package com.community;

import android.content.Context;
import android.content.SharedPreferences;
import android.app.DownloadManager;
import android.net.Uri;
import android.os.Environment;
import android.util.Log;
import android.webkit.JavascriptInterface;
import org.json.JSONArray;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * UpdateManager - Manifest-based OTA Update System
 * 
 * Fetches version manifest from GitHub and determines applicable updates
 * based on upgrade paths defined in versions.json
 */
public class UpdateManager {
    private static final String TAG = "UpdateManager";
    private static final String UPDATE_API_URL = "https://raw.githubusercontent.com/project-real-resurrection-3/rr3-releases/main/versions.json";
    private static final String PREFS_NAME = "com.ea.games.r3_row_preferences";
    private static final String KEY_WIFI_ONLY = "wifi_only_updates";
    private static final String KEY_AUTO_CHECK = "auto_check_updates";
    private static final String KEY_LAST_CHECK = "last_update_check";
    private static final String KEY_SKIPPED_VERSIONS = "skipped_versions";
    private static final String KEY_DOWNLOAD_ID = "download_id";
    
    // IMPORTANT: Update these values for each build
    private static final String CURRENT_VERSION = "15.0.0-community-alpha";
    private static final int CURRENT_VERSION_CODE = 150000;
    
    private Context context;
    private DownloadManager downloadManager;
    private long downloadId = -1;
    
    public UpdateManager(Context context) {
        this.context = context;
        this.downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
    }
    
    /**
     * Check for updates using version manifest
     * Returns JSON with update info or "no update" status
     */
    @JavascriptInterface
    public String checkForUpdates() {
        Log.i(TAG, "Checking for updates from manifest...");
        JSONObject result = new JSONObject();
        HttpURLConnection connection = null;
        
        try {
            // Fetch versions.json manifest
            URL url = new URL(UPDATE_API_URL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.setRequestProperty("User-Agent", "RR3-Community-Updater");
            connection.setConnectTimeout(10000);
            connection.setReadTimeout(10000);
            
            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(
                    new InputStreamReader(connection.getInputStream())
                );
                StringBuilder response = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    response.append(line);
                }
                reader.close();
                
                // Parse manifest
                JSONObject manifest = new JSONObject(response.toString());
                JSONArray versions = manifest.getJSONArray("versions");
                
                // Get current version (strip suffix like -alpha, -beta)
                String currentVersionClean = CURRENT_VERSION;
                if (currentVersionClean.contains("-")) {
                    currentVersionClean = currentVersionClean.split("-")[0];
                }
                
                // Search for applicable update
                JSONObject updateVersion = findApplicableUpdate(versions, currentVersionClean, CURRENT_VERSION_CODE);
                
                if (updateVersion != null) {
                    // Found an update!
                    result.put("hasUpdate", true);
                    result.put("version", updateVersion.getString("version"));
                    result.put("downloadUrl", updateVersion.getString("download_url"));
                    result.put("fileSize", updateVersion.getLong("file_size"));
                    result.put("changelog", updateVersion.optString("changelog", ""));
                    result.put("releaseDate", updateVersion.optString("release_date", ""));
                    
                    Log.i(TAG, "Update available: " + updateVersion.getString("version"));
                } else {
                    // No update found
                    result.put("hasUpdate", false);
                    Log.i(TAG, "No update available");
                }
                
                // Update last check time
                SharedPreferences prefs = getSharedPreferences();
                prefs.edit()
                    .putLong(KEY_LAST_CHECK, System.currentTimeMillis())
                    .apply();
            } else {
                result.put("hasUpdate", false);
                result.put("error", "HTTP " + responseCode);
            }
            
        } catch (Exception e) {
            Log.e(TAG, "Error checking for updates", e);
            try {
                result.put("hasUpdate", false);
                result.put("error", "Failed to check for updates");
            } catch (Exception ignored) {}
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
        
        return result.toString();
    }
    
    /**
     * Find applicable update from versions array
     * Checks if version_code is newer AND current version is in upgrade_from
     */
    private JSONObject findApplicableUpdate(JSONArray versions, String currentVersion, int currentVersionCode) {
        try {
            for (int i = 0; i < versions.length(); i++) {
                JSONObject version = versions.getJSONObject(i);
                
                // Get version code
                int versionCode = version.getInt("version_code");
                
                // Only consider versions newer than current
                if (versionCode <= currentVersionCode) {
                    continue;
                }
                
                // Check if current version is in upgrade_from array
                JSONArray upgradeFrom = version.optJSONArray("upgrade_from");
                if (upgradeFrom == null) {
                    continue;
                }
                
                // Check each entry in upgrade_from
                for (int j = 0; j < upgradeFrom.length(); j++) {
                    String allowedVersion = upgradeFrom.getString(j);
                    
                    // Check for exact match
                    if (allowedVersion.equals(currentVersion)) {
                        return version;
                    }
                    
                    // Check for wildcard match (e.g., "15.0.x" matches "15.0.0")
                    if (allowedVersion.endsWith(".x")) {
                        String wildcardPrefix = allowedVersion.substring(0, allowedVersion.length() - 2);
                        if (currentVersion.startsWith(wildcardPrefix)) {
                            return version;
                        }
                    }
                    
