MTU-Dining/app/src/main/java/com/thebrokenrail/mtudining/activity/menu/ItemDialog.java

package com.thebrokenrail.mtudining.activity.menu;

import android.app.Dialog;
import android.content.Context;
import android.graphics.Typeface;
import android.os.Bundle;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.style.StyleSpan;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.StringRes;
import androidx.fragment.app.DialogFragment;

import com.google.android.material.dialog.MaterialAlertDialogBuilder;
import com.thebrokenrail.mtudining.R;
import com.thebrokenrail.mtudining.api.method.PeriodDetail;

import java.util.ArrayList;
import java.util.List;

/**
 * Dialog for a food item.
 */
public class ItemDialog {
    private static final String ALLERGEN_FILTER = "allergen";
    private static final String LABEL_FILTER = "label";

    /**
     * Fragment for dialog.
     */
    public static class Fragment extends DialogFragment {
        // Required Public Default Constructor
        public Fragment() {
        }

        private Fragment(CharSequence title, CharSequence message) {
            Bundle arguments = new Bundle();
            arguments.putCharSequence("title", title);
            arguments.putCharSequence("message", message);
            setArguments(arguments);
        }

        @NonNull
        @Override
        public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
            // Create Material Dialog
            Bundle arguments = getArguments();
            assert arguments != null;
            return new MaterialAlertDialogBuilder(requireActivity())
                .setTitle(arguments.getCharSequence("title"))
                .setMessage(arguments.getCharSequence("message"))
                .setPositiveButton(R.string.ok, null)
                .create();
        }
    }

    /**
     * Show dialog.
     * @param context The context
     * @param item The food item to display
     */
    public static void show(Context context, PeriodDetail.Response.Menu.PeriodData.MenuCategory.MenuItem item) {
        // Build Message
        SpannableStringBuilder message = new SpannableStringBuilder(item.desc != null ? item.desc.trim() : "");
        writeNewline(message, 2);
        for (String filterType : new String[]{LABEL_FILTER, ALLERGEN_FILTER}) {
            List<String> filters = getFilters(item, filterType);
            if (filters.size() > 0) {
                writeNewline(message, 2);
                @StringRes int filterName = filterType.equals(LABEL_FILTER) ? R.string.labels : R.string.allergens;
                message.append(context.getString(filterName), new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
                for (String filter : filters) {
                    writeBullet(message, null, filter);
                }
            }
        }
        writeNewline(message, 2);
        if (item.portion != null) {
            message.append(context.getString(R.string.portion), new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            message.append(item.portion);
        }
        writeNewline(message, 2);
        if (item.ingredients != null) {
            message.append(context.getString(R.string.ingredients), new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            message.append(item.ingredients);
        }
        writeNewline(message, 2);
        if (item.nutrients.size() > 0) {
            message.append(context.getString(R.string.nutrients), new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            for (PeriodDetail.Response.Menu.PeriodData.MenuCategory.MenuItem.Nutrient nutrient : item.nutrients) {
                writeBullet(message, nutrient.name, nutrient.value);
            }
        }

        // Remove Newlines From End
        while (message.length() > 0 && message.charAt(message.length() - 1) == '\n') {
            message.delete(message.length() - 1, message.length());
        }

        // Show
        Fragment fragment = new Fragment(item.name, message);
        fragment.show(((MenuActivity) context).getSupportFragmentManager(), "item_" + item.name.hashCode());
    }

    /**
     * Get filters of a specific type in food item.
     * @param item The item
     * @param type The filter type
     * @return List of filters
     */
    private static List<String> getFilters(PeriodDetail.Response.Menu.PeriodData.MenuCategory.MenuItem item, String type) {
        List<String> out = new ArrayList<>();
        if (item.filters != null) {
            for (PeriodDetail.Response.Menu.PeriodData.MenuCategory.MenuItem.Filter filter : item.filters) {
                if (filter.type.equals(type)) {
                    out.add(filter.name);
                }
            }
        }
        return out;
    }

    /**
     * Write bullet point to string.
     * @param message The string to modify
     * @param name The first part
     * @param value The second part
     */
    private static void writeBullet(SpannableStringBuilder message, String name, String value) {
        writeNewline(message, 1);
        message.append("• ", new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        if (name != null) {
            message.append(name + ": ", new StyleSpan(Typeface.BOLD), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        if (value != null) {
            message.append(value);
        }
    }

    /**
     * Write newline to string.
     * @param message The string to modify
     * @param count The amount of newlines to write
     */
    private static void writeNewline(SpannableStringBuilder message, int count) {
        if (message.length() > 0) {
            int existingCount = 0;
            for (int i = message.length() - 1; i >= 0; i--) {
                if (message.charAt(i) == '\n') {
                    existingCount++;
                } else {
                    break;
                }
            }
            count -= existingCount;
            if (count > 0) {
                for (int i = 0; i < count; i++) {
                    message.append('\n');
                }
            }
        }
    }
}