// Project-wise File Management System with Local Storage
// Comprehensive project organization and file handling

interface ProjectFile {
  id: string;
  name: string;
  type: 'calculation' | 'report' | 'data' | 'image' | 'document';
  content: any;
  size: number;
  createdAt: Date;
  modifiedAt: Date;
  tags: string[];
  metadata: Record<string, any>;
}

interface Project {
  id: string;
  name: string;
  description: string;
  createdAt: Date;
  modifiedAt: Date;
  files: ProjectFile[];
  settings: ProjectSettings;
  status: 'active' | 'completed' | 'archived';
}

interface ProjectSettings {
  autoSave: boolean;
  backupFrequency: number; // hours
  compressionEnabled: boolean;
  maxFileSize: number; // MB
  allowedFileTypes: string[];
}

class ProjectManager {
  private readonly STORAGE_KEY = 'prithvi_projects';
  private readonly MAX_STORAGE_SIZE = 50 * 1024 * 1024; // 50MB limit
  private projects: Map<string, Project> = new Map();

  constructor() {
    this.loadProjects();
    this.setupAutoSave();
  }

  // Project Management
  async createProject(name: string, description: string = ''): Promise<Project> {
    try {
      if (!name || name.trim().length === 0) {
        throw new Error('Project name is required');
      }

      if (name.length > 100) {
        throw new Error('Project name must be less than 100 characters');
      }

      // Check for duplicate names
      const existingProject = Array.from(this.projects.values()).find(p => p.name === name);
      if (existingProject) {
        throw new Error('Project with this name already exists');
      }

      const project: Project = {
        id: this.generateId(),
        name: name.trim(),
        description: description.trim(),
        createdAt: new Date(),
        modifiedAt: new Date(),
        files: [],
        settings: this.getDefaultSettings(),
        status: 'active'
      };

      this.projects.set(project.id, project);
      await this.saveProjects();
      
      return project;
    } catch (error) {
      throw new Error(`Failed to create project: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async updateProject(projectId: string, updates: Partial<Project>): Promise<Project> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      // Validate updates
      if (updates.name !== undefined) {
        if (!updates.name || updates.name.trim().length === 0) {
          throw new Error('Project name cannot be empty');
        }
        if (updates.name.length > 100) {
          throw new Error('Project name must be less than 100 characters');
        }
      }

      const updatedProject = {
        ...project,
        ...updates,
        id: project.id, // Prevent ID changes
        modifiedAt: new Date()
      };

      this.projects.set(projectId, updatedProject);
      await this.saveProjects();
      
      return updatedProject;
    } catch (error) {
      throw new Error(`Failed to update project: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async deleteProject(projectId: string): Promise<boolean> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      this.projects.delete(projectId);
      await this.saveProjects();
      
      return true;
    } catch (error) {
      throw new Error(`Failed to delete project: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  getProject(projectId: string): Project | undefined {
    return this.projects.get(projectId);
  }

  getAllProjects(): Project[] {
    return Array.from(this.projects.values()).sort((a, b) => 
      b.modifiedAt.getTime() - a.modifiedAt.getTime()
    );
  }

  getProjectsByStatus(status: Project['status']): Project[] {
    return this.getAllProjects().filter(p => p.status === status);
  }

  searchProjects(query: string): Project[] {
    if (!query || query.trim().length === 0) {
      return this.getAllProjects();
    }

    const searchTerm = query.toLowerCase().trim();
    return this.getAllProjects().filter(project => 
      project.name.toLowerCase().includes(searchTerm) ||
      project.description.toLowerCase().includes(searchTerm) ||
      project.files.some(file => 
        file.name.toLowerCase().includes(searchTerm) ||
        file.tags.some(tag => tag.toLowerCase().includes(searchTerm))
      )
    );
  }

  // File Management
  async addFile(projectId: string, file: Omit<ProjectFile, 'id' | 'createdAt' | 'modifiedAt'>): Promise<ProjectFile> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      // Validate file
      this.validateFile(file, project.settings);

      // Check storage limits
      await this.checkStorageLimit(file.size);

      const newFile: ProjectFile = {
        ...file,
        id: this.generateId(),
        createdAt: new Date(),
        modifiedAt: new Date()
      };

      project.files.push(newFile);
      project.modifiedAt = new Date();

      this.projects.set(projectId, project);
      await this.saveProjects();

      return newFile;
    } catch (error) {
      throw new Error(`Failed to add file: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async updateFile(projectId: string, fileId: string, updates: Partial<ProjectFile>): Promise<ProjectFile> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      const fileIndex = project.files.findIndex(f => f.id === fileId);
      if (fileIndex === -1) {
        throw new Error('File not found');
      }

      const updatedFile = {
        ...project.files[fileIndex],
        ...updates,
        id: fileId, // Prevent ID changes
        modifiedAt: new Date()
      };

