package org.fox.ttrss;

import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

import org.jsoup.Jsoup;

import android.animation.LayoutTransition;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteStatement;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.provider.BaseColumns;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.LinearLayout;
import android.widget.ViewFlipper;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.reflect.TypeToken;

public class MainActivity extends Activity {
	private final String TAG = this.getClass().getSimpleName();

	private final static int UPDATE_INITIAL = 1;
	private final static int UPDATE_SEQUENTIAL = 2;
	private final static int UPDATE_OFFLINE = 3;

	private final static int OFFSET_MAX = 100;

	private SharedPreferences m_prefs;
	private String m_themeName = "";
	private boolean m_feedsOpened = false;
	private boolean m_splashDisabled = false;
	protected String m_sessionId;
	protected int m_offset = 0;
	protected int m_limit = 30;
	protected int m_maxId = 0;
	protected int m_updateMode = UPDATE_INITIAL;

	protected enum SyncStatus { SYNC_INITIAL, SYNC_ONLINE, SYNC_OFFLINE };

	protected MenuItem m_syncStatus;

	protected String getSessionId() {
		return m_sessionId;
	}

	protected synchronized void setSessionId(String sessionId) {
		m_sessionId = sessionId;

		SharedPreferences.Editor editor = m_prefs.edit();
		editor.putString("last_session_id", m_sessionId);	
		editor.commit();
	}

	private Timer m_articlesTimer;
	private Timer m_feedsTimer;
	private ArticlesTask m_articlesTask;
	private FeedsTask m_feedsTask;

	private class ArticlesTask extends TimerTask {
		@Override
		public void run() {
			downloadArticles();
		}		
	};

	private class FeedsTask extends TimerTask {
		@Override
		public void run() {
			downloadFeeds();			
		}		
	};

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		m_prefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());       

		if (m_prefs.getString("theme", "THEME_DARK").equals("THEME_DARK")) {
			setTheme(R.style.DarkTheme);
		} else {
			setTheme(R.style.LightTheme);
		}

		m_themeName = m_prefs.getString("theme", "THEME_DARK");

		m_sessionId = m_prefs.getString("last_session_id", null);

		if (savedInstanceState != null) {
			m_feedsOpened = savedInstanceState.getBoolean("feedsOpened");
			m_sessionId = savedInstanceState.getString("sessionId");
			m_offset = savedInstanceState.getInt("offset");
			m_limit = savedInstanceState.getInt("limit");
			m_updateMode = savedInstanceState.getInt("updateMode");
			m_maxId = savedInstanceState.getInt("maxId");
			m_splashDisabled = savedInstanceState.getBoolean("splashDisabled");
		}

		// allow database to upgrade before we do anything else
		DatabaseHelper dh = new DatabaseHelper(getApplicationContext());
		SQLiteDatabase db = dh.getWritableDatabase();

		if (m_updateMode == UPDATE_INITIAL && !m_splashDisabled) {
			db.execSQL("DELETE FROM feeds;");
			db.execSQL("DELETE FROM articles;");
		}

		db.close();

		setContentView(R.layout.main);

		LinearLayout wrapper = (LinearLayout) findViewById(R.id.headlines_wrapper);
		
		LayoutTransition transitioner = new LayoutTransition();
        wrapper.setLayoutTransition(transitioner);

		if (!m_feedsOpened) {
			Log.d(TAG, "Opening feeds fragment...");

			FragmentTransaction ft = getFragmentManager().beginTransaction();			
			FeedsFragment frag = new FeedsFragment();

			ft.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out);
			ft.replace(R.id.feeds_container, frag, "FEEDLIST");
			ft.commit();

			m_feedsOpened = true;

		}
		
		if (m_splashDisabled) {
			ViewFlipper vf = (ViewFlipper) findViewById(R.id.main_flipper);
			
			if (vf != null && vf.getDisplayedChild() == 0)
				vf.showNext();
			
			scheduleNextUpdate();
		} else {
			m_feedsTask = new FeedsTask();
			m_feedsTimer = new Timer("UpdateFeeds");
			m_feedsTimer.schedule(m_feedsTask, 1000L, 60*1000L);
		}

