package com.mydreamjob.company;

import com.mydreamjob.common.exception.BusinessException;
import com.mydreamjob.common.exception.ErrorCode;
import com.mydreamjob.security.UserRoleGuard;
import com.mydreamjob.verification.CompanyVerification;
import com.mydreamjob.verification.CompanyVerificationRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.List;

@Service
@RequiredArgsConstructor
public class CompanyOnboardingService {
    private final UserRoleGuard userRoleGuard;
    private final CompanyRepository companyRepository;
    private final CompanyVerificationRepository verificationRepository;

    @Transactional(readOnly = true)
    public CompanyOnboardingResponse get(Long userId) {
        userRoleGuard.requireCompany(userId);
        Company company = companyRepository.findByOwnerUserId(userId)
                .orElseThrow(() -> new BusinessException(ErrorCode.COMPANY_NOT_FOUND));
        CompanyVerification latest = verificationRepository.findTopByCompanyIdOrderByIdDesc(company.getId())
                .orElse(null);

        String status;
        if (Boolean.TRUE.equals(company.getVerified())) {
            status = "VERIFIED";
        } else if (latest == null) {
            status = "UNVERIFIED";
        } else if ("PENDING".equals(latest.getStatus()) || "RESUBMITTED".equals(latest.getStatus())) {
            status = "PENDING";
        } else if ("REJECTED".equals(latest.getStatus())) {
            status = "REJECTED";
        } else if ("APPROVED".equals(latest.getStatus())) {
            throw new BusinessException(ErrorCode.COMPANY_ONBOARDING_INCONSISTENT_STATE);
        } else {
            throw new BusinessException(ErrorCode.COMPANY_ONBOARDING_INCONSISTENT_STATE);
        }

        List<String> missing = new ArrayList<>();
        if (isBlank(company.getName())) missing.add("name");
        if (isBlank(company.getIndustry())) missing.add("industry");
        if (isBlank(company.getDescription())) missing.add("description");
        if (isBlank(company.getAddress())) missing.add("address");

        List<String> actions = switch (status) {
            case "UNVERIFIED", "REJECTED" -> List.of("UPDATE_PROFILE", "SUBMIT_VERIFICATION");
            case "PENDING" -> List.of("UPDATE_PROFILE", "WAIT_REVIEW");
            case "VERIFIED" -> List.of("ENTER_COMPANY_WORKSPACE");
            default -> List.of();
        };
        CompanyOnboardingResponse.VerificationSummary verification = latest == null ? null
                : new CompanyOnboardingResponse.VerificationSummary(latest.getId(), latest.getStatus(),
                latest.getSubmittedAt(), latest.getDecidedAt());
        CompanyOnboardingResponse.CompanySummary summary = new CompanyOnboardingResponse.CompanySummary(
                company.getId(), company.getName(), company.getLogoUrl(), company.getDescription(),
                company.getIndustry(), company.getWebsite(), company.getAddress(), company.getVerified());
        return new CompanyOnboardingResponse(summary, status, verification, missing, actions);
    }

    private boolean isBlank(String value) {
        return value == null || value.isBlank();
    }
}