package com.yunhai.flowcenter.service;

import com.yunhai.flowcenter.model.FlowModels;
import org.junit.jupiter.api.Test;

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

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
import static org.junit.jupiter.api.Assertions.assertNotEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * 流程图服务端出图（2026-09-16 "CAS 验证码式嵌入"）：
 * renderPng 恒出非空 PNG；布局对环/孤儿/缺失端点防御出图（外部 img 场景无错误页可跳）。
 */
class DiagramImageServiceTest {

    private final DiagramImageService service = new DiagramImageService(new DiagramLayoutService());

    private FlowModels.NodeVo node(String id, String type, String label, String sub, String state) {
        FlowModels.NodeVo n = new FlowModels.NodeVo();
        n.setId(id);
        n.setType(type);
        n.setLabel(label);
        n.setSubLabel(sub);
        n.setState(state);
        return n;
    }

    private FlowModels.EdgeVo edge(String from, String to, String name) {
        FlowModels.EdgeVo e = new FlowModels.EdgeVo();
        e.setFrom(from);
        e.setTo(to);
        e.setName(name);
        return e;
    }

    private FlowModels.DiagramVo vo(List<FlowModels.NodeVo> nodes, List<FlowModels.EdgeVo> edges) {
        FlowModels.DiagramVo vo = new FlowModels.DiagramVo();
        vo.setName("教师入职审批");
        vo.setMode("auto");
        vo.setNodes(nodes);
        vo.setEdges(edges);
        return vo;
    }

    @Test
    void render_instanceVo_producesPngWithStateColors() {
        List<FlowModels.NodeVo> nodes = new ArrayList<>(Arrays.asList(
                node("n1", "START", "开始", null, null),
                node("n2", "APPROVAL", "审核节点", "张三、李四 · 任一人通过", null),
                node("n3", "APPROVAL", "科室审批", "教学处 · 3人 · 时限24h", "active"),
                node("n4", "END", "结束", null, null)));
        List<FlowModels.EdgeVo> edges = new ArrayList<>(Arrays.asList(
                edge("n1", "n2", null), edge("n2", "n3", null), edge("n3", "n4", null)));
        byte[] png = service.renderPng(vo(nodes, edges));
        // PNG 头 89 50 4E 47
        assertEquals(0x89, png[0] & 0xFF);
        assertEquals(0x50, png[1] & 0xFF);
        assertTrue(png.length > 2000, "渲染结果过小，疑似空图");
        // 状态无关的纯定义图也恒出图（flowGuid 口径）
        for (FlowModels.NodeVo n : nodes) {
            n.setState(null);
        }
        assertNotEquals(0, service.renderPng(vo(nodes, edges)).length);
    }

    @Test
    void smoke_writeSamplePng_forVisualCheck() throws Exception {
        List<FlowModels.NodeVo> nodes = new ArrayList<>(Arrays.asList(
                node("n1", "START", "开始", null, null),
                node("n2", "APPROVAL", "教师入职审批", "刘文娟 · 时限48h", "done"),
                node("n3", "APPROVAL", "科室审批", "教学处 · 云海小学001 · 任一人通过 · 时限24h", "active"),
                node("n4", "END", "结束", null, null)));
        List<FlowModels.EdgeVo> edges = new ArrayList<>(Arrays.asList(
                edge("n1", "n2", null), edge("n2", "n3", "同意"), edge("n3", "n4", null)));
        java.nio.file.Files.write(
                java.nio.file.Paths.get("target", "diagram-smoke.png"),
                service.renderPng(vo(nodes, edges)));
    }

    @Test
    void render_defensive_missingEndpointAndCycle_stillProducesImage() {
        // 成环 + 指向不存在端点的边：不抛，仍出图（外部 img 场景防御）
        List<FlowModels.NodeVo> nodes = new ArrayList<>(Arrays.asList(
                node("n1", "START", "开始", null, null),
                node("n2", "APPROVAL", "审核节点", null, "done"),
                node("n3", "APPROVAL", "孤儿节点", null, null)));
        List<FlowModels.EdgeVo> edges = new ArrayList<>(Arrays.asList(
                edge("n1", "n2", null), edge("n2", "n1", null), edge("n2", "ghost", null)));
        assertDoesNotThrow(() -> service.renderPng(vo(nodes, edges)));
    }
}