hermes-agent/ui-tui/src/lib/virtualHeights.ts

import type { Msg } from '../types.js'

import { transcriptBodyWidth } from './inputMetrics.js'
import { boundedHistoryRenderText } from './text.js'

const hashText = (text: string) => {
  let h = 5381

  for (let i = 0; i < text.length; i++) {
    h = ((h << 5) + h) ^ text.charCodeAt(i)
  }

  return (h >>> 0).toString(36)
}

export const messageHeightKey = (msg: Msg) => {
  const todoSig = msg.todos?.map(t => `${t.status}:${t.content}`).join('\u0001') ?? ''

  const panelSig =
    msg.panelData?.sections
      .map(s => `${s.title ?? ''}:${s.text?.length ?? 0}:${s.items?.length ?? 0}:${s.rows?.length ?? 0}`)
      .join('\u0001') ?? ''

  const introSig = msg.kind === 'intro' ? (msg.info?.version ?? '') : ''

  return [
    msg.role,
    msg.kind ?? '',
    hashText([msg.text, msg.thinking ?? '', msg.tools?.join('\n') ?? '', todoSig, panelSig, introSig].join('\0'))
  ].join(':')
}

export const wrappedLines = (text: string, width: number) => {
  const w = Math.max(1, width)

  return text.split('\n').reduce((n, line) => n + Math.max(1, Math.ceil(line.length / w)), 0)
}

export const estimatedMsgHeight = (
  msg: Msg,
  cols: number,
  {
    compact,
    details,
    limitHistory = false,
    userPrompt = ''
  }: { compact: boolean; details: boolean; limitHistory?: boolean; userPrompt?: string }
) => {
  if (msg.kind === 'intro') {
    return msg.info?.version ? 9 : 5
  }

  if (msg.kind === 'panel') {
    return Math.max(3, (msg.panelData?.sections.length ?? 1) * 2 + 1)
  }

  if (msg.kind === 'trail' && msg.todos?.length) {
    if (msg.todoCollapsedByDefault) {
      return 2
    }

    return Math.max(2, msg.todos.length + 2)
  }

  const bodyWidth = transcriptBodyWidth(cols, msg.role, userPrompt)
  const text = msg.role === 'assistant' && limitHistory ? boundedHistoryRenderText(msg.text) : msg.text
  let h = wrappedLines(text || ' ', bodyWidth)

  if (!compact && msg.role === 'assistant') {
    h += Math.min(6, (text.match(/\n\s*\n/g) ?? []).length)
  }

  if (details) {
    h += (msg.tools?.length ?? 0) + wrappedLines(msg.thinking ?? '', bodyWidth)
  }

  if (msg.role === 'user' || msg.kind === 'diff') {
    h += 2
  } else if (msg.kind === 'slash') {
    h++
  }

  return Math.max(1, h)
}