import { fitLine, type FlowNode, type FlowTone, type FlowVariant } from "./flow-layout";

/**
 * 流程图节点/连线的共用画笔:FlowDiagram(diagram-js 渲染)与 FlowEditor(手绘编辑)
 * 都从这里取形——同一套配色/字级/几何,编辑态与展示态不许有视觉漂移。
 */

const svgNS = "http://www.w3.org/2000/svg";

export function svgEl<K extends keyof SVGElementTagNameMap>(
  tag: K,
  attrs: Record<string, string | number>,
  text?: string,
): SVGElementTagNameMap[K] {
  const el = document.createElementNS(svgNS, tag);
  for (const [key, value] of Object.entries(attrs)) el.setAttribute(key, String(value));
  if (text !== undefined) el.textContent = text;
  return el;
}

export const FLOW_SANS = '"PingFang SC","Noto Sans SC","Hiragino Sans GB","Microsoft YaHei",sans-serif';
export const FLOW_MONO = '"SF Mono","JetBrains Mono",Menlo,ui-monospace,monospace';

export const TONE_COLOR: Record<FlowTone, string> = { main: "#46586A", ok: "#3F7A5C", bad: "#B0413E" };

/** 节点画形(往 group 里追加图元;调用方自己定位 group)。 */
export function paintNode(group: SVGElement, node: FlowNode, w: number, h: number, variant: FlowVariant): void {
  if (node.kind === "start" || node.kind === "end" || node.kind === "end-bad") {
    const bad = node.kind === "end-bad";
    group.append(
      svgEl("circle", {
        cx: w / 2,
        cy: h / 2,
        r: w / 2,
        fill: bad ? "#F6E7E6" : "#E6F1EA",
        stroke: bad ? "#B0413E" : "#3F7A5C",
        "stroke-width": node.kind === "start" ? 1.8 : bad ? 2.4 : 2.6,
      }),
    );
  } else if (node.kind === "gateway") {
    const hd = w / 2;
    // 2026-07 精简:网关无弹窗、无铜点——判据存于节点数据,导出派生表与 L3 upstreamGates 承接。
    group.append(
      svgEl("polygon", {
        points: `${hd},0 ${w},${hd} ${hd},${h} 0,${hd}`,
        fill: "#EEF1F5",
        stroke: "#46586A",
        "stroke-width": 1.3,
      }),
    );
    group.append(
      svgEl(
        "text",
        {
          x: hd,
          y: hd + 4,
          "text-anchor": "middle",
          "font-family": FLOW_MONO,
          "font-size": variant === "business" ? 13 : 12,
          "font-weight": 700,
          fill: "#46586A",
        },
        node.mode === "and" ? "+" : "×",
      ),
    );
  } else if (node.kind === "callout") {
    // 卡点统一红(绿色让位给 Case 活动节点);去向以框内 →id 表达。
    group.append(
      svgEl("rect", {
        x: 0,
        y: 0,
        width: w,
        height: h,
        rx: variant === "business" ? 5 : 6,
        fill: "#F6E7E6",
        stroke: "#B0413E",
        "stroke-width": variant === "business" ? 1.2 : 1.3,
      }),
    );
    const fitted = fitLine(
      node.to ? `${node.label}→${node.to}` : node.label,
      w - 12,
      variant === "business" ? 10 : 11.5,
      9,
    );
    group.append(
      svgEl(
        "text",
        {
          x: w / 2,
          y: h / 2 + 3.5,
          "text-anchor": "middle",
          "font-family": FLOW_SANS,
          "font-size": fitted.size,
          "font-weight": 600,
          fill: "#8F3330",
        },
        fitted.text,
      ),
    );
  } else {
    // 方框三色:标准活动 浅蓝(缺省)/ 案例活动 绿(一事一议)/ 审批点 琥珀(人裁节点)。
    // 审批点非活动,只是共用方框几何——模型上它是系统内置的编排要素(见 flow-layout 的 flavor 注释)。
    // 活动调用已整体退役(2026-07 终拍:所有节点都是内置节点;schema 容忍遗留 wait 但不再有专属画法)。
    const ghost = node.ghost === true;
    const isCase = node.flavor === "case";
    const isApproval = node.flavor === "approval";
    const skin = isApproval
      ? { fill: "#FBF0DC", stroke: "#B98432", ink: "#6E4B12" }
      : isCase
        ? { fill: "#E6F1EA", stroke: "#3F7A5C", ink: "#2F5C45" }
        : { fill: "#E8F1FB", stroke: "#4E7DAF", ink: "#161B22" };
    group.append(
      svgEl("rect", {
        x: 0,
        y: 0,
        width: w,
        height: h,
        rx: 6,
        fill: ghost ? "#F4F6F9" : skin.fill,
        stroke: ghost ? "#9AA6B4" : skin.stroke,
        "stroke-width": ghost ? 1.2 : 1.3,
        ...(ghost ? { "stroke-dasharray": "4 3" } : {}),
      }),
    );
    const titleSize = variant === "business" ? 12 : 11.5;
    const inkColor = ghost ? "#6A7686" : skin.ink;
    const title = fitLine(node.label, w - 12, titleSize, 10);
    // L2 主图只留 标号/活动名/责任角标(2026-07 精简)——sub 小字仅步骤图(steps)渲染。
    if (node.sub && variant !== "business") {
      const sub = fitLine(node.sub, w - 12, 8.6, 8);
      group.append(
        svgEl(
          "text",
          { x: w / 2, y: 18, "text-anchor": "middle", "font-family": FLOW_SANS, "font-size": title.size, "font-weight": 600, fill: inkColor },
          title.text,
        ),
      );
      group.append(
        svgEl(
          "text",
          { x: w / 2, y: 32, "text-anchor": "middle", "font-family": FLOW_SANS, "font-size": sub.size, fill: ghost ? "#9AA6B4" : "#6A7686" },
          sub.text,
        ),
      );
    } else {
      group.append(
        svgEl(
          "text",
          { x: w / 2, y: h / 2 + 4, "text-anchor": "middle", "font-family": FLOW_SANS, "font-size": title.size, "font-weight": 600, fill: inkColor },
          title.text,
        ),
      );
    }
    // 标号角标:business 一贯有;步骤图(steps)的真实节点也要 S#/B# 编号与指导书条目对齐
    // (2026-07 用户纠正)——ghost 骨架节点不标。
    if (variant === "business" || !ghost) {
      group.append(
        svgEl("text", { x: 6, y: 11, "font-family": FLOW_MONO, "font-size": 8.5, fill: "#8A93A0" }, node.code ?? node.id),
      );
    }
    /* 责任人角标已退役(2026-07-30):编排不带岗位 —— 谁来干是运营时分配的,不画在图上。 */
    // 分工角标已随词签退役(2026-07 user「删除 AI/系统/人 选项配置」):步骤图不再画 assign 角标。
  }
}

