// Path: Backend/internal/bootstrap/project_disk_folders.go

package bootstrap

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/google/uuid"
)

func (service *Service) createProjectFolderOnDisk(projectSlug, parentFolderID, name string, rootPathBuilder func(projectSlug string) string) (string, string, error) {
	posixRoot := strings.TrimSpace(service.posixRoot)
	if posixRoot == "" {
		return "", "", fmt.Errorf("POSIX root is not configured")
	}
	trimmedName := strings.TrimSpace(name)
	if trimmedName == "" {
		return "", "", fmt.Errorf("folder name is required")
	}
	containerProjectionPath := rootPathBuilder(projectSlug)
	parentDir := filepath.Join(posixRoot, filepath.FromSlash(containerProjectionPath))
	if strings.TrimSpace(parentFolderID) != "" {
		containerProjectionPath = filepath.ToSlash(filepath.Join(strings.TrimSpace(parentFolderID), "children"))
		parentDir = filepath.Join(posixRoot, filepath.FromSlash(containerProjectionPath))
		info, err := os.Stat(parentDir)
		if err != nil {
			if os.IsNotExist(err) {
				return "", "", ErrProjectFolderNotFound
			}
			return "", "", fmt.Errorf("stat parent project folder: %w", err)
		}
		if !info.IsDir() {
			return "", "", ErrProjectFolderNotFound
		}
	}
	if err := os.MkdirAll(parentDir, 0o755); err != nil {
		return "", "", fmt.Errorf("create parent project folder path: %w", err)
	}
	baseSlug := normalizePOSIXSlug(trimmedName)
	folderName := slugDir("folder", baseSlug)
	folderDir := filepath.Join(parentDir, folderName)
	folderSlug := baseSlug
	for attempt := 2; ; attempt += 1 {
		if _, err := os.Stat(folderDir); os.IsNotExist(err) {
			break
		} else if err != nil {
			return "", "", fmt.Errorf("stat candidate project folder: %w", err)
		}
		folderSlug = fmt.Sprintf("%s-%d", baseSlug, attempt)
		folderName = slugDir("folder", folderSlug)
		folderDir = filepath.Join(parentDir, folderName)
	}
	if err := os.MkdirAll(filepath.Join(folderDir, "children"), 0o755); err != nil {
		return "", "", fmt.Errorf("create project hierarchy folder: %w", err)
	}
	folderID := uuid.NewString()
	if err := writeCBORFile(filepath.Join(folderDir, posixFolderFileName), map[string]any{"id": folderID, "name": trimmedName, "slug": folderSlug, "type": "folder"}); err != nil {
		return "", "", fmt.Errorf("write project %s: %w", posixFolderFileName, err)
	}
	if err := writeCBORFile(filepath.Join(folderDir, posixACLFileName), map[string]any{"version": 1, "inherits": true, "rules": []any{}}); err != nil {
		return "", "", fmt.Errorf("write project %s: %w", posixACLFileName, err)
	}
	return filepath.ToSlash(filepath.Join(containerProjectionPath, folderName)), folderSlug, nil
}

func (service *Service) deleteProjectFolderOnDisk(projectSlug, folderID string, rootPathBuilder func(projectSlug string) string) (string, error) {
	posixRoot := strings.TrimSpace(service.posixRoot)
	if posixRoot == "" {
		return "", fmt.Errorf("POSIX root is not configured")
	}
	trimmedFolderID := strings.TrimSpace(folderID)
	if trimmedFolderID == "" {
		return "", ErrProjectFolderNotFound
	}
	rootProjectionPath := rootPathBuilder(projectSlug)
	folderProjectionPath := strings.TrimPrefix(filepath.ToSlash(filepath.Clean("/"+trimmedFolderID)), "/")
	if folderProjectionPath == "." || folderProjectionPath == rootProjectionPath || !strings.HasPrefix(folderProjectionPath, rootProjectionPath+"/") {
		return "", ErrProjectFolderNotFound
	}
	folderDir := filepath.Join(posixRoot, filepath.FromSlash(folderProjectionPath))
	info, err := os.Stat(folderDir)
	if err != nil {
		if os.IsNotExist(err) {
			return "", ErrProjectFolderNotFound
		}
		return "", fmt.Errorf("stat project folder: %w", err)
	}
	if !info.IsDir() {
		return "", ErrProjectFolderNotFound
	}
	if err := os.RemoveAll(folderDir); err != nil {
		return "", fmt.Errorf("delete project folder: %w", err)
	}
	return folderProjectionPath, nil
}

