import http.server
import socketserver
import json
import os
import sys
from urllib.parse import urlparse, parse_qs

PORT = 8000
DB_FILE = 'database.json'

def load_db():
    if not os.path.exists(DB_FILE):
        return {"users": [], "posts": []}
    try:
        with open(DB_FILE, 'r') as f:
            return json.load(f)
    except:
        return {"users": [], "posts": []}

def save_db(data):
    with open(DB_FILE, 'w') as f:
        json.dump(data, f, indent=2)

class CustomHandler(http.server.SimpleHTTPRequestHandler):
    def do_GET(self):
        parsed = urlparse(self.path)
        if parsed.path == '/api/users':
            self.send_response(200)
            self.send_header('Content-type', 'application/json')
            self.send_header('Cache-Control', 'no-store, no-cache, must-revalidate')
            self.end_headers()
            db = load_db()
            self.wfile.write(json.dumps(db.get("users", [])).encode())
            return
        elif parsed.path == '/api/posts':
            self.send_response(200)
            self.send_header('Content-type', 'application/json')
            self.send_header('Cache-Control', 'no-store, no-cache, must-revalidate')
            self.end_headers()
            db = load_db()
            self.wfile.write(json.dumps(db.get("posts", [])).encode())
            return
        
        # Default behavior (serve files)
        super().do_GET()

    def do_POST(self):
        parsed = urlparse(self.path)
        length = int(self.headers.get('Content-Length', 0))
        body = self.rfile.read(length).decode('utf-8')
        try:
            payload = json.loads(body)
        except:
            payload = None

        if parsed.path == '/api/users/add':
            db = load_db()
            db["users"].append(payload)
            save_db(db)
            self.success(payload)
            return

        elif parsed.path == '/api/posts/add':
            db = load_db()
            # New posts go to top
            db["posts"].insert(0, payload)
            save_db(db)
            self.success(payload)
            return
        
        elif parsed.path == '/api/posts/update':
            # Expects full post object, finds by ID and replaces
            db = load_db()
            posts = db.get("posts", [])
            for i, p in enumerate(posts):
                if p["id"] == payload["id"]:
                    posts[i] = payload
                    break
            db["posts"] = posts
            save_db(db)
            self.success(payload)
            return

        elif parsed.path == '/api/posts/delete':
            # Expects { "id": "..." }
            db = load_db()
            posts = db.get("posts", [])
            db["posts"] = [p for p in posts if p["id"] != payload["id"]]
            save_db(db)
            self.success({"deleted": True})
            return

        self.send_error(404, "API Endpoint not found")

    def success(self, data):
        self.send_response(200)
        self.send_header('Content-type', 'application/json')
        self.end_headers()
        self.wfile.write(json.dumps(data).encode())

# Support binding to all interfaces
Handler = CustomHandler
with socketserver.TCPServer(("0.0.0.0", PORT), Handler) as httpd:
    print(f"Serving at http://0.0.0.0:{PORT}")
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        print("\nStopping server...")