/** 箭头三角(按折线最后一段方向)。 */
export function arrowHeadPoints(waypoints: Array<{ x: number; y: number }>): string {
  const tip = waypoints[waypoints.length - 1];
  const prev = waypoints[waypoints.length - 2];
  // 严格索引:两点以下画不出箭头,直接退空(布局引擎不会产出这种连线,此处只为类型闭合)
  if (tip === undefined || prev === undefined) return "";
  const dx = Math.sign(tip.x - prev.x);
  const dy = Math.sign(tip.y - prev.y);
  return dx !== 0
    ? `${tip.x},${tip.y} ${tip.x - dx * 9},${tip.y - 4.5} ${tip.x - dx * 9},${tip.y + 4.5}`
    : `${tip.x},${tip.y} ${tip.x - 4.5},${tip.y - dy * 9} ${tip.x + 4.5},${tip.y - dy * 9}`;
}

export const CAPTION_STYLE: Record<string, { fill: string; size: (v: FlowVariant) => number; font: string; weight?: number }> = {
  gateway: { fill: "#3A4452", size: (v) => (v === "business" ? 10 : 9), font: FLOW_SANS, weight: 600 },
  start: { fill: "#3F7A5C", size: (v) => (v === "business" ? 10 : 8.6), font: FLOW_SANS, weight: 600 },
  end: { fill: "#2F5C45", size: (v) => (v === "business" ? 10 : 8.6), font: FLOW_SANS, weight: 600 },
  "end-bad": { fill: "#8F3330", size: (v) => (v === "business" ? 10 : 8.6), font: FLOW_SANS, weight: 600 },
  note: { fill: "#8A5F1C", size: (v) => (v === "business" ? 9.8 : 8.6), font: FLOW_MONO },
};