import type { ReactElement } from 'react'
import type { Inline, InlinePart, ItemDiff, ItemsDiff, PropertyItem, PropertyRow, Removed, RowsDiff } from './types'
import { ChevronDown, ChevronRight } from 'lucide-react'
import { Fragment } from 'react'
import { DiffInline, DiffText } from './DiffText'
import { inlineText } from './segments'
import { SegmentText } from './SegmentText'
import { subRowsLayout, tableCells, tableTemplate } from './subRows'
import { TextPreview } from './TextPreview'
import { propertyItemId, propertyRowId, tableId } from './viewState'

/** 列表子行里除最后一列以外各列的宽度（字典的键），最后一列占满剩下的；编辑区窄时按比例收，不把最后一列挤没 */
const CELL_WIDTHS = ['min(150px, 28%)', 'min(220px, 38%)']

function gridTemplate(count: number): string {
  const fixed = Array.from({ length: count - 1 }, (_, i) => CELL_WIDTHS[i] ?? CELL_WIDTHS[CELL_WIDTHS.length - 1])
  return [...fixed, 'minmax(0, 1fr)'].join(' ')
}

/** 眼下折叠着哪些属性行、子行，点折叠箭头时切换哪个。 */
interface Folding {
  collapsed: ReadonlySet<string>
  onToggleFold: (id: string) => void
}

/** 删掉的行下面的子行：总是展开，点了也不收（旧内容只是看看）。 */
const FIXED: Folding = { collapsed: new Set(), onToggleFold: () => {} }

/** 表格行第一格前的记号：加的 +、删的 −，没变的空一格，列照样对齐。 */
const SIGNS = { add: '+', del: '−', none: ' ' } as const

/** 删掉的行（子行）里排在新的第 after 行后面的那些，带着它在删掉的行里的序号（页面上认它用）。 */
function removedAt<T>(removed: readonly Removed<T>[] | undefined, after: number): { value: T, index: number }[] {
  return (removed ?? []).flatMap((entry, index) => entry.after === after ? [{ value: entry.value, index }] : [])
}

/** 一格的字：这一格的值改了就逐截标（DiffInline），否则照常。 */
function CellText({ cell, parts }: { cell: Inline[], parts: InlinePart[] | undefined }): ReactElement {
  return parts ? <DiffInline parts={parts} /> : <SegmentText segments={cell} />
}

/**
 * 子行的第一列（字典的键）：带下一层的子行前面是折叠箭头（图标、大小、颜色同属性行的），点箭头或这一列切换；
 * 同一层里不带下一层的子行在同样的位置留空，第一列才对得齐。
 */
function ItemHead({ id, cell, foldable, folding }: { id: string, cell: Inline[], foldable: boolean, folding: Folding }): ReactElement {
  if (!foldable) {
    return (
      <div className="flex min-w-0 gap-1">
        <span className="w-3.5 shrink-0" />
        <p className="cr-code min-w-0">
          <SegmentText segments={cell} />
        </p>
      </div>
    )
  }
  const folded = folding.collapsed.has(id)
  const Chevron = folded ? ChevronRight : ChevronDown
  return (
    <button
      type="button"
      className="group flex min-w-0 items-start gap-1 rounded-sm text-left"
      aria-label={`${folded ? '展开' : '折叠'}${inlineText(cell)}`}
      aria-expanded={!folded}
      onClick={() => folding.onToggleFold(id)}
    >
      <span className="flex h-5 w-3.5 shrink-0 items-center">
        <Chevron size={14} strokeWidth={1.8} className="text-[var(--vscode-descriptionForeground)] group-hover:text-[var(--vscode-foreground)]" />
      </span>
      <span className="cr-code min-w-0">
        <SegmentText segments={cell} />
      </span>
    </button>
  )
}

