herdr-statusline

1import { atom, read, update } from 'claude-code'
2import type { EngineInterface, Register } from 'claude-code'
3
4import type { Git, Herdr, Status } from '../types'
5import { herdrLabel, parseGitStatus, shortenPath } from './status'
6
7const status = atom({ plugin: 'herdr-statusline', key: 'status' } as const, null)
8
9const REFRESH_MS = 20_000
10const HERDR_TTL_MS = 60_000
11
12let herdrCache: { value: Herdr | null; at: number } | undefined
13
14const readGit = async ($: EngineInterface, cwd: string): Promise<Git | null> => {
15  try {
16    const r = await $.process.run(['git', 'status', '--porcelain=v2', '--branch'], { cwd, timeoutMs: 5000 })
17    return r.exitCode === 0 ? parseGitStatus(r.stdout) : null
18  } catch {
19    return null
20  }
21}
22
23// The herdr workspace label and pane id, from the env herdr gives its panes.
24const readHerdr = async ($: EngineInterface): Promise<Herdr | null> => {
25  const workspace = await $.env.get('HERDR_WORKSPACE_ID')
26  const pane = await $.env.get('HERDR_PANE_ID')
27  if (!workspace || !pane) return null
28  const bin = (await $.env.get('HERDR_BIN_PATH')) ?? 'herdr'
29  let label = workspace
30  try {
31    const r = await $.process.run([bin, 'workspace', 'list'], { timeoutMs: 5000 })
32    if (r.exitCode === 0) label = herdrLabel(r.stdout, workspace) ?? workspace
33  } catch {
34    // herdr not answering: the id is still a fine label
35  }
36  return { label, pane }
37}
38
39const refresh = async ($: EngineInterface): Promise<void> => {
40  const now = await $.clock.now()
41  if (herdrCache === undefined || now - herdrCache.at > HERDR_TTL_MS) {
42    herdrCache = { value: await readHerdr($), at: now }
43  }
44  const cwd = await $.session.cwd()
45  const next: Status = {
46    herdr: herdrCache.value,
47    // HOME on Linux and macOS; Windows keeps the home directory in USERPROFILE.
48    cwd: shortenPath(cwd, (await $.env.get('HOME')) ?? (await $.env.get('USERPROFILE'))),
49    git: await readGit($, cwd),
50  }
51  await update($, status, () => next)
52}
53
54export const register: Register = on => {
55  on('session.start', async ($, e, next) => {
56    // The band first: nothing below may keep it from drawing.
57    await refresh($)
58    $.clock.every(REFRESH_MS, () => void refresh($))
59    try {
60      // `/statusline` is a built-in, so the refresh command gets its own name.
61      await $.command.register({ name: 'herdr-status', description: 'Refresh the herdr status band now' })
62    } catch {
63      // no command, still a band
64    }
65    return next(e)
66  })
67
68  on('command.run', { command: 'herdr-status' }, async $ => {
69    await refresh($)
70    return { text: 'Status band refreshed.' }
71  })
72
73  // Git state mostly changes inside a turn: redraw at both ends of one.
74  on('turn.start', ($, e, next) => {
75    void refresh($)
76    return next(e)
77  })
78  on('turn.complete', ($, e, next) => {
79    void refresh($)
80    return next(e)
81  })
82
83  on('ui.render', { component: 'AbovePrompt' }, async ($, e, next) => {
84    const s = await read($, status)
85    if (e.props.hasSurvey || s === null) return next(e)
86
87    const { Box, Text } = $.ui.resolve(e)
88    const parts: JSX.Element[] = []
89    const sep = (key: string) => <Text key={key} color="subtle">  │  </Text>
90
91    if (s.herdr !== null) {
92      parts.push(
93        <Text key="ws" color="claude" bold>▣ {s.herdr.label}</Text>,
94        <Text key="pane" color="subtle"> {s.herdr.pane}</Text>,
95        sep('sep1'),
96      )
97    }
98    parts.push(<Text key="cwd" color="text">{s.cwd}</Text>)
99    if (s.git !== null) {
100      const dirty = s.git.changed > 0
101      parts.push(
102        sep('sep2'),
103        <Text key="branch" color={dirty ? 'warning' : 'success'} bold>⎇ {s.git.branch}</Text>,
104        dirty
105          ? <Text key="changed" color="warning"> ✎ {s.git.changed}</Text>
106          : <Text key="clean" color="success"> ✓</Text>,
107      )
108      if (s.git.ahead > 0) parts.push(<Text key="ahead" color="subtle"> ↑{s.git.ahead}</Text>)
109      if (s.git.behind > 0) parts.push(<Text key="behind" color="subtle"> ↓{s.git.behind}</Text>)
110    }
111    if (e.props.isWorking) parts.push(<Text key="working" color="claude">  ●</Text>)
112
113    return <Box flexDirection="row">{parts}</Box>
114  })
115}
116

1import type { Git } from '../types'
2
3const isSep = (c: string | undefined): boolean => c === '/' || c === '\\'
4
5/** `~` for the home directory, and the last three path segments at most; `/` or `\` as the path uses. */
6export const shortenPath = (cwd: string, home: string | undefined): string => {
7  const sep = cwd.includes('\\') && !cwd.includes('/') ? '\\' : '/'
8  const fold = (s: string) => (sep === '\\' ? s.toLowerCase() : s)
9  let p = cwd
10  if (home) {
11    const h = home.replace(/[\\/]+$/, '')
12    if (fold(p) === fold(h)) p = '~'
13    else if (fold(p.slice(0, h.length)) === fold(h) && isSep(p[h.length])) p = `~${p.slice(h.length)}`
14  }
15  const parts = p.split(/[\\/]/)
16  return parts.length > 4 ? `…${sep}${parts.slice(-3).join(sep)}` : p
17}
18
19/** Reads `git status --porcelain=v2 --branch` output. */
20export const parseGitStatus = (text: string): Git => {
21  let branch = '?'
22  let ahead = 0
23  let behind = 0
24  let changed = 0
25  for (const line of text.split('\n')) {
26    if (line.startsWith('# branch.head ')) branch = line.slice('# branch.head '.length).trim()
27    else if (line.startsWith('# branch.ab ')) {
28      const m = /\+(\d+) -(\d+)/.exec(line)
29      if (m) {
30        ahead = Number(m[1])
31        behind = Number(m[2])
32      }
33    } else if (line.length > 0 && !line.startsWith('#')) changed += 1
34  }
35  if (branch === '(detached)') branch = 'detached'
36  return { branch, changed, ahead, behind }
37}
38
39/** The workspace's label from `herdr workspace list` JSON, when it is there. */
40export const herdrLabel = (json: string, workspaceId: string): string | undefined => {
41  try {
42    const parsed = JSON.parse(json) as { result?: { workspaces?: { workspace_id: string; label?: string }[] } }
43    return parsed.result?.workspaces?.find(w => w.workspace_id === workspaceId)?.label || undefined
44  } catch {
45    return undefined
46  }
47}
48

1export type Herdr = { label: string; pane: string }
2export type Git = { branch: string; changed: number; ahead: number; behind: number }
3export type Status = { herdr: Herdr | null; cwd: string; git: Git | null }
4
5declare module 'claude-code' {
6  interface PluginState {
7    'herdr-statusline': { status: Status | null }
8  }
9}
10