		//scheduleNextUpdate();
	}

	@Override
	public void onSaveInstanceState (Bundle out) {
		super.onSaveInstanceState(out);

		out.putBoolean("feedsOpened", m_feedsOpened);
		out.putString("sessionId", m_sessionId);
		out.putInt("offset", m_offset);
		out.putInt("limit", m_limit);
		out.putInt("updateMode", m_updateMode);
		out.putInt("maxId", m_maxId);
		out.putBoolean("splashDisabled", m_splashDisabled);
	}

	@Override
	public void onResume() {
		super.onResume();

		if (!m_prefs.getString("theme", "THEME_DARK").equals(m_themeName)) {
			Intent refresh = new Intent(this, MainActivity.class);
			startActivity(refresh);
			finish();
		}			
	}

	@Override
	public void onDestroy() {
		super.onDestroy();

		if (m_feedsTask != null) m_feedsTask.cancel();
		if (m_articlesTask != null) m_articlesTask.cancel();
		
		if (m_feedsTimer != null)  m_feedsTimer.cancel();
		m_feedsTimer = null;
		
		if (m_articlesTimer != null)  m_articlesTimer.cancel();
		m_articlesTimer = null;
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		MenuInflater inflater = getMenuInflater();
		inflater.inflate(R.menu.main_menu, menu);

		m_syncStatus = menu.findItem(R.id.sync_status);

		switch (m_updateMode) {
		case UPDATE_INITIAL:
			setSyncStatus(SyncStatus.SYNC_INITIAL);
			break;
		case UPDATE_SEQUENTIAL:
			setSyncStatus(SyncStatus.SYNC_ONLINE);
			break;
		default:
			setSyncStatus(SyncStatus.SYNC_OFFLINE);
		}		

		return true;
	}

	public void setSyncStatus(SyncStatus status) {
		switch (status) {
		case SYNC_INITIAL:
			m_syncStatus.setTitle(R.string.synchronizing);
			m_syncStatus.setIcon(android.R.drawable.presence_online);
			break;
		case SYNC_ONLINE:
			m_syncStatus.setTitle(R.string.online);
			m_syncStatus.setIcon(android.R.drawable.presence_online);
			break;
		case SYNC_OFFLINE:
			m_syncStatus.setTitle(R.string.offline);
			m_syncStatus.setIcon(android.R.drawable.presence_offline);
			break;
		}
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		switch (item.getItemId()) {
		case R.id.preferences:
			Intent intent = new Intent(this, PreferencesActivity.class);
			startActivityForResult(intent, 0);
			return true;
		default:
			return super.onOptionsItemSelected(item);
		}
	}

	private synchronized void downloadArticles() {
		ApiRequest api = new ApiRequest(m_sessionId, 
				m_prefs.getString("ttrss_url", null),
				m_prefs.getString("login", null),
				m_prefs.getString("password", null));

		JsonElement result = api.sendRequest(new HashMap<String,String>() {   
			{
				put("sid", m_sessionId);
				put("op", "getHeadlines");
				put("feed_id", "-4");
				put("show_content", "1");
				put("limit", String.valueOf(m_limit));
				put("skip", String.valueOf(m_offset));
				put("view_mode", "unread");

				if (m_updateMode != UPDATE_INITIAL) {
					put("since_id", String.valueOf(m_maxId));
				}
			}			 
		});

		if (result != null && api.getAuthStatus() == ApiRequest.STATUS_OK) {
			try {
				setSessionId(api.getSessionId());

				int articlesFound = 0;

				try {
					JsonArray feeds_object = (JsonArray) result.getAsJsonArray();

					Type listType = new TypeToken<List<Article>>() {}.getType();
					List<Article> articles = api.m_gson.fromJson(feeds_object, listType);

					DatabaseHelper dh = new DatabaseHelper(getApplicationContext());
					SQLiteDatabase db = dh.getWritableDatabase(); // TODO rework to m_writableDb etc to prevent crashes on rotate/recreate

					/* db.execSQL("DELETE FROM articles"); */

					SQLiteStatement stmtInsert = db.compileStatement("INSERT INTO articles " +
							"("+BaseColumns._ID+", unread, marked, published, updated, is_updated, title, link, feed_id, tags, content, excerpt) " +
					"VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);");

