// services/rmOvgSettingsStore.js
// Admin-configured Raw Material "Ovg%" override — maps an item code and/or
// its SAP item group to a default overage percentage. Used by work-order.html
// to pre-fill a raw material row's Ovg. cell and to recompute "Qty Req./100 ml"
// as (BOM value) − (BOM value × Ovg%/100) instead of the plain BOM figure,
// for any item this resolves a match for. See [[work-order-qty-req-two-way-sync]]
// for the existing Raw Material calc model this feature layers on top of.
const sql = require('mssql');

const TABLE = `[dbo].[ZRM_OVG_SETTINGS]`;

let _conn = null;
async function getConn() {
  if (_conn) return _conn;
  _conn = await sql.connect({
    server: process.env.APP_SQL_HOST,
    port: parseInt(process.env.APP_SQL_PORT),
    user: process.env.APP_SQL_USER,
    password: process.env.APP_SQL_PASSWORD,
    database: process.env.APP_SQL_DATABASE,
    options: { encrypt: true, trustServerCertificate: true },
  });
  return _conn;
}
async function exec(sqlQuery, params = []) {
  const conn = await getConn();
  const request = conn.request();
  params.forEach((param, index) => { request.input(`param${index}`, param); });
  const replacedSql = sqlQuery.replace(/\?/g, (m, offset, string) => {
    const i = (string.slice(0, offset).match(/\?/g) || []).length;
    return `@param${i}`;
  });
  const result = await request.query(replacedSql);
  return result.recordset || [];
}
function isAlreadyExists(e) {
  const m = (e.message || '').toLowerCase();
  return m.includes('already exists') || m.includes('duplicate') || m.includes('existing object') || m.includes('there is already an object');
}

async function bootstrap() {
  console.log('[RM-OVG-SETTINGS] Checking table', TABLE, '...');
  await exec(`
    CREATE TABLE ${TABLE} (
      ID          INT IDENTITY(1,1) PRIMARY KEY,
      ITEM_CODE   NVARCHAR(60) NULL,
      ITEM_GROUP  INT NULL,
      OVG_PERCENT FLOAT NOT NULL,
      CREATED_BY  NVARCHAR(50),
      CREATED_AT  DATETIME2,
      UPDATED_BY  NVARCHAR(50),
      UPDATED_AT  DATETIME2
    )
  `).catch(e => {
    if (isAlreadyExists(e)) { console.log('[RM-OVG-SETTINGS] Table exists — OK'); }
    else throw e;
  });
  console.log('[RM-OVG-SETTINGS] ✅ Ready');
}

function fromRow(row) {
  return {
    id: row.ID,
    itemCode: row.ITEM_CODE || '',
    itemGroup: row.ITEM_GROUP != null ? row.ITEM_GROUP : null,
    ovgPercent: row.OVG_PERCENT,
    createdBy: row.CREATED_BY || '',
    createdAt: row.CREATED_AT ? new Date(row.CREATED_AT).toISOString() : null,
    updatedBy: row.UPDATED_BY || '',
    updatedAt: row.UPDATED_AT ? new Date(row.UPDATED_AT).toISOString() : null,
  };
}

async function listAll() {
  const rows = await exec(`SELECT * FROM ${TABLE} ORDER BY ITEM_CODE, ITEM_GROUP`);
  return rows.map(fromRow);
}

async function create({ itemCode, itemGroup, ovgPercent, by }) {
  const code = (itemCode || '').trim().toUpperCase() || null;
  const group = itemGroup != null && itemGroup !== '' ? parseInt(itemGroup) : null;
  if (!code && group == null) throw new Error('Provide an Item Code and/or Item Group');
  const pct = parseFloat(ovgPercent);
  if (isNaN(pct)) throw new Error('Ovg% must be a number');
  const now = new Date().toISOString();
  const idRows = await exec(`
    INSERT INTO ${TABLE} (ITEM_CODE, ITEM_GROUP, OVG_PERCENT, CREATED_BY, CREATED_AT, UPDATED_BY, UPDATED_AT)
    VALUES (?,?,?,?,?,?,?);
    SELECT SCOPE_IDENTITY() AS ID;
  `, [code, group, pct, by || '', now.replace('T', ' ').substring(0, 23), by || '', now.replace('T', ' ').substring(0, 23)]);
  const rows = await exec(`SELECT * FROM ${TABLE} WHERE ID = ?`, [idRows[0].ID]);
  return fromRow(rows[0]);
}

async function update(id, { itemCode, itemGroup, ovgPercent, by }) {
  const code = (itemCode || '').trim().toUpperCase() || null;
  const group = itemGroup != null && itemGroup !== '' ? parseInt(itemGroup) : null;
  if (!code && group == null) throw new Error('Provide an Item Code and/or Item Group');
  const pct = parseFloat(ovgPercent);
  if (isNaN(pct)) throw new Error('Ovg% must be a number');
  const now = new Date().toISOString().replace('T', ' ').substring(0, 23);
  await exec(`UPDATE ${TABLE} SET ITEM_CODE=?, ITEM_GROUP=?, OVG_PERCENT=?, UPDATED_BY=?, UPDATED_AT=? WHERE ID=?`,
    [code, group, pct, by || '', now, parseInt(id)]);
  const rows = await exec(`SELECT * FROM ${TABLE} WHERE ID = ?`, [parseInt(id)]);
  if (!rows.length) throw new Error('Not found');
  return fromRow(rows[0]);
}

async function remove(id) {
  await exec(`DELETE FROM ${TABLE} WHERE ID = ?`, [parseInt(id)]);
}

// Resolves an Ovg% for each item code, given that item's own SAP item group
// (caller looks the group up from OITM — this store has no SAP connection of
// its own). Item-code-specific rows win over item-group rows for the same
// item. Returns { itemCode: percent } — items with no match are simply
// absent from the result (never a 0 entry, since 0 IS a valid configured %).
async function resolveForItems(itemCodesUpper, groupByItemCode) {
  const rows = await listAll();
  const byCode = {};
  const byGroup = {};
  rows.forEach(r => {
    if (r.itemCode) byCode[r.itemCode] = r.ovgPercent;
    else if (r.itemGroup != null) byGroup[r.itemGroup] = r.ovgPercent;
  });
  const out = {};
  itemCodesUpper.forEach(code => {
    if (byCode[code] != null) { out[code] = byCode[code]; return; }
    const grp = groupByItemCode[code];
    if (grp != null && byGroup[grp] != null) out[code] = byGroup[grp];
  });
  return out;
}

module.exports = { bootstrap, listAll, create, update, remove, resolveForItems };