import type { DocPageLayout } from "@/lib/drive/doc-page-setup"
import { buildParagraphStylesCss } from "@/lib/drive/docs-paragraph-styles-css"
import type { DocParagraphStylesCatalog } from "@/lib/drive/docs-paragraph-styles"
import type { DocsExportSnapshot } from "@/lib/drive/docs-export-snapshot"
import { DOCS_PAGE_GAP_PX } from "@/lib/drive/docs-page-layout-constants"

const PRINT_STYLE_ID = "docs-print-dynamic-styles"
const PRINT_IFRAME_ID = "docs-print-iframe"

function buildPageRule(pageLayout: DocPageLayout): string {
  const wMm = pageLayout.format.widthMm
  const hMm = pageLayout.format.heightMm
  const landscape = pageLayout.format.widthMm > pageLayout.format.heightMm
  const size = landscape ? `${hMm}mm ${wMm}mm` : `${wMm}mm ${hMm}mm`
  return `@page { size: ${size}; margin: 0; }`
}

function buildPrintLayoutRules(pageLayout: DocPageLayout): string {
  const pageWidth = pageLayout.widthPx
  const pageHeight = pageLayout.heightPx
  return `
    html, body {
      margin: 0 !important;
      padding: 0 !important;
      background: white !important;
      width: ${pageWidth}px !important;
      min-height: 0 !important;
      overflow: visible !important;
    }

    .docs-print-root {
      margin: 0 !important;
      padding: 0 !important;
      width: ${pageWidth}px !important;
      background: white !important;
    }

    [data-docs-page-stack] {
      position: relative !important;
      left: 0 !important;
      top: 0 !important;
      transform: none !important;
      transform-origin: top left !important;
      width: ${pageWidth}px !important;
      margin: 0 !important;
    }

    .ultidrive-docs-page {
      width: ${pageWidth}px !important;
      height: ${pageHeight}px !important;
      box-shadow: none !important;
      border: none !important;
      break-after: page;
      page-break-after: always;
      print-color-adjust: exact;
      -webkit-print-color-adjust: exact;
    }

    .ultidrive-docs-page:last-child {
      break-after: auto;
      page-break-after: auto;
    }

    .docs-body-margin-mask {
      border-color: transparent !important;
    }

    .docs-hf-chrome,
    .docs-graphic-handle,
    .docs-graphic-rotate-handle,
    .docs-graphic-outline,
    .docs-graphic-snap-guides {
      display: none !important;
    }

    .docs-hf-band .docs-region-editor-root {
      border: none !important;
      background: transparent !important;
    }
  `
}

type StyleRestore = () => void

function patchInlineStyle(el: HTMLElement, property: string, value: string): StyleRestore {
  const previous = el.style.getPropertyValue(property)
  const priority = el.style.getPropertyPriority(property)
  el.style.setProperty(property, value)
  return () => {
    if (previous) {
      el.style.setProperty(property, previous, priority)
    } else {
      el.style.removeProperty(property)
    }
  }
}

/** Collapse on-screen page gaps and zoom offsets so print matches page size. */
function adjustPageStackForPrint(
  stack: HTMLElement,
  pageLayout: DocPageLayout,
  pageCount: number
): StyleRestore {
  const restores: StyleRestore[] = []
  const pageWidth = pageLayout.widthPx
  const pageHeight = pageLayout.heightPx
  const pageStep = pageHeight + DOCS_PAGE_GAP_PX
  const gapTotal = Math.max(0, pageCount - 1) * DOCS_PAGE_GAP_PX

  restores.push(patchInlineStyle(stack, "transform", "none"))
  restores.push(patchInlineStyle(stack, "left", "0"))
  restores.push(patchInlineStyle(stack, "width", `${pageWidth}px`))

  let wrapper = stack.parentElement
  while (wrapper && !wrapper.classList.contains("ultidrive-docs-canvas")) {
    restores.push(patchInlineStyle(wrapper, "width", `${pageWidth}px`))
    restores.push(patchInlineStyle(wrapper, "height", "auto"))
    restores.push(patchInlineStyle(wrapper, "min-height", "0"))
    restores.push(patchInlineStyle(wrapper, "padding-top", "0"))
    restores.push(patchInlineStyle(wrapper, "padding-bottom", "0"))
    restores.push(patchInlineStyle(wrapper, "margin-left", "0"))
    restores.push(patchInlineStyle(wrapper, "margin-right", "0"))
    wrapper = wrapper.parentElement
  }

  const stackHeight = parseFloat(stack.style.height)
  if (Number.isFinite(stackHeight) && gapTotal > 0) {
    restores.push(patchInlineStyle(stack, "height", `${stackHeight - gapTotal}px`))
  }

  stack.querySelectorAll<HTMLElement>("[style]").forEach((el) => {
    const top = parseFloat(el.style.top)
    if (!Number.isFinite(top) || top <= 0) return
    const pageIndex = Math.floor(top / pageStep)
    const nextTop = top - pageIndex * DOCS_PAGE_GAP_PX
    if (nextTop !== top) {
      restores.push(patchInlineStyle(el, "top", `${nextTop}px`))
    }
  })

  stack.querySelectorAll<HTMLElement>(".docs-page-flow-spacer").forEach((spacer) => {
    const height = parseFloat(spacer.style.height)
    if (Number.isFinite(height) && height >= DOCS_PAGE_GAP_PX) {
      restores.push(
        patchInlineStyle(spacer, "height", `${height - DOCS_PAGE_GAP_PX}px`)
      )
    }
  })

