import type { CSSProperties, ReactElement, ReactNode } from 'react'
import type { DiffTree, FoldedRuns, PlacedRemoved } from './diffView'
import type { GridSlots } from './PropertyGrid'
import type { QaState } from './qa'
import type { PendingImage } from './qaImages'
import type { RewriteRun } from './rewriteRun'
import type { BlockMarks, BlockView } from './types'
import { ChevronDown, ChevronRight, ChevronsUpDown, EyeOff } from 'lucide-react'
import { Fragment, useState } from 'react'
import { AskThread, RewriteThread } from './AskThread'
import { BlockTools } from './BlockTools'
import { CodeEditor } from './CodeEditor'
import { DiffText } from './DiffText'
import { removedTitle } from './diffView'
import { KindIcon } from './kindIcons'
import { PropertyGrid, PropertyTable } from './PropertyGrid'
import { asksOf, historyOf } from './qa'
import { TextPreview } from './TextPreview'
import { tableId } from './viewState'

/**
 * 块树里改代码的那部分：哪些块在编辑、点「编辑」、按注释规范重写。页面上的块树才有；定义卡片浮窗里的块树没有，
 * 卡片只读，不画右上角的按钮
 */
export interface EditTree {
  version: number
  editing: ReadonlySet<string>
  /** 刚点了「编辑」、要把光标放进去的块 */
  focusId: string | null
  onFocused: () => void
  onToggleEdit: (id: string) => void
  /** 按注释规范重写的过程，按块的记号。只在这一页上 */
  rewrites: ReadonlyMap<string, RewriteRun>
  onRewriteComment: (anchor: string) => void
  /** 叫停这块正在进行的重写，不写文件 */
  onStopRewrite: (anchor: string) => void
}

export interface BlockTreeState {
  /** 能编辑（页面上的块树）；定义卡片浮窗里没有 */
  edit?: EditTree
  /** 眼下折叠着的块 id、属性行 id 和子行 id（propertyRowId、propertyItemId）：用户的选择叠在默认上，见 collapsedIds */
  collapsed: ReadonlySet<string>
  /** 按筛选不画的块（连同子孙），见 applyFilter */
  hidden: ReadonlySet<string>
  /** 本来被筛掉、跳到定义时临时显示的块 */
  temporary: ReadonlySet<string>
  /** 被正在编辑的祖先盖住、不画的块（它们的代码在祖先的编辑框里），见 coveredByEditing */
  covered: ReadonlyMap<string, string>
  /** 种类叫什么（种类图标的悬停提示和 aria-label）：翻译插件给种类起的名字（库规则的种类是规则给的 badge.label），没给就是 id */
  kindName: (kind: string) => string
  onToggleFold: (id: string) => void
  /** 一次记下几块、几行折叠还是展开（点子行展开一块、同一行里别的收起） */
  onSetFolds: (folds: Record<string, boolean>) => void
  /** 问 AI；文件不在工作区文件夹里（问答没地方存）时没有 */
  qa?: QaTree
  /** 代码差异：新增、修改的块和删掉的块；侧栏开着「未提交的更改」或审查工单、基准里有这个文件时才有 */
  diff?: DiffTree
  /** 「只看改动」开着时折起来的连着没变的块（见 foldUnchanged）；onOpenRun 点开一段（按第一块的 id） */
  folded?: FoldedRuns
  onOpenRun: (id: string) => void
}

/** 问 AI 的状态和动作，块按自己的记号（anchor）取 */
export interface QaTree {
  state: QaState
  onToggle: (anchor: string) => void
  onClose: (anchor: string) => void
  /** images 是贴进输入框的图片，随问题一起发 */
  onAsk: (anchor: string, question: string, images: PendingImage[]) => void
  onStop: (askId: string) => void
  onDelete: (anchor: string, entryId: string) => void
  /** 换「问 AI」用的 profile（所有块共用），id 同 ProfileOption.id */
  onSelectProfile: (id: string) => void
}

/**
 * 块下面有没有画出来的子块（删掉的子块也算）：子块都被筛掉、被盖住时不留空的一层、不给折叠箭头。
 * 挂在卡片子行上的子块（BlockSlot）画在卡片属性表里，不算。
 */
function hasShownChildren(block: BlockView, tree: BlockTreeState): boolean {
  return block.children.some(child => !child.slot && shown(child, tree)) || (!tree.covered.has(block.id) && tree.diff?.removed.has(block.id) === true)
}

const CHANGE_NAMES = { add: '新增', mod: '修改', del: '删除' } as const

/** 标差异时卡片左边外侧的改动色条（没变的留一条透明的，同一层照样对齐）；不标差异时原样。 */
function ChangeRow({ tree, change, children }: { tree: BlockTreeState, change: keyof typeof CHANGE_NAMES | undefined, children: ReactNode }): ReactElement {
  if (!tree.diff)
    return <>{children}</>
  return (
    <div className="cr-change-row flex gap-[5px]">
      <span className="cr-change-bar" data-change={change} data-tooltip={change && CHANGE_NAMES[change]} />
      <div className="min-w-0 flex-1">{children}</div>
    </div>
  )
}

