package org.dynmap;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import org.dynmap.storage.MapStorage;
import org.dynmap.utils.BufferInputStream;
import org.dynmap.utils.BufferOutputStream;
import org.dynmap.web.Json;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import static org.dynmap.JSONUtils.*;

import java.nio.charset.Charset;
import java.util.concurrent.CompletableFuture;

public class JsonFileClientUpdateComponent extends ClientUpdateComponent {
    protected long jsonInterval;
    protected long currentTimestamp = 0;
    protected long lastTimestamp = 0;
    protected long lastChatTimestamp = 0;
    protected JSONParser parser = new JSONParser();
    private boolean hidewebchatip;
    private boolean useplayerloginip;
    private boolean requireplayerloginip;
    private boolean trust_client_name;
    private boolean checkuserban;
    private boolean req_login;
    private boolean chat_perms;
    private int lengthlimit;
    private HashMap<String,String> useralias = new HashMap<String,String>();
    private int aliasindex = 1;
    private long last_confighash;
    private MessageDigest md;
    private MapStorage storage;
    private File baseStandaloneDir;

    private static class FileToWrite {
        String filename;
        byte[] content;
        boolean phpwrapper;
        @Override
        public boolean equals(Object o) {
            if(o instanceof FileToWrite) {
                return ((FileToWrite)o).filename.equals(this.filename);
            }
            return false;
        }
    }
    private class FileProcessor implements Runnable {
        public void run() {
            while(true) {
                FileToWrite f = null;
                synchronized(lock) {
                    if(files_to_write.isEmpty() == false) {
                        f = files_to_write.removeFirst();
                    }
                    else {
                        pending = null;
                        return;
                    }
                }
                BufferOutputStream buf = null;
                if (f.content != null) {
                    buf = new BufferOutputStream();
                    if(f.phpwrapper) {
                        buf.write("<?php /*\n".getBytes(cs_utf8));
                    }
                    buf.write(f.content);
                    if(f.phpwrapper) {
                        buf.write("\n*/ ?>\n".getBytes(cs_utf8));
                    }
                }
                if (!storage.setStandaloneFile(f.filename, buf)) {
                    Log.severe("Exception while writing JSON-file - " + f.filename);
                }
            }
        }
    }
    private Object lock = new Object();
    private FileProcessor pending;
    private LinkedList<FileToWrite> files_to_write = new LinkedList<FileToWrite>();

    private void enqueueFileWrite(String filename, byte[] content, boolean phpwrap) {
        FileToWrite ftw = new FileToWrite();
        ftw.filename = filename;
        ftw.content = content;
        ftw.phpwrapper = phpwrap;
        synchronized(lock) {
            boolean didadd = false;
            if(pending == null) {
                didadd = true;
                pending = new FileProcessor();
            }
            files_to_write.remove(ftw);
            files_to_write.add(ftw);
            if(didadd) {
                MapManager.scheduleDelayedJob(new FileProcessor(), 0);
            }
        }
    }
    
    private static Charset cs_utf8 = Charset.forName("UTF-8");
    public JsonFileClientUpdateComponent(final DynmapCore core, final ConfigurationNode configuration) {
        super(core, configuration);
        
        if (!core.isInternalWebServerDisabled) {
        	Log.severe("Using JsonFileClientUpdateComponent with disable-webserver=false is not supported: there will likely be problems");        	
        }

        final boolean allowwebchat = configuration.getBoolean("allowwebchat", false);
        jsonInterval = (long)(configuration.getFloat("writeinterval", 1) * 1000);
        hidewebchatip = configuration.getBoolean("hidewebchatip", false);
        useplayerloginip = configuration.getBoolean("use-player-login-ip", true);
        requireplayerloginip = configuration.getBoolean("require-player-login-ip", false);
        trust_client_name = configuration.getBoolean("trustclientname", false);
        checkuserban = configuration.getBoolean("block-banned-player-chat", true);
        req_login = configuration.getBoolean("webchat-requires-login", false);
        chat_perms = configuration.getBoolean("webchat-permissions", false);
        lengthlimit = configuration.getInteger("chatlengthlimit", 256); 
        storage = core.getDefaultMapStorage();
        baseStandaloneDir = new File(core.configuration.getString("webpath", "web"), "standalone");
        if (!baseStandaloneDir.isAbsolute()) {
            baseStandaloneDir = new File(core.getDataFolder(), baseStandaloneDir.toString());
        }
        try {
            md = MessageDigest.getInstance("SHA-1");
        } catch (NoSuchAlgorithmException nsax) {
            Log.severe("Unable to get message digest SHA-1");
        }
        /* Generate our config.js file */
        generateConfigJS(core);
        
