package com.example.model;

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

/**
 * 分页响应类
 */
public class PageResponse<T> {
    private int page;
    private int size;
    private long total;
    private List<T> data;

    public PageResponse() {
        this.data = new ArrayList<>();
    }

    public PageResponse(int page, int size, long total, List<T> data) {
        this.page = page;
        this.size = size;
        this.total = total;
        this.data = data != null ? data : new ArrayList<>();
    }

    public static <T> PageResponse<T> of(PageRequest request, long total, List<T> data) {
        return new PageResponse<>(request.getPage(), request.getSize(), total, data);
    }

    public int getPage() {
        return page;
    }

    public void setPage(int page) {
        this.page = page;
    }

    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    public long getTotal() {
        return total;
    }

    public void setTotal(long total) {
        this.total = total;
    }

    public List<T> getData() {
        return data;
    }

    public void setData(List<T> data) {
        this.data = data != null ? data : new ArrayList<>();
    }

    public int getTotalPages() {
        return size == 0 ? 0 : (int) Math.ceil((double) total / (double) size);
    }

    public boolean isHasNext() {
        return page < getTotalPages();
    }

    public boolean isHasPrevious() {
        return page > 1;
    }

    @Override
    public String toString() {
        return "PageResponse{" +
                "page=" + page +
                ", size=" + size +
                ", total=" + total +
                ", data=" + data +
                '}';
    }
}