chore: refactoring and tests (#12468)

packages/app/src/components/prompt-input/history.ts

@@ -0,0 +1,160 @@
+import type { Prompt } from "@/context/prompt"
+
+const DEFAULT_PROMPT: Prompt = [{ type: "text", content: "", start: 0, end: 0 }]
+
+export const MAX_HISTORY = 100
+
+export function clonePromptParts(prompt: Prompt): Prompt {
+  return prompt.map((part) => {
+    if (part.type === "text") return { ...part }
+    if (part.type === "image") return { ...part }
+    if (part.type === "agent") return { ...part }
+    return {
+      ...part,
+      selection: part.selection ? { ...part.selection } : undefined,
+    }
+  })
+}
+
+export function promptLength(prompt: Prompt) {
+  return prompt.reduce((len, part) => len + ("content" in part ? part.content.length : 0), 0)
+}
+
+export function prependHistoryEntry(entries: Prompt[], prompt: Prompt, max = MAX_HISTORY) {
+  const text = prompt
+    .map((part) => ("content" in part ? part.content : ""))
+    .join("")
+    .trim()
+  const hasImages = prompt.some((part) => part.type === "image")
+  if (!text && !hasImages) return entries
+
+  const entry = clonePromptParts(prompt)
+  const last = entries[0]
+  if (last && isPromptEqual(last, entry)) return entries
+  return [entry, ...entries].slice(0, max)
+}
+
+function isPromptEqual(promptA: Prompt, promptB: Prompt) {
+  if (promptA.length !== promptB.length) return false
+  for (let i = 0; i < promptA.length; i++) {
+    const partA = promptA[i]
+    const partB = promptB[i]
+    if (partA.type !== partB.type) return false
+    if (partA.type === "text" && partA.content !== (partB.type === "text" ? partB.content : "")) return false
+    if (partA.type === "file") {
+      if (partA.path !== (partB.type === "file" ? partB.path : "")) return false
+      const a = partA.selection
+      const b = partB.type === "file" ? partB.selection : undefined
+      const sameSelection =
+        (!a && !b) ||
+        (!!a &&
+          !!b &&
+          a.startLine === b.startLine &&
+          a.startChar === b.startChar &&
+          a.endLine === b.endLine &&
+          a.endChar === b.endChar)
+      if (!sameSelection) return false
+    }
+    if (partA.type === "agent" && partA.name !== (partB.type === "agent" ? partB.name : "")) return false
+    if (partA.type === "image" && partA.id !== (partB.type === "image" ? partB.id : "")) return false
+  }
+  return true
+}
+
+type HistoryNavInput = {
+  direction: "up" | "down"
+  entries: Prompt[]
+  historyIndex: number
+  currentPrompt: Prompt
+  savedPrompt: Prompt | null
+}
+
+type HistoryNavResult =
+  | {
+      handled: false
+      historyIndex: number
+      savedPrompt: Prompt | null
+    }
+  | {
+      handled: true
+      historyIndex: number
+      savedPrompt: Prompt | null
+      prompt: Prompt
+      cursor: "start" | "end"
+    }
+
+export function navigatePromptHistory(input: HistoryNavInput): HistoryNavResult {
+  if (input.direction === "up") {
+    if (input.entries.length === 0) {
+      return {
+        handled: false,
+        historyIndex: input.historyIndex,
+        savedPrompt: input.savedPrompt,
+      }
+    }
+
+    if (input.historyIndex === -1) {
+      return {
+        handled: true,
+        historyIndex: 0,
+        savedPrompt: clonePromptParts(input.currentPrompt),
+        prompt: input.entries[0],
+        cursor: "start",
+      }
+    }
+
+    if (input.historyIndex < input.entries.length - 1) {
+      const next = input.historyIndex + 1
+      return {
+        handled: true,
+        historyIndex: next,
+        savedPrompt: input.savedPrompt,
+        prompt: input.entries[next],
+        cursor: "start",
+      }
+    }
+
+    return {
+      handled: false,
+      historyIndex: input.historyIndex,
+      savedPrompt: input.savedPrompt,
+    }
+  }
+
+  if (input.historyIndex > 0) {
+    const next = input.historyIndex - 1
+    return {
+      handled: true,
+      historyIndex: next,
+      savedPrompt: input.savedPrompt,
+      prompt: input.entries[next],
+      cursor: "end",
+    }
+  }
+
+  if (input.historyIndex === 0) {
+    if (input.savedPrompt) {
+      return {
+        handled: true,
+        historyIndex: -1,
+        savedPrompt: null,
+        prompt: input.savedPrompt,
+        cursor: "end",
+      }
+    }
+
+    return {
+      handled: true,
+      historyIndex: -1,
+      savedPrompt: null,
+      prompt: DEFAULT_PROMPT,
+      cursor: "end",
+    }
+  }
+
+  return {
+    handled: false,
+    historyIndex: input.historyIndex,
+    savedPrompt: input.savedPrompt,
+  }
+}