        core.getServer().scheduleServerTask(new Runnable() {
            @Override
            public void run() {
                currentTimestamp = System.currentTimeMillis();
                if(last_confighash != core.getConfigHashcode()) {
                    writeConfiguration();
                }
                writeUpdates();
                if (allowwebchat) {
                    handleWebChat();
                }
                if(core.isLoginSupportEnabled())
                    handleRegister();
                lastTimestamp = currentTimestamp;
                core.getServer().scheduleServerTask(this, jsonInterval/50);
            }}, jsonInterval/50);
        
        core.events.addListener("buildclientconfiguration", new Event.Listener<JSONObject>() {
            @Override
            public void triggered(JSONObject t) {
                s(t, "jsonfile", true);
                s(t, "allowwebchat", allowwebchat);
                s(t, "webchat-requires-login", req_login);
                s(t, "loginrequired", core.isLoginRequired());
                // For 'sendmessage.php'
                s(t, "webchat-interval", configuration.getFloat("webchat-interval", 5.0f));
                s(t, "chatlengthlimit", lengthlimit);
            }
        });
        core.events.addListener("initialized", new Event.Listener<Object>() {
            @Override
            public void triggered(Object t) {
                writeConfiguration();
                writeUpdates(); /* Make sure we stay in sync */
                writeLogins();
                writeAccess();
            }
        });
        core.events.addListener("server-started", new Event.Listener<Object>() {
            @Override
            public void triggered(Object t) {
                writeConfiguration();
                writeUpdates(); /* Make sure we stay in sync */
                writeLogins();
                writeAccess();
            }
        });
        core.events.addListener("worldactivated", new Event.Listener<DynmapWorld>() {
            @Override
            public void triggered(DynmapWorld t) {
                writeConfiguration();
                writeUpdates(); /* Make sure we stay in sync */
                writeAccess();
            }
        });
        core.events.addListener("loginupdated", new Event.Listener<Object>() {
            @Override
            public void triggered(Object t) {
                writeLogins();
                writeAccess();
            }
        });
        core.events.addListener("playersetupdated", new Event.Listener<Object>() {
            @Override
            public void triggered(Object t) {
                writeAccess();
            }
        });
    }
        
    private void generateConfigJS(DynmapCore core) {
        /* Test if login support is enabled */
        boolean login_enabled = core.isLoginSupportEnabled();

        // configuration: 'standalone/dynmap_config.json?_={timestamp}',
        // update: 'standalone/dynmap_{world}.json?_={timestamp}',
        // sendmessage: 'standalone/sendmessage.php',
        // login: 'standalone/login.php',
        // register: 'standalone/register.php',
        // tiles : 'tiles/',
        // markers : 'tiles/'

        // configuration: 'standalone/configuration.php',
        // update: 'standalone/update.php?world={world}&ts={timestamp}',
        // sendmessage: 'standalone/sendmessage.php',
        // login: 'standalone/login.php',
        // register: 'standalone/register.php',
        // tiles : 'standalone/tiles.php?tile=',
        // markers : 'standalone/markers.php?marker='
        
        MapStorage store = core.getDefaultMapStorage();
        
        StringBuilder sb = new StringBuilder();
        sb.append("var config = {\n");
        sb.append(" url : {\n");
        /* Get configuration URL */
        sb.append("  configuration: '");
        sb.append(core.configuration.getString("url/configuration", store.getConfigurationJSONURI(login_enabled)));
        sb.append("',\n");
        /* Get update URL */
        sb.append("  update: '");
        sb.append(core.configuration.getString("url/update", store.getUpdateJSONURI(login_enabled)));
        sb.append("',\n");
        /* Get sendmessage URL */
        sb.append("  sendmessage: '");
        sb.append(core.configuration.getString("url/sendmessage", store.getSendMessageURI()));
        sb.append("',\n");
        /* Get login URL */
        sb.append("  login: '");
        sb.append(core.configuration.getString("url/login", store.getStandaloneLoginURI()));
        sb.append("',\n");
        /* Get register URL */
        sb.append("  register: '");
        sb.append(core.configuration.getString("url/register", store.getStandaloneRegisterURI()));
        sb.append("',\n");
        /* Get tiles URL */
        sb.append("  tiles: '");
        sb.append(core.configuration.getString("url/tiles", store.getTilesURI(login_enabled)));
        sb.append("',\n");
        /* Get markers URL */
        sb.append("  markers: '");
        sb.append(core.configuration.getString("url/markers", store.getMarkersURI(login_enabled)));
        sb.append("'\n }\n};\n");
        