                    // Check for major version wildcard (e.g., "14.x" matches any 14.x.x)
                    if (allowedVersion.matches("\\d+\\.x")) {
                        String majorVersion = allowedVersion.split("\\.")[0];
                        if (currentVersion.startsWith(majorVersion + ".")) {
                            return version;
                        }
                    }
                }
            }
        } catch (Exception e) {
            Log.e(TAG, "Error finding applicable update", e);
        }
        
        return null;
    }
    
    /**
     * Download update APK
     */
    @JavascriptInterface
    public boolean downloadUpdate(String downloadUrl, String version) {
        try {
            Log.i(TAG, "Starting download: " + version);
            
            // Check network preference
            boolean wifiOnly = getSharedPreferences().getBoolean(KEY_WIFI_ONLY, false);
            
            Uri uri = Uri.parse(downloadUrl);
            DownloadManager.Request request = new DownloadManager.Request(uri);
            request.setTitle("RR3 Community Update");
            request.setDescription("Downloading v" + version);
            request.setDestinationInExternalPublicDir(
                Environment.DIRECTORY_DOWNLOADS, 
                "RR3-Community-v" + version + ".apk"
            );
            
            // Set network type based on preference
            if (wifiOnly) {
                request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI);
            } else {
                request.setAllowedNetworkTypes(
                    DownloadManager.Request.NETWORK_WIFI | 
                    DownloadManager.Request.NETWORK_MOBILE
                );
            }
            
            request.setNotificationVisibility(
                DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED
            );
            request.setMimeType("application/vnd.android.package-archive");
            
            downloadId = downloadManager.enqueue(request);
            
            // Save download ID
            getSharedPreferences().edit()
                .putLong(KEY_DOWNLOAD_ID, downloadId)
                .apply();
            
            return true;
        } catch (Exception e) {
            Log.e(TAG, "Error starting download", e);
            return false;
        }
    }
    
    /**
     * Get download progress (0-100, or -1 if not downloading)
     */
    @JavascriptInterface
    public int getDownloadProgress() {
        if (downloadId == -1) {
            return -1;
        }
        
        try {
            DownloadManager.Query query = new DownloadManager.Query();
            query.setFilterById(downloadId);
            android.database.Cursor cursor = downloadManager.query(query);
            
            if (cursor.moveToFirst()) {
                int bytesDownloaded = cursor.getInt(
                    cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR)
                );
                int bytesTotal = cursor.getInt(
                    cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES)
                );
                
                if (bytesTotal > 0) {
                    return (int) ((bytesDownloaded * 100L) / bytesTotal);
                }
            }
            cursor.close();
        } catch (Exception e) {
            Log.e(TAG, "Error getting download progress", e);
        }
        
        return -1;
    }
    
    /**
     * Check if download is complete
     */
    @JavascriptInterface
    public boolean isDownloadComplete() {
        if (downloadId == -1) {
            return false;
        }
        
        try {
            DownloadManager.Query query = new DownloadManager.Query();
            query.setFilterById(downloadId);
            android.database.Cursor cursor = downloadManager.query(query);
            
            if (cursor.moveToFirst()) {
                int status = cursor.getInt(
                    cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
                );
                cursor.close();
                return status == DownloadManager.STATUS_SUCCESSFUL;
            }
        } catch (Exception e) {
            Log.e(TAG, "Error checking download status", e);
        }
        
        return false;
    }
    
    /**
     * Get WiFi-only preference
     */
    @JavascriptInterface
    public boolean getWifiOnlyPreference() {
        return getSharedPreferences().getBoolean(KEY_WIFI_ONLY, false);
    }
    
    /**
     * Set WiFi-only preference
     */
    @JavascriptInterface
    public void setWifiOnlyPreference(boolean wifiOnly) {
        getSharedPreferences().edit()
            .putBoolean(KEY_WIFI_ONLY, wifiOnly)
            .apply();
    }
    
    /**
     * Get auto-check preference
     */
    @JavascriptInterface
    public boolean getAutoCheckPreference() {
        return getSharedPreferences().getBoolean(KEY_AUTO_CHECK, true);
    }
    
    /**
     * Set auto-check preference
     */
    @JavascriptInterface
    public void setAutoCheckPreference(boolean autoCheck) {
        getSharedPreferences().edit()
            .putBoolean(KEY_AUTO_CHECK, autoCheck)
            .apply();
    }
    
    /**
     * Get SharedPreferences instance
     */
    private SharedPreferences getSharedPreferences() {
        return context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    }
    
    /**
     * Parse version string to version code
     * Format: "15.0.0" -> 150000
     */
    private int parseVersionCode(String version) {
        try {
            String[] parts = version.split("\\.");
            if (parts.length >= 3) {
                int major = Integer.parseInt(parts[0]);
                int minor = Integer.parseInt(parts[1]);
                String patchPart = parts[2].split("-")[0]; // Remove suffix
                int patch = Integer.parseInt(patchPart);
                
                return (major * 100000) + (minor * 1000) + patch;
            }
        } catch (NumberFormatException e) {
            Log.e(TAG, "Error parsing version code", e);
        }
        
        return 0;
    }
}