	}

	fmt.Println("New files:")
	PrintFilesOrLength(fsStatus.NewFiles, Color.Green)

	fmt.Println("Added files:")
	PrintFilesOrLength(fsStatus.PickedFiles, Color.Green)

	fmt.Println("Modified files:")
	PrintFilesOrLength(fsStatus.ModifiedFiles, Color.Warning)

	fmt.Println("Deleted files:")
	PrintFilesOrLength(fsStatus.MissingFiles, Color.Fatal)

	return nil
}

func GetFilesystemLength(root string) (int, error) {
	var (
		rootStat os.FileInfo
		fsCount  int = 0
		e        error
	)

	rootStat, e = os.Stat(root)
	if e != nil {
		return fsCount, e
	}

	if rootStat.IsDir() && root[len(root)-1:] != "/" {
		root = root + "/"
	}

	filepath.Walk(root, func(p string, i os.FileInfo, _ error) error {

		// Ignore path in Variables.PruneRegexPaths
		if i.IsDir() && matchAny(p, PruneRegex) {
			log.Println("Prune", p)
			return filepath.SkipDir
		}

		// Ignore path in Variables.IgnoreRegexPaths
		if matchAny(p, IgnoreRegex) {
			return nil
		}

		if !i.Mode().IsRegular() && (i.Mode()&os.ModeSymlink == 0) {
			return nil
		}

		fsCount++

		return nil
	})

	return fsCount, e
}

func GetFilesystemDiff(root string) (FilesystemStatus, error) {
	var (
		fsStatus FilesystemStatus = FilesystemStatus{}

		rootStat os.FileInfo

		picksBucket *bolt.Bucket
		indexBucket *bolt.Bucket

		pick, known []byte

		newFileObject   FileObject
		knownFileObject FileObject

		e error
	)

	rootStat, e = os.Stat(root)
	if e != nil {
		return fsStatus, e
	}

	if rootStat.IsDir() && root[len(root)-1:] != "/" {
		root = root + "/"
	}

	e = Database.FsDB.View(func(tx *bolt.Tx) error {

		picksBucket = tx.Bucket(Variables.FsHashPicksBucket)
		indexBucket = tx.Bucket(Variables.FsHashIndexBucket)

		filepath.Walk(root, func(p string, i os.FileInfo, _ error) error {

			// Ignore path in Variables.PruneRegexPaths
			if i.IsDir() && matchAny(p, PruneRegex) {
				log.Println("Prune", p)
				return filepath.SkipDir
			}

			// Ignore path in Variables.IgnoreRegexPaths
			if matchAny(p, IgnoreRegex) {
				return nil
			}

			if !i.Mode().IsRegular() && (i.Mode()&os.ModeSymlink == 0) {
				return nil
			}

			pick = picksBucket.Get([]byte(p))
			known = indexBucket.Get([]byte(p))

			if pick != nil {
				fsStatus.PickedFiles = append(fsStatus.PickedFiles, p)
				return nil
			}

			if known != nil {
				newFileObject, e = CreateFileObject(p)
				if os.IsNotExist(e) {
					return nil
				}
				if e != nil {
					return e
				}

				knownFileObject, e = FromBytes(known)
				if e != nil {
					return e
				}

				e = newFileObject.IsDifferent(knownFileObject)
				if e != nil {
					fsStatus.ModifiedFiles = append(fsStatus.ModifiedFiles, p)
				}

				return nil
			}

			fsStatus.NewFiles = append(fsStatus.NewFiles, p)

			return nil
		})

		indexBucket.ForEach(func(k, v []byte) error {
			_, e = os.Lstat(string(k))
			if os.IsNotExist(e) {
				fsStatus.MissingFiles = append(fsStatus.MissingFiles, string(k))
			}
			return nil
		})

		return nil
	})

	return fsStatus, e
}