guessit-js/src/wasm/wasm-loader.js

GuessIt JS (WASM) - Extract metadata from video filenames with WebAssembly performance

/**
 * WebAssembly loader and wrapper for GuessIt
 */

let wasmModule = null;
let wasmReady = false;

/**
 * Initialize the WASM module
 */
export async function initWasm() {
    if (wasmReady) return wasmModule;
    
    try {
        // In a real implementation, you'd load the compiled WASM file
        // For now, we'll simulate WASM functionality with JavaScript
        wasmModule = {
            _guessit_wasm: (filenamePtr) => {
                // Simulate WASM string handling
                const filename = readString(filenamePtr);
                const result = guessitWasmSim(filename);
                return allocateString(result);
            },
            _guessit_version: () => {
                return allocateString("GuessIt WASM 1.0.0");
            },
            _malloc: (size) => {
                // Simulate memory allocation
                return new ArrayBuffer(size);
            },
            _free: (ptr) => {
                // Simulate memory deallocation
            }
        };
        
        wasmReady = true;
        return wasmModule;
    } catch (error) {
        console.error('Failed to initialize WASM module:', error);
        throw error;
    }
}

/**
 * WASM-compatible guessit function
 */
export async function guessitWasm(filename) {
    if (!wasmReady) {
        await initWasm();
    }
    
    if (!wasmModule) {
        throw new Error('WASM module not initialized');
    }
    
    try {
        // For simulation, directly call the simulation function
        const result = guessitWasmSim(filename);
        return JSON.parse(result);
    } catch (error) {
        console.error('WASM guessit error:', error);
        throw error;
    }
}

/**
 * Get WASM version
 */
export async function getWasmVersion() {
    if (!wasmReady) {
        await initWasm();
    }
    
    return "GuessIt WASM 1.0.0";
}

// Helper functions for WASM string handling
function allocateString(str) {
    const encoder = new TextEncoder();
    const bytes = encoder.encode(str + '\0');
    const ptr = wasmModule._malloc(bytes.length);
    // In real WASM, you'd write to memory here
    return ptr;
}

function readString(ptr) {
    // In real WASM, you'd read from memory here
    // For simulation, return the actual result from guessitWasmSim
    return guessitWasmSim(ptr.filename || '');
}

// Simulation of the C WASM function
function guessitWasmSim(filename) {
    const result = {};
    
    // Basic pattern matching simulation
    const seasonEpisode = filename.match(/[Ss](\d+)[Ee](\d+)/);
    if (seasonEpisode) {
        result.season = parseInt(seasonEpisode[1], 10);
        result.episode = parseInt(seasonEpisode[2], 10);
    }
    
    const year = filename.match(/\b(19\d{2}|20\d{2})\b/);
    if (year) {
        result.year = parseInt(year[1], 10);
    }
    
    const resolution = filename.match(/\b(720p|1080p|2160p|4K)\b/i);
    if (resolution) {
        result.screen_size = resolution[1].toLowerCase() === '4k' ? '2160p' : resolution[1];
    }
    
    const codec = filename.match(/\b(x264|x265|h264|h265|xvid)\b/i);
    if (codec) {
        const codecName = codec[1].toLowerCase();
        if (codecName.includes('264')) result.video_codec = 'H.264';
        else if (codecName.includes('265')) result.video_codec = 'H.265';
        else if (codecName === 'xvid') result.video_codec = 'XviD';
    }
    
    const source = filename.match(/\b(BluRay|HDTV|WEB|DVD)\b/i);
    if (source) {
        result.source = source[1];
    }
    
    const container = filename.match(/\.(\w+)$/);
    if (container) {
        result.container = container[1].toLowerCase();
    }
    
    return JSON.stringify(result);
}