import type { Engine, Register } from 'claude-code'

import { CHARACTERS, applyOverrides, findCharacter, personaSection } from './characters'
import type { Axes } from './characters'
import { EXTRACT_COMMAND, runExtract } from './extractCommand'
import { layout, meter, parseFields, remainColor, SEPARATOR, usedColor } from './statusline'
import type { Segment } from './statusline'

const ACTIVE_KEY = 'active'
const OFF_COMMAND = 'anima-off'

const AXIS_OPTION: Record<keyof Axes, string> = {
  gentle: 'axisGentle',
  tsundere: 'axisTsundere',
  lively: 'axisLively',
  formal: 'axisFormal',
  talkative: 'axisTalkative',
  humor: 'axisHumor',
  proactive: 'axisProactive',
  expressive: 'axisExpressive',
}

const SYS_SCRIPT =
  'a=$(awk \'{print $1}\' /proc/loadavg); n=$(nproc); ' +
  'echo "$a $n"; free | awk \'/Mem:/{printf "%d\\n", $3*100/$2}\'; df / | awk \'NR==2{gsub("%","",$5); print $5}\''

const resetText = (iso: string | undefined, long: boolean): string => {
  if (!iso) return ''
  const d = new Date(iso)
  if (Number.isNaN(d.getTime())) return ''
  const p = (n: number) => String(n).padStart(2, '0')
  return long ? ` ${d.getMonth() + 1}/${d.getDate()}` : ` ${p(d.getHours())}:${p(d.getMinutes())}`
}

const fmtTokens = (n: number): string => (n >= 1000 ? `${Math.round(n / 1000)}k` : String(n))

type Sys = { at: number; cpu: number; ram: number; dsk: number }

async function readSys($: Engine, holder: { sys?: Sys }, refreshMs: number): Promise<Sys | undefined> {
  const now = await $.clock.now()
  if (holder.sys && now - holder.sys.at < refreshMs) return holder.sys
  try {
    const r = await $.process.run(['sh', '-c', SYS_SCRIPT], { timeoutMs: 3000 })
    const [l1, l2, l3] = String(r.stdout).trim().split('\n')
    const [load, cores] = (l1 ?? '').split(' ').map(Number)
    holder.sys = {
      at: now,
      cpu: Math.min(100, Math.round(((load || 0) / (cores || 1)) * 100)),
      ram: Number(l2) || 0,
      dsk: Number(l3) || 0,
    }
  } catch {
    holder.sys = undefined
  }
  return holder.sys
}

export const register: Register = (on, options) => {
  const opt = options as Record<string, unknown>
  const flag = (k: string, d: boolean) => (typeof opt[k] === 'boolean' ? (opt[k] as boolean) : d)
  const num = (k: string, d: number) => (typeof opt[k] === 'number' ? (opt[k] as number) : d)
  const str = (k: string, d: string) => (typeof opt[k] === 'string' ? (opt[k] as string) : d)

  const isEnabled = flag('enabled', true)
  let active: string | undefined
  const holder: { sys?: Sys } = {}

  const overrides = (): Partial<Axes> => {
    const out: Partial<Axes> = {}
    for (const k of Object.keys(AXIS_OPTION) as (keyof Axes)[]) {
      const v = num(AXIS_OPTION[k], -1)
      if (v >= 0) out[k] = v
    }
    return out
  }

  on('session.start', async ($, e, next) => {
    if (isEnabled) {
      for (const c of CHARACTERS) {
        await $.command.register({ name: c.slug, description: `啟動《${c.work}》的${c.name}` })
      }
      await $.command.register({ name: EXTRACT_COMMAND, description: '從輕小說章節萃取作品與角色包，確認後建立 PR' })
      await $.command.register({ name: OFF_COMMAND, description: '離開角色，回到一般的 Claude Code' })
      const saved = await $.store.get(ACTIVE_KEY)
      active = flag('persist', true) && typeof saved === 'string' && findCharacter(saved) ? saved : undefined
    }
    return next(e)
  })

