/**
 * 预览顶部的问答：文件、文件夹按「工作区文件夹 + 相对路径」，「了解一块代码」的功能对话页按功能的 id，记在这个窗口的 workspaceState 里。
 * 不写进按块存的 `.spx/code-qa.json`。
 */

import type { QaEntry } from './qaMap'
import * as path from 'node:path'
import { normalizeKey } from '../pathMap'

/** workspaceState 里这份表的键 */
export const PATH_QA_STATE_KEY = 'codeReader.pathQa'

/**
 * 顶部这一轮的记号。块的记号是「种类 名字」，不会是这个，
 * 所以页面上按记号取问答时，顶部的不会挂到某一块下面。
 */
export const PATH_ASK_ANCHOR = '\0path'

/** 工作区文件夹 Uri → 那条路径上的问答（按问的先后） */
export type PathQaMap = Record<string, QaEntry[]>

/** 工作区根的相对路径是空字符串，跟任何一个文件或子目录都不同。 */
export function relativeQaKey(rootPath: string, targetPath: string): string | undefined {
  const relative = path.posix.relative(rootPath, targetPath)
  if (relative === '')
    return ''
  return normalizeKey(relative)
}

/** 同一工作区文件夹、同一相对路径才是同一条记录。 */
export function pathQaKey(folderUri: string, relativePath: string): string {
  return `${folderUri}\n${relativePath}`
}

/** 「了解一块代码」一个功能的对话记录的键。工作区文件夹的 Uri 带协议名（`file://`），和它撞不上。 */
export function featureQaKey(id: string): string {
  return `feature\n${id}`
}

/** 给人看的相对路径；工作区根写成 `.`。 */
export function displayRelativePath(relativePath: string): string {
  return relativePath === '' ? '.' : relativePath
}

export function pathQaEntries(map: PathQaMap, key: string): QaEntry[] {
  return map[key] ?? []
}

/** 新的一次问答接在这条路径已有的后面，别的路径不动。 */
export function withPathQa(map: PathQaMap, key: string, entry: QaEntry): PathQaMap {
  return { ...map, [key]: [...pathQaEntries(map, key), entry] }
}

/** 删掉这一次；这条路径问光了就把键拿掉。没有这一次时原样返回。 */
export function withoutPathQa(map: PathQaMap, key: string, entryId: string): PathQaMap {
  const entries = pathQaEntries(map, key)
  const kept = entries.filter(entry => entry.id !== entryId)
  if (kept.length === entries.length)
    return map
  if (kept.length === 0) {
    const next = { ...map }
    delete next[key]
    return next
  }
  return { ...map, [key]: kept }
}

/** 去掉这个键下的全部问答；没有这个键时原样返回。 */
export function withoutPathQaKey(map: PathQaMap, key: string): PathQaMap {
  if (!(key in map))
    return map
  const next = { ...map }
  delete next[key]
  return next
}

/** 读 workspaceState 里存的表；认不出的丢掉，不让一条坏数据把整份弄丢。 */
export function parsePathQa(value: unknown): PathQaMap {
  if (!isRecord(value))
    return {}
  const map: PathQaMap = {}
  for (const [key, entries] of Object.entries(value)) {
    if (!Array.isArray(entries))
      continue
    const parsed = entries.flatMap((entry) => {
      const one = parseEntry(entry)
      return one ? [one] : []
    })
    if (parsed.length > 0)
      map[key] = parsed
  }
  return map
}

function parseEntry(value: unknown): QaEntry | undefined {
  if (!isRecord(value))
    return undefined
  const { id, question, answer, createdAt, sessionId, profile, images } = value
  if (typeof id !== 'string' || typeof question !== 'string' || typeof answer !== 'string' || typeof createdAt !== 'string' || typeof sessionId !== 'string')
    return undefined
  const entry: QaEntry = { id, question, answer, createdAt, sessionId }
  if (typeof profile === 'string' && profile !== '')
    entry.profile = profile
  if (Array.isArray(images) && images.every(name => typeof name === 'string'))
    entry.images = images
  return entry
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === 'object' && value !== null && !Array.isArray(value)
}