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

package bootstrap

import (
	"context"
	"fmt"
	"strings"
)

func (service *Service) CreateProjectFolder(ctx context.Context, input CreateProjectFolderInput) (CreateProjectFolderResult, error) {
	return service.createProjectHierarchyFolder(ctx, input, projectHierarchyRootPath, service.createProjectHierarchyFolderOnDisk)
}

func (service *Service) CreateProjectTreeFolder(ctx context.Context, input CreateProjectFolderInput) (CreateProjectFolderResult, error) {
	return service.createProjectHierarchyFolder(ctx, input, projectTreeRootPath, service.createProjectTreeFolderOnDisk)
}

func (service *Service) DeleteProjectFolder(ctx context.Context, input DeleteProjectFolderInput) (DeleteProjectFolderResult, error) {
	return service.deleteProjectHierarchyFolder(ctx, input, projectHierarchyRootPath, service.deleteProjectHierarchyFolderOnDisk)
}

func (service *Service) DeleteProjectTreeFolder(ctx context.Context, input DeleteProjectFolderInput) (DeleteProjectFolderResult, error) {
	return service.deleteProjectHierarchyFolder(ctx, input, projectTreeRootPath, service.deleteProjectTreeFolderOnDisk)
}

func (service *Service) RenameProjectFolder(ctx context.Context, input RenameProjectFolderInput) (RenameProjectFolderResult, error) {
	return service.renameProjectHierarchyFolder(ctx, input, projectHierarchyRootPath, service.renameProjectHierarchyFolderOnDisk)
}

func (service *Service) RenameProjectTreeFolder(ctx context.Context, input RenameProjectFolderInput) (RenameProjectFolderResult, error) {
	return service.renameProjectHierarchyFolder(ctx, input, projectTreeRootPath, service.renameProjectTreeFolderOnDisk)
}

func (service *Service) MoveProjectFolder(ctx context.Context, input MoveProjectFolderInput) (MoveProjectFolderResult, error) {
	return service.moveProjectHierarchyFolder(ctx, input, projectHierarchyRootPath, service.moveProjectHierarchyFolderOnDisk)
}

func (service *Service) MoveProjectTreeFolder(ctx context.Context, input MoveProjectFolderInput) (MoveProjectFolderResult, error) {
	return service.moveProjectHierarchyFolder(ctx, input, projectTreeRootPath, service.moveProjectTreeFolderOnDisk)
}

func (service *Service) CreateProjectTreeItem(ctx context.Context, input CreateProjectItemInput) (CreateProjectItemResult, error) {
	return service.createProjectTreeItem(ctx, input, projectTreeRootPath)
}

func (service *Service) DeleteProjectTreeItem(ctx context.Context, input DeleteProjectItemInput) (DeleteProjectItemResult, error) {
	return service.deleteProjectTreeItem(ctx, input, projectTreeRootPath)
}

func (service *Service) MoveProjectTreeItem(ctx context.Context, input MoveProjectItemInput) (MoveProjectItemResult, error) {
	return service.moveProjectTreeItem(ctx, input, projectTreeRootPath)
}

func (service *Service) createProjectHierarchyFolder(
	ctx context.Context,
	input CreateProjectFolderInput,
	rootPath func(projectSlug string) string,
	createOnDisk func(projectSlug, parentFolderPath, name string) (string, string, error),
) (CreateProjectFolderResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return CreateProjectFolderResult{}, err
	}

	currentFolders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectFolderResult{}, err
	}

	parentOrderID := ""
	trimmedParentFolderPath := strings.TrimSpace(input.ParentFolderPath)
	if trimmedParentFolderPath != "" {
		parentFolder, found := findProjectHierarchyFolderByPath(currentFolders, trimmedParentFolderPath)
		if !found {
			return CreateProjectFolderResult{}, ErrProjectFolderNotFound
		}
		parentOrderID = parentFolder.ID
	}

	createdPath, _, err := createOnDisk(project.Slug, strings.TrimSpace(input.ParentFolderPath), input.Name)
	if err != nil {
		return CreateProjectFolderResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return CreateProjectFolderResult{}, err
	}

	folders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectFolderResult{}, err
	}

	createdFolder, ok := findProjectHierarchyFolderByPath(folders, createdPath)
	if !ok {
		return CreateProjectFolderResult{}, fmt.Errorf("created project folder missing from projection")
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	seedFolderOrderParent(folderOrder, currentFolders, parentOrderID)
	insertFolderOrder(folderOrder, parentOrderID, createdFolder.ID, len(folderOrderChildren(folderOrder, parentOrderID)))
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return CreateProjectFolderResult{}, err
	}