      // Validate updated file
      this.validateFile(updatedFile, project.settings);

      project.files[fileIndex] = updatedFile;
      project.modifiedAt = new Date();

      this.projects.set(projectId, project);
      await this.saveProjects();

      return updatedFile;
    } catch (error) {
      throw new Error(`Failed to update file: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async deleteFile(projectId: string, fileId: string): Promise<boolean> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      const fileIndex = project.files.findIndex(f => f.id === fileId);
      if (fileIndex === -1) {
        throw new Error('File not found');
      }

      project.files.splice(fileIndex, 1);
      project.modifiedAt = new Date();

      this.projects.set(projectId, project);
      await this.saveProjects();

      return true;
    } catch (error) {
      throw new Error(`Failed to delete file: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  getFile(projectId: string, fileId: string): ProjectFile | undefined {
    const project = this.projects.get(projectId);
    return project?.files.find(f => f.id === fileId);
  }

  getFilesByType(projectId: string, type: ProjectFile['type']): ProjectFile[] {
    const project = this.projects.get(projectId);
    return project?.files.filter(f => f.type === type) || [];
  }

  searchFiles(projectId: string, query: string): ProjectFile[] {
    const project = this.projects.get(projectId);
    if (!project || !query.trim()) {
      return project?.files || [];
    }

    const searchTerm = query.toLowerCase().trim();
    return project.files.filter(file =>
      file.name.toLowerCase().includes(searchTerm) ||
      file.tags.some(tag => tag.toLowerCase().includes(searchTerm)) ||
      (typeof file.content === 'string' && file.content.toLowerCase().includes(searchTerm))
    );
  }

  // Data Export/Import
  async exportProject(projectId: string): Promise<string> {
    try {
      const project = this.projects.get(projectId);
      if (!project) {
        throw new Error('Project not found');
      }

      const exportData = {
        project,
        exportedAt: new Date().toISOString(),
        version: '1.0',
        metadata: {
          totalFiles: project.files.length,
          totalSize: this.calculateProjectSize(project)
        }
      };

      return JSON.stringify(exportData, null, 2);
    } catch (error) {
      throw new Error(`Failed to export project: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async importProject(importData: string): Promise<Project> {
    try {
      const data = JSON.parse(importData);
      
      if (!data.project) {
        throw new Error('Invalid import data: missing project information');
      }

      const project = data.project;
      
      // Validate project structure
      if (!project.name || !project.id) {
        throw new Error('Invalid project data: missing required fields');
      }

      // Generate new ID to avoid conflicts
      project.id = this.generateId();
      project.createdAt = new Date();
      project.modifiedAt = new Date();

      // Validate and regenerate file IDs
      if (project.files) {
        project.files.forEach((file: ProjectFile) => {
          file.id = this.generateId();
          file.createdAt = new Date(file.createdAt);
          file.modifiedAt = new Date(file.modifiedAt);
        });
      }

      // Check storage limits
      const projectSize = this.calculateProjectSize(project);
      await this.checkStorageLimit(projectSize);

      this.projects.set(project.id, project);
      await this.saveProjects();

      return project;
    } catch (error) {
      throw new Error(`Failed to import project: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Storage Management
  async getStorageInfo(): Promise<{
    used: number;
    available: number;
    total: number;
    projects: number;
    files: number;
  }> {
    try {
      const projects = this.getAllProjects();
      const totalFiles = projects.reduce((sum, p) => sum + p.files.length, 0);
      const usedSpace = this.calculateTotalSize();

      return {
        used: usedSpace,
        available: this.MAX_STORAGE_SIZE - usedSpace,
        total: this.MAX_STORAGE_SIZE,
        projects: projects.length,
        files: totalFiles
      };
    } catch (error) {
      throw new Error(`Failed to get storage info: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async cleanupStorage(daysOld: number = 30): Promise<{
    deletedProjects: number;
    freedSpace: number;
  }> {
    try {
      const cutoffDate = new Date();
      cutoffDate.setDate(cutoffDate.getDate() - daysOld);

      let deletedProjects = 0;
      let freedSpace = 0;

      for (const [projectId, project] of this.projects) {
        if (project.status === 'archived' && project.modifiedAt < cutoffDate) {
          freedSpace += this.calculateProjectSize(project);
          this.projects.delete(projectId);
          deletedProjects++;
        }
      }