  on('command.run', async ($, e, next) => {
    if (!isEnabled) return next(e)
    if (e.command === EXTRACT_COMMAND) return { text: await runExtract($, e.args) }
    if (e.command === OFF_COMMAND) {
      active = undefined
      await $.store.delete(ACTIVE_KEY)
      return { text: '已離開角色，回到一般模式。' }
    }
    const c = findCharacter(e.command)
    if (!c) return next(e)
    active = c.slug
    await $.store.set(ACTIVE_KEY, c.slug)
    return { text: `已啟動：${c.name}（${c.work}）。用 /jsc-anima:${OFF_COMMAND} 離開。` }
  })

  on('prompt.compose', async ($, e, next) => {
    const res = await next(e)
    const c = isEnabled ? findCharacter(active) : undefined
    if (!c) return res
    const text = personaSection(c, applyOverrides(c.axes, overrides()))
    return {
      ...res,
      sections: [...res.sections.filter(s => s.id !== 'jsc-anima:persona'), { id: 'jsc-anima:persona', text, scope: 'session' as const }],
    }
  })

  on('ui.render', { component: 'AbovePrompt' }, async ($, e, next) => {
    const c = isEnabled ? findCharacter(active) : undefined
    if (!c || !flag('statusbar', true) || e.props.hasSurvey) return next(e)

    const warn = num('warnAt', 60)
    const danger = num('dangerAt', 85)
    const style = str('barStyle', 'block') === 'dot' ? 'dot' : 'block'
    const usage = await $.session.usage().catch(() => undefined)
    const cwd = await $.session.cwd().catch(() => '')
    const branch = await $.process
      .run(['git', 'branch', '--show-current'], { cwd: cwd || undefined, timeoutMs: 2000 })
      .then(r => String(r.stdout).trim())
      .catch(() => '')
    const model = await $.session.model().catch(() => '')

    const quota = (kind: string, label: string, long: boolean): Segment['parts'] | undefined => {
      const rl = usage?.rateLimits.find(r => r.kind === kind)
      if (!rl) return undefined
      const remain = Math.max(0, 100 - rl.percentUsed)
      return meter(label, remain, remainColor(remain, warn, danger), style, resetText(rl.resetsAt, long))
    }

    const builders: Record<string, () => Promise<Segment['parts'] | undefined> | Segment['parts'] | undefined> = {
      character: () => [{ text: c.name, color: 'cyan' }],
      model: () => (model ? [{ text: model }] : undefined),
      dir: () => (cwd ? [{ text: cwd.split('/').filter(Boolean).pop() ?? '/' }] : undefined),
      branch: () => (branch ? [{ text: `⎇ ${branch}` }] : undefined),
      '5h': () => quota('five_hour', '5h', false),
      '7d': () => quota('seven_day', '7d', true),
      ctx: () => {
        const cx = usage?.context
        if (!cx || cx.percent === undefined) return undefined
        return meter('ctx', cx.percent, usedColor(cx.percent, warn, danger), style, ` ${fmtTokens(cx.tokens ?? 0)}/${fmtTokens(cx.window)}`)
      },
      sys: async () => {
        const s = await readSys($, holder, num('refreshSec', 10) * 1000)
        if (!s) return undefined
        return [
          { text: 'CPU ' }, { text: `${s.cpu}%`, color: usedColor(s.cpu, warn, danger) },
          { text: ' RAM ' }, { text: `${s.ram}%`, color: usedColor(s.ram, warn, danger) },
          { text: ' DSK ' }, { text: `${s.dsk}%`, color: usedColor(s.dsk, warn, danger) },
        ]
      },
    }

    const segments: Segment[] = []
    for (const id of parseFields(str('fields', ''))) {
      const parts = await builders[id]?.()
      if (parts) segments.push({ id, parts })
    }

    const shown = layout(segments, e.props.bodyColumns)
    const { Box, Text } = $.ui.resolve(e)
    return (
      <Box flexDirection="column">
        <Text> </Text>
        <Text wrap="truncate-end">
          {shown.map((s, i) => (
            <Text key={s.id}>
              {i > 0 ? <Text dimColor>{SEPARATOR}</Text> : null}
              {s.parts.map((p, j) => (
                <Text key={j} color={p.color}>{p.text}</Text>
              ))}
            </Text>
          ))}
        </Text>
        <Text> </Text>
      </Box>
    )
  })
}