	folders, err = service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectFolderResult{}, err
	}

	createdFolder, ok = findProjectHierarchyFolderByPath(folders, createdPath)
	if !ok {
		return CreateProjectFolderResult{}, fmt.Errorf("created project folder missing from ordered projection")
	}

	return CreateProjectFolderResult{ProjectID: project.ID, CreatedFolder: createdFolder, Folders: folders}, nil
}

func (service *Service) deleteProjectHierarchyFolder(
	ctx context.Context,
	input DeleteProjectFolderInput,
	rootPath func(projectSlug string) string,
	deleteOnDisk func(projectSlug, folderPath string) (string, error),
) (DeleteProjectFolderResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return DeleteProjectFolderResult{}, err
	}

	currentFolders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectFolderResult{}, err
	}

	deletedFolder, found := findProjectHierarchyFolderByPath(currentFolders, strings.TrimSpace(input.FolderPath))
	if !found {
		return DeleteProjectFolderResult{}, ErrProjectFolderNotFound
	}

	deletedFolderPath, err := deleteOnDisk(project.Slug, input.FolderPath)
	if err != nil {
		return DeleteProjectFolderResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return DeleteProjectFolderResult{}, err
	}

	folders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectFolderResult{}, err
	}

	if _, found := findProjectHierarchyFolderByPath(folders, deletedFolderPath); found {
		return DeleteProjectFolderResult{}, fmt.Errorf("deleted project folder still present in projection")
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	removeFolderOrder(folderOrder, deletedFolder.ID)
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return DeleteProjectFolderResult{}, err
	}

	folders, err = service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectFolderResult{}, err
	}

	return DeleteProjectFolderResult{ProjectID: project.ID, DeletedFolderStableID: deletedFolder.ID, DeletedFolderPath: deletedFolderPath, Folders: folders}, nil
}

func (service *Service) renameProjectHierarchyFolder(
	ctx context.Context,
	input RenameProjectFolderInput,
	rootPath func(projectSlug string) string,
	renameOnDisk func(projectSlug, folderPath, name string) (string, string, error),
) (RenameProjectFolderResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return RenameProjectFolderResult{}, err
	}

	previousFolderPath, renamedFolderPath, err := renameOnDisk(project.Slug, input.FolderPath, input.Name)
	if err != nil {
		return RenameProjectFolderResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return RenameProjectFolderResult{}, err
	}

	folders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return RenameProjectFolderResult{}, err
	}

	renamedFolder, found := findProjectHierarchyFolderByPath(folders, renamedFolderPath)
	if !found {
		return RenameProjectFolderResult{}, fmt.Errorf("renamed project folder missing from projection")
	}

	if _, found := findProjectHierarchyFolderByPath(folders, previousFolderPath); found {
		return RenameProjectFolderResult{}, fmt.Errorf("previous project folder path still present in projection")
	}

	return RenameProjectFolderResult{ProjectID: project.ID, PreviousFolderStableID: renamedFolder.ID, PreviousFolderPath: previousFolderPath, RenamedFolder: renamedFolder, Folders: folders}, nil
}

func (service *Service) moveProjectHierarchyFolder(
	ctx context.Context,
	input MoveProjectFolderInput,
	rootPath func(projectSlug string) string,
	moveOnDisk func(projectSlug, folderPath, parentFolderPath string) (string, string, error),
) (MoveProjectFolderResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return MoveProjectFolderResult{}, err
	}

	currentFolders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectFolderResult{}, err
	}

	currentFolder, found := findProjectHierarchyFolderByPath(currentFolders, strings.TrimSpace(input.FolderPath))
	if !found {
		return MoveProjectFolderResult{}, ErrProjectFolderNotFound
	}

	movedFolderStableID := currentFolder.ID
	providedFolderStableID := strings.TrimSpace(input.FolderStableID)
	if providedFolderStableID != "" && providedFolderStableID != movedFolderStableID {
		return MoveProjectFolderResult{}, ErrInvalidProjectFolderMove
	}