      if (deletedProjects > 0) {
        await this.saveProjects();
      }

      return { deletedProjects, freedSpace };
    } catch (error) {
      throw new Error(`Failed to cleanup storage: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Backup and Recovery
  async createBackup(): Promise<string> {
    try {
      const backup = {
        projects: Array.from(this.projects.values()),
        backupDate: new Date().toISOString(),
        version: '1.0'
      };

      return JSON.stringify(backup, null, 2);
    } catch (error) {
      throw new Error(`Failed to create backup: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  async restoreFromBackup(backupData: string): Promise<boolean> {
    try {
      const backup = JSON.parse(backupData);
      
      if (!backup.projects || !Array.isArray(backup.projects)) {
        throw new Error('Invalid backup data');
      }

      // Clear existing projects
      this.projects.clear();

      // Restore projects
      backup.projects.forEach((project: Project) => {
        // Regenerate dates
        project.createdAt = new Date(project.createdAt);
        project.modifiedAt = new Date(project.modifiedAt);
        
        if (project.files) {
          project.files.forEach((file: ProjectFile) => {
            file.createdAt = new Date(file.createdAt);
            file.modifiedAt = new Date(file.modifiedAt);
          });
        }

        this.projects.set(project.id, project);
      });

      await this.saveProjects();
      return true;
    } catch (error) {
      throw new Error(`Failed to restore from backup: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Private helper methods
  private generateId(): string {
    return `proj_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
  }

  private getDefaultSettings(): ProjectSettings {
    return {
      autoSave: true,
      backupFrequency: 24,
      compressionEnabled: true,
      maxFileSize: 10,
      allowedFileTypes: [
        'text/plain', 'application/json', 'text/csv',
        'image/jpeg', 'image/png', 'image/gif',
        'application/pdf', 'text/html'
      ]
    };
  }

  private validateFile(file: Partial<ProjectFile>, settings: ProjectSettings): void {
    if (!file.name || file.name.trim().length === 0) {
      throw new Error('File name is required');
    }

    if (file.name.length > 255) {
      throw new Error('File name must be less than 255 characters');
    }

    if (file.size !== undefined && file.size > settings.maxFileSize * 1024 * 1024) {
      throw new Error(`File size exceeds limit of ${settings.maxFileSize}MB`);
    }

    if (file.tags && file.tags.some(tag => tag.length > 50)) {
      throw new Error('Tag length must be less than 50 characters');
    }
  }

  private calculateProjectSize(project: Project): number {
    return project.files.reduce((total, file) => total + file.size, 0);
  }

  private calculateTotalSize(): number {
    let total = 0;
    for (const project of this.projects.values()) {
      total += this.calculateProjectSize(project);
    }
    return total;
  }

  private async checkStorageLimit(additionalSize: number): Promise<void> {
    const currentSize = this.calculateTotalSize();
    if (currentSize + additionalSize > this.MAX_STORAGE_SIZE) {
      throw new Error(`Storage limit exceeded. Available: ${((this.MAX_STORAGE_SIZE - currentSize) / 1024 / 1024).toFixed(2)}MB, Required: ${(additionalSize / 1024 / 1024).toFixed(2)}MB`);
    }
  }

  private loadProjects(): void {
    try {
      const data = localStorage.getItem(this.STORAGE_KEY);
      if (data) {
        const projects = JSON.parse(data);
        projects.forEach((project: Project) => {
          // Convert date strings back to Date objects
          project.createdAt = new Date(project.createdAt);
          project.modifiedAt = new Date(project.modifiedAt);
          
          if (project.files) {
            project.files.forEach((file: ProjectFile) => {
              file.createdAt = new Date(file.createdAt);
              file.modifiedAt = new Date(file.modifiedAt);
            });
          }

          this.projects.set(project.id, project);
        });
      }
    } catch (error) {
      console.error('Failed to load projects from storage:', error);
    }
  }

  private async saveProjects(): Promise<void> {
    try {
      const projects = Array.from(this.projects.values());
      localStorage.setItem(this.STORAGE_KEY, JSON.stringify(projects));
    } catch (error) {
      throw new Error(`Failed to save projects: ${error instanceof Error ? error.message : 'Storage quota exceeded'}`);
    }
  }

  private setupAutoSave(): void {
    // Auto-save every 5 minutes
    setInterval(() => {
      this.saveProjects().catch(error => {
        console.error('Auto-save failed:', error);
      });
    }, 5 * 60 * 1000);
  }
}

export const projectManager = new ProjectManager();
export { Project, ProjectFile, ProjectSettings };