import { z } from 'zod';

// Simplified approval level schema - only requires email and tatHours
// Backend will enrich with user details (approverId, approverName, levelName)
const simplifiedApprovalLevelSchema = z.object({
  email: z.string().email('Valid email is required'),
  tatHours: z.number().positive('TAT hours must be positive'),
  isFinalApprover: z.boolean().optional(),
  // Optional fields that backend will auto-populate if not provided
  levelNumber: z.number().int().min(1).max(10).optional(),
  levelName: z.string().optional(),
  approverId: z.string().uuid().optional(),
  approverEmail: z.string().email().optional(),
  approverName: z.string().optional(),
});

// Simplified spectator schema - only requires email
const simplifiedSpectatorSchema = z.object({
  email: z.string().email('Valid email is required').optional(),
  // Optional fields that backend will auto-populate if not provided
  userId: z.string().uuid().optional(),
  userEmail: z.string().email().optional(),
  userName: z.string().optional(),
  participantType: z.enum(['INITIATOR', 'APPROVER', 'SPECTATOR'] as const).optional(),
  canComment: z.boolean().optional(),
  canViewDocuments: z.boolean().optional(),
  canDownloadDocuments: z.boolean().optional(),
  notificationEnabled: z.boolean().optional(),
});

export const createWorkflowSchema = z.object({
  templateType: z.enum(['CUSTOM', 'TEMPLATE']),
  title: z.string().min(1, 'Title is required').max(500, 'Title too long'),
  description: z.string().min(1, 'Description is required'),
  priority: z.enum(['STANDARD', 'EXPRESS'] as const),
  approvalLevels: z.array(simplifiedApprovalLevelSchema)
    .min(1, 'At least one approval level is required')
    .max(10, 'Maximum 10 approval levels allowed'),
  participants: z.array(simplifiedSpectatorSchema).optional(),
  spectators: z.array(simplifiedSpectatorSchema).optional(), // Alias for participants
  // Additional frontend compatibility fields
  approverCount: z.number().optional(),
  approvers: z.array(z.any()).optional(),
  priorityUi: z.string().optional(),
  templateId: z.string().optional(),
  ccList: z.array(z.any()).optional(),
  isDraft: z.boolean().optional(),
});

export const updateWorkflowSchema = z.object({
  title: z.string().min(1).max(500).optional(),
  description: z.string().min(1).optional(),
  priority: z.enum(['STANDARD', 'EXPRESS'] as const).optional(),
  status: z.enum(['DRAFT', 'PENDING', 'APPROVED', 'REJECTED', 'CLOSED', 'PAUSED'] as const).optional(),
  conclusionRemark: z.string().optional(),
  // For draft updates - allow updating approval levels and participants
  approvalLevels: z.array(z.object({
    levelNumber: z.number().int().min(1).max(10),
    levelName: z.string().optional(),
    approverId: z.string().uuid(),
    approverEmail: z.string().email(),
    approverName: z.string().min(1),
    tatHours: z.number().positive(),
    isFinalApprover: z.boolean().optional(),
  })).optional(),
  participants: z.array(z.object({
    userId: z.string().uuid(),
    userEmail: z.string().email(),
    userName: z.string().min(1),
    participantType: z.enum(['INITIATOR', 'APPROVER', 'SPECTATOR'] as const),
    canComment: z.boolean().optional(),
    canViewDocuments: z.boolean().optional(),
    canDownloadDocuments: z.boolean().optional(),
    notificationEnabled: z.boolean().optional(),
  })).optional(),
  deleteDocumentIds: z.array(z.string().uuid()).optional(),
  isDraft: z.boolean().optional(),
});

// Helper to validate UUID or requestNumber format
// Supports both old format (REQ-YYYY-NNNNN) and new format (REQ-YYYY-MM-XXXX)
const workflowIdValidator = z.string().refine(
  (val) => {
    // Check if it's a valid UUID
    const uuidRegex = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
    if (uuidRegex.test(val)) {
      return true;
    }
    // Check if it's a valid requestNumber format
    // Old format: REQ-YYYY-NNNNN (e.g., REQ-2025-12057) - 5+ digits after year
    // New format: REQ-YYYY-MM-XXXX (e.g., REQ-2025-11-0001) - 2-digit month, 4-digit counter
    const oldFormatRegex = /^REQ-\d{4}-\d{5,}$/i; // Old: REQ-2025-12057
    const newFormatRegex = /^REQ-\d{4}-\d{2}-\d{4}$/i; // New: REQ-2025-11-0001
    if (oldFormatRegex.test(val) || newFormatRegex.test(val)) {
      return true;
    }
    return false;
  },
  {
    message: 'Invalid workflow ID - must be a valid UUID or requestNumber (e.g., REQ-2025-11-0001 or REQ-2025-12057)',
  }
);

export const workflowParamsSchema = z.object({
  id: workflowIdValidator,
});

export const workflowQuerySchema = z.object({
  page: z.string().transform(Number).pipe(z.number().int().min(1)).optional(),
  limit: z.string().transform(Number).pipe(z.number().int().min(1).max(100)).optional(),
  status: z.enum(['DRAFT', 'PENDING', 'APPROVED', 'REJECTED', 'CLOSED', 'PAUSED'] as const).optional(),
  priority: z.enum(['STANDARD', 'EXPRESS'] as const).optional(),
  sortBy: z.string().optional(),
  sortOrder: z.enum(['ASC', 'DESC'] as const).optional(),
});

export const validateCreateWorkflow = (data: any) => {
  return createWorkflowSchema.parse(data);
};

export const validateUpdateWorkflow = (data: any) => {
  return updateWorkflowSchema.parse(data);
};