        byte[] outputBytes = sb.toString().getBytes(cs_utf8);
        MapManager.scheduleDelayedJob(new Runnable() {
        	public void run() {
        		if (core.getDefaultMapStorage().needsStaticWebFiles()) {
        			BufferOutputStream os = new BufferOutputStream();
        			os.write(outputBytes);
        			core.getDefaultMapStorage().setStaticWebFile("standalone/config.js", os);
        		}
        		else {
	                File f = new File(baseStandaloneDir, "config.js");
	                FileOutputStream fos = null;
	                try {
	                    fos = new FileOutputStream(f);
	                    fos.write(outputBytes);
	                } catch (IOException iox) {
	                    Log.severe("Exception while writing " + f.getPath(), iox);
	                } finally {
	                    if(fos != null) {
	                        try {
	                            fos.close();
	                        } catch (IOException x) {}
	                        fos = null;
	                    }
	                }        	
        		}
        	}
        }, 0);
    }
    
    protected void writeConfiguration() {
        JSONObject clientConfiguration = new JSONObject();
        core.events.trigger("buildclientconfiguration", clientConfiguration);
        last_confighash = core.getConfigHashcode();
        
        byte[] content = clientConfiguration.toJSONString().getBytes(cs_utf8);

        String outputFile;
        boolean dowrap = storage.wrapStandaloneJSON(core.isLoginSupportEnabled());
        if(dowrap) {
            outputFile = "dynmap_config.php";
        }
        else {
            outputFile = "dynmap_config.json";
        }
        
        enqueueFileWrite(outputFile, content, dowrap);
    }
    
    @SuppressWarnings("unchecked")
    protected void writeUpdates() {
        if(core.mapManager == null) return;
        //Handles Updates
        ArrayList<DynmapWorld> wlist = new ArrayList<DynmapWorld>(core.mapManager.getWorlds());	// Grab copy of world list
        for (int windx = 0; windx < wlist.size(); windx++) {
        	DynmapWorld dynmapWorld = wlist.get(windx);
            JSONObject update = new JSONObject();
            update.put("timestamp", currentTimestamp);
            ClientUpdateEvent clientUpdate = new ClientUpdateEvent(currentTimestamp - 30000, dynmapWorld, update);
            clientUpdate.include_all_users = true;
            core.events.trigger("buildclientupdate", clientUpdate);

            String outputFile;
            boolean dowrap = storage.wrapStandaloneJSON(core.isLoginSupportEnabled());
            if(dowrap) {
                outputFile = "updates_" + dynmapWorld.getName() + ".php";
            }
            else {
                outputFile = "dynmap_" + dynmapWorld.getName() + ".json";
            }

            CompletableFuture.runAsync(() -> {
                byte[] content = Json.stringifyJson(update).getBytes(cs_utf8);

                enqueueFileWrite(outputFile, content, dowrap);
            });
        }
    }
    
    private byte[] loginhash = new byte[16];
    
    protected void writeLogins() {
        String loginFile = "dynmap_login.php";

        if(core.isLoginSupportEnabled()) {
            String s = core.getLoginPHP(storage.wrapStandalonePHP());
            if(s != null) {
                byte[] bytes = s.getBytes(cs_utf8);
                md.reset();
                byte[] hash = md.digest(bytes);
                if(Arrays.equals(hash, loginhash)) {
                    return;
                }
                enqueueFileWrite(loginFile, bytes, false);
                loginhash = hash;
            }
        }
        else {
            enqueueFileWrite(loginFile, null, false);
        }
    }

    private byte[] accesshash = new byte[16];

    protected void writeAccess() {
        String accessFile = "dynmap_access.php";

        String s = core.getAccessPHP(storage.wrapStandalonePHP());
        if(s != null) {
            byte[] bytes = s.getBytes(cs_utf8);
            md.reset();
            byte[] hash = md.digest(bytes);
            if(Arrays.equals(hash, accesshash)) {
                return;
            }
            enqueueFileWrite(accessFile, bytes, false);
            accesshash = hash;
        }
    }