/**
 * 展开在一行或一个子行（parentId）下面的一层子行：左边一条竖线，每个子行几列对齐。
 * 带下一层的子行（字典 / 对象的值又是字典 / 对象），下一层展开在它下面、再往右缩进一层，默认展开。
 * 标差异时（marks）新加的子行淡绿底、左边 +，删掉的放回原来的位置、淡红底划掉、左边 −，改了的格子逐截标。
 */
function PropertyItems({ parentId, items, folding, marks }: { parentId: string, items: PropertyItem[], folding: Folding, marks?: ItemsDiff }): ReactElement {
  const nested = items.some(item => (item.items?.length ?? 0) > 0)
  /** 一个子行：删掉的（change 是 del）不带 id、下面的子行总是展开 */
  const itemRow = (item: PropertyItem, id: string, change: 'add' | 'del' | undefined, mark: ItemDiff | undefined): ReactElement => {
    const children = item.items ?? []
    const folds = change === 'del' ? FIXED : folding
    return (
      <>
        <div
          className="cr-prop-item grid gap-x-3"
          data-id={change === 'del' ? undefined : id}
          data-diff={change}
          style={{ gridTemplateColumns: gridTemplate(item.cells.length) }}
        >
          {item.cells.map((cell, i) => i === 0 && nested
            ? <ItemHead key={i} id={id} cell={cell} foldable={children.length > 0 && change !== 'del'} folding={folds} />
            : (
                <p key={i} className="cr-code min-w-0">
                  <CellText cell={cell} parts={mark?.cells?.[i]} />
                </p>
              ))}
        </div>
        {children.length > 0 && !folds.collapsed.has(id) && (change === 'del'
          ? (
              <div className="cr-diff-gone">
                <PropertyItems parentId={id} items={children} folding={folds} />
              </div>
            )
          : <PropertyItems parentId={id} items={children} folding={folds} marks={mark?.items} />)}
      </>
    )
  }
  const removed = (after: number): ReactElement[] => removedAt(marks?.removed, after)
    .map(({ value, index }) => <Fragment key={`removed-${index}`}>{itemRow(value, `${parentId}/x${index}`, 'del', undefined)}</Fragment>)
  return (
    <div className="flex gap-2.5 pl-[5px]">
      <div className="cr-guide w-px shrink-0" />
      <div className="flex min-w-0 flex-1 flex-col gap-0.5">
        {removed(-1)}
        {items.map((item, index) => {
          const mark = marks?.changed[index]
          return (
            <Fragment key={index}>
              {itemRow(item, propertyItemId(parentId, index), mark?.added && 'add', mark)}
              {removed(index)}
            </Fragment>
          )
        })}
      </div>
    </div>
  )
}

/**
 * 给了列名的子行（输入参数、数据表的字段）排成表格：第一行是表头（列名），下面每个子行一行；外框圆角，格子之间、行之间一条分隔线。
 * 列宽按整列的内容定（见 tableTemplate），最后一列分剩下的，长了在格子里换行。一行译文下面摊开实参的表也用它；
 * 行带 table（实参的值里跨几行写的调用）时，那张表排在最后一格里、文字下面，往右缩一点，一层层往下套。
 * 标差异时（marks）有加行、删行的表每行第一格前多一个记号位（+ / −，没变的空着），加的行淡绿底，删的行放回原来的位置、淡红底划掉。
 */
export function PropertyTable({ parentId, columns, items, marks }: { parentId: string, columns: string[], items: PropertyItem[], marks?: ItemsDiff }): ReactElement {
  // 有加行、删行的表每行第一格前留一个记号位
  const signed = marks !== undefined && (marks.removed.length > 0 || Object.values(marks.changed).some(mark => mark.added))
  /** 一行：删掉的（change 是 del）不带 id，套着的表不再标 */
  const tableRow = (item: PropertyItem, id: string, change: 'add' | 'del' | undefined, mark: ItemDiff | undefined): ReactElement => {
    const cells = tableCells(item, columns)
    const text = (cell: Inline[], i: number): ReactElement => (
      <>
        {signed && i === 0 && <span className="cr-diff-sign" data-change={change} aria-hidden>{SIGNS[change ?? 'none']}</span>}
        <CellText cell={cell} parts={mark?.cells?.[i]} />
      </>
    )
    return (
      <div className="cr-table-row" role="row" data-id={change === 'del' ? undefined : id} data-diff={change}>
        {cells.map((cell, i) => item.table && i === cells.length - 1
          ? (
              <div key={i} className="cr-table-cell flex min-w-0 flex-col gap-[3px]" role="cell">
                <p className="cr-code">{text(cell, i)}</p>
                <PropertyTable parentId={tableId(id)} columns={item.table.columns} items={item.table.items} marks={mark?.table} />
              </div>
            )
          : <p key={i} className="cr-table-cell cr-code min-w-0" role="cell">{text(cell, i)}</p>)}
      </div>
    )
  }
  const removed = (after: number): ReactElement[] => removedAt(marks?.removed, after)
    .map(({ value, index }) => <Fragment key={`removed-${index}`}>{tableRow(value, `${parentId}/x${index}`, 'del', undefined)}</Fragment>)
  return (
    <div className="pl-[5px]">
      <div className="cr-table" role="table" style={{ gridTemplateColumns: tableTemplate(columns.length) }}>
        <div className="cr-table-head" role="row">
          {columns.map((name, i) => <span key={i} className="cr-table-cell" role="columnheader">{name}</span>)}
        </div>
        {removed(-1)}
        {items.map((item, index) => {
          const mark = marks?.changed[index]
          return (
            <Fragment key={index}>
              {tableRow(item, propertyItemId(parentId, index), mark?.added && 'add', mark)}
              {removed(index)}
            </Fragment>
          )
        })}
      </div>
    </div>
  )
}

