#!/usr/bin/env python3
"""Minimal HTTP server for digital-psychology — serves static files + mindmap persistence."""
import json, os, sys
from http.server import HTTPServer, SimpleHTTPRequestHandler

ROOT = os.path.dirname(os.path.abspath(__file__))
MINDMAP_FILE = os.path.join(ROOT, "mindmap_data.json")

class Handler(SimpleHTTPRequestHandler):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, directory=ROOT, **kwargs)

    def end_headers(self):
        # no-cache for HTML and JSON endpoints
        if self.path == '/' or self.path.endswith('.html') or self.path == '/load':
            self.send_header("Cache-Control", "no-cache, no-store, must-revalidate")
            self.send_header("Pragma", "no-cache")
            self.send_header("Expires", "0")
        super().end_headers()

    def do_GET(self):
        if self.path == "/load":
            if os.path.exists(MINDMAP_FILE):
                with open(MINDMAP_FILE, "r", encoding="utf-8") as f:
                    data = f.read()
                self.send_response(200)
                self.send_header("Content-Type", "application/json")
                self.end_headers()
                self.wfile.write(data.encode())
            else:
                self.send_response(200)
                self.send_header("Content-Type", "application/json")
                self.end_headers()
                self.wfile.write(b"{}")
        else:
            super().do_GET()

    def do_POST(self):
        if self.path == "/save":
            length = int(self.headers.get("Content-Length", 0))
            data = self.rfile.read(length)
            try:
                json.loads(data)
            except json.JSONDecodeError:
                self.send_error(400, "Invalid JSON")
                return
            with open(MINDMAP_FILE, "w", encoding="utf-8") as f:
                f.write(data.decode())
            self.send_response(200)
            self.send_header("Content-Type", "application/json")
            self.end_headers()
            self.wfile.write(b'{"ok":true}')
        elif self.path == "/load":
            if os.path.exists(MINDMAP_FILE):
                with open(MINDMAP_FILE, "r", encoding="utf-8") as f:
                    data = f.read()
                self.send_response(200)
                self.send_header("Content-Type", "application/json")
                self.end_headers()
                self.wfile.write(data.encode())
            else:
                self.send_response(200)
                self.send_header("Content-Type", "application/json")
                self.end_headers()
                self.wfile.write(b"{}")
        else:
            self.send_error(404)

    def log_message(self, format, *args):
        if "/save" in str(args) or "/load" in str(args):
            print(f"[{self.log_date_time_string()}] {args[0]}")

if __name__ == "__main__":
    port = int(sys.argv[1]) if len(sys.argv) > 1 else 8001
    server = HTTPServer(("127.0.0.1", port), Handler)
    server.socket.settimeout(30)  # 30s timeout so hung clients don't block the single-thread server
    print(f"Serving {ROOT} on port {port} (save/load enabled)")
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        server.shutdown()