					SQLiteStatement stmtUpdate = db.compileStatement("UPDATE articles SET " +
							"unread = ?, marked = ?, published = ?, updated = ?, is_updated = ?, title = ?, link = ?, feed_id = ?, " +
							"tags = ?, content = ?, excerpt = ? WHERE " + BaseColumns._ID + " = ?");

					for (Article article : articles) {
						//Log.d(TAG, "Processing article #" + article.id);

						m_maxId = Math.max(m_maxId, article.id);

						++articlesFound;

						Cursor c = db.query("articles", new String[] { BaseColumns._ID } , BaseColumns._ID + "=?", 
								new String[] { String.valueOf(article.id) }, null, null, null);

						String excerpt = Jsoup.parse(article.content).text(); 

						if (excerpt.length() > 250) {
							excerpt = excerpt.substring(0, 250) + "...";
						}

						if (c.getCount() != 0) {
							stmtUpdate.bindLong(1, article.unread ? 1 : 0);
							stmtUpdate.bindLong(2, article.marked ? 1 : 0);
							stmtUpdate.bindLong(3, article.published ? 1 : 0);
							stmtUpdate.bindLong(4, article.updated);
							stmtUpdate.bindLong(5, article.is_updated ? 1 : 0);
							stmtUpdate.bindString(6, article.title);
							stmtUpdate.bindString(7, article.link);
							stmtUpdate.bindLong(8, article.feed_id);
							stmtUpdate.bindString(9, ""); // comma-separated tags
							stmtUpdate.bindString(10, article.content);
							stmtUpdate.bindString(11, excerpt);
							stmtUpdate.bindLong(12, article.id);
							stmtUpdate.execute();

						} else {
							//Log.d(TAG, "article not found");

							stmtInsert.bindLong(1, article.id);
							stmtInsert.bindLong(2, article.unread ? 1 : 0);
							stmtInsert.bindLong(3, article.marked ? 1 : 0);
							stmtInsert.bindLong(4, article.published ? 1 : 0);
							stmtInsert.bindLong(5, article.updated);
							stmtInsert.bindLong(6, article.is_updated ? 1 : 0);
							stmtInsert.bindString(7, article.title);
							stmtInsert.bindString(8, article.link);
							stmtInsert.bindLong(9, article.feed_id);
							stmtInsert.bindString(10, ""); // comma-separated tags
							stmtInsert.bindString(11, article.content);
							stmtInsert.bindString(12, excerpt);
							stmtInsert.execute();	
						}

						c.close();
					}

					db.close();

					runOnUiThread(new Runnable() {
						@Override
						public void run() {
							FeedsFragment ff = (FeedsFragment) getFragmentManager().findFragmentByTag("FEEDLIST");
							if (ff != null) ff.updateListView();
						}
					});

				} catch (Exception e) {
					e.printStackTrace();
				}

				Log.d(TAG, articlesFound + " articles processed");

				if (articlesFound == m_limit && m_offset < OFFSET_MAX) {

					m_offset += m_limit;

				} else {
					m_offset = 0;

					if (m_updateMode == UPDATE_INITIAL) {
						Log.i(TAG, "Switching to sequential mode...");

						runOnUiThread(new Runnable() {
							@Override
							public void run() {
								setSyncStatus(SyncStatus.SYNC_ONLINE);	
							}
						});
						m_updateMode = UPDATE_SEQUENTIAL;
					}
				}

				m_splashDisabled = true;

				runOnUiThread(new Runnable() {
					@Override
					public void run() {
						ViewFlipper vf = (ViewFlipper) findViewById(R.id.main_flipper);
						
						if (vf != null && vf.getDisplayedChild() == 0) {
							vf.showNext();
						}
					}
				});
				
				scheduleNextUpdate();

