using PetCompanion.Models;
using PetCompanion.Repositories;

namespace PetCompanion.Services
{
    public class PetSkillService
    {
        private readonly PetSkillRepository _petSkillRepository;
        private readonly PetRepository _petRepository;

        public PetSkillService(PetSkillRepository petSkillRepository, PetRepository petRepository)
        {
            _petSkillRepository = petSkillRepository;
            _petRepository = petRepository;
        }

        public IEnumerable<PetSkill> GetPetSkills(string petId, string userId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            return _petSkillRepository.GetPetSkills(petId);
        }

        public PetSkill UpgradeSkill(string petId, string userId, int skillId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var skill = _petSkillRepository.GetSkill(skillId);

            if (skill == null)
                throw new Exception("Skill not found");

            foreach (var req in skill.SkillRequirements)
            {
                if (req.Resource.ToLower() == "wisdom" && pet.Resources.Wisdom < req.Cost)
                    throw new Exception("Insufficient resources");
                if (req.Resource.ToLower() == "food" && pet.Resources.Food < req.Cost)
                    throw new Exception("Insufficient resources");
                if (req.Resource.ToLower() == "gold" && pet.Resources.Gold < req.Cost)
                    throw new Exception("Insufficient resources");
                if (req.Resource.ToLower() == "junk" && pet.Resources.Junk < req.Cost)
                    throw new Exception("Insufficient resources");
            }

            var skills = _petSkillRepository.GetPetSkills(petId);
            var existingSkill = skills.FirstOrDefault(s => s.SkillId == skillId);

            if (existingSkill != null)
            {
                if (existingSkill.CurrentTier == SkillTier.III)
                    throw new Exception("Skill already at maximum tier");

                existingSkill.CurrentTier++;
                _petSkillRepository.SavePetSkill(existingSkill);
            }
            else
            {
                if (!skill.SkillsIdRequired?.TrueForAll(ni => pet.Skills.Any(s => s.SkillId == ni)) ?? false)
                {
                    throw new Exception("Missing required skill");
                }

                existingSkill = new PetSkill
                {
                    PetId = petId,
                    SkillId = skillId,
                    CurrentTier = SkillTier.I
                };
                _petSkillRepository.SavePetSkill(existingSkill);
            }

            foreach (var req in skill.SkillRequirements)
            {
                if (req.Resource.ToLower() == "wisdom") pet.Resources.Wisdom -= req.Cost;
                if (req.Resource.ToLower() == "food") pet.Resources.Food -= req.Cost;
                if (req.Resource.ToLower() == "gold") pet.Resources.Gold -= req.Cost;
                if (req.Resource.ToLower() == "junk") pet.Resources.Junk -= req.Cost;
            }

            _petRepository.UpdatePet(pet);

            return existingSkill;
        }
    }
}