  const surface = stack.querySelector<HTMLElement>(".ultidrive-docs-editor-surface")
  if (surface) {
    const surfaceHeight = parseFloat(surface.style.height)
    if (Number.isFinite(surfaceHeight) && gapTotal > 0) {
      restores.push(
        patchInlineStyle(surface, "height", `${surfaceHeight - gapTotal}px`)
      )
    }
  }

  return () => {
    for (let i = restores.length - 1; i >= 0; i -= 1) {
      restores[i]()
    }
  }
}

function buildDynamicPrintStyles(
  pageLayout: DocPageLayout,
  paragraphStyles: DocParagraphStylesCatalog
): string {
  return [
    buildPageRule(pageLayout),
    buildPrintLayoutRules(pageLayout),
    buildParagraphStylesCss(paragraphStyles, ".ultidrive-richtext-editor, .ultidrive-richtext-region-editor"),
  ].join("\n")
}

function injectPrintStyles(
  pageLayout: DocPageLayout,
  paragraphStyles: DocParagraphStylesCatalog
): () => void {
  const existing = document.getElementById(PRINT_STYLE_ID)
  existing?.remove()

  const style = document.createElement("style")
  style.id = PRINT_STYLE_ID
  style.textContent = buildDynamicPrintStyles(pageLayout, paragraphStyles)
  document.head.appendChild(style)

  return () => {
    style.remove()
  }
}

function copyDocumentStyles(targetDoc: Document): void {
  document.querySelectorAll('style, link[rel="stylesheet"]').forEach((node) => {
    targetDoc.head.appendChild(node.cloneNode(true))
  })
}

async function waitForDocumentReady(doc: Document): Promise<void> {
  const links = Array.from(doc.querySelectorAll('link[rel="stylesheet"]'))
  await Promise.all(
    links.map(
      (link) =>
        new Promise<void>((resolve) => {
          const sheet = link as HTMLLinkElement
          if (sheet.sheet) {
            resolve()
            return
          }
          link.addEventListener("load", () => resolve(), { once: true })
          link.addEventListener("error", () => resolve(), { once: true })
        })
    )
  )
  if (doc.fonts?.ready) {
    await doc.fonts.ready
  }
  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
}

function removePrintIframe(): void {
  document.getElementById(PRINT_IFRAME_ID)?.remove()
}

async function printStackInIframe(
  stack: HTMLElement,
  snapshot: DocsExportSnapshot
): Promise<void> {
  removePrintIframe()

  const iframe = document.createElement("iframe")
  iframe.id = PRINT_IFRAME_ID
  iframe.setAttribute("aria-hidden", "true")
  iframe.style.cssText =
    "position:fixed;right:0;bottom:0;width:0;height:0;border:0;opacity:0;pointer-events:none"
  document.body.appendChild(iframe)

  const doc = iframe.contentDocument
  const win = iframe.contentWindow
  if (!doc || !win) {
    removePrintIframe()
    throw new Error("Impossible de préparer la fenêtre d'impression")
  }

  copyDocumentStyles(doc)

  const printStyle = doc.createElement("style")
  printStyle.textContent = buildDynamicPrintStyles(
    snapshot.pageLayout,
    snapshot.paragraphStyles
  )
  doc.head.appendChild(printStyle)

  doc.documentElement.classList.add("docs-printing")

  const root = doc.createElement("div")
  root.className = "docs-print-root"
  root.appendChild(stack.cloneNode(true))
  doc.body.replaceChildren(root)

  await waitForDocumentReady(doc)

  await new Promise<void>((resolve, reject) => {
    const cleanup = () => {
      win.removeEventListener("afterprint", onAfterPrint)
      removePrintIframe()
    }

    const onAfterPrint = () => {
      cleanup()
      resolve()
    }

    win.addEventListener("afterprint", onAfterPrint)

    try {
      win.focus()
      win.print()
    } catch (error) {
      cleanup()
      reject(error)
      return
    }

    window.setTimeout(() => {
      if (document.getElementById(PRINT_IFRAME_ID)) {
        cleanup()
        resolve()
      }
    }, 2000)
  })
}

async function waitForPrintLayout(): Promise<void> {
  if (typeof document !== "undefined" && document.fonts?.ready) {
    await document.fonts.ready
  }
  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
  await new Promise<void>((resolve) => requestAnimationFrame(() => resolve()))
}

export type DocsPrintMode = "print" | "pdf-capture"

export async function prepareDocsPrintEnvironment(
  snapshot: DocsExportSnapshot,
  mode: DocsPrintMode = "print"
): Promise<() => void> {
  const root = document.documentElement
  root.classList.add("docs-printing")
  if (mode === "pdf-capture") {
    root.classList.add("docs-pdf-capture")
  }

  const removeStyles = injectPrintStyles(snapshot.pageLayout, snapshot.paragraphStyles)

  const stack = snapshot.getPageStackElement()
  const restoreStackLayout =
    stack != null
      ? adjustPageStackForPrint(stack, snapshot.pageLayout, snapshot.pageCount)
      : () => {}

  await waitForPrintLayout()

  return () => {
    restoreStackLayout()
    root.classList.remove("docs-printing", "docs-pdf-capture")
    removeStyles()
  }
}

export async function printDocsDocument(snapshot: DocsExportSnapshot): Promise<void> {
  const cleanup = await prepareDocsPrintEnvironment(snapshot, "print")

  try {
    const stack = snapshot.getPageStackElement()
    if (!stack) {
      window.print()
      return
    }

    await printStackInIframe(stack, snapshot)
  } finally {
    cleanup()
  }
}