import type { CSSProperties, ReactElement } from 'react'
import type { QaState } from './qa'
import type { PendingImage } from './qaImages'
import type { BlockView } from './types'
import { ChevronDown, ChevronRight, EyeOff } from 'lucide-react'
import { Fragment } from 'react'
import { AskThread } from './AskThread'
import { BlockTools } from './BlockTools'
import { CodeEditor } from './CodeEditor'
import { KindIcon } from './kindIcons'
import { PropertyGrid, PropertyTable } from './PropertyGrid'
import { asksOf, historyOf } from './qa'
import { TextPreview } from './TextPreview'
import { translationTableId } from './viewState'

export interface BlockTreeState {
  version: number
  editing: ReadonlySet<string>
  /** 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（它们的行在祖先的编辑范围里），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
  /** 刚点了「编辑」、要把光标放进去的块 */
  focusId: string | null
  onFocused: () => void
  onToggleEdit: (id: string) => void
  onToggleFold: (id: string) => 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
}

/** 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：子块都被筛掉、被盖住时不留空的一层、不给折叠箭头。 */
function hasShownChildren(block: BlockView, tree: BlockTreeState): boolean {
  return block.children.some(child => shown(child, tree))
}

/** 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），悬停它时竖线换成它的种类色。
 */
export function BlockLevel({ blocks, owner, tree }: { blocks: BlockView[], owner?: BlockView, tree: BlockTreeState }): ReactElement {
  return (
    <div className="cr-level flex gap-2" {...kindProps(owner)}>
      <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">
        {blocks.filter(block => shown(block, tree)).map(block => (
          <Fragment key={block.id}>
            <BlockCard block={block} tree={tree} />
            {tree.qa && <BlockQa key={block.anchor} anchor={block.anchor} qa={tree.qa} />}
            {hasShownChildren(block, tree) && !tree.collapsed.has(block.id) && (
              <BlockLevel blocks={block.children} owner={block} tree={tree} />
            )}
          </Fragment>
        ))}
      </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)}
    />
  )
}

/**
 * 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。
 */
function BlockPreview({ block, tree }: { block: BlockView, tree: BlockTreeState }): ReactElement {
  if ('properties' in block)
    return <PropertyGrid blockId={block.id} rows={block.properties} collapsed={tree.collapsed} onToggleFold={tree.onToggleFold} />
  return (
    <>
      <TextPreview text={block.translation} />
      {block.table && (
        <div className="mt-[3px]">
          <PropertyTable parentId={translationTableId(block.id)} columns={block.table.columns} items={block.table.items} />
        </div>
      )}
      {block.doc && <TextPreview text={block.doc} className="mt-0.5" />}
    </>
  )
}

/** 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）。 */
function BlockCard({ block, tree }: { block: BlockView, tree: BlockTreeState }): ReactElement {
  const editing = tree.editing.has(block.id)
  const collapsed = tree.collapsed.has(block.id)
  const hasChildren = hasShownChildren(block, tree)
  const Chevron = collapsed ? ChevronRight : ChevronDown
  return (
    <div
      className="cr-block 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}
    >
      {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={collapsed ? '展开子块' : '折叠子块'}
              aria-expanded={!collapsed}
              onClick={() => tree.onToggleFold(block.id)}
            >
              <Chevron size={14} strokeWidth={1.8} />
            </button>
          )
        : <span className="w-3.5 shrink-0" />}
      <KindIcon block={block} name={tree.kindName(block.kind)} />
      <div className="min-w-0 flex-1">
        {editing
          ? (
              <CodeEditor
                block={block}
                version={tree.version}
                autoFocus={tree.focusId === block.id}
                onAutoFocused={tree.onFocused}
                onExit={() => tree.onToggleEdit(block.id)}
              />
            )
          : <BlockPreview block={block} tree={tree} />}
      </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>
      )}
      <BlockTools
        editing={editing}
        onToggleEdit={() => tree.onToggleEdit(block.id)}
        asking={tree.qa?.state.open.includes(block.anchor)}
        onToggleAsk={tree.qa && (() => tree.qa?.onToggle(block.anchor))}
      />
    </div>
  )
}