package com.example.portfolio2;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

import java.io.IOException;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class HelloApplication extends Application {
    // Initializing model, controller and database objects
    private Model model = new Model();
    private Controller con = new Controller(model,this);
    MyDB myDB = new MyDB();

    /* Below is the original implementation of the UI elements with
    accompanying, individual calls to setOnAction to specify functionality.
    Before changing to a list format,
    we made sure methods in controller and model
    were generalized to allow for the new structure seamlessly.
    private ComboBox<String> programCombo = new ComboBox<>();
    private ComboBox<String> subject1Combo = new ComboBox<>();
    private ComboBox<String> subject2Combo = new ComboBox<>();
    private ComboBox<String> electiveCombo = new ComboBox<>();

    private ComboBox<String> programSelect = new ComboBox<>();
    private ComboBox<String> subject1Select = new ComboBox<>();
    private ComboBox<String> subject2Select = new ComboBox<>();
    private ComboBox<String> electiveSelect = new ComboBox<>();

    private TextArea programArea = new TextArea();
    private TextArea subject1Area = new TextArea();
    private TextArea subject2Area = new TextArea();
    private TextArea electiveArea = new TextArea();

    private Label programEcts = new Label();
    private Label subject1Ects = new Label();
    private Label subject2Ects = new Label();
    private Label electiveEcts = new Label();

    private VBox program = new VBox(new Label("Program"), programCombo, programSelect, programArea, programEcts);
    private VBox subject1 = new VBox(new Label("Subject 1"), subject1Combo, subject1Select, subject1Area, subject1Ects);
    private VBox subject2 = new VBox(new Label("Subject 2"), subject2Combo, subject2Select, subject2Area, subject2Ects);
    private VBox elective = new VBox(new Label("Elective"), electiveCombo, electiveSelect, electiveArea, electiveEcts);
    */

    @Override
    public void start(Stage stage) throws IOException {
        // Clears old insertions into the participation table
        con.initialize();

        // Defines a list of columns based on their names.
        List<ActivityColumn> columns = List.of(
                new ActivityColumn("Program"),
                new ActivityColumn("Subject 1"),
                new ActivityColumn("Subject 2"),
                new ActivityColumn("Elective")
        );

        // Defines a list of subject modules
        List<String> subjectModules = List.of("Computer Science", "Informatik", "Astrology");

        // Loop for defining button funtionality for each activity column
        for (ActivityColumn col : columns) {
            col.nameLabel.setStyle("-fx-font-size: 18px; -fx-padding: 10px;"); // Styling
            col.ectsLabel.setStyle("-fx-font-size: 18px; -fx-padding: 10px");
            col.categoryCombo.setPrefSize(250, 35);
            col.activitySelect.setPrefSize(250, 35);
            col.area.setPrefWidth(250);

            // All boxes share the same activity logic
            col.activitySelect.setOnAction(event -> {
                con.onActivitySelected(col.categoryCombo, col.activitySelect, col.area);
                con.updateEcts(col.ectsLabel, col.categoryCombo);
            });

            switch (col.name) { // Switch statement handles different category boxes
                case "Program" -> {
                        col.categoryCombo.getItems().addAll("HumTek", "NatBach");
                        col.categoryCombo.setOnAction(event -> {
                            con.onComboSelected(col.categoryCombo, col.activitySelect, col.area);
                        });
                }
                case "Subject 1" -> { // We considered using the list for filling the box but couldn't figure it out
                    col.categoryCombo.getItems().addAll("Computer Science", "Informatik", "Astrology");
                    col.categoryCombo.setOnAction(event -> {
                        con.onSubjectModuleSelected(col.categoryCombo, columns.get(2).categoryCombo, subjectModules);
                        con.onComboSelected(col.categoryCombo, col.activitySelect, col.area);
                    });
                }
                case "Subject 2" -> {
                        col.categoryCombo.getItems().addAll("Computer Science", "Informatik", "Astrology");
                        col.categoryCombo.setOnAction(event -> { // We figured we have to specify
                            // the second column like this but reckon there's a better way.
                            con.onSubjectModuleSelected(col.categoryCombo, columns.get(1).categoryCombo, subjectModules);
                            con.onComboSelected(col.categoryCombo, col.activitySelect, col.area);
                    });
                }
                case "Elective" -> {
                        col.categoryCombo.setVisible(false); // Hide useless box
                        con.fillElective(col.activitySelect);
                }
            }
        }

        // Define an HBox based on the columns and define the scene based on it.
        HBox root = new HBox(columns.get(0).asVBox(), columns.get(1).asVBox(), columns.get(2).asVBox(), columns.get(3).asVBox());
        Scene scene = new Scene(root, 1000, 500);
        stage.setTitle("Course Selector RUC: Ultimate Deluxe Edition");
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch();
    }

    // Class for each column of activities
    private class ActivityColumn {
        // Each column contains these elements
        String name;
        Label nameLabel;
        ComboBox<String> categoryCombo;
        ComboBox<String> activitySelect;
        TextArea area;
        Label ectsLabel;

        ActivityColumn(String name) {
            this.name = name;
            nameLabel = new Label(name);
            categoryCombo = new ComboBox<>();
            activitySelect = new ComboBox<>();
            area = new TextArea();
            ectsLabel = new Label();
            // new column, "this.name" to define and saved in the text felt,
            // new "nameLabel" to show visual text.
            // CategoryCombo creat a dropdown list
            // activitySelect creat one more dropdown list with Combobox, possible to choose activity.
            // area = new TextArea helps create a text felt to describe the chosen activity
            // ectsLabel = new Label shows text for ects points

