FileManager.java

import java.io.*;
import java.text.SimpleDateFormat;
import java.util.*;

public class FileManager {
    public static final String DATA_FILE = "data.txt";         // raw CSV entries
    public static final String HISTORY_FILE = "history.txt";   // formatted recommendations
    public static final String ALERT_FILE = "alerts.txt";      // alerts
    public static final String DAILY_REPORT = "daily_report.txt";

    // Append text safely
    public static synchronized void writeToFile(String fileName, String content) {
        try (FileWriter fw = new FileWriter(fileName, true);
             BufferedWriter bw = new BufferedWriter(fw);
             PrintWriter out = new PrintWriter(bw)) {
            out.println(content);
        } catch (IOException e) {
            System.out.println("Error writing to file (" + fileName + "): " + e.getMessage());
        }
    }

    // Overwrite file with empty content (clear)
    public static synchronized void clearFile(String fileName) {
        try (PrintWriter pw = new PrintWriter(new FileWriter(fileName, false))) {
            // overwrite with nothing
        } catch (IOException e) {
            System.out.println("Error clearing file (" + fileName + "): " + e.getMessage());
        }
    }

    // Read whole file as string (for GUI display)
    public static String readFileAsString(String fileName) {
        File f = new File(fileName);
        if (!f.exists()) return "";
        StringBuilder sb = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(f))) {
            String line;
            while ((line = br.readLine()) != null) sb.append(line).append("\n");
        } catch (IOException e) {
            System.out.println("Error reading file (" + fileName + "): " + e.getMessage());
        }
        return sb.toString();
    }

    // Compute today's stats by reading DATA_FILE (CSV lines). Then write daily_report.txt
    public static synchronized Map<String, Integer> computeTodayStats() {
        Map<String, Integer> m = new HashMap<>();
        m.put("total", 0);
        m.put("needWater", 0);
        m.put("tempWarn", 0);
        m.put("alerts", 0);

        File f = new File(DATA_FILE);
        if (!f.exists()) return m;

        String today = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
        try (BufferedReader br = new BufferedReader(new FileReader(f))) {
            String line;
            while ((line = br.readLine()) != null) {
                // CSV: timestamp,moisture,pH,temperature,humidity,light,location
                String[] p = line.split(",", 7);
                if (p.length < 7) continue;
                String ts = p[0];
                if (!ts.startsWith(today)) continue; // only today's records
                m.put("total", m.get("total") + 1);

                double moisture = Double.parseDouble(p[1]);
                double temp = Double.parseDouble(p[3]);
                double ph = Double.parseDouble(p[2]);

                if (moisture < 40) m.put("needWater", m.get("needWater") + 1);
                if (temp > 35) m.put("tempWarn", m.get("tempWarn") + 1);

                // quick alert checks
                if (moisture < 20 || temp > 40 || ph < 4.5 || ph > 9.0) {
                    m.put("alerts", m.get("alerts") + 1);
                }
            }
        } catch (IOException e) {
            System.out.println("Error computing stats: " + e.getMessage());
        } catch (NumberFormatException e) {
            System.out.println("Malformed data entry while computing stats: " + e.getMessage());
        }
        return m;
    }

    // Recompute and write daily report from DATA_FILE
    public static synchronized void updateDailyReport() {
        Map<String, Integer> stats = computeTodayStats();
        try (PrintWriter pw = new PrintWriter(new FileWriter(DAILY_REPORT, false))) {
            String today = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
            pw.println("Date: " + today);
            pw.println("Total Records Today: " + stats.getOrDefault("total", 0));
            pw.println("Fields Needing Water (moisture < 40): " + stats.getOrDefault("needWater", 0));
            pw.println("Temperature Warnings (temp > 35): " + stats.getOrDefault("tempWarn", 0));
            pw.println("Alerts Today: " + stats.getOrDefault("alerts", 0));
            pw.println("--------------------------");
        } catch (IOException e) {
            System.out.println("Error writing daily report: " + e.getMessage());
        }
    }
}