	parentOrderID := ""
	trimmedParentFolderPath := strings.TrimSpace(input.ParentFolderPath)
	providedParentStableID := strings.TrimSpace(input.ParentStableID)
	if trimmedParentFolderPath != "" {
		parentFolder, found := findProjectHierarchyFolderByPath(currentFolders, trimmedParentFolderPath)
		if !found {
			return MoveProjectFolderResult{}, ErrProjectFolderNotFound
		}
		parentOrderID = parentFolder.ID
		if providedParentStableID != "" && providedParentStableID != parentOrderID {
			return MoveProjectFolderResult{}, ErrInvalidProjectFolderMove
		}
	} else if providedParentStableID != "" {
		return MoveProjectFolderResult{}, ErrInvalidProjectFolderMove
	}

	previousFolderPath, movedFolderPath, err := moveOnDisk(project.Slug, input.FolderPath, input.ParentFolderPath)
	if err != nil {
		return MoveProjectFolderResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return MoveProjectFolderResult{}, err
	}

	folders, err := service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectFolderResult{}, err
	}

	movedFolder, found := findProjectHierarchyFolderByPath(folders, movedFolderPath)
	if !found {
		return MoveProjectFolderResult{}, fmt.Errorf("moved project folder missing from projection")
	}

	if previousFolderPath != movedFolderPath {
		if _, found := findProjectHierarchyFolderByPath(folders, previousFolderPath); found {
			return MoveProjectFolderResult{}, fmt.Errorf("previous project folder path still present in projection")
		}
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	seedFolderOrderParent(folderOrder, currentFolders, parentOrderID)
	removeFolderOrderReference(folderOrder, movedFolderStableID)
	removeFolderOrderReference(folderOrder, movedFolder.ID)
	insertFolderOrder(folderOrder, parentOrderID, movedFolder.ID, input.TargetIndex)
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return MoveProjectFolderResult{}, err
	}

	folders, err = service.getProjectHierarchyFoldersByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectFolderResult{}, err
	}

	movedFolder, found = findProjectHierarchyFolderByPath(folders, movedFolderPath)
	if !found {
		return MoveProjectFolderResult{}, fmt.Errorf("moved project folder missing from ordered projection")
	}

	return MoveProjectFolderResult{ProjectID: project.ID, PreviousFolderStableID: movedFolder.ID, PreviousFolderPath: previousFolderPath, MovedFolder: movedFolder, Folders: folders}, nil
}

func (service *Service) createProjectTreeItem(ctx context.Context, input CreateProjectItemInput, rootPath func(projectSlug string) string) (CreateProjectItemResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return CreateProjectItemResult{}, err
	}

	currentNodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectItemResult{}, err
	}

	parentOrderID := ""
	trimmedParentFolderPath := strings.TrimSpace(input.ParentFolderPath)
	if trimmedParentFolderPath != "" {
		parentFolder, found := findProjectTreeFolderByPath(currentNodes, trimmedParentFolderPath)
		if !found {
			return CreateProjectItemResult{}, ErrProjectFolderNotFound
		}
		parentOrderID = parentFolder.ID
	}

	createdPath, err := service.createProjectTreeItemOnDisk(project.Slug, trimmedParentFolderPath, input.Name, input.ItemType)
	if err != nil {
		return CreateProjectItemResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return CreateProjectItemResult{}, err
	}

	nodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectItemResult{}, err
	}

	createdItem, ok := findProjectTreeNodeByPath(nodes, createdPath)
	if !ok || createdItem.Kind != "item" {
		return CreateProjectItemResult{}, fmt.Errorf("created project item missing from projection")
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	seedProjectTreeOrderParent(folderOrder, currentNodes, parentOrderID)
	insertFolderOrder(folderOrder, parentOrderID, createdItem.ID, len(folderOrderChildren(folderOrder, parentOrderID)))
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return CreateProjectItemResult{}, err
	}

	nodes, err = service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return CreateProjectItemResult{}, err
	}

	createdItem, ok = findProjectTreeNodeByPath(nodes, createdPath)
	if !ok || createdItem.Kind != "item" {
		return CreateProjectItemResult{}, fmt.Errorf("created project item missing from ordered projection")
	}

	return CreateProjectItemResult{ProjectID: project.ID, CreatedItem: createdItem, Nodes: nodes}, nil
}

func (service *Service) deleteProjectTreeItem(ctx context.Context, input DeleteProjectItemInput, rootPath func(projectSlug string) string) (DeleteProjectItemResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return DeleteProjectItemResult{}, err
	}

	currentNodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectItemResult{}, err
	}

	deletedItem, found := findProjectTreeNodeByPath(currentNodes, strings.TrimSpace(input.ItemPath))
	if !found || deletedItem.Kind != "item" {
		return DeleteProjectItemResult{}, ErrProjectItemNotFound
	}

