/**
 * Table node parser — handles graphicFrame elements containing a:tbl.
 */

import { emuToPx } from '../../parser/units'
import type { SafeXmlNode } from '../../parser/xml-parser'
import { type BaseNodeData, parseBaseProps } from './base-node'
import { parseTextBody, type TextBody } from './shape-node'

export interface TableCell {
  gridSpan: number
  rowSpan: number
  hMerge: boolean
  vMerge: boolean
  textBody?: TextBody
  /** @internal Raw XML node — opaque to consumers. Use serializePresentation() for JSON-safe data. */
  properties?: SafeXmlNode
}

interface TableRow {
  height: number
  cells: TableCell[]
}

export interface TableNodeData extends BaseNodeData {
  nodeType: 'table'
  columns: number[]
  rows: TableRow[]
  /** @internal Raw XML node — opaque to consumers. Use serializePresentation() for JSON-safe data. */
  properties?: SafeXmlNode
  tableStyleId?: string
}

/**
 * Parse a single table cell (`a:tc`).
 */
function parseCell(tcNode: SafeXmlNode): TableCell {
  const gridSpan = tcNode.numAttr('gridSpan') ?? 1
  const rowSpan = tcNode.numAttr('rowSpan') ?? 1
  const hMerge = tcNode.attr('hMerge') === '1' || tcNode.attr('hMerge') === 'true'
  const vMerge = tcNode.attr('vMerge') === '1' || tcNode.attr('vMerge') === 'true'

  // Cell text body
  const txBody = tcNode.child('txBody')
  const textBody = parseTextBody(txBody)

  // Cell properties
  const tcPr = tcNode.child('tcPr')

  return {
    gridSpan,
    rowSpan,
    hMerge,
    vMerge,
    textBody,
    properties: tcPr.exists() ? tcPr : undefined,
  }
}

/**
 * Parse a table row (`a:tr`).
 */
function parseRow(trNode: SafeXmlNode): TableRow {
  const height = emuToPx(trNode.numAttr('h') ?? 0)
  const cells: TableCell[] = []

  for (const tcNode of trNode.children('tc')) {
    cells.push(parseCell(tcNode))
  }

  return { height, cells }
}

/**
 * Locate the `a:tbl` element inside a graphicFrame.
 * Path: `a:graphic > a:graphicData > a:tbl`
 */
function findTable(frameNode: SafeXmlNode): SafeXmlNode {
  const graphic = frameNode.child('graphic')
  const graphicData = graphic.child('graphicData')
  return graphicData.child('tbl')
}

/**
 * Extract the table style ID from tblPr.
 * It can be in `a:tblStyle@val` or as a direct `tblStyle` attribute.
 */
function extractTableStyleId(tblPr: SafeXmlNode): string | undefined {
  // Try <a:tableStyleId>{UUID}</a:tableStyleId> (most common in OOXML)
  const tableStyleIdNode = tblPr.child('tableStyleId')
  if (tableStyleIdNode.exists()) {
    return tableStyleIdNode.text() || tableStyleIdNode.attr('val') || undefined
  }
  // Try <a:tblStyle val="{UUID}"/>
  const tblStyleNode = tblPr.child('tblStyle')
  if (tblStyleNode.exists()) {
    return tblStyleNode.attr('val') ?? (tblStyleNode.text() || undefined)
  }
  // Try direct attribute
  return tblPr.attr('tblStyle') ?? undefined
}

/**
 * Parse a graphicFrame XML node containing a table into TableNodeData.
 */
export function parseTableNode(frameNode: SafeXmlNode): TableNodeData {
  const base = parseBaseProps(frameNode)
  const tbl = findTable(frameNode)

  // --- Column widths ---
  const tblGrid = tbl.child('tblGrid')
  const columns: number[] = []
  for (const gridCol of tblGrid.children('gridCol')) {
    columns.push(emuToPx(gridCol.numAttr('w') ?? 0))
  }

  // --- Rows ---
  const rows: TableRow[] = []
  for (const trNode of tbl.children('tr')) {
    rows.push(parseRow(trNode))
  }

  // --- Table properties ---
  const tblPr = tbl.child('tblPr')
  const tableStyleId = extractTableStyleId(tblPr)

  return {
    ...base,
    nodeType: 'table',
    columns,
    rows,
    properties: tblPr.exists() ? tblPr : undefined,
    tableStyleId,
  }
}