/** 「只看改动」时连着没变的几块折成的一条「… N 块没变」，点开恢复这几块。 */
function UnchangedStrip({ count, tree, onOpen }: { count: number, tree: BlockTreeState, onOpen: () => void }): ReactElement {
  return (
    <ChangeRow tree={tree} change={undefined}>
      <button type="button" className="cr-unchanged flex h-[22px] w-full items-center gap-1.5 rounded px-2.5 text-xs" onClick={onOpen}>
        <ChevronsUpDown size={12} strokeWidth={1.8} className="shrink-0" aria-hidden />
        {`… ${count} 块没变`}
        <span className="cr-link">点开</span>
      </button>
    </ChangeRow>
  )
}

/** 块画不画：被筛掉的、被正在编辑的祖先盖住的都不画。 */
function shown(block: BlockView, tree: BlockTreeState): boolean {
  return !tree.hidden.has(block.id) && !tree.covered.has(block.id)
}

/**
 * 块的种类色写在哪：内置种类按 data-kind 取 CSS 里的配色；库规则认领的块（带 badge）按规则给的颜色，
 * 暗色、亮色两个都写在 style 上，CSS 按主题挑一个（见 [data-badge]）。
 */
function kindProps(block: BlockView | undefined): { 'data-kind'?: string, 'data-badge'?: '', 'style'?: CSSProperties } {
  if (!block)
    return {}
  if (!block.badge)
    return { 'data-kind': block.kind }
  const { dark, light } = block.badge.color
  return { 'data-kind': block.kind, 'data-badge': '', 'style': { '--kind-dark': dark, '--kind-light': light } as CSSProperties }
}

/**
 * 一层代码块：左边一条竖线标出这一层，每块的子块紧跟在它下面、再往右缩进一层。被筛掉、被盖住的块不画，不留空位，竖线跟着变短。
 * owner 是这一层所属的块（顶层没有，记在 data-owner 上，钉住外层卡片时按它认哪张卡片的子块画出来了），悬停它时竖线换成它的种类色。
 * 标差异时每张卡片左边外侧一条改动色条，删掉的块收成一行放回原来的位置（见 RemovedCard）；「只看改动」时连着没变的块折成一条（UnchangedStrip）。
 * slotted：这一层是画在卡片属性表某一行下面的子块（BlockSlot），blocks 只有那几块。
 */
export function BlockLevel({ blocks, owner, tree, slotted = false }: { blocks: BlockView[], owner?: BlockView, tree: BlockTreeState, slotted?: boolean }): ReactElement {
  // 挂在卡片子行上的子块画在卡片属性表里（slotted 的那一层），这一层不画；删掉的块都放回卡片后面这一层
  const listed = slotted ? blocks : blocks.filter(block => !block.slot)
  const removed = slotted ? [] : tree.diff?.removed.get(owner?.id ?? '') ?? []
  const listedIds = new Set(listed.map(block => block.id))
  // 删掉的块排在它原来前面那块后面；那块被筛掉了也照排，不跟着消失；那块画在卡片里时排到这一层最后
  const removedAfter = (id: string | undefined): ReactElement[] => removed
    .filter(item => item.after === id)
    .map(item => <RemovedCard key={item.id} placed={item} tree={tree} />)
  const removedElsewhere = removed
    .filter(item => item.after !== undefined && !listedIds.has(item.after))
    .map(item => <RemovedCard key={item.id} placed={item} tree={tree} />)
  return (
    <div className="cr-level flex gap-2" {...kindProps(owner)} data-owner={owner?.id}>
      <div className="flex w-3 shrink-0 justify-center">
        <div className="cr-guide w-px" />
      </div>
      <div className="flex min-w-0 flex-1 flex-col gap-2">
        {removedAfter(undefined)}
        {listed.map(block => (
          <Fragment key={block.id}>
            {tree.folded?.runs.has(block.id) && <UnchangedStrip count={tree.folded.runs.get(block.id) ?? 0} tree={tree} onOpen={() => tree.onOpenRun(block.id)} />}
            {shown(block, tree) && !tree.folded?.folded.has(block.id) && (
              <>
                <ChangeRow tree={tree} change={tree.diff?.changes.get(block.id)?.change}>
                  <BlockCard block={block} tree={tree} />
                </ChangeRow>
                {tree.qa && <BlockQa key={block.anchor} anchor={block.anchor} qa={tree.qa} />}
                {tree.edit && <BlockRewrite anchor={block.anchor} edit={tree.edit} />}
                {hasShownChildren(block, tree) && !tree.collapsed.has(block.id) && (
                  <BlockLevel blocks={block.children} owner={block} tree={tree} />
                )}
              </>
            )}
            {removedAfter(block.id)}
          </Fragment>
        ))}
        {removedElsewhere}
      </div>
    </div>
  )
}

