/**
 * Handles Binary Data Ingestion via Fetch.
 */
(function (global) {
    global.DataLoader = {
        /**
         * Fetches and parses the binary simulation data.
         * @param {string} url - URL to the binary file.
         * @returns {Promise<Object>} - { labels, data } or error.
         */
        async loadBinary(url = 'simulation.bin') {
            try {
                const response = await fetch(url, { cache: "no-store" });
                if (!response.ok) throw new Error(`HTTP Error: ${response.status}`);

                const buffer = await response.arrayBuffer();
                return this.parseBuffer(buffer);
            } catch (err) {
                console.error("Load Failed:", err);
                throw err;
            }
        },

        parseBuffer(buffer) {
            const dataView = new DataView(buffer);
            let offset = 0;

            // 1. Read Header
            const magic = dataView.getUint32(offset, true); // Little Endian
            offset += 4;

            const count = dataView.getUint32(offset, true);
            offset += 4;

            if (magic !== 0xFEAA01) {
                throw new Error(`Invalid Magic Number: 0x${magic.toString(16)}`);
            }

            // 2. Read X Data
            const xData = [];
            for (let i = 0; i < count; i++) {
                xData.push(dataView.getFloat32(offset, true));
                offset += 4;
            }

            // 3. Read Y Data
            const yData = [];
            for (let i = 0; i < count; i++) {
                yData.push(dataView.getFloat32(offset, true));
                offset += 4;
            }

            // Format for Plotter (Labels as strings/numbers, Data as numbers)
            // Plotter expects labels, but for scatter/line with x,y numbers we might adjust plotter. 
            // For now, mapping X to labels is fine for simple line plots.
            return {
                labels: xData.map(x => x.toFixed(2)),
                data: yData
            };
        }
    };
})(window);