/** Default line height for Normal text (matches built-in paragraph styles). */
export const DOCS_DEFAULT_LINE_HEIGHT = 1.15

/** Quick spacing added by « Insérer un espacement avant/après » (Google Docs ≈ 12 pt). */
export const DOCS_QUICK_PARAGRAPH_SPACE_PT = 12

export const DOCS_LINE_HEIGHT_PRESETS = [
  { id: "1", value: 1, label: "Simple" },
  { id: "1.15", value: 1.15, label: "1,15" },
  { id: "1.5", value: 1.5, label: "1,5" },
  { id: "2", value: 2, label: "Double" },
] as const

export type DocsLineHeightPresetId = (typeof DOCS_LINE_HEIGHT_PRESETS)[number]["id"]

export type DocsParagraphSpacingAttrs = {
  lineHeight: number | null
  spaceBeforePt: number
  spaceAfterPt: number
  keepWithNext: boolean
  keepLinesTogether: boolean
  preventWidowOrphan: boolean
  pageBreakBefore: boolean
}

export const DOCS_DEFAULT_PARAGRAPH_SPACING: DocsParagraphSpacingAttrs = {
  lineHeight: null,
  spaceBeforePt: 0,
  spaceAfterPt: 0,
  keepWithNext: false,
  keepLinesTogether: false,
  preventWidowOrphan: false,
  pageBreakBefore: false,
}

export function lineHeightPresetId(value: number | null | undefined): DocsLineHeightPresetId | "custom" | null {
  if (value == null) return null
  for (const preset of DOCS_LINE_HEIGHT_PRESETS) {
    if (Math.abs(preset.value - value) < 0.001) return preset.id
  }
  return "custom"
}

export function parseLineHeightAttr(raw: unknown): number | null {
  if (raw == null || raw === "") return null
  const value = typeof raw === "number" ? raw : Number.parseFloat(String(raw))
  return Number.isFinite(value) && value > 0 ? value : null
}

export function parseSpacingPt(raw: unknown): number {
  if (raw == null || raw === "") return 0
  const value = typeof raw === "number" ? raw : Number.parseFloat(String(raw))
  return Number.isFinite(value) && value > 0 ? Math.round(value * 100) / 100 : 0
}

export function readParagraphSpacingAttrs(node: ProseMirrorNodeLike): DocsParagraphSpacingAttrs {
  const attrs = node.attrs as Record<string, unknown>
  return {
    lineHeight: parseLineHeightAttr(attrs.lineHeight),
    spaceBeforePt: parseSpacingPt(attrs.spaceBeforePt),
    spaceAfterPt: parseSpacingPt(attrs.spaceAfterPt),
    keepWithNext: Boolean(attrs.keepWithNext),
    keepLinesTogether: Boolean(attrs.keepLinesTogether),
    preventWidowOrphan: Boolean(attrs.preventWidowOrphan),
    pageBreakBefore: Boolean(attrs.pageBreakBefore),
  }
}

type ProseMirrorNodeLike = { attrs: Record<string, unknown> }

export function buildParagraphSpacingStyle(attrs: DocsParagraphSpacingAttrs): string {
  const parts: string[] = []
  if (attrs.lineHeight != null) parts.push(`line-height: ${attrs.lineHeight}`)
  if (attrs.spaceBeforePt > 0) parts.push(`margin-top: ${attrs.spaceBeforePt}pt`)
  if (attrs.spaceAfterPt > 0) parts.push(`margin-bottom: ${attrs.spaceAfterPt}pt`)
  if (attrs.keepWithNext) parts.push("break-after: avoid")
  if (attrs.keepLinesTogether) parts.push("break-inside: avoid")
  if (attrs.preventWidowOrphan) parts.push("orphans: 2; widows: 2")
  if (attrs.pageBreakBefore) parts.push("break-before: page")
  return parts.join("; ")
}