package com.example.app.project;

import com.example.app.project.ProjectDtos.CreateProjectRequest;
import com.example.app.project.ProjectDtos.ProjectResponse;
import com.example.app.time.TimeEntryRepository;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class ProjectService {

  private final ProjectRepository projectRepository;
  private final TimeEntryRepository timeEntryRepository;

  public ProjectService(
      ProjectRepository projectRepository, TimeEntryRepository timeEntryRepository) {
    this.projectRepository = projectRepository;
    this.timeEntryRepository = timeEntryRepository;
  }

  @Transactional(readOnly = true)
  public List<ProjectResponse> findAll() {
    List<Project> projects = projectRepository.findAll();

    // one aggregate query for totals across all entries
    Map<Long, long[]> totals = new HashMap<>();
    for (Object[] row : timeEntryRepository.aggregateAllByProject()) {
      long projectId = ((Number) row[0]).longValue();
      long minutes = ((Number) row[1]).longValue();
      long cost = ((Number) row[2]).longValue();
      totals.put(projectId, new long[] {minutes, cost});
    }

    return projects.stream()
        .map(
            p -> {
              long[] t = totals.getOrDefault(p.getId(), new long[] {0, 0});
              return ProjectResponse.from(p, t[0], t[1]);
            })
        .toList();
  }

  @Transactional
  public ProjectResponse create(CreateProjectRequest req) {
    Project p = new Project();
    p.setName(req.name());
    p.setTimeBudgetMinutes(req.timeBudgetMinutes());
    p.setCostBudgetCents(req.costBudgetCents());
    p.setHourlyRateCents(req.hourlyRateCents());
    Project saved = projectRepository.save(p);
    return ProjectResponse.from(saved, 0, 0);
  }
}