/**
 * Badge management and achievement utilities
 */

import {
  Badge,
  UserBadge,
  RequirementType
} from './types';
import {
  getAllBadges,
  getUserBadges,
  createUserBadge,
  hasUserEarnedBadge,
  getUserCompletedTasks,
  findBadge
} from './db/store';
import { getBalance } from './points';

/**
 * Check user's progress towards badge requirements
 */
function checkRequirement(
  userId: string,
  requirementType: RequirementType,
  requirementValue: number
): boolean {
  switch (requirementType) {
    case RequirementType.POINTS_TOTAL: {
      const balance = getBalance(userId);
      return balance >= requirementValue;
    }

    case RequirementType.TASKS_COMPLETED: {
      const completedTasks = getUserCompletedTasks(userId);
      return completedTasks.length >= requirementValue;
    }

    case RequirementType.STREAK_DAYS: {
      // For MVP, we'll implement basic streak tracking
      // In production, this would check consecutive daily check-ins
      const completedTasks = getUserCompletedTasks(userId);
      const uniqueDays = new Set(
        completedTasks.map(task =>
          task.completedAt.toISOString().split('T')[0]
        )
      );
      return uniqueDays.size >= requirementValue;
    }

    case RequirementType.REFERRALS: {
      // This would check referral count from referrals table
      // For MVP, simplified implementation
      return false; // Will be implemented with referral system
    }

    default:
      return false;
  }
}

/**
 * Check and award all eligible badges to a user
 */
export function checkAndAwardBadges(userId: string): Badge[] {
  const allBadges = getAllBadges();
  const newlyEarnedBadges: Badge[] = [];

  for (const badge of allBadges) {
    // Skip if user already has this badge
    if (hasUserEarnedBadge(userId, badge.id)) {
      continue;
    }

    // Check if user meets the requirement
    const meetsRequirement = checkRequirement(
      userId,
      badge.requirementType,
      badge.requirementValue
    );

    if (meetsRequirement) {
      // Award the badge
      createUserBadge(userId, badge.id);
      newlyEarnedBadges.push(badge);
    }
  }

  return newlyEarnedBadges;
}

/**
 * Get all badges earned by a user with badge details
 */
export function getUserBadgesWithDetails(userId: string): (UserBadge & { badge: Badge })[] {
  const userBadges = getUserBadges(userId);

  return userBadges.map(ub => {
    const badge = findBadge(ub.badgeId);
    if (!badge) {
      throw new Error(`Badge not found: ${ub.badgeId}`);
    }
    return { ...ub, badge };
  }).sort((a, b) => b.earnedAt.getTime() - a.earnedAt.getTime());
}

/**
 * Get available badges (not yet earned)
 */
export function getAvailableBadges(userId: string): Badge[] {
  const allBadges = getAllBadges();
  const earnedBadgeIds = new Set(
    getUserBadges(userId).map(ub => ub.badgeId)
  );

  return allBadges.filter(badge => !earnedBadgeIds.has(badge.id));
}

/**
 * Get badge progress for a specific badge
 */
export function getBadgeProgress(
  userId: string,
  badgeId: string
): {
  badge: Badge;
  earned: boolean;
  progress: number;
  requirement: number;
  percentage: number;
} {
  const badge = findBadge(badgeId);
  if (!badge) {
    throw new Error(`Badge not found: ${badgeId}`);
  }

  const earned = hasUserEarnedBadge(userId, badgeId);

  let progress = 0;
  const requirement = badge.requirementValue;

  switch (badge.requirementType) {
    case RequirementType.POINTS_TOTAL:
      progress = getBalance(userId);
      break;

    case RequirementType.TASKS_COMPLETED:
      progress = getUserCompletedTasks(userId).length;
      break;

    case RequirementType.STREAK_DAYS: {
      const completedTasks = getUserCompletedTasks(userId);
      const uniqueDays = new Set(
        completedTasks.map(task =>
          task.completedAt.toISOString().split('T')[0]
        )
      );
      progress = uniqueDays.size;
      break;
    }

    case RequirementType.REFERRALS:
      progress = 0; // Will be implemented with referral system
      break;
  }

  const percentage = Math.min((progress / requirement) * 100, 100);

  return {
    badge,
    earned,
    progress,
    requirement,
    percentage
  };
}

/**
 * Get all badge progress for a user
 */
export function getAllBadgeProgress(userId: string): ReturnType<typeof getBadgeProgress>[] {
  const allBadges = getAllBadges();
  return allBadges.map(badge => getBadgeProgress(userId, badge.id));
}

/**
 * Get recently earned badges
 */
export function getRecentlyEarnedBadges(
  userId: string,
  limit: number = 5
): (UserBadge & { badge: Badge })[] {
  const earnedBadges = getUserBadgesWithDetails(userId);
  return earnedBadges.slice(0, limit);
}

/**
 * Get badge statistics for a user
 */
export function getBadgeStats(userId: string): {
  totalEarned: number;
  totalAvailable: number;
  completionPercentage: number;
  recentlyEarned: (UserBadge & { badge: Badge })[];
} {
  const allBadges = getAllBadges();
  const earnedBadges = getUserBadges(userId);
  const recentlyEarned = getRecentlyEarnedBadges(userId, 3);

  return {
    totalEarned: earnedBadges.length,
    totalAvailable: allBadges.length,
    completionPercentage: (earnedBadges.length / allBadges.length) * 100,
    recentlyEarned
  };
}

/**
 * Check if badge should be awarded after a specific action
 */
export function checkBadgesAfterAction(
  userId: string,
  action: 'task_complete' | 'points_earned' | 'referral' | 'streak'
): Badge[] {
  // This is a convenience wrapper for checkAndAwardBadges
  // In a real implementation, you might want to optimize by only checking
  // relevant badges based on the action type
  return checkAndAwardBadges(userId);
}