package cn.iocoder.yudao.module.qcreport.service.render;

import cn.iocoder.yudao.module.qcreport.engine.PageMargin;
import cn.iocoder.yudao.module.qcreport.engine.PageSetting;
import cn.iocoder.yudao.module.qcreport.engine.PageSizes;
import cn.iocoder.yudao.module.qcreport.engine.ResolvedPage;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

import java.util.Arrays;
import java.util.List;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * 打印参数换算。
 * <p>
 * 这里守的是一条很容易悄悄坏掉的约束：**PDF 的纸面几何必须与 HTML 里那行 @page 逐字相同**。
 * 两者一旦漂移，表现不是报错，而是「页面预览正常、打出来裁掉一截」——
 * 这种偏差肉眼很难在几十个项目里发现，所以用同源断言把它钉死在单测里。
 */
class PdfPrintOptionsTest {

    @Test
    @DisplayName("常见纸张与方向换算成 mm")
    void sizes() {
        assertEquals(List.of("210mm", "297mm"), size(PdfPrintOptions.of(a4(), true)));
        assertEquals(List.of("420mm", "297mm"), size(PdfPrintOptions.of(a3Landscape(), true)));
        assertEquals(List.of("148mm", "210mm"), size(PdfPrintOptions.of(a5(), true)));
    }

    @Test
    @DisplayName("Letter 的 215.9mm 不被收成整数")
    void letterKeepsDecimal() {
        PageSetting page = new PageSetting("Letter", "portrait", PageMargin.none());
        assertEquals(List.of("215.9mm", "279.4mm"), size(PdfPrintOptions.of(page, true)));
    }

    @Test
    @DisplayName("未配纸张时回退到默认 A4 纵向")
    void fallbackToDefault() {
        assertEquals(List.of("210mm", "297mm"),
                size(PdfPrintOptions.of(PageSetting.defaultSetting(), true)));
    }

    @Test
    @DisplayName("未配页边距时四周都是默认 10mm，配了就原样透传")
    void margins() {
        assertEquals(List.of("10mm", "10mm", "10mm", "10mm"), margins(PdfPrintOptions.of(a4(), true)));

        PageSetting custom = new PageSetting("A4", "portrait", new PageMargin(5.5, 20.0, 12.0, 20.5));
        assertEquals(List.of("5.5mm", "20mm", "12mm", "20.5mm"),
                margins(PdfPrintOptions.of(custom, true)));

        // 只配了一边，其余仍落到默认值：与前端 margin?.top ?? DEFAULT 的语义一致
        PageSetting partial = new PageSetting("A4", "portrait", new PageMargin(25.0, null, null, null));
        assertEquals(List.of("25mm", "10mm", "10mm", "10mm"), margins(PdfPrintOptions.of(partial, true)));
    }

    @Test
    @DisplayName("纸面几何与 @page 同源：宽度+高度与四边距必须逐字等于 ResolvedPage 的输出")
    void geometryMatchesCssPage() {
        List<PageSetting> cases = List.of(
                PageSetting.defaultSetting(), a4(), a3Landscape(), a5(),
                new PageSetting("Letter", "landscape", new PageMargin(3.0, 4.5, 5.0, 6.0)),
                new PageSetting("A4", "portrait", new PageMargin(0.0, 0.0, 0.0, 0.0)));
        for (PageSetting page : cases) {
            PdfPrintOptions options = PdfPrintOptions.of(page, true);
            ResolvedPage resolved = PageSizes.resolve(page);
            assertEquals(resolved.cssSize(), options.widthCss() + " " + options.heightCss(),
                    "纸面宽高与 @page 的 size 不一致，page=" + page);
            assertEquals(resolved.cssMargin(), options.marginTopCss() + " " + options.marginRightCss()
                            + " " + options.marginBottomCss() + " " + options.marginLeftCss(),
                    "页边距与 @page 的 margin 不一致，page=" + page);
        }
    }

