feat: 初版

lib/ai/json.ts

@@ -0,0 +1,103 @@
+import {
+  AI_CATEGORY_ENUM,
+  AI_DIFFICULTY_ENUM,
+  AI_MASTERY_ENUM,
+  AI_TAG_ENUM,
+  type AIDraftItem,
+} from "./types"
+
+export type ParseResult =
+  | { ok: true; items: AIDraftItem[] }
+  | { ok: false; error: string; raw: string }
+
+/** Strip markdown code fences and locate the JSON payload. */
+function stripFences(input: string): string {
+  let text = input.trim()
+  // remove ```json ... ``` or ``` ... ``` wrappers
+  const fenceMatch = text.match(/```(?:json)?\s*([\s\S]*?)```/i)
+  if (fenceMatch) {
+    text = fenceMatch[1].trim()
+  }
+  // fall back: slice from first { to last }
+  if (!text.startsWith("{")) {
+    const first = text.indexOf("{")
+    const last = text.lastIndexOf("}")
+    if (first !== -1 && last !== -1 && last > first) {
+      text = text.slice(first, last + 1)
+    }
+  }
+  return text
+}
+
+function toStr(value: unknown): string {
+  if (typeof value === "string") return value
+  if (value == null) return ""
+  return String(value)
+}
+
+function sanitizeTags(value: unknown): string[] {
+  if (!Array.isArray(value)) return []
+  const allowed = new Set<string>(AI_TAG_ENUM)
+  const out: string[] = []
+  for (const t of value) {
+    const tag = toStr(t).trim()
+    if (allowed.has(tag) && !out.includes(tag)) out.push(tag)
+  }
+  return out
+}
+
+function sanitizeItem(raw: Record<string, unknown>): AIDraftItem {
+  const category = toStr(raw.category).trim()
+  const difficulty = toStr(raw.difficulty).trim()
+  const mastery = toStr(raw.mastery).trim()
+
+  return {
+    title: toStr(raw.title).trim(),
+    summary: toStr(raw.summary).trim(),
+    content: toStr(raw.content).trim(),
+    code_snippet: toStr(raw.code_snippet),
+    tags: sanitizeTags(raw.tags),
+    category: (AI_CATEGORY_ENUM as readonly string[]).includes(category) ? category : "其他",
+    difficulty: (AI_DIFFICULTY_ENUM as readonly string[]).includes(difficulty)
+      ? (difficulty as AIDraftItem["difficulty"])
+      : "medium",
+    mastery: (AI_MASTERY_ENUM as readonly string[]).includes(mastery)
+      ? (mastery as AIDraftItem["mastery"])
+      : "new",
+    source_url: toStr(raw.source_url).trim(),
+    notes: toStr(raw.notes).trim(),
+  }
+}
+
+/**
+ * Safely parse AI output into a list of draft knowledge items.
+ * - tolerant of markdown fences
+ * - validates items is an array
+ * - filters/normalizes enum fields with sensible fallbacks
+ * - drops items without a title
+ */
+export function safeParseAIJson(input: string): ParseResult {
+  const cleaned = stripFences(input)
+  let data: unknown
+  try {
+    data = JSON.parse(cleaned)
+  } catch {
+    return { ok: false, error: "无法解析 AI 返回的 JSON", raw: input }
+  }
+
+  const itemsRaw = (data as { items?: unknown })?.items
+  if (!Array.isArray(itemsRaw)) {
+    return { ok: false, error: 'JSON 顶层缺少数组字段 "items"', raw: input }
+  }
+
+  const items = itemsRaw
+    .filter((it): it is Record<string, unknown> => !!it && typeof it === "object")
+    .map(sanitizeItem)
+    .filter((it) => it.title.length > 0)
+
+  if (items.length === 0) {
+    return { ok: false, error: "未能从返回内容中提取到有效条目", raw: input }
+  }
+
+  return { ok: true, items }
+}