/** 块下面的问答区，紧跟在块后面、子块前面；输入框、展开状态跟着块的记号走，文档刷新块 id 变了也不丢 */
function BlockQa({ anchor, qa }: { anchor: string, qa: QaTree }): ReactElement {
  return (
    <AskThread
      history={historyOf(qa.state, anchor)}
      asks={asksOf(qa.state, anchor)}
      open={qa.state.open.includes(anchor)}
      profiles={qa.state.profiles}
      onSelectProfile={qa.onSelectProfile}
      onAsk={(question, images) => qa.onAsk(anchor, question, images)}
      onStop={qa.onStop}
      onDelete={entryId => qa.onDelete(anchor, entryId)}
      onClose={() => qa.onClose(anchor)}
    />
  )
}

function BlockRewrite({ anchor, edit }: { anchor: string, edit: EditTree }): ReactElement | null {
  const run = edit.rewrites.get(anchor)
  if (!run)
    return null
  return <RewriteThread run={run} onStop={() => edit.onStopRewrite(anchor)} />
}

/**
 * 预览状态的内容：函数、类、枚举、导入、常量、变量块和库规则的卡片是属性表，其余是一行译文；
 * 译文下面依次接着摊开实参的表（跨几行写的调用）、说明。标差异时 marks 是这块自己的内容改了哪些（页面上正是差异算的那一版才给）。
 */
function BlockPreview({ block, tree, marks }: { block: BlockView, tree: BlockTreeState, marks?: BlockMarks }): ReactElement {
  if ('properties' in block)
    return <PropertyGrid blockId={block.id} rows={block.properties} collapsed={tree.collapsed} onToggleFold={tree.onToggleFold} marks={marks?.rows} slots={cardSlots(block, tree)} />
  return (
    <>
      {marks?.translation ? <DiffText diff={marks.translation} /> : <TextPreview text={block.translation} />}
      {block.table && (
        <div className="mt-[3px]">
          <PropertyTable parentId={tableId(block.id)} columns={block.table.columns} items={block.table.items} marks={marks?.table} />
        </div>
      )}
      {marks?.doc ? <DiffText diff={marks.doc} className="mt-0.5" /> : block.doc && <TextPreview text={block.doc} className="mt-0.5" />}
    </>
  )
}

/**
 * 挂在卡片子行上的子块（BlockSlot）怎么画：一行下面展开着的几块画成一层块（同块树）；点那个子行的第一格展开它、
 * 同一行里别的收起，展开着的再点收起。卡片没有挂在子行上的子块时没有。
 */
function cardSlots(block: BlockView, tree: BlockTreeState): GridSlots | undefined {
  const blocks = block.children.filter(child => child.slot)
  if (blocks.length === 0)
    return undefined
  return {
    blocks,
    render: list => <BlockLevel blocks={list} owner={block} tree={tree} slotted />,
    onToggle: (child) => {
      if (!tree.collapsed.has(child.id)) {
        tree.onSetFolds({ [child.id]: true })
        return
      }
      const others = blocks.filter(other => other !== child && other.slot?.row === child.slot?.row)
      tree.onSetFolds({ ...Object.fromEntries(others.map(other => [other.id, true])), [child.id]: false })
    },
  }
}

