Architecture Overview

// State Service - Centralized data management
state.init()              // Load bootstrap data + progress
state.getCourse(...)      // Navigate course hierarchy
state.markClassComplete() // Update progress
state.saveProgress()      // Persist to localStorage + server

// API Service - Backend communication
ApiService.getBootstrap()        // Fetch course catalog
ApiService.getCourseDetail(...)  // Load course details
ApiService.getVideoUrl(fileId)   // Build Drive streaming URL

# server.py:583
def init_cache():
    """Inicializa el caché cargando courses_cache.json."""
    # Loads and validates cache file
    # Pre-compresses JSON with gzip for fast API responses
    # Stores in global memory for multi-threaded access

# server.py:38-54
courses_cache = None           # Full course data
bootstrap_cache = None         # Lightweight summary
full_cache_json_bytes = b""    # Pre-serialized JSON
full_cache_json_gzip_bytes = b"" # Pre-compressed
cache_lock = threading.Lock()  # Thread-safe access

# server.py:730
class PlatziHandler(SimpleHTTPRequestHandler):
    # Each request handled in separate thread
    # ThreadingHTTPServer creates thread pool
    
# Thread-safe cache access
with cache_lock:
    data = courses_cache  # Protected read

# drive_service.py:102
def _get_session(self):
    # Shared AuthorizedSession with lock
    # Avoids per-thread authentication overhead
    with self._shared_session_lock:
        if self._shared_session is None:
            self._shared_session = AuthorizedSession(self.creds)

python server.py
# Binds to 127.0.0.1:8080
# CORS allowed for localhost only

# server.py:297-312
def _load_cache_file(path):
    # Validates JSON schema
    # Returns (data, mtime, error)
    # Invalid caches marked to avoid retry loops

// api.js:13-28
static async _fetchWithTimeout(url, options = {}, timeoutMs = DEFAULT_TIMEOUT_MS) {
    const controller = new AbortController();
    const timer = window.setTimeout(() => controller.abort(), timeoutMs);
    // Timeout protection + structured error codes
}