    @Test
    @DisplayName("页脚模板：开启时带页码占位符，关闭时为空串")
    void footerTemplate() {
        String withPageNumber = PdfPrintOptions.of(a4(), true).footerTemplate();
        assertTrue(withPageNumber.contains("pageNumber"), "页脚缺少当前页码占位符");
        assertTrue(withPageNumber.contains("totalPages"), "页脚缺少总页数占位符");
        assertTrue(withPageNumber.contains("font-size"), "页脚没带字号，浏览器会按 0 号字处理，等于看不见");

        assertEquals("", PdfPrintOptions.of(a4(), false).footerTemplate());
    }

    @Test
    @DisplayName("页眉模板非空：留空会让 Chromium 补上它自带的「打印日期 + 文档标题」")
    void headerTemplateMustNotBeEmpty() {
        String header = PdfPrintOptions.HEADER_TEMPLATE;
        assertTrue(header != null && !header.isBlank(),
                "页眉模板为空/null 时 Chromium 会打印自带的日期与标题，报告上会多出没人要的时间戳");
        assertFalse(header.contains("class=\"date\""), "页眉里不该出现 Chromium 的日期占位类");
        assertFalse(header.contains("class=\"title\""), "页眉里不该出现 Chromium 的标题占位类");
    }

    @Test
    @DisplayName("打印加固样式：跨页重复表头 + 打印背景色")
    void printCss() {
        String printCss = PdfPrintOptions.of(a4(), true).printCss();
        assertTrue(printCss.contains("table-header-group"), "缺少跨页重复表头，长表格第二页会没有表头");
        assertTrue(printCss.contains("break-inside"), "缺少禁止行内断页，一行会从中间劈开");
        assertTrue(printCss.contains("print-color-adjust"), "缺少打印背景色，判定结果的底色打不出来");
        assertFalse(printCss.contains("@page"), "打印样式里不该再写 @page：纸面几何的唯一权威是 HTML 里那一行");
    }

    @Test
    @DisplayName("长表允许跨页：break-inside:avoid 只加在行/单元格/图片上，绝不能加在整张表上")
    void longTableMayBreakAcrossPages() {
        List<String> guarded = selectorsDeclaring(PdfPrintOptions.of(a4(), true).printCss(), "break-inside");
        assertFalse(guarded.contains("table"),
                "整张表禁止断页会把放不下的长表整体推到下一页，第 1 页只剩页眉与大片空白；"
                        + "跨页要靠 thead 每页重复表头 + 行内不断页，不能靠把整张表搬走");
        assertTrue(guarded.contains("tr"), "行内禁止断页不能一并去掉，否则一行会从中间劈开");
        assertTrue(guarded.contains("thead") || PdfPrintOptions.of(a4(), true).printCss()
                        .contains("table-header-group"),
                "表头必须在每页重复，否则第 2 页起的表格没有列名");
    }

    /** 取出声明了指定属性的那条规则的「选择器列表」；没有这样的规则时返回空列表。 */
    private static List<String> selectorsDeclaring(String css, String property) {
        for (String rule : css.split("}")) {
            int brace = rule.indexOf('{');
            if (brace < 0 || !rule.substring(brace + 1).contains(property + ":")) {
                continue;
            }
            return Arrays.stream(rule.substring(0, brace).split(","))
                    .map(String::trim).filter(selector -> !selector.isEmpty()).toList();
        }
        return List.of();
    }

    private static PageSetting a4() {
        return new PageSetting("A4", "portrait", PageMargin.none());
    }

    private static PageSetting a3Landscape() {
        return new PageSetting("A3", "landscape", PageMargin.none());
    }

    private static PageSetting a5() {
        return new PageSetting("A5", "portrait", PageMargin.none());
    }

    private static List<String> size(PdfPrintOptions options) {
        return List.of(options.widthCss(), options.heightCss());
    }

    private static List<String> margins(PdfPrintOptions options) {
        return List.of(options.marginTopCss(), options.marginRightCss(),
                options.marginBottomCss(), options.marginLeftCss());
    }

}