/** 一块：折叠箭头、种类图标、预览内容或源码、右上角的一排图标按钮（BlockTools，只读的块树没有）。 */
function BlockCard({ block, tree }: { block: BlockView, tree: BlockTreeState }): ReactElement {
  const { edit } = tree
  const editing = edit?.editing.has(block.id) ?? false
  const collapsed = tree.collapsed.has(block.id)
  // 点父卡片子行才展开的子块：画出来就是展开着的，箭头收起整张
  const toggled = block.slot !== undefined
  const hasChildren = toggled || hasShownChildren(block, tree)
  const Chevron = collapsed && !toggled ? ChevronRight : ChevronDown
  const change = tree.diff?.changes.get(block.id)
  return (
    <div
      className="cr-block relative flex items-start gap-2.5 rounded-lg py-2 pr-2.5 pl-2"
      {...kindProps(block)}
      data-id={block.id}
      data-line={block.startLine}
      data-editing={editing ? '' : undefined}
      data-change={change?.change}
    >
      {change?.outermost && <span className="cr-added-badge">新增</span>}
      {hasChildren
        ? (
            <button
              type="button"
              className="flex h-5 w-3.5 shrink-0 items-center justify-center rounded-sm text-[var(--vscode-descriptionForeground)] hover:text-[var(--vscode-foreground)]"
              aria-label={toggled ? '收起' : collapsed ? '展开子块' : '折叠子块'}
              aria-expanded={toggled || !collapsed}
              onClick={() => tree.onToggleFold(block.id)}
            >
              <Chevron size={14} strokeWidth={1.8} />
            </button>
          )
        : <span className="w-3.5 shrink-0" />}
      <KindIcon concepts={block.concepts} />
      <div className="min-w-0 flex-1">
        {edit && editing
          ? (
              <CodeEditor
                block={block}
                version={edit.version}
                autoFocus={edit.focusId === block.id}
                onAutoFocused={edit.onFocused}
                onExit={() => edit.onToggleEdit(block.id)}
              />
            )
          : <BlockPreview block={block} tree={tree} marks={tree.diff?.current ? change?.marks : undefined} />}
      </div>
      {tree.temporary.has(block.id) && (
        <span className="cr-temporary flex h-5 shrink-0 items-center gap-1 rounded px-1.5 text-[11px] whitespace-nowrap">
          <EyeOff size={12} strokeWidth={1.8} aria-hidden />
          已被筛选隐藏，临时显示
        </span>
      )}
      {edit && (
        <BlockTools
          editing={editing}
          onToggleEdit={() => edit.onToggleEdit(block.id)}
          asking={tree.qa?.state.open.includes(block.anchor)}
          onToggleAsk={tree.qa && (() => tree.qa?.onToggle(block.anchor))}
          rewriting={edit.rewrites.get(block.anchor)?.status === 'running'}
          onRewrite={block.commentStartLine !== undefined ? () => edit.onRewriteComment(block.anchor) : undefined}
        />
      )}
    </div>
  )
}

/**
 * 删掉的一块，放在原来的位置：红色虚线边、半透明，没有编辑、问 AI 按钮。默认收成一行「已删除 · 种类 名字」，
 * 点箭头或这一行展开，下面是旧内容（整张划掉，名字不能跳定义）；子块不画。
 */
function RemovedCard({ placed, tree }: { placed: PlacedRemoved, tree: BlockTreeState }): ReactElement {
  const [open, setOpen] = useState(false)
  const { block, kindName } = placed.removed
  const title = removedTitle(block)
  const Chevron = open ? ChevronDown : ChevronRight
  const toggle = (): void => setOpen(value => !value)
  return (
    <ChangeRow tree={tree} change="del">
      <div className="cr-block cr-removed flex items-start gap-2.5 rounded-lg py-2 pr-2.5 pl-2" {...kindProps(block)} data-id={placed.id}>
        <button
          type="button"
          className="flex h-5 w-3.5 shrink-0 items-center justify-center rounded-sm text-[var(--vscode-descriptionForeground)] hover:text-[var(--vscode-foreground)]"
          aria-label={open ? '收起删掉的内容' : '展开删掉的内容'}
          aria-expanded={open}
          onClick={toggle}
        >
          <Chevron size={14} strokeWidth={1.8} />
        </button>
        <KindIcon concepts={block.concepts} />
        <div className="min-w-0 flex-1">
          <div className="cr-removed-head cursor-pointer truncate text-[12.5px] leading-5" onClick={toggle}>
            <span className="cr-removed-label">已删除 · </span>
            {kindName}
            {title && <span className="cr-removed-title">{` ${title}`}</span>}
          </div>
          {open && (
            <div className="cr-removed-old mt-1">
              {/* 旧块的 id 是旧版本里的位置，换成页面上认删掉的块用的 id，属性行的 id 才不和现在的块撞上 */}
              <BlockPreview block={{ ...block, id: placed.id }} tree={tree} />
            </div>
          )}
        </div>
      </div>
    </ChangeRow>
  )
}