func (service *Service) renameProjectFolderOnDisk(projectSlug, folderID, name string, rootPathBuilder func(projectSlug string) string) (string, string, error) {
	posixRoot := strings.TrimSpace(service.posixRoot)
	if posixRoot == "" {
		return "", "", fmt.Errorf("POSIX root is not configured")
	}
	trimmedFolderID := strings.TrimSpace(folderID)
	if trimmedFolderID == "" {
		return "", "", ErrProjectFolderNotFound
	}
	trimmedName := strings.TrimSpace(name)
	if trimmedName == "" {
		return "", "", fmt.Errorf("folder name is required")
	}
	rootProjectionPath := rootPathBuilder(projectSlug)
	folderProjectionPath := strings.TrimPrefix(filepath.ToSlash(filepath.Clean("/"+trimmedFolderID)), "/")
	if folderProjectionPath == "." || folderProjectionPath == rootProjectionPath || !strings.HasPrefix(folderProjectionPath, rootProjectionPath+"/") {
		return "", "", ErrProjectFolderNotFound
	}
	folderDir := filepath.Join(posixRoot, filepath.FromSlash(folderProjectionPath))
	info, err := os.Stat(folderDir)
	if err != nil {
		if os.IsNotExist(err) {
			return "", "", ErrProjectFolderNotFound
		}
		return "", "", fmt.Errorf("stat project folder: %w", err)
	}
	if !info.IsDir() {
		return "", "", ErrProjectFolderNotFound
	}
	parentDir := filepath.Dir(folderDir)
	baseSlug := normalizePOSIXSlug(trimmedName)
	folderName := slugDir("folder", baseSlug)
	folderSlug := baseSlug
	destinationDir := filepath.Join(parentDir, folderName)
	for attempt := 2; ; attempt += 1 {
		if destinationDir == folderDir {
			break
		}
		if _, err := os.Stat(destinationDir); os.IsNotExist(err) {
			break
		} else if err != nil {
			return "", "", fmt.Errorf("stat candidate renamed project folder: %w", err)
		}
		folderSlug = fmt.Sprintf("%s-%d", baseSlug, attempt)
		folderName = slugDir("folder", folderSlug)
		destinationDir = filepath.Join(parentDir, folderName)
	}
	renamedProjectionPath := filepath.ToSlash(filepath.Join(filepath.Dir(folderProjectionPath), folderName))
	if destinationDir != folderDir {
		if err := os.Rename(folderDir, destinationDir); err != nil {
			return "", "", fmt.Errorf("rename project folder: %w", err)
		}
	}
	folderPayload := readStructuredFileMap(filepath.Join(destinationDir, posixFolderFileName))
	folderMetadataID, _ := folderPayload["id"].(string)
	if strings.TrimSpace(folderMetadataID) == "" {
		folderMetadataID = uuid.NewString()
	}
	if err := writeCBORFile(filepath.Join(destinationDir, posixFolderFileName), map[string]any{"id": folderMetadataID, "name": trimmedName, "slug": folderSlug, "type": "folder"}); err != nil {
		return "", "", fmt.Errorf("write renamed project %s: %w", posixFolderFileName, err)
	}
	return folderProjectionPath, renamedProjectionPath, nil
}

