interface Skill {
  id: string;
  name: string;
}

export const calculateSkillsMatch = (
  userSkills: Skill[],
  vacancySkills: Skill[],
): {
  percentage: number;
  matchedSkills: Skill[];
  missingSkills: Skill[];
} => {
  if (vacancySkills.length === 0) {
    return {
      percentage: 0,
      matchedSkills: [],
      missingSkills: [],
    };
  }

  // Create sets of skill IDs for efficient lookup
  const userSkillIds = new Set(userSkills.map((s) => s.id));
  const _vacancySkillIds = new Set(vacancySkills.map((s) => s.id));

  // Find matched and missing skills
  const matchedSkills = vacancySkills.filter((skill) =>
    userSkillIds.has(skill.id),
  );
  const missingSkills = vacancySkills.filter(
    (skill) => !userSkillIds.has(skill.id),
  );

  // Calculate percentage
  const percentage = Math.round(
    (matchedSkills.length / vacancySkills.length) * 100,
  );

  return {
    percentage,
    matchedSkills,
    missingSkills,
  };
};