opencode/packages/tui/src/util/collapse-tool-output.ts

export function collapseToolOutput(output: string, maxLines: number, maxChars: number) {
  const lines = output.split("\n")
  if (lines.length <= maxLines && Array.from(output).length <= maxChars) {
    return { output, overflow: false }
  }

  const preview = lines.slice(0, maxLines).join("\n")
  if (Array.from(preview).length > maxChars) {
    return {
      output:
        Array.from(preview)
          .slice(0, Math.max(0, maxChars - 1))
          .join("") + "…",
      overflow: true,
    }
  }

  return { output: [...lines.slice(0, maxLines), "…"].join("\n"), overflow: true }
}