func (service *Service) moveProjectFolderOnDisk(projectSlug, folderID, parentFolderID string, rootPathBuilder func(projectSlug string) string) (string, string, error) {
	posixRoot := strings.TrimSpace(service.posixRoot)
	if posixRoot == "" {
		return "", "", fmt.Errorf("POSIX root is not configured")
	}
	rootProjectionPath := rootPathBuilder(projectSlug)
	folderProjectionPath := strings.TrimPrefix(filepath.ToSlash(filepath.Clean("/"+strings.TrimSpace(folderID))), "/")
	if folderProjectionPath == "." || folderProjectionPath == rootProjectionPath || !strings.HasPrefix(folderProjectionPath, rootProjectionPath+"/") {
		return "", "", ErrProjectFolderNotFound
	}
	folderDir := filepath.Join(posixRoot, filepath.FromSlash(folderProjectionPath))
	info, err := os.Stat(folderDir)
	if err != nil {
		if os.IsNotExist(err) {
			return "", "", ErrProjectFolderNotFound
		}
		return "", "", fmt.Errorf("stat project folder: %w", err)
	}
	if !info.IsDir() {
		return "", "", ErrProjectFolderNotFound
	}
	trimmedParentFolderID := strings.TrimSpace(parentFolderID)
	parentChildrenProjectionPath := rootProjectionPath
	parentDir := filepath.Join(posixRoot, filepath.FromSlash(rootProjectionPath))
	if trimmedParentFolderID != "" {
		parentProjectionPath := strings.TrimPrefix(filepath.ToSlash(filepath.Clean("/"+trimmedParentFolderID)), "/")
		if parentProjectionPath == "." || parentProjectionPath == rootProjectionPath || !strings.HasPrefix(parentProjectionPath, rootProjectionPath+"/") {
			return "", "", ErrProjectFolderNotFound
		}
		if parentProjectionPath == folderProjectionPath || strings.HasPrefix(parentProjectionPath, folderProjectionPath+"/children/") {
			return "", "", ErrInvalidProjectFolderMove
		}
		parentChildrenProjectionPath = filepath.ToSlash(filepath.Join(parentProjectionPath, "children"))
		parentDir = filepath.Join(posixRoot, filepath.FromSlash(parentChildrenProjectionPath))
	}
	parentInfo, err := os.Stat(parentDir)
	if err != nil {
		if os.IsNotExist(err) {
			return "", "", ErrProjectFolderNotFound
		}
		return "", "", fmt.Errorf("stat project folder parent: %w", err)
	}
	if !parentInfo.IsDir() {
		return "", "", ErrProjectFolderNotFound
	}
	currentParentDir := filepath.Dir(folderDir)
	if samePath(currentParentDir, parentDir) {
		return folderProjectionPath, folderProjectionPath, nil
	}
	folderPayload := readStructuredFileMap(filepath.Join(folderDir, posixFolderFileName))
	folderMetadataID, _ := folderPayload["id"].(string)
	if strings.TrimSpace(folderMetadataID) == "" {
		folderMetadataID = uuid.NewString()
	}
	folderName, _ := folderPayload["name"].(string)
	if strings.TrimSpace(folderName) == "" {
		folderName = fallbackFolderLabel(folderProjectionPath)
	}
	currentBase := filepath.Base(folderDir)
	baseSlug := strings.TrimPrefix(currentBase, "folder-")
	if strings.TrimSpace(baseSlug) == "" {
		baseSlug = normalizePOSIXSlug(folderName)
	}
	folderSlug := baseSlug
	folderDirName := slugDir("folder", folderSlug)
	destinationDir := filepath.Join(parentDir, folderDirName)
	for attempt := 2; ; attempt += 1 {
		if _, err := os.Stat(destinationDir); os.IsNotExist(err) {
			break
		} else if err != nil {
			return "", "", fmt.Errorf("stat candidate moved project folder: %w", err)
		}
		folderSlug = fmt.Sprintf("%s-%d", baseSlug, attempt)
		folderDirName = slugDir("folder", folderSlug)
		destinationDir = filepath.Join(parentDir, folderDirName)
	}
	if err := os.Rename(folderDir, destinationDir); err != nil {
		return "", "", fmt.Errorf("move project folder: %w", err)
	}
	folderPayload["id"] = folderMetadataID
	folderPayload["name"] = folderName
	folderPayload["slug"] = folderSlug
	folderPayload["type"] = "folder"
	if err := writeCBORFile(filepath.Join(destinationDir, posixFolderFileName), folderPayload); err != nil {
		return "", "", fmt.Errorf("write moved project %s: %w", posixFolderFileName, err)
	}
	movedProjectionPath := filepath.ToSlash(filepath.Join(parentChildrenProjectionPath, folderDirName))
	return folderProjectionPath, movedProjectionPath, nil
}