"use strict";

/**
 * For CREATE — plain text array, no IDs needed
 * objectives: ["text1"] or [{ text: "text1" }]
 */
async function syncObjectivesCreate(Model, parentField, parentId, objectives, transaction) {
  if (!objectives?.length) return;

  await Model.bulkCreate(
    objectives.map((o, i) => ({
      [parentField]: parentId,
      text: typeof o === "string" ? o : o.text,
      order_index: i,
    })),
    { transaction }
  );
}

/**
 * For UPDATE — upsert by objective_id, hard delete removed ones
 * objectives: [{ objective_id: "123", text: "text1" }, { text: "new" }]
 */
async function syncObjectivesUpdate(Model, parentField, parentId, objectives, transaction) {
  if (!objectives?.length) {
    await Model.destroy({ where: { [parentField]: parentId }, force: true, transaction });
    return;
  }

  const existing    = await Model.findAll({ where: { [parentField]: parentId }, transaction });
  const existingMap = new Map(existing.map((o) => [String(o.objective_id), o]));
  const incomingIds = new Set(
    objectives.filter((o) => o.objective_id).map((o) => String(o.objective_id))
  );

  // Hard delete removed
  const toDelete = existing.filter((o) => !incomingIds.has(String(o.objective_id)));
  if (toDelete.length) {
    await Model.destroy({
      where: { objective_id: toDelete.map((o) => o.objective_id) },
      force: true,
      transaction,
    });
  }

  // Update existing or create new
  for (let i = 0; i < objectives.length; i++) {
    const item   = objectives[i];
    const record = item.objective_id ? existingMap.get(String(item.objective_id)) : null;

    if (record) {
      await record.update({ text: item.text, order_index: i }, { transaction });
    } else {
      await Model.create(
        { [parentField]: parentId, text: item.text, order_index: i },
        { transaction }
      );
    }
  }
}

module.exports = { syncObjectivesCreate, syncObjectivesUpdate };