/**
 * Renderer 一致性测试（对应设计文档 §15 的
 * "HTML、SVG、PDF Renderer 的公共布局结果一致性测试"）。
 *
 * 核心断言：同一份 LayoutDocument 经 HTML / SVG 渲染后，
 * 分页结构一致（页数相同、节点都能找到）。
 */
import { describe, expect, it } from "vitest"
import { createDocument, createTableElement, type ReportDocument } from "@report/core"
import { createEstimateMeasurer, createPassthroughFontResolver } from "@report/layout"
import { layoutDocument } from "@report/layout"
import { renderHtml, renderSvg, createPdfRenderer } from "../src/index.js"
import type { RenderContext } from "@report/layout"

const measurer = createEstimateMeasurer()
const fontResolver = createPassthroughFontResolver()

async function layout(doc: ReportDocument, context: RenderContext) {
  return layoutDocument(doc, context, { textMeasurer: measurer, fontResolver })
}

/** 构造一份含页眉、文本、明细表、页脚的报表文档。 */
function sampleDoc(): ReportDocument {
  const doc = createDocument({ name: "渲染测试" })
  doc.datasets = { sales: { id: "sales" } }

  const header = doc.sections.find((s) => s.kind === "page-header")!
  header.children.push({
    id: "h1",
    type: "text",
    frame: { x: 0, y: 0, width: 100, height: 8 },
    props: { text: "销售单" },
  })

  const detail = doc.sections.find((s) => s.kind === "detail")!
  detail.children.push(
    createTableElement("tbl1", { x: 0, y: 0, width: 180, height: 20 }, "sales", [
      { id: "c1", width: 90, header: "商品", binding: { field: "name" } },
      { id: "c2", width: 90, header: "金额", binding: { field: "amount" }, align: "right" },
    ]),
  )

  const footer = doc.sections.find((s) => s.kind === "page-footer")!
  footer.children.push({
    id: "f1",
    type: "text",
    frame: { x: 0, y: 0, width: 100, height: 6 },
    binding: { expression: "'第 ' + page.pageNumber + ' 页'" },
  })

  return doc
}

const ROWS = [
  { name: "苹果", amount: 100 },
  { name: "香蕉", amount: 200 },
  { name: "橙子", amount: 300 },
]

describe("HTML / SVG 分页一致性", () => {
  it("同一文档渲染为 HTML 与 SVG 时页数一致", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const html = renderHtml(result)
    const svg = renderSvg(result)

    expect(html.target).toBe("html")
    expect(svg.target).toBe("svg")
    expect(html.pageCount).toBe(result.pageCount)
    expect(svg.pageCount).toBe(result.pageCount)
    expect(html.pageCount).toBe(svg.pageCount)
  })

  it("HTML 输出包含与页数一致的 .rd-page 容器", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const html = renderHtml(result)
    const pageCount = (html.content.match(/class="rd-page"/g) ?? []).length
    expect(pageCount).toBe(result.pageCount)
  })

  it("SVG 输出包含与页数一致的 <svg> 元素", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const svg = renderSvg(result)
    const svgCount = (svg.content.match(/<svg /g) ?? []).length
    expect(svgCount).toBe(result.pageCount)
  })

  it("文本节点在 HTML 与 SVG 中都被渲染", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const html = renderHtml(result)
    const svg = renderSvg(result)

    // 页眉文本 "销售单" 应出现在两种输出中
    expect(html.content).toContain("销售单")
    expect(svg.content).toContain("销售单")
  })

  it("明细表数据在 HTML 与 SVG 中都被渲染", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const html = renderHtml(result)
    const svg = renderSvg(result)

    expect(html.content).toContain("苹果")
    expect(html.content).toContain("橙子")
    expect(svg.content).toContain("苹果")
    expect(svg.content).toContain("橙子")
  })

  it("页脚页码占位符在渲染前已被替换", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const html = renderHtml(result)
    // 页脚应有 "第 1 页" 而非原始占位符
    expect(html.content).toContain("第 1 页")
    expect(html.content).not.toContain("{pageNumber}")
  })
})

describe("多页渲染", () => {
  it("多页文档在 HTML 与 SVG 中页数一致", async () => {
    const doc = sampleDoc()
    const manyRows = Array.from({ length: 200 }, (_, i) => ({
      name: `商品${i}`,
      amount: i,
    }))
    const result = await layout(doc, { data: { sales: manyRows }, parameters: {} })

    expect(result.pageCount).toBeGreaterThan(1)

    const html = renderHtml(result)
    const svg = renderSvg(result)

    const htmlPages = (html.content.match(/class="rd-page"/g) ?? []).length
    const svgPages = (svg.content.match(/<svg /g) ?? []).length

    expect(htmlPages).toBe(result.pageCount)
    expect(svgPages).toBe(result.pageCount)
  })
})

describe("SVG 输出结构", () => {
  it("SVG 使用 mm 标注宽度和 viewBox", async () => {
    const doc = sampleDoc()
    const result = await layout(doc, { data: { sales: ROWS }, parameters: {} })

    const svg = renderSvg(result)
    const page = result.pages[0]!
    // width 与 height 用 mm，viewBox 用无单位数值
    expect(svg.content).toContain(`width="${page.width}mm"`)
    expect(svg.content).toContain(`viewBox="0 0 ${page.width} ${page.height}"`)
  })

  it("矩形节点渲染为 <rect>", async () => {
    const doc = createDocument({ name: "矩形测试" })
    const detail = doc.sections.find((s) => s.kind === "detail")!
    detail.children.push({
      id: "r1",
      type: "rect",
      frame: { x: 5, y: 5, width: 50, height: 20 },
    })
    const result = await layout(doc, { data: {}, parameters: {} })

    const svg = renderSvg(result)
    expect(svg.content).toContain("<rect")
    expect(svg.content).toContain('id="r1"')
  })
})

describe("PDF 后端契约", () => {
  it("未配置后端时返回诊断而非抛异常", () => {
    const result = createPdfRenderer().render({
      pages: [],
      diagnostics: [],
      pageCount: 0,
    })
    expect(result.target).toBe("pdf")
    expect(result.bytes).toBeInstanceOf(Uint8Array)
    expect(result.bytes.length).toBe(0)
    expect(result.diagnostics.some((d) => d.code === "render.pdf-backend-missing")).toBe(true)
  })

  it("后端抛错时返回错误诊断", () => {
    const backend = {
      name: "mock",
      render: () => {
        throw new Error("boom")
      },
    }
    const result = createPdfRenderer(backend).render({
      pages: [],
      diagnostics: [],
      pageCount: 0,
    })
    expect(result.diagnostics.some((d) => d.code === "render.pdf-backend-error")).toBe(true)
  })

  it("后端正常时返回字节", () => {
    const backend = {
      name: "mock",
      render: () => new Uint8Array([1, 2, 3]),
    }
    const result = createPdfRenderer(backend).render({
      pages: [],
      diagnostics: [],
      pageCount: 0,
    })
    expect(result.bytes.length).toBe(3)
    expect(result.diagnostics).toHaveLength(0)
  })
})