import * as repo from './repository.js';
import * as projectsRepo from '../projects/repository.js';
import { recalcProjectProgress, canWriteProject } from '../projects/service.js';
import { HttpError } from '../../utils/http.js';
import { logAudit } from '../../utils/audit.js';
import { ROLES } from '../../middleware/auth.js';
import { createNotification } from '../notifications/service.js';

async function getProjectOr404(projectId) {
  const project = await projectsRepo.findById(projectId);
  if (!project) throw new HttpError(404, 'Proyecto no encontrado');
  return project;
}

// admin/it_manager siempre; project_lead si tiene acceso al proyecto; collaborator solo si es
// el responsable de la actividad (no puede crear actividades nuevas ni reasignarlas a otros).
export async function canWriteActivity(user, project, activity) {
  if ([ROLES.SUPERADMIN, ROLES.ADMIN, ROLES.IT_MANAGER].includes(user.roleCode)) return true;
  if (user.roleCode === ROLES.PROJECT_LEAD) return canWriteProject(user, project);
  if (user.roleCode === ROLES.COLLABORATOR && activity) return activity.responsible_user_id === user.id;
  return false;
}

export const listByProject = (projectId) => repo.findByProject(projectId);

export async function getActivity(id) {
  const activity = await repo.findById(id);
  if (!activity) throw new HttpError(404, 'Actividad no encontrada');
  const dependencies = await repo.listDependencies(id);
  return { ...activity, dependencies };
}

export async function createActivity(projectId, payload, currentUser) {
  const project = await getProjectOr404(projectId);
  if (!(await canWriteProject(currentUser, project))) {
    throw new HttpError(403, 'No tienes permisos para crear actividades en este proyecto');
  }
  if (!payload.name || !payload.priorityId || !payload.statusId) {
    throw new HttpError(400, 'Nombre, prioridad y estado son obligatorios');
  }
  const activity = await repo.create(projectId, { ...payload, createdBy: currentUser.id });
  await logAudit({ userId: currentUser.id, action: 'create', entityType: 'activity', entityId: activity.id });

  if (activity.responsible_user_id && activity.responsible_user_id !== currentUser.id) {
    await createNotification({
      userId: activity.responsible_user_id,
      type: 'activity_assigned',
      message: `Te asignaron la actividad "${activity.name}"`,
      entityType: 'activity',
      entityId: activity.id,
    });
  }
  await recalcProjectProgress(projectId);
  return activity;
}

export async function updateActivity(id, payload, currentUser) {
  const activity = await repo.findById(id);
  if (!activity) throw new HttpError(404, 'Actividad no encontrada');
  const project = await getProjectOr404(activity.project_id);
  if (!(await canWriteActivity(currentUser, project, activity))) {
    throw new HttpError(403, 'No tienes permisos sobre esta actividad');
  }
  if (!payload.name || !payload.priorityId || !payload.statusId) {
    throw new HttpError(400, 'Nombre, prioridad y estado son obligatorios');
  }

  // Colaborador no puede reasignar la actividad a otra persona ni cambiar avance manual si hay subtareas.
  const nextResponsible = currentUser.roleCode === ROLES.COLLABORATOR
    ? activity.responsible_user_id
    : (payload.responsibleUserId ?? activity.responsible_user_id);

  const subtaskCount = await repo.countSubtasks(id);
  const updated = await repo.update(id, { ...payload, responsibleUserId: nextResponsible });

  if (subtaskCount === 0 && payload.progressPct !== undefined) {
    const pct = Math.max(0, Math.min(100, Number(payload.progressPct)));
    await repo.updateProgress(id, pct);
    updated.progress_pct = pct;
  }

  await logAudit({ userId: currentUser.id, action: 'update', entityType: 'activity', entityId: id });

  if (nextResponsible && nextResponsible !== activity.responsible_user_id && nextResponsible !== currentUser.id) {
    await createNotification({
      userId: nextResponsible,
      type: 'activity_assigned',
      message: `Te asignaron la actividad "${updated.name}"`,
      entityType: 'activity',
      entityId: id,
    });
  }

  await recalcProjectProgress(activity.project_id);
  return repo.findById(id);
}

export async function addDependency(activityId, dependsOnActivityId, currentUser) {
  if (activityId === dependsOnActivityId) throw new HttpError(400, 'Una actividad no puede depender de si misma');
  const activity = await repo.findById(activityId);
  if (!activity) throw new HttpError(404, 'Actividad no encontrada');
  const dependsOn = await repo.findById(dependsOnActivityId);
  if (!dependsOn || dependsOn.project_id !== activity.project_id) {
    throw new HttpError(400, 'La dependencia debe ser una actividad del mismo proyecto');
  }
  const project = await getProjectOr404(activity.project_id);
  if (!(await canWriteActivity(currentUser, project, activity))) throw new HttpError(403, 'No tienes permisos sobre esta actividad');
  const deps = await repo.addDependency(activityId, dependsOnActivityId);
  await logAudit({ userId: currentUser.id, action: 'add_dependency', entityType: 'activity', entityId: activityId, detail: { dependsOnActivityId } });
  return deps;
}

export async function removeDependency(activityId, dependsOnActivityId, currentUser) {
  const activity = await repo.findById(activityId);
  if (!activity) throw new HttpError(404, 'Actividad no encontrada');
  const project = await getProjectOr404(activity.project_id);
  if (!(await canWriteActivity(currentUser, project, activity))) throw new HttpError(403, 'No tienes permisos sobre esta actividad');
  const deps = await repo.removeDependency(activityId, dependsOnActivityId);
  await logAudit({ userId: currentUser.id, action: 'remove_dependency', entityType: 'activity', entityId: activityId, detail: { dependsOnActivityId } });
  return deps;
}

// Recalcula el avance de una actividad a partir de sus subtareas (si tiene) y propaga al proyecto.
export async function recalcFromSubtasks(activityId, doneCount, totalCount) {
  if (totalCount === 0) return;
  const pct = Math.round((doneCount / totalCount) * 10000) / 100;
  await repo.updateProgress(activityId, pct);
  const activity = await repo.findById(activityId);
  await recalcProjectProgress(activity.project_id);
}