/**
 * 函数、类、枚举、导入、常量、变量块和库规则的卡片的预览：属性名一列对齐，值按词性着色；输入参数、导入项、字典 / 对象的值下面展开子行，
 * 给了列名的（输入参数、数据表的字段）排成表格，没给的排成列表。
 * 标差异时（marks）新加的行淡绿底、左边 +，删掉的行放回原来的位置、淡红底划掉、左边 −，值改了的按旧值 → 新值或逐词标。
 */
export function PropertyGrid({ blockId, rows, collapsed, onToggleFold, marks }: {
  blockId: string
  rows: PropertyRow[]
  collapsed: ReadonlySet<string>
  onToggleFold: (id: string) => void
  /** 标差异时这张属性表改了哪些行 */
  marks?: RowsDiff
}): ReactElement {
  const removed = (after: number): ReactElement[] => removedAt(marks?.removed, after)
    .map(({ value, index }) => <RemovedRow key={`removed-${index}`} id={`${blockId}/x${index}`} row={value} />)
  return (
    <div className="grid grid-cols-[minmax(76px,max-content)_minmax(0,1fr)] gap-x-3 gap-y-[3px] *:col-span-full">
      {removed(-1)}
      {rows.map((row, index) => {
        const layout = subRowsLayout(row)
        const id = propertyRowId(blockId, index)
        const folded = collapsed.has(id)
        const Chevron = folded ? ChevronRight : ChevronDown
        const mark = marks?.changed[index]
        return (
          <Fragment key={index}>
            <div className="cr-prop-row grid grid-cols-subgrid" data-id={id} data-diff={mark?.added && 'add'}>
              {layout
                ? (
                    <button
                      type="button"
                      className="cr-prop-label group flex h-5 items-center gap-1 rounded-sm"
                      aria-label={`${folded ? '展开' : '折叠'}${row.label}`}
                      aria-expanded={!folded}
                      onClick={() => onToggleFold(id)}
                    >
                      <Chevron size={14} strokeWidth={1.8} className="shrink-0 text-[var(--vscode-descriptionForeground)] group-hover:text-[var(--vscode-foreground)]" />
                      {row.label}
                    </button>
                  )
                : <span className="cr-prop-label flex h-5 items-center">{row.label}</span>}
              {mark?.value ? <DiffText diff={mark.value} className="min-w-0" /> : <TextPreview text={row.value} className="min-w-0" />}
            </div>
            {!folded && layout === 'table' && <PropertyTable parentId={id} columns={row.columns ?? []} items={row.items ?? []} marks={mark?.items} />}
            {!folded && layout === 'list' && <PropertyItems parentId={id} items={row.items ?? []} folding={{ collapsed, onToggleFold }} marks={mark?.items} />}
            {removed(index)}
          </Fragment>
        )
      })}
    </div>
  )
}

/** 属性表里删掉的一行：整行淡红底、划掉，左边 −；它下面的子行照样摊开、划掉。 */
function RemovedRow({ id, row }: { id: string, row: PropertyRow }): ReactElement {
  const layout = subRowsLayout(row)
  return (
    <>
      <div className="cr-prop-row grid grid-cols-subgrid" data-diff="del">
        <span className="cr-prop-label flex h-5 items-center">{row.label}</span>
        <TextPreview text={row.value} className="min-w-0" />
      </div>
      {layout && (
        <div className="cr-diff-gone">
          {layout === 'table'
            ? <PropertyTable parentId={id} columns={row.columns ?? []} items={row.items ?? []} />
            : <PropertyItems parentId={id} items={row.items ?? []} folding={FIXED} />}
        </div>
      )}
    </>
  )
}