/// <reference path="../pb_data/types.d.ts" />
migrate(
  (app) => {
    // ── 1. Create collection (rules set to empty string = no filter) ─
    var auditCol = new Collection({
      name: 'roFinancialAudit',
      type: 'base',
      schema: [
        new TextField({ name: 'roId', required: true }),
        new TextField({ name: 'field', required: true }),
        new JSONField({ name: 'from', required: false }),
        new JSONField({ name: 'to', required: false }),
        new TextField({ name: 'by', required: false }),
        new TextField({ name: 'at', required: true }),
        new TextField({ name: 'prevHash', required: false }),
        new TextField({ name: 'hash', required: true }),
      ],
      listRule: '',
      viewRule: '',
      createRule: null,
      updateRule: null,
      deleteRule: null,
    });
    app.save(auditCol);
    console.log('[M25] created roFinancialAudit collection');

    // ── 2. Hook: diff financial changes ──────────────────────────────
    app.onRecordUpdateRequest(function(e) {
      if (e.collection.name !== 'repairOrders') return;
      if (!e.oldRecord) return;

      var oldFinancial = e.oldRecord.get('financial');
      var newFinancial = e.record.get('financial');
      if (!oldFinancial && !newFinancial) return;

      var oldMap = (typeof oldFinancial === 'object' && oldFinancial) ? oldFinancial : {};
      var newMap = (typeof newFinancial === 'object' && newFinancial) ? newFinancial : {};

      var allKeys = [];
      var seen = {};
      Object.keys(oldMap).concat(Object.keys(newMap)).forEach(function(k) {
        if (!seen[k]) { seen[k] = true; allKeys.push(k); }
      });

      var changedKeys = [];
      allKeys.forEach(function(key) {
        var oldVal = JSON.stringify(oldMap[key] !== undefined ? oldMap[key] : null);
        var newVal = JSON.stringify(newMap[key] !== undefined ? newMap[key] : null);
        if (oldVal !== newVal) changedKeys.push(key);
      });
      if (changedKeys.length === 0) return;

      var prevHash = '';
      try {
        var lastEntry = e.dao.findFirstRecordByFilter(
          'roFinancialAudit',
          'roId = "' + e.record.id.replace(/"/g, '') + '"',
          { sort: '-at' },
        );
        if (lastEntry) prevHash = lastEntry.get('hash') || '';
      } catch (_) {}

      var roId = e.record.id;
      var by = e.record.get('advisorName') || '';
      var now = new Date().toISOString();

      function simpleHash(str) {
        var h = 0;
        for (var i = 0; i < str.length; i++) {
          h = ((h << 5) - h) + str.charCodeAt(i);
          h = h & h;
        }
        return (h >>> 0).toString(16);
      }

      var auditCollection = app.findCollectionByNameOrId('roFinancialAudit');

      changedKeys.forEach(function(key) {
        var fromVal = oldMap[key] !== undefined ? oldMap[key] : null;
        var toVal = newMap[key] !== undefined ? newMap[key] : null;

        var payload = roId + key + now + JSON.stringify(fromVal) + JSON.stringify(toVal) + by + prevHash;
        var hash = simpleHash(payload);

        var data = {
          roId: roId,
          field: key,
          from: fromVal,
          to: toVal,
          by: by,
          at: now,
          prevHash: prevHash,
          hash: hash,
        };

        try {
          var auditRec = new Record(auditCollection, data);
          e.dao.saveRecord(auditRec);
        } catch (err) {
          console.error('[M25] audit save error: ' + String(err));
        }

        prevHash = hash;
      });
    });
  },
  function(app) {
    var col = app.findCollectionByNameOrId('roFinancialAudit');
    if (col) {
      app.deleteCollection(col);
      console.log('[M25] removed roFinancialAudit collection');
    }
  }
);