/**
 * 富文本表格操作与行内样式/属性注入工具
 * 注入 border="1"、cellpadding="8"、cellspacing="0" 以及 style 属性
 * 保证在 H5、App-plus 原生 editor、小程序以及 rich-text 中均能拥有清晰的表格边框与样式
 */

const TABLE_STYLE = 'border-collapse: collapse; width: 100%; border: 1px solid #dcdfe6; margin: 12px 0; table-layout: auto;'
const TR_STYLE = 'border-bottom: 1px solid #ebeef5;'
const TH_STYLE = 'border: 1px solid #dcdfe6; background-color: #f5f7fa; color: #303133; font-weight: 600; padding: 8px 12px; font-size: 14px; text-align: left; min-width: 44px; word-break: break-word;'
const TD_STYLE = 'border: 1px solid #dcdfe6; background-color: #ffffff; color: #303133; padding: 8px 12px; font-size: 14px; vertical-align: top; word-break: break-word; min-width: 44px;'

/**
 * 给 HTML 字符串中的所有 table/tr/th/td 注入高优先级的行内样式与原生 HTML 边框属性
 * （双重保障，即使 Quill 或原生组件重置了部分 CSS，border="1" 仍能强制渲染出边框）
 */
export function injectTableInlineStyles(html) {
	if (!html || typeof html !== 'string') return ''
	let res = html

	// 注入 table 属性与样式
	res = res.replace(/<table(\s+[^>]*)?>/gi, (match, attrs = '') => {
		let cleanAttrs = attrs
		cleanAttrs = cleanAttrs.replace(/\s+(border|cellspacing|cellpadding)\s*=\s*["'][^"']*["']/gi, '')
		if (/style\s*=\s*["']/i.test(cleanAttrs)) {
			cleanAttrs = cleanAttrs.replace(/style\s*=\s*["']([^"']*)["']/i, (m, s) => `style="${s}; ${TABLE_STYLE}"`)
		} else {
			cleanAttrs = ` style="${TABLE_STYLE}"` + cleanAttrs
		}
		return `<table border="1" cellpadding="8" cellspacing="0"${cleanAttrs}>`
	})

	// 注入 tr 样式
	res = res.replace(/<tr(\s+[^>]*)?>/gi, (match, attrs = '') => {
		if (/style\s*=\s*["']/i.test(attrs)) {
			return `<tr${attrs.replace(/style\s*=\s*["']([^"']*)["']/i, (m, s) => `style="${s}; ${TR_STYLE}"`)}>`
		}
		return `<tr style="${TR_STYLE}"${attrs}>`
	})

	// 注入 th 属性与样式
	res = res.replace(/<th(\s+[^>]*)?>/gi, (match, attrs = '') => {
		let cleanAttrs = attrs.replace(/\s+border\s*=\s*["'][^"']*["']/gi, '')
		if (/style\s*=\s*["']/i.test(cleanAttrs)) {
			cleanAttrs = cleanAttrs.replace(/style\s*=\s*["']([^"']*)["']/i, (m, s) => `style="${s}; ${TH_STYLE}"`)
		} else {
			cleanAttrs = ` style="${TH_STYLE}"` + cleanAttrs
		}
		return `<th border="1"${cleanAttrs}>`
	})

	// 注入 td 属性与样式
	res = res.replace(/<td(\s+[^>]*)?>/gi, (match, attrs = '') => {
		let cleanAttrs = attrs.replace(/\s+border\s*=\s*["'][^"']*["']/gi, '')
		if (/style\s*=\s*["']/i.test(cleanAttrs)) {
			cleanAttrs = cleanAttrs.replace(/style\s*=\s*["']([^"']*)["']/i, (m, s) => `style="${s}; ${TD_STYLE}"`)
		} else {
			cleanAttrs = ` style="${TD_STYLE}"` + cleanAttrs
		}
		return `<td border="1"${cleanAttrs}>`
	})