			} catch (Exception e) {
				e.printStackTrace();
			}										
		} else if (result != null && api.getAuthStatus() != ApiRequest.STATUS_OK) {
			// TODO handle error, e.g auth failed
		} else if (result == null) {
			// TODO could not parse result, server/network error?
		}
	}

	private synchronized void downloadFeeds() {
		ApiRequest api = new ApiRequest(m_sessionId, 
				m_prefs.getString("ttrss_url", null),
				m_prefs.getString("login", null),
				m_prefs.getString("password", null));

		JsonElement result = api.sendRequest(new HashMap<String,String>() {   
			{
				put("sid", m_sessionId);
				put("op", "getFeeds");
				put("cat_id", "-3");
				put("unread_only", "1");
			}			 
		});

		if (result != null && api.getAuthStatus() == ApiRequest.STATUS_OK) {
			try {
				try {
					setSessionId(api.getSessionId());
				} catch (NullPointerException e) {
					//
				}

				JsonArray feeds_object = (JsonArray) result.getAsJsonArray();

				Type listType = new TypeToken<List<Feed>>() {}.getType();
				List<Feed> feeds = api.m_gson.fromJson(feeds_object, listType);

				DatabaseHelper dh = new DatabaseHelper(this);
				SQLiteDatabase db = dh.getWritableDatabase();

				SQLiteStatement stmtUpdate = db.compileStatement("UPDATE feeds SET " +
						"title = ?, feed_url = ?, has_icon = ?, cat_id = ?, last_updated = ? WHERE " +
						BaseColumns._ID + " = ?");

				SQLiteStatement stmtInsert = db.compileStatement("INSERT INTO feeds " +
						"("+BaseColumns._ID+", title, feed_url, has_icon, cat_id, last_updated) " +
				"VALUES (?, ?, ?, ?, ?, ?);");

				for (Feed feed : feeds) {
					Cursor c = db.query("feeds", new String[] { BaseColumns._ID } , BaseColumns._ID + "=?", 
							new String[] { String.valueOf(feed.id) }, null, null, null);

					if (c.getCount() != 0) {
						stmtUpdate.bindString(1, feed.title);
						stmtUpdate.bindString(2, feed.feed_url);								
						stmtUpdate.bindLong(3, feed.has_icon ? 1 : 0);
						stmtUpdate.bindLong(4, feed.cat_id);
						stmtUpdate.bindLong(5, feed.last_updated);
						stmtUpdate.bindLong(6, feed.id);
						stmtUpdate.execute();								

					} else {
						stmtInsert.bindLong(1, feed.id);
						stmtInsert.bindString(2, feed.title);
						stmtInsert.bindString(3, feed.feed_url);
						stmtInsert.bindLong(4, feed.has_icon ? 1 : 0);
						stmtInsert.bindLong(5, feed.cat_id);
						stmtInsert.bindLong(6, feed.last_updated);
						stmtInsert.execute();
					}

					c.close();
				} 

				// TODO delete not returned feeds which has no data here

				db.close();

				runOnUiThread(new Runnable() {
					@Override
					public void run() {
						/* View pb = findViewById(R.id.loading_progress);
						if (pb != null) pb.setVisibility(View.INVISIBLE); */

						FeedsFragment frag = (FeedsFragment)getFragmentManager().findFragmentByTag("FEEDLIST");
						
						if (frag != null) {						
							frag.updateListView();
						}						
					}
				});
				
				scheduleNextUpdate();

			} catch (Exception e) {
				e.printStackTrace();
			}										
		} else if (result != null && api.getAuthStatus() != ApiRequest.STATUS_OK) {
			// TODO handle error, e.g auth failed
		} else if (result == null) {
			// TODO could not parse result, server/network error?
		}

	}

	protected void scheduleNextUpdate() {

		if (m_articlesTask != null) m_articlesTask.cancel();

		m_articlesTask = new ArticlesTask();

		if (m_updateMode == UPDATE_INITIAL) {
			Log.i(TAG, "Scheduling initial update...");
			m_articlesTimer = new Timer("DownloadInitial");
			m_articlesTimer.schedule(m_articlesTask, 1000L);
		} else {
			Log.i(TAG, "Scheduling sequential update...");
			m_articlesTimer = new Timer("DownloadSequential");
			m_articlesTimer.schedule(m_articlesTask, 60*1000L);
		}
	}				

}