import java.util.List;
import java.util.Scanner;

/**
 * View: 所有 I/O 集中在这里，颜色常量统一管理
 * 选做暗色主题：只需改 THEME_PRIMARY / THEME_SECONDARY 两个常量即可
 */
public class ConsoleView {

    // ── ANSI 基础色 ──
    private static final String ANSI_RESET  = "\033[0m";
    private static final String ANSI_GREEN  = "\033[32m";
    private static final String ANSI_RED    = "\033[31m";
    private static final String ANSI_YELLOW = "\033[33m";
    private static final String ANSI_CYAN   = "\033[36m";
    private static final String ANSI_BOLD   = "\033[1m";

    // ── 选做：主题常量（暗色主题只改这两行）──
    private static final String THEME_PRIMARY   = ANSI_CYAN;    // 暗色主题可换 ANSI_GREEN
    private static final String THEME_SECONDARY = ANSI_YELLOW;  // 暗色主题可换 ANSI_CYAN

    private final Scanner scanner = new Scanner(System.in);

    public void printSuccess(String msg) {
        System.out.println(ANSI_GREEN + msg + ANSI_RESET);
    }

    public void printError(String msg) {
        System.out.println(ANSI_RED + "[ERROR] " + msg + ANSI_RESET);
    }

    public void printInfo(String msg) {
        System.out.println(THEME_PRIMARY + msg + ANSI_RESET);
    }

    public void printWarning(String msg) {
        System.out.println(THEME_SECONDARY + "[WARN] " + msg + ANSI_RESET);
    }

    public void printBold(String msg) {
        System.out.println(ANSI_BOLD + msg + ANSI_RESET);
    }

    /** 展示文章列表 */
    public void display(List<Article> articles) {
        if (articles.isEmpty()) {
            printWarning("暂无文章，请先使用 crawl <url> 抓取。");
            return;
        }
        printBold("── 文章列表 (" + articles.size() + " 篇) ──");
        for (int i = 0; i < articles.size(); i++) {
            Article a = articles.get(i);
            if (a == null) {
                printWarning((i + 1) + ". [null 条目，已跳过]");
                continue;
            }
            System.out.printf(THEME_PRIMARY + "%2d. %s" + ANSI_RESET + "%n", i + 1, a);
        }
    }

    /** 读取一行用户输入，显示提示符 */
    public String readLine() {
        System.out.print(ANSI_BOLD + "> " + ANSI_RESET);
        return scanner.nextLine().trim();
    }
}