const express = require('express');
const { requirePermission, requireAdmin } = require('../middleware/auth');
const { logCuratorAction } = require('../audit-log');
const {
  listLinks,
  createLink,
  deleteLink,
  listDeleteVotes,
  castDeleteVote,
  withdrawDeleteVote,
  seedDefaultsIfEmpty,
} = require('../movement-lineage-service');

const router = express.Router();

/** Optional staff session for vote annotations on list (public otherwise). */
async function optionalStaff(req, _res, next) {
  try {
    if (req.session?.userId) {
      const { loadStaffUser } = require('../middleware/auth');
      const user = await loadStaffUser(req.session.userId);
      if (user && user.is_active) {
        req.curatorUser = user;
      }
    }
  } catch {
    /* ignore — list stays public */
  }
  next();
}

/** Public: timeline / tree consumers. */
router.get('/', optionalStaff, async (req, res) => {
  try {
    await seedDefaultsIfEmpty();
    const q = typeof req.query.q === 'string' ? req.query.q : '';
    const limit = Number(req.query.limit) || 500;
    const offset = Number(req.query.offset) || 0;
    const data = await listLinks({
      q,
      limit,
      offset,
      viewerUserId: req.curatorUser?.id || null,
    });
    res.json(data);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Failed to list movement links' });
  }
});

router.post('/', requirePermission('influences'), async (req, res) => {
  try {
    const item = await createLink(req.body || {}, { userId: req.session?.userId });
    await logCuratorAction({
      userId: req.session.userId,
      action: 'movement_link.create',
      resourceType: 'movement_lineage_link',
      resourceId: item.id,
      details: {
        source_movement_id: item.source_movement_id,
        target_movement_id: item.target_movement_id,
        proof_url: item.proof_url,
      },
      req,
    });
    res.status(201).json({ item });
  } catch (err) {
    const status = err.status || 500;
    if (status >= 500) console.error(err);
    res.status(status).json({ error: err.message || 'Failed to create movement link' });
  }
});

router.get('/:id/delete-votes', requirePermission('influences'), async (req, res) => {
  try {
    const data = await listDeleteVotes(req.params.id);
    res.json(data);
  } catch (err) {
    const status = err.status || 500;
    if (status >= 500) console.error(err);
    res.status(status).json({ error: err.message || 'Failed to list delete votes' });
  }
});

router.post('/:id/delete-votes', requirePermission('influences'), async (req, res) => {
  try {
    const vote = await castDeleteVote(req.params.id, req.body || {}, {
      userId: req.session.userId,
    });
    await logCuratorAction({
      userId: req.session.userId,
      action: 'movement_link.delete_vote',
      resourceType: 'movement_lineage_link',
      resourceId: Number(req.params.id),
      details: { reason: vote.reason },
      req,
    });
    res.status(201).json({ vote });
  } catch (err) {
    const status = err.status || 500;
    if (status >= 500) console.error(err);
    res.status(status).json({ error: err.message || 'Failed to cast delete vote' });
  }
});

router.delete('/:id/delete-votes/me', requirePermission('influences'), async (req, res) => {
  try {
    const result = await withdrawDeleteVote(req.params.id, { userId: req.session.userId });
    await logCuratorAction({
      userId: req.session.userId,
      action: 'movement_link.delete_vote_withdraw',
      resourceType: 'movement_lineage_link',
      resourceId: result.linkId,
      details: {},
      req,
    });
    res.json({ ok: true, ...result });
  } catch (err) {
    const status = err.status || 500;
    if (status >= 500) console.error(err);
    res.status(status).json({ error: err.message || 'Failed to withdraw delete vote' });
  }
});

/** Hard delete — admin only. Curators vote instead. */
router.delete('/:id', requireAdmin, async (req, res) => {
  try {
    const votes = await listDeleteVotes(req.params.id).catch(() => ({ votes: [] }));
    const result = await deleteLink(req.params.id);
    await logCuratorAction({
      userId: req.session.userId,
      action: 'movement_link.delete',
      resourceType: 'movement_lineage_link',
      resourceId: result.id,
      details: {
        prior_votes: (votes.votes || []).map((v) => ({
          username: v.username,
          reason: v.reason,
        })),
      },
      req,
    });
    res.json({ ok: true, id: result.id });
  } catch (err) {
    const status = err.status || 500;
    if (status >= 500) console.error(err);
    res.status(status).json({ error: err.message || 'Failed to delete movement link' });
  }
});

module.exports = router;