package ui;

import model.ca.Template;

/**
 * The screen that allows users to list templates and manage them.
 */
public class TemplatesScreen implements UIHandler {
    private final JCA session;

    /**
     * EFFECTS: Init with the session.
     */
    public TemplatesScreen(JCA session) {
        this.session = session;
    }

    /**
     * EFFECTS: Print help.
     */
    @Override
    public void help() {
        System.out.println("show\tList templates\n"
                + "add\tCreate a new template\n"
                + "enable\tEnable a template\n"
                + "disable\tDisable a template\n"
                + "delete\tDelete a template\n"
                + "exit\tGo to main menu\n"
                + "help\tPrint this message");
    }

    /**
     * EFFECTS: List templates in Name[ENABLED / DISABLED] Subject Validity format.
     */
    @Override
    public void show() {
        session.getTemplates().forEach(tem ->
                System.out.printf("%s[%s]\t%s\t%d Days\n",
                        tem.getName(),
                        tem.isEnabled() ? "ENABLED" : "DISABLED",
                        tem.getSubject(),
                        tem.getValidity()));
    }

    /**
     * EFFECTS: Create a new template with the given name and switch to the template set screen.
     */
    private void handleAdd(String... args) {
        if (args.length <= 1) {
            System.out.println("Usage: add <name>");
            return;
        }
        if (session.findTemplate(args[1], false) != null) {
            System.out.println("The template already exists.");
            return;
        }

        session.setScreen(Screen.TEMPLATE_SET,
                new Template(args[1], false, null, 30));
    }

    /**
     * EFFECTS: Handle the enable / disable commands.
     * MODIFIES: session
     */
    private void handleEnableDisable(boolean enable, String... args) {
        if (args.length <= 1) {
            System.out.printf("Usage: %s <template>\n", enable ? "enable" : "disable");
            return;
        }
        Template tmp = session.findTemplate(args[1], false);
        if (tmp == null) {
            System.out.println("Cannot find the template specified");
            return;
        }
        tmp.setEnabled(enable);
        session.log("A template was enabled / disabled.");
    }

    /**
     * EFFECTS: Handle the delete command
     * MODIFIES: session
     */
    private void handleDelete(String... args) {
        if (args.length <= 1) {
            System.out.println("Usage: delete <template>");
            return;
        }
        Template tmp = session.findTemplate(args[1], true);
        if (tmp == null) {
            System.out.println("Cannot find the template specified");
            return;
        }
        session.getTemplates().remove(tmp);
        session.log("A template was deleted.");
    }

    /**
     * EFFECTS: Handle commands.
     */
    @Override
    public void command(String... args) {
        switch (args[0]) {
            case "add":
                handleAdd(args);
                break;
            case "enable":
                handleEnableDisable(true, args);
                break;
            case "disable":
                handleEnableDisable(false, args);
                break;
            case "delete":
                handleDelete(args);
                break;
            default:
                help();
                break;
        }
    }

    /**
     * EFFECTS: Go to main menu.
     */
    @Override
    public Screen exit() {
        return Screen.MAIN;
    }

    /**
     * EFFECTS: Return "/templates/ %"
     */
    @Override
    public String getPS1() {
        return "/templates/ %";
    }
}