/* BARE_OS_BIN_API 1.0.0 — bump when staged /bin script semantics change (see developer guide). */
/** Shared helpers for drive-resident /bin scripts (prepended before each command). */
function bareStdin(ctx) {
  return typeof ctx.shellStdin === 'string' ? ctx.shellStdin : ''
}

/** @param {number} mode @param {'file' | 'directory' | 'symlink'} type */
function bareFormatModeString(mode, type) {
  const typeChar = type === 'directory' ? 'd' : type === 'symlink' ? 'l' : '-'
  const perm = mode & 0o777
  const r = (bit) => (perm & bit ? 'r' : '-')
  const w = (bit) => (perm & bit ? 'w' : '-')
  const x = (bit) => (perm & bit ? 'x' : '-')
  return (
    typeChar +
    r(0o400) +
    w(0o200) +
    x(0o100) +
    r(0o040) +
    w(0o020) +
    x(0o010) +
    r(0o004) +
    w(0o002) +
    x(0o001)
  )
}

/** @param {number} mtimeMs @param {number} [nowMs] */
function bareFormatLsMtime(mtimeMs, nowMs) {
  const now = nowMs != null ? nowMs : Date.now()
  const d = new Date(mtimeMs)
  const months = [
    'Jan',
    'Feb',
    'Mar',
    'Apr',
    'May',
    'Jun',
    'Jul',
    'Aug',
    'Sep',
    'Oct',
    'Nov',
    'Dec'
  ]
  const mon = months[d.getMonth()]
  const day = String(d.getDate()).padStart(2, ' ')
  const sixMo = 180 * 24 * 3600 * 1000
  if (Math.abs(now - mtimeMs) > sixMo) {
    const yr = String(d.getFullYear()).padStart(4, ' ')
    return mon + ' ' + day + '  ' + yr
  }
  const hh = String(d.getHours()).padStart(2, '0')
  const mm = String(d.getMinutes()).padStart(2, '0')
  return mon + ' ' + day + ' ' + hh + ':' + mm
}

/** @param {number} size */
function barePosixBlocks(size) {
  return Math.ceil(Number(size) / 512) || 0
}

/**
 * Theme switcher: list presets, show current, set preset (updates ~/.barerc), re-apply.
 * Uses ctx.bareOsListThemes / ctx.bareOsApplyTheme when provided by the booter.
 */

const FALLBACK_THEMES = [
  'catppuccin_mocha',
  'default',
  'dracula',
  'github_dark',
  'gruvbox_dark',
  'nord',
  'solarized_dark',
  'tokyo_night'
]

function themeListFromCtx(ctx) {
  if (typeof ctx.bareOsListThemes === 'function') {
    try {
      const names = ctx.bareOsListThemes()
      if (Array.isArray(names) && names.length) return names
    } catch {
      /* fall through */
    }
  }
  return FALLBACK_THEMES.slice().sort()
}

async function readBarerc(ctx) {
  try {
    const buf = await ctx.vfs.readFile('~/.barerc')
    return buf ? ctx.b4a.toString(buf) : ''
  } catch {
    return ''
  }
}

async function writeBarerc(ctx, text) {
  await ctx.vfs.writeFile('~/.barerc', ctx.b4a.from(text))
}

/**
 * Ensure ~/.barerc contains `theme <name>` (replace first theme line or append).
 * @param {Record<string, unknown>} ctx
 * @param {string} name
 */
async function persistThemeLine(ctx, name) {
  let text = await readBarerc(ctx)
  const lines = text.split(/\r?\n/)
  const themeRe = /^\s*theme\s+/
  let replaced = false
  const out = []
  for (const line of lines) {
    if (themeRe.test(line)) {
      if (!replaced) {
        out.push('theme ' + name)
        replaced = true
      }
    } else out.push(line)
  }
  if (!replaced) {
    if (out.length && out[out.length - 1].trim() !== '') out.push('')
    out.push('theme ' + name)
  }
  const newText = out.join('\n')
  if (!/\n$/.test(newText) && newText.length) await writeBarerc(ctx, newText + '\n')
  else await writeBarerc(ctx, newText || 'theme ' + name + '\n')
}

async function run(ctx, argv) {
  const env = ctx.vfs?.env || ctx.env || {}
  const sub = argv[1] || 'list'

  if (sub === 'list') {
    for (const n of themeListFromCtx(ctx)) ctx.console.log(n)
    return
  }

  if (sub === 'current') {
    const t = env.BARE_OS_THEME != null ? String(env.BARE_OS_THEME) : 'default'
    ctx.console.log(t)
    const ls = env.LS_COLORS
    if (ls != null && String(ls).length) {
      ctx.console.log('LS_COLORS_len=' + String(ls).length)
    }
    return
  }

  if (sub === 'apply') {
    if (typeof ctx.bareOsApplyTheme === 'function') {
      await ctx.bareOsApplyTheme()
    } else {
      ctx.console.error('theme: bareOsApplyTheme not available')
      ctx.exitCode = 1
    }
    return
  }

  if (sub === 'set') {
    const name = argv[2]
    if (!name) {
      ctx.console.error('theme: usage: theme set <name>')
      ctx.exitCode = 1
      return
    }
    const norm = String(name)
      .toLowerCase()
      .trim()
      .replace(/\s+/g, '_')
    const valid = new Set(themeListFromCtx(ctx).map((s) => s.toLowerCase()))
    if (!valid.has(norm)) {
      ctx.console.error('theme: unknown preset: ' + name)
      ctx.exitCode = 1
      return
    }
    try {
      await persistThemeLine(ctx, norm)
    } catch (e) {
      ctx.console.error('theme: ' + ((e && e.message) || e))
      ctx.exitCode = 2
      return
    }
    env.BARE_OS_THEME = norm
    if (typeof ctx.bareOsApplyTheme === 'function') {
      await ctx.bareOsApplyTheme()
    }
    return
  }

  ctx.console.error(
    'theme: usage: theme [list|current|set <name>|apply]'
  )
  ctx.exitCode = 1
}