chore: refactor packages/app files (#13236)

Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: Frank <frank@anoma.ly>

packages/app/src/components/session/session-context-breakdown.ts

@@ -0,0 +1,132 @@
+import type { Message, Part } from "@opencode-ai/sdk/v2/client"
+
+export type SessionContextBreakdownKey = "system" | "user" | "assistant" | "tool" | "other"
+
+export type SessionContextBreakdownSegment = {
+  key: SessionContextBreakdownKey
+  tokens: number
+  width: number
+  percent: number
+}
+
+const estimateTokens = (chars: number) => Math.ceil(chars / 4)
+const toPercent = (tokens: number, input: number) => (tokens / input) * 100
+const toPercentLabel = (tokens: number, input: number) => Math.round(toPercent(tokens, input) * 10) / 10
+
+const charsFromUserPart = (part: Part) => {
+  if (part.type === "text") return part.text.length
+  if (part.type === "file") return part.source?.text.value.length ?? 0
+  if (part.type === "agent") return part.source?.value.length ?? 0
+  return 0
+}
+
+const charsFromAssistantPart = (part: Part) => {
+  if (part.type === "text") return { assistant: part.text.length, tool: 0 }
+  if (part.type === "reasoning") return { assistant: part.text.length, tool: 0 }
+  if (part.type !== "tool") return { assistant: 0, tool: 0 }
+
+  const input = Object.keys(part.state.input).length * 16
+  if (part.state.status === "pending") return { assistant: 0, tool: input + part.state.raw.length }
+  if (part.state.status === "completed") return { assistant: 0, tool: input + part.state.output.length }
+  if (part.state.status === "error") return { assistant: 0, tool: input + part.state.error.length }
+  return { assistant: 0, tool: input }
+}
+
+const build = (
+  tokens: { system: number; user: number; assistant: number; tool: number; other: number },
+  input: number,
+) => {
+  return [
+    {
+      key: "system",
+      tokens: tokens.system,
+    },
+    {
+      key: "user",
+      tokens: tokens.user,
+    },
+    {
+      key: "assistant",
+      tokens: tokens.assistant,
+    },
+    {
+      key: "tool",
+      tokens: tokens.tool,
+    },
+    {
+      key: "other",
+      tokens: tokens.other,
+    },
+  ]
+    .filter((x) => x.tokens > 0)
+    .map((x) => ({
+      key: x.key,
+      tokens: x.tokens,
+      width: toPercent(x.tokens, input),
+      percent: toPercentLabel(x.tokens, input),
+    })) as SessionContextBreakdownSegment[]
+}
+
+export function estimateSessionContextBreakdown(args: {
+  messages: Message[]
+  parts: Record<string, Part[] | undefined>
+  input: number
+  systemPrompt?: string
+}) {
+  if (!args.input) return []
+
+  const counts = args.messages.reduce(
+    (acc, msg) => {
+      const parts = args.parts[msg.id] ?? []
+      if (msg.role === "user") {
+        const user = parts.reduce((sum, part) => sum + charsFromUserPart(part), 0)
+        return { ...acc, user: acc.user + user }
+      }
+
+      if (msg.role !== "assistant") return acc
+      const assistant = parts.reduce(
+        (sum, part) => {
+          const next = charsFromAssistantPart(part)
+          return {
+            assistant: sum.assistant + next.assistant,
+            tool: sum.tool + next.tool,
+          }
+        },
+        { assistant: 0, tool: 0 },
+      )
+      return {
+        ...acc,
+        assistant: acc.assistant + assistant.assistant,
+        tool: acc.tool + assistant.tool,
+      }
+    },
+    {
+      system: args.systemPrompt?.length ?? 0,
+      user: 0,
+      assistant: 0,
+      tool: 0,
+    },
+  )
+
+  const tokens = {
+    system: estimateTokens(counts.system),
+    user: estimateTokens(counts.user),
+    assistant: estimateTokens(counts.assistant),
+    tool: estimateTokens(counts.tool),
+  }
+  const estimated = tokens.system + tokens.user + tokens.assistant + tokens.tool
+
+  if (estimated <= args.input) {
+    return build({ ...tokens, other: args.input - estimated }, args.input)
+  }
+
+  const scale = args.input / estimated
+  const scaled = {
+    system: Math.floor(tokens.system * scale),
+    user: Math.floor(tokens.user * scale),
+    assistant: Math.floor(tokens.assistant * scale),
+    tool: Math.floor(tokens.tool * scale),
+  }
+  const total = scaled.system + scaled.user + scaled.assistant + scaled.tool
+  return build({ ...scaled, other: Math.max(0, args.input - total) }, args.input)
+}