// hooks/useAutoSizeColumns.ts
import { useEffect, useRef } from "react"
import { Table } from "@tanstack/react-table"

export function useAutoSizeColumns<T>(
  table: Table<T>,
  enabled: boolean = true
) {
  const hasResized = useRef(false)
  
  useEffect(() => {
    if (!enabled || hasResized.current) return
    
    // Wait for the table to render
    const timer = setTimeout(() => {
      const calculateColumnWidths = () => {
        const defaultMinWidth = 80
        const defaultPadding = 24
        
        const newColumnSizing: Record<string, number> = {}
        
        // Process each visible column
        table.getAllColumns().forEach(column => {
          if (column.id === 'select' || column.id === 'actions') {
            // Fixed width for utility columns
            newColumnSizing[column.id] = column.id === 'select' ? 40 : 60
            return
          }
          
          const columnId = column.id
          // Get column-specific padding from meta if available
          const paddingFactor = column.columnDef.meta?.paddingFactor as number || 1
          const extraPadding = paddingFactor * defaultPadding
          
          // Get all cells for this column
          const headerElement = document.querySelector(`th[data-column-id="${columnId}"]`)
          const cells = document.querySelectorAll(`tbody td[data-column-id="${columnId}"]`)
          
          // Create measuring element
          const measureElement = document.createElement('div')
          measureElement.style.position = 'absolute'
          measureElement.style.visibility = 'hidden'
          measureElement.style.whiteSpace = 'nowrap'
          measureElement.style.font = headerElement 
            ? window.getComputedStyle(headerElement).font 
            : window.getComputedStyle(document.body).font
          document.body.appendChild(measureElement)
          
          // Measure header
          const headerText = headerElement?.textContent || ""
          measureElement.textContent = headerText
          let maxWidth = measureElement.getBoundingClientRect().width
          
          // Measure cells (limit to first 20 for performance)
          Array.from(cells).slice(0, 20).forEach(cell => {
            const cellText = cell.textContent || ""
            measureElement.textContent = cellText
            const cellWidth = measureElement.getBoundingClientRect().width
            maxWidth = Math.max(maxWidth, cellWidth)
          })
          
          // Clean up measuring element
          document.body.removeChild(measureElement)
          
          // Calculate final width
          let finalWidth = maxWidth + extraPadding
          const minWidth = column.columnDef.minSize || defaultMinWidth
          finalWidth = Math.max(finalWidth, minWidth)
          
          // Add to sizing object
          newColumnSizing[columnId] = finalWidth
        })
        
        // Apply all column sizes at once
        table.setColumnSizing(newColumnSizing)
        hasResized.current = true
      }
      
      calculateColumnWidths()
    }, 100) // Short delay to ensure DOM is ready
    
    return () => clearTimeout(timer)
  }, [table, enabled])
  
  return { resetAutoSize: () => { hasResized.current = false } }
}