	deletedItemPath, err := service.deleteProjectTreeItemOnDisk(project.Slug, input.ItemPath)
	if err != nil {
		return DeleteProjectItemResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return DeleteProjectItemResult{}, err
	}

	nodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectItemResult{}, err
	}

	if _, found := findProjectTreeNodeByPath(nodes, deletedItemPath); found {
		return DeleteProjectItemResult{}, fmt.Errorf("deleted project item still present in projection")
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	removeFolderOrderReference(folderOrder, deletedItem.ID)
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return DeleteProjectItemResult{}, err
	}

	nodes, err = service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return DeleteProjectItemResult{}, err
	}

	return DeleteProjectItemResult{ProjectID: project.ID, DeletedItemStableID: deletedItem.ID, DeletedItemPath: deletedItemPath, Nodes: nodes}, nil
}

func (service *Service) moveProjectTreeItem(ctx context.Context, input MoveProjectItemInput, rootPath func(projectSlug string) string) (MoveProjectItemResult, error) {
	project, err := service.loadProjectByID(ctx, strings.TrimSpace(input.ProjectID))
	if err != nil {
		return MoveProjectItemResult{}, err
	}

	currentNodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectItemResult{}, err
	}

	currentItem, found := findProjectTreeNodeByPath(currentNodes, strings.TrimSpace(input.ItemPath))
	if !found || currentItem.Kind != "item" {
		return MoveProjectItemResult{}, ErrProjectItemNotFound
	}

	movedItemStableID := currentItem.ID
	providedItemStableID := strings.TrimSpace(input.ItemStableID)
	if providedItemStableID != "" && providedItemStableID != movedItemStableID {
		return MoveProjectItemResult{}, ErrInvalidProjectItemMove
	}

	parentOrderID := ""
	trimmedParentFolderPath := strings.TrimSpace(input.ParentFolderPath)
	providedParentStableID := strings.TrimSpace(input.ParentStableID)
	if trimmedParentFolderPath != "" {
		parentFolder, found := findProjectTreeFolderByPath(currentNodes, trimmedParentFolderPath)
		if !found {
			return MoveProjectItemResult{}, ErrProjectFolderNotFound
		}
		parentOrderID = parentFolder.ID
		if providedParentStableID != "" && providedParentStableID != parentOrderID {
			return MoveProjectItemResult{}, ErrInvalidProjectItemMove
		}
	} else if providedParentStableID != "" {
		return MoveProjectItemResult{}, ErrInvalidProjectItemMove
	}

	previousItemPath, movedItemPath, err := service.moveProjectTreeItemOnDisk(project.Slug, input.ItemPath, input.ParentFolderPath)
	if err != nil {
		return MoveProjectItemResult{}, err
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return MoveProjectItemResult{}, err
	}

	nodes, err := service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectItemResult{}, err
	}

	movedItem, found := findProjectTreeNodeByPath(nodes, movedItemPath)
	if !found || movedItem.Kind != "item" {
		return MoveProjectItemResult{}, fmt.Errorf("moved project item missing from projection")
	}

	if previousItemPath != movedItemPath {
		if _, found := findProjectTreeNodeByPath(nodes, previousItemPath); found {
			return MoveProjectItemResult{}, fmt.Errorf("previous project item path still present in projection")
		}
	}

	folderOrder := service.readProjectFolderOrder(project.Slug, rootPath(project.Slug))
	seedProjectTreeOrderParent(folderOrder, currentNodes, parentOrderID)
	removeFolderOrderReference(folderOrder, movedItemStableID)
	removeFolderOrderReference(folderOrder, movedItem.ID)
	insertFolderOrder(folderOrder, parentOrderID, movedItem.ID, input.TargetIndex)
	if err := service.writeProjectFolderOrder(project.Slug, rootPath(project.Slug), folderOrder); err != nil {
		return MoveProjectItemResult{}, err
	}

	nodes, err = service.getProjectTreeNodesByRootPath(ctx, project.ID, rootPath)
	if err != nil {
		return MoveProjectItemResult{}, err
	}

	movedItem, found = findProjectTreeNodeByPath(nodes, movedItemPath)
	if !found || movedItem.Kind != "item" {
		return MoveProjectItemResult{}, fmt.Errorf("moved project item missing from ordered projection")
	}

	return MoveProjectItemResult{ProjectID: project.ID, PreviousItemStableID: movedItem.ID, PreviousItemPath: previousItemPath, MovedItem: movedItem, Nodes: nodes}, nil
}