	return res
}

export function createEmptyCell(tagName = 'td') {
	const cell = document.createElement(tagName)
	cell.innerHTML = '<p><br></p>'
	cell.setAttribute('border', '1')
	if (tagName === 'th') {
		cell.style.cssText = TH_STYLE
	} else {
		cell.style.cssText = TD_STYLE
	}
	return cell
}

export function buildTableHtml(rows = 3, cols = 3) {
	let html = `<table border="1" cellpadding="8" cellspacing="0" style="${TABLE_STYLE}"><tbody>`
	for (let r = 0; r < rows; r += 1) {
		html += `<tr style="${TR_STYLE}">`
		for (let c = 0; c < cols; c += 1) {
			if (r === 0) {
				html += `<th border="1" style="${TH_STYLE}"><p><br></p></th>`
			} else {
				html += `<td border="1" style="${TD_STYLE}"><p><br></p></td>`
			}
		}
		html += '</tr>'
	}
	html += '</tbody></table><p><br></p>'
	return html
}

export function getCurrentCell(editorEl) {
	const sel = window.getSelection()
	if (!sel || sel.rangeCount === 0) return null
	let node = sel.anchorNode
	if (node?.nodeType === Node.TEXT_NODE) node = node.parentElement
	const cell = node?.closest?.('td, th')
	if (!cell || !editorEl?.contains(cell)) return null
	return cell
}

export function addRowBefore(cell) {
	const row = cell.closest('tr')
	const newRow = row.cloneNode(true)
	newRow.style.cssText = TR_STYLE
	newRow.querySelectorAll('td, th').forEach((item) => {
		item.innerHTML = '<p><br></p>'
		item.removeAttribute('colspan')
		item.removeAttribute('rowspan')
		item.setAttribute('border', '1')
		item.style.cssText = item.tagName.toLowerCase() === 'th' ? TH_STYLE : TD_STYLE
	})
	row.before(newRow)
	return newRow.cells[cell.cellIndex] || newRow.cells[0]
}

export function addRowAfter(cell) {
	const row = cell.closest('tr')
	const newRow = row.cloneNode(true)
	newRow.style.cssText = TR_STYLE
	newRow.querySelectorAll('td, th').forEach((item) => {
		item.innerHTML = '<p><br></p>'
		item.removeAttribute('colspan')
		item.removeAttribute('rowspan')
		item.setAttribute('border', '1')
		item.style.cssText = item.tagName.toLowerCase() === 'th' ? TH_STYLE : TD_STYLE
	})
	row.after(newRow)
	return newRow.cells[cell.cellIndex] || newRow.cells[0]
}

export function deleteRow(cell) {
	const row = cell.closest('tr')
	const section = row?.parentElement
	if (!row || !section || section.querySelectorAll('tr').length <= 1) return null
	const focusCell =
		row.nextElementSibling?.cells[cell.cellIndex] ||
		row.previousElementSibling?.cells[cell.cellIndex] ||
		null
	row.remove()
	return focusCell
}

export function addColBefore(cell) {
	const index = cell.cellIndex
	const table = cell.closest('table')
	table.querySelectorAll('tr').forEach((row) => {
		const refCell = row.cells[index]
		if (!refCell) return
		refCell.before(createEmptyCell(refCell.tagName.toLowerCase()))
	})
	return cell.parentElement.cells[index]
}

export function addColAfter(cell) {
	const index = cell.cellIndex
	const table = cell.closest('table')
	table.querySelectorAll('tr').forEach((row) => {
		const refCell = row.cells[index]
		if (!refCell) return
		refCell.after(createEmptyCell(refCell.tagName.toLowerCase()))
	})
	return cell.parentElement.cells[index + 1]
}

export function deleteCol(cell) {
	const index = cell.cellIndex
	const table = cell.closest('table')
	if (cell.parentElement.cells.length <= 1) return null
	let focusCell = null
	table.querySelectorAll('tr').forEach((row) => {
		const target = row.cells[index]
		if (!target) return
		if (row === cell.parentElement) {
			focusCell = row.cells[index + 1] || row.cells[index - 1] || null
		}
		target.remove()
	})
	return focusCell
}

export function deleteTable(cell) {
	cell.closest('table')?.remove()
}