/**
 * Shared vendor-dropdown auto-select for the Inventory Create/Edit forms.
 *
 * Why this exists: catalog lookup, AI lookup, label scan, and manual manufacturer entry
 * all need to pick the right Vendor option, and they used to each carry their own copy of
 * the matching logic. They disagreed on WHAT to match on — the AI path keyed off the
 * price-derived `vendorName` (which is null unless a price was scraped), so the vendor
 * only got selected "sometimes". This centralizes the rule:
 *
 *   For ~95% of powders the manufacturer IS the vendor (Prismatic, Columbia,
 *   All Powder Paints, Tiger, Powder Buy The Pound). So match on the Manufacturer
 *   field first — it's almost always populated — and only fall back to the
 *   AI/catalog-supplied vendor name when the manufacturer is blank.
 *
 * Brands sold by more than one distributor (e.g. PPG, KP Pigments) are intentionally
 * skipped so the user picks the vendor manually rather than getting a wrong guess.
 */
(function () {
    'use strict';

    // Brands carried by multiple distributors — never auto-pick a vendor for these.
    // Lowercase; matched as a substring against the manufacturer name. Extend as needed.
    const AMBIGUOUS_BRANDS = ['ppg', 'kp pigments', 'kp pigment'];

    function normalize(s) {
        return (s || '').toLowerCase().trim();
    }

    function isAmbiguousBrand(name) {
        const n = normalize(name);
        return n.length > 0 && AMBIGUOUS_BRANDS.some(b => n.includes(b));
    }

    /**
     * Selects the vendor dropdown option that best matches a manufacturer/vendor name.
     *
     * @param {HTMLSelectElement} vendorSelect   the #field-vendor element
     * @param {string} manufacturerName          primary name to match on (the Manufacturer field)
     * @param {string} fallbackVendorName        AI/catalog vendor name, used only if manufacturer is blank
     * @param {{force?: boolean}} [opts]         force=true overrides an existing selection (bad-match retry)
     * @returns {boolean} true if a vendor option was selected.
     */
    window.matchInventoryVendor = function (vendorSelect, manufacturerName, fallbackVendorName, opts) {
        opts = opts || {};
        if (!vendorSelect) return false;
        // Don't clobber a choice the user (or a prior fill) already made, unless forcing a re-fill.
        if (vendorSelect.value && !opts.force) return false;

        // Manufacturer drives the match; the price-derived vendor name is only a fallback.
        const name = normalize(manufacturerName) || normalize(fallbackVendorName);
        if (!name) return false;

        // Brands sold by multiple distributors stay manual — don't guess.
        if (isAmbiguousBrand(name)) return false;

        const match = Array.from(vendorSelect.options).find(function (o) {
            const t = normalize(o.text);
            // Skip the placeholder and the "Add new vendor" sentinel; require a real name to
            // avoid spurious substring hits (e.g. empty option text matches everything).
            if (!o.value || o.value === '__new__' || t.length < 3) return false;
            return t.includes(name) || name.includes(t);
        });

        if (match) { vendorSelect.value = match.value; return true; }
        return false;
    };
})();