        }

        VBox asVBox() {
            return new VBox(nameLabel, categoryCombo, activitySelect, area, ectsLabel);
        }
    }
}
class Controller{
    private Model model;
    private HelloApplication view; // We do this without using the view directly like this, instead passing options.
    void initialize() { // calls on the database
        model.initialize();
    }
    Controller(Model model, HelloApplication view){
        this.model=model; this.view=view;
    }
    void onComboSelected(ComboBox<String> combo, ComboBox<String> select, TextArea area) {
        select.getItems().clear(); // Clear the activity selection box
        area.clear(); // Clear text area
        select.getItems().addAll(model.selectProgram((String) combo.getValue())); // Fill activity box using model method
    }
    void onActivitySelected(ComboBox<String> combo, ComboBox<String> select, TextArea area) {
        addActivity((String) select.getValue(), area); // Passes the value chosen in the box
        updateArea(combo, area); // Updates the text area based on the category choice
        // users can choose from the ComboBox, string (activity) and the area would update.
    }
    void onSubjectModuleSelected(ComboBox<String> subject1, ComboBox<String> subject2, List<String> subjectModules) {
        // Beautiful loop we've created to remove option chosen in one subject module box from the other
        for (String sub : subjectModules) {
            if (sub.equals(subject1.getValue())) {
                subject2.getItems().remove(subject1.getValue());
            } else if (!sub.equals(subject1.getValue()) && !subject2.getItems().contains(sub)) {
                subject2.getItems().add(sub);
            }
        }
    }
    void addActivity(String s, TextArea textArea) { // Calls on model method to add participation in the database
        model.addParticipation(model.getActivityIndeks(s));
    }
    void updateArea(ComboBox combo, TextArea textArea) { // Clears the text area and adds all activity names from activities in participation
        textArea.clear();
        for(String s : model.getParticipation((String) combo.getValue())) {
            textArea.appendText(s + "\n");
        }
    }
    void updateEcts(Label ectslabel, ComboBox<String> comboBox) { // Updates the labels with the current ECTS of the program type
        ectslabel.setText("ECTS: "+model.getSumEcts(comboBox.getValue()));
    }
    void fillElective(ComboBox<String> electiveBox) {
        electiveBox.getItems().addAll(model.getAllActivities());
    }
}

class Model{ // The model handles all interactions with the database
    MyDB db=new MyDB();
    Model(){}
    void initialize() { // When running the program, it clears the participation database
        clearParticipation();
    }
    int getActivityIndeks(String name) { // Returns the integer value of the activity's index
        if(name ==null) return -1;
        ArrayList<String> result = db.query("select indeks from activity a where name is '"+name+"';", "indeks");
        return Integer.parseInt(result.getFirst());

    }
    void addParticipation(int activityIndex) { // Inserts the given activity into participation using the activity's index
        db.cmd("insert into participation values(123, "+activityIndex+");");
    }
    ArrayList<String> getParticipation(String program) { // Returns all activity names from activities currently in participation
        return db.query("select name from participation p inner join activity a on p.indeks = a.indeks where program is '" + program + "';", "name");
    }
    void clearParticipation() { // Removes all entries in the participation database
        db.cmd("delete from participation");
    }
    ArrayList<String> selectProgram(String program) { // Returns an arraylist of activities within the given program
        return db.query("select name from activity where program is '" + program + "';", "name");
    }
    String getSumEcts(String program){ // Returns the sum of ECTS points under the given category from the student as a string
        if(program==null)return "0";
        ArrayList<String> result = db.query("select sum(activity.ects) as total_ects,student.name from student left outer join participation on student.studid = participation.studid inner join activity on participation.indeks = activity.indeks where program is '"+program+"' group by student.studid ;", "total_ects");
        if (result.isEmpty()) return "0";
        return result.getFirst();
    }
    ArrayList<String> getAllActivities() {
        return db.query("select name from activity;", "name");
    }
}

class MyDB { // MyDB is all standard Database configuration that was gotten from Mads
    Connection conn = null;

    MyDB() {
        if (conn == null) open();
    }

    public void open() {
        try {
            String url = "jdbc:sqlite:identifier.sqlite";
            conn = DriverManager.getConnection(url);
        } catch (SQLException e) {
            System.out.println("cannot open");
            if (conn != null) close();
            throw new RuntimeException(e);
        }
        ;
    }

    public void close() {
        try {
            if (conn != null) conn.close();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        conn = null;
    }
    public void cmd(String sql) {
        if (conn == null) open();
        if (conn == null) {
            System.out.println("No connection");
            return;
        }
        Statement stmt = null;
        try {
            stmt = conn.createStatement();
            stmt.executeUpdate(sql);
        } catch (SQLException e) {
            System.out.println("Error in statement " + sql);
            throw new RuntimeException(e);
        }
        try {
            if (stmt != null) {
                stmt.close();
            }
        } catch (SQLException e) {
            System.out.println("Error in statement " + sql);
            throw new RuntimeException(e);
        }
    }

    public ArrayList<String> query(String query, String fld) {
        ArrayList<String> res = new ArrayList<>();
        if (conn == null) open();
        if (conn == null) {
            System.out.println("No connection");
            throw new RuntimeException("No connection");
        }
        Statement stmt = null;
        try {
            stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            while (rs.next()) {
                String name = rs.getString(fld);
                res.add(name);
            }
        } catch (SQLException e) {
            System.out.println("Error in statement " + query + " " + fld);
            throw new RuntimeException(e);
        }
        try {
            if (stmt != null) {
                stmt.close();
            }
        } catch (SQLException e) {
            System.out.println("Error in statement " + query + " " + fld);
            throw new RuntimeException(e);
        }
        return res;
    }
}