    private void processWebChat(JSONArray jsonMsgs) {
    	Iterator<?> iter = jsonMsgs.iterator();
		boolean init_skip = (lastChatTimestamp == 0);
		while (iter.hasNext()) {
			boolean ok = true;
			JSONObject o = (JSONObject) iter.next();
			String ts = String.valueOf(o.get("timestamp"));
			if(ts.equals("null")) ts = "0";
			long cts;
			try {
				cts = Long.parseLong(ts);
			} catch (NumberFormatException nfx) {
				try {
					cts = (long) Double.parseDouble(ts);
				} catch (NumberFormatException nfx2) {
					cts = 0;
				}
			}
			if (cts > lastChatTimestamp) {
				String name = String.valueOf(o.get("name"));
				String ip = String.valueOf(o.get("ip"));
				String uid = null;
				Object usr = o.get("userid");
				if(usr != null) {
					uid = String.valueOf(usr);
				}
				boolean isip = true;
				lastChatTimestamp = cts;
				if(init_skip)
					continue;
				if(uid == null) {
					if((!trust_client_name) || (name == null) || (name.equals(""))) {
						if(ip != null)
							name = ip;
					}
					if(useplayerloginip) {  /* Try to match using IPs of player logins */
						List<String> ids = core.getIDsForIP(name);
						if(ids != null && !ids.isEmpty()) {
							name = ids.get(0);
							isip = false;
							if(checkuserban) {
								if(core.getServer().isPlayerBanned(name)) {
									Log.info("Ignore message from '" + ip + "' - banned player (" + name + ")");
									ok = false;
								}
							}
							if(chat_perms && !core.getServer().checkPlayerPermission(name, "webchat")) {
								Log.info("Rejected web chat from " + ip + ": not permitted (" + name + ")");
								ok = false;
							}
						}
						else if(requireplayerloginip) {
							Log.info("Ignore message from '" + name + "' - no matching player login recorded");
							ok = false;
						}
					}
					if(hidewebchatip && isip) {
						String n = useralias.get(name);
						if(n == null) { /* Make ID */
							n = String.format("web-%03d", aliasindex);
							aliasindex++;
							useralias.put(name, n);
						}
						name = n;
					}
				}
				else {
					if(core.getServer().isPlayerBanned(uid)) {
						Log.info("Ignore message from '" + uid + "' - banned user");
						ok = false;
					}
					if(chat_perms && !core.getServer().checkPlayerPermission(uid, "webchat")) {
						Log.info("Rejected web chat from " + uid + ": not permitted");
						ok = false;
					}
					name = uid;
				}
				if(ok) {
					String message = String.valueOf(o.get("message"));
					if((lengthlimit > 0) && (message.length() > lengthlimit))
						message = message.substring(0, lengthlimit);
					core.webChat(name, message);
				}
			}
		}    	
    }
    
    protected void handleWebChat() {
    	MapManager.scheduleDelayedJob(new Runnable() {
    		public void run() {
    			BufferInputStream bis = storage.getStandaloneFile("dynmap_webchat.json");
    			if (bis != null && lastTimestamp != 0) {
    				JSONArray jsonMsgs = null;
    				Reader inputFileReader = null;
    				try {
    					inputFileReader = new InputStreamReader(bis, cs_utf8);
    					jsonMsgs = (JSONArray) parser.parse(inputFileReader);
    				} catch (IOException ex) {
    					Log.severe("Exception while reading JSON-file.", ex);
    					storage.setStandaloneFile("dynmap_webchat.json", null);	// Delete it
    				} catch (ParseException ex) {
    					Log.severe("Exception while parsing JSON-file.", ex);
    					storage.setStandaloneFile("dynmap_webchat.json", null);	// Delete it
    				} finally {
    					if(inputFileReader != null) {
    						try {
    							inputFileReader.close();
    						} catch (IOException iox) {

    						}
    						inputFileReader = null;
    					}
    				}
    				if (jsonMsgs != null) {
        				final JSONArray json = jsonMsgs;
    					// Process content on server thread
    					core.getServer().scheduleServerTask(new Runnable() {
    						@Override
    						public void run() {
    							processWebChat(json);
    						}
    					}, 0);
    				}
    			}
    		}
		}, 0);
    }
    protected void handleRegister() {
        if(core.pendingRegisters() == false)
            return;
        BufferInputStream bis = storage.getStandaloneFile("dynmap_reg.php");
        if (bis != null) {
            BufferedReader br = null;
            ArrayList<String> lines = new ArrayList<String>();
            try {
                br = new BufferedReader(new InputStreamReader(bis));
                String line;
                while ((line = br.readLine()) != null)   {
                    if(line.startsWith("<?") || line.startsWith("*/")) {
                        continue;
                    }
                    lines.add(line);
                }
            } catch (IOException iox) {
                Log.severe("Exception while reading dynmap_reg.php", iox);
            } finally {
                if (br != null) {
                    try {
                        br.close();
                    } catch (IOException x) {
                    }
                    br = null;
                }
            }
            for(int i = 0; i < lines.size(); i++) {
                String[] vals = lines.get(i).split("=");
                if(vals.length == 3) {
                    core.processCompletedRegister(vals[0].trim(), vals[1].trim(), vals[2].trim());
                }
            }
        }
    }
    
    @Override
    public void dispose() {
        super.dispose();
    }
}