import { getMembers, updateMember } from './nocodb';
import type { Member } from '~/utils/types';

/**
 * Generates a unique member ID in the format MUSA-YYYY-XXXX
 * where YYYY is the current year and XXXX is a sequential number
 * Checks against existing member IDs to ensure uniqueness
 * @returns Promise<string> - The unique member ID
 */
export async function generateMemberID(): Promise<string> {
  console.log('[member-id] Generating new member ID...');
  
  const currentYear = new Date().getFullYear();
  let memberID: string;
  let isUnique = false;
  let attempts = 0;
  const maxAttempts = 1000; // Prevent infinite loops

  // Get all existing member IDs for this year to find the highest number
  const members = await getMembers();
  const memberList = Array.isArray(members) ? members : members?.list || [];
  
  // Filter member IDs that match the current year format
  const yearPrefix = `MUSA-${currentYear}-`;
  const existingYearIds = memberList
    .filter((member: Member) => member.member_id?.startsWith(yearPrefix))
    .map((member: Member) => {
      const parts = member.member_id!.split('-');
      return parts.length === 3 ? parseInt(parts[2], 10) : 0;
    })
    .filter((num: number) => !isNaN(num));

  // Find the highest number used this year
  const highestNumber = existingYearIds.length > 0 ? Math.max(...existingYearIds) : 0;
  let nextNumber = highestNumber + 1;

  while (!isUnique && attempts < maxAttempts) {
    attempts++;
    
    // Format with leading zeros (4 digits)
    const formattedNumber = String(nextNumber).padStart(4, '0');
    memberID = `MUSA-${currentYear}-${formattedNumber}`;
    
    console.log(`[member-id] Attempt ${attempts}: Checking uniqueness of ${memberID}`);
    
    // Check if ID already exists in database
    const existingMember = await checkMemberIDExists(memberID);
    isUnique = !existingMember;
    
    if (!isUnique) {
      console.log(`[member-id] ID ${memberID} already exists, trying next number...`);
      nextNumber++;
    }
  }
  
  if (attempts >= maxAttempts) {
    console.error('[member-id] Failed to generate unique member ID after maximum attempts');
    throw new Error('Failed to generate unique member ID after maximum attempts');
  }
  
  console.log(`[member-id] ✅ Generated unique member ID: ${memberID!} (attempts: ${attempts})`);
  return memberID!;
}

/**
 * Alias for generateMemberID to match the import in other files
 */
export async function generateUniqueMemberId(): Promise<string> {
  return generateMemberID();
}

/**
 * Checks if a member ID already exists in the database
 * @param memberID - The member ID to check
 * @returns Promise<boolean> - True if the member ID exists, false otherwise
 */
export async function checkMemberIDExists(memberID: string): Promise<boolean> {
  try {
    console.log(`[member-id] Checking if member ID exists: ${memberID}`);
    
    // Get all members and check for duplicate member_id
    const members = await getMembers();
    const memberList = Array.isArray(members) ? members : members?.list || [];
    
    const existingMember = memberList.find((member: Member) => member.member_id === memberID);
    const exists = !!existingMember;
    
    console.log(`[member-id] Member ID ${memberID} exists: ${exists}`);
    return exists;
    
  } catch (error: any) {
    console.error('[member-id] Error checking member ID existence:', error);
    // In case of error, assume it doesn't exist to allow generation to continue
    // The actual creation will fail if there's a real database issue
    return false;
  }
}

/**
 * Finds all members without a member_id field
 * Used for migration purposes
 * @returns Promise<Member[]> - Array of members without member IDs
 */
export async function findMembersWithoutMemberID(): Promise<Member[]> {
  try {
    console.log('[member-id] Finding members without member IDs for migration...');
    
    const members = await getMembers();
    const memberList = Array.isArray(members) ? members : members?.list || [];
    
    const membersWithoutId = memberList.filter((member: Member) => 
      !member.member_id || member.member_id.trim() === ''
    );
    
    console.log(`[member-id] Found ${membersWithoutId.length} members without member IDs`);
    return membersWithoutId;
    
  } catch (error: any) {
    console.error('[member-id] Error finding members without member IDs:', error);
    throw error;
  }
}

/**
 * Validates a member ID format
 * @param memberID - The member ID to validate
 * @returns boolean - True if valid format, false otherwise
 */
export function isValidMemberIDFormat(memberID: string): boolean {
  if (!memberID || typeof memberID !== 'string') {
    return false;
  }
  
  // Check format: MUSA-YYYY-XXXX (year and 4 digits)
  const memberIDRegex = /^MUSA-\d{4}-\d{4}$/;
  return memberIDRegex.test(memberID);
}

/**
 * Extracts the numeric part from a member ID
 * @param memberID - The member ID (e.g., "MUSA-123456")
 * @returns number - The numeric part or null if invalid
 */
export function extractMemberIDNumber(memberID: string): number | null {
  if (!isValidMemberIDFormat(memberID)) {
    return null;
  }
  
  const numericPart = memberID.replace('MUSA-', '